Teruaki Ito, Tetsuo Ichikawa, Nevan C. Hanumara and Alexander H. Slocum : Teaching Creativity in Design Through Project-Based Learning in a Collaborative Distributed Educational Setting, --- in Cloud-based Design and Manufacturing (CBDM) (Dirk Schaefer, Ed.) ---, Springer-Verlag, London, Jul. 2014.
Tetsuo Ichikawa and Naeko Kawamoto : New Magnetic Applications in Clinical Dentistry, --- Biological Effects of Magnetic Attachment on the Human Body and Tissue ---, Quintessence Publishing CO.,Ltd., Tokyo, Dec. 2004.
Yuki Iwawaki, Takaharu Goto, Takahiro Kishimoto, Takashi Matsuda, Keiko Fujimoto, Kan Nagao, Kenji Yoshimura, Teppei Tajikara, Yoshiyuki Eshita, Yoshitaka Yano and Tetsuo Ichikawa : Efficacy evaluation with stratified randomized controlled study of foam dentifrice containing isodecyl galactosides in older adults, Journal of Oral Science, 67, 3, 134-139, 2025.
(要約)
Oral hygiene is mainly maintained by mechanical plaque removal, but this is often inadequate in older adults. Isodecyl galactosides (ID-Gal) inhibits bacterial co-aggregation and could promote the maintenance and improvement of oral hygiene. In this study, the efficacy of ID-Gal-containing foam dentifrice in oral hygiene among older adults was evaluated. Fifty-six subjects aged 65 years or older visited Tokushima University Hospital and were randomly assigned to interventions using ID-Gal-containing foam dentifrice applied to the dorsum of the tongue, or to controls using their usual dentifrice. Microbiological and clinical oral health parameters were evaluated before, and at 1 and 2 months after the intervention. The intervention group showed significant decreases in black pigment-producing bacteria on the dorsum of the tongue, Fusobacterium, and total bacterial counts on the mucosa below the denture base after 1 month. Additionally, the intervention group showed significant decrease in the Winkle Tongue Coating Index (WTCI) after 2 months. ID-Gal-containing foam dentifrice decreased the number of bacteria by suppressing plaque formation and contributed to a reduction in the number of bacteria on the tongue and the WTCI. Collectively, these results suggest that ID-Gal-containing foam dentifrice is effective in maintaining and improving oral hygiene.
(キーワード)
Humans / Dentifrices / Female / Male / Aged / Oral Hygiene / Dental Plaque / Treatment Outcome / Aged, 80 and over / Tongue
Tetsuo Ichikawa, Tomoya Koda, Mio Kitamura, Takahiro Kishimoto, Takashi Matsuda, Takaharu Goto, Masayuki Domichi, Akiko Suganuma, Shinji Fujiwara, Yasuhiko Shirayama, Kazuhiko Kotani and Naoki Sakane : Subjective assessment of sensory function and oral function decline in older adults, PLoS ONE, 20, 6, e0326788, 2025.
(要約)
Sensory decline in older adults significantly affects quality of life and contributes to cognitive decline, depression, falls, and injuries. Although several studies exist in this area, most were focused on individual senses, with few being conducted on comprehensive assessments of all five senses. The aim of this study was to investigate the relationship between subjective sensory assessment and oral function, to developing health strategies. This study was conducted as part of the Mima-SONGS Study for examining relationships between oral, cognitive, and physical functions, social factors, nutrition, and health, in older adults living in a mountainous region of Japan. The cohort included 62 participants (40 women and 22 men; mean age: 80.8 yrs.) as of December 2023. Participants completed a questionnaire assessing sensory perception and eating enjoyment rated on a four-point scale. Oral health was evaluated based on the conditions of remaining teeth, tongue coating, oral dryness, occlusal force, oral diadochokinesis, and repetitive salivary swallow test. Sensory assessments indicated minimal overall issues, with auditory problems scoring the highest and taste/tactile issues scoring the lowest. Males scored higher in hearing and maximum occlusal force. Eating enjoyment was generally high and negatively correlated with olfactory and taste problems. Subjective sensory issues were less strongly associated with oral function and age. Most older adults were not subjectively aware of sensory problems, especially olfaction, taste, and tactile problems. Subjective sensory problems showed a moderate but meaningful association with oral health conditions and age. The findings might be valuable data developing future support measures.
(キーワード)
Humans / Male / Female / Aged, 80 and over / Aged / Oral Health / Surveys and Questionnaires / Quality of Life / Japan / Sensation / Taste
Haruna Konishi, Yuichi Ishida, Takaharu Goto and Tetsuo Ichikawa : Assessing discrimination and acceptance for lightness and chroma during shade selection: A comparison of dental and non-dental professionals, Dentistry Journal, 13, 4, 163, 2025.
Yuri Oku, Hideki Suito, Keiko Fujimoto, Tetsuo Ichikawa and Kan Nagao : Relationship between vertical hyoid bone position and swallowing function in older adults., Journal of Oral Science, 67, 2, 91-95, 2025.
(要約)
JOF may affect swallowing function in older males with lowered hyoid bone position.
Mio Kitamura, Takaharu Goto, Tetsuo Ichikawa and Yasuhiko Shirayama : Clarifying the actual situation of old-old adults with unknown health conditions and those indifferent to health using the National Health Insurance Database (KDB) system, Geriatrics, 9, 6, 156, 2024.
(要約)
: This study aimed to investigate the actual situation of individuals with unknown health conditions (UHCs) and those indifferent to health (IH) among old-old adults (OOAs) aged 75 years and above using the National Health Insurance Database (KDB) system. : A total of 102 individuals with no history of medical examinations were selected from the KDB system in a city in Japan. Data were collected through home visit interviews and blood pressure monitors distributed by public health nurses (PHNs) from Community Comprehensive Support Centers (CCSCs). The collected data included personal attributes, health concern levels, and responses to a 15-item OOA questionnaire. Semi-structured interviews were conducted with seven PHNs. The control group consisted of 76 users of the "Kayoinoba" service (Kayoinoba users: KUs). : Of the 83 individuals who could be interviewed, 50 (49.0%) were classified as UHCs and 11 (10.8%) were classified as IH, including 5 from the low health concern group and 6 who refused to participate. In the word cloud generated from the PHNs' interviews, the words and phrases "community welfare commissioner", "community development", "blood pressure monitor", "troublesome", "suspicious", and "young" were highlighted. In the comparison of health assessments between UHCs and KUs, "body weight loss" and "cognitive function" were more prevalent among KUs, and "smoking" and "social participation" were more prevalent among UHCs. : The home visit activities of CCSCs utilizing the KDB system may contribute to an understanding of the actual situation of UHCs, including IHs, among OOAs. UHCs (including patients with IH status) had a higher proportion of risk factors related to smoking and lower social participation than KUs.
Takaharu Goto, Yukako Masutomi and Tetsuo Ichikawa : Distribution of main occluding area and associated factors in adolescents, Journal of Oral Science, 66, 4, 237-240, 2024.
Takaharu Goto, Shinji Fujiwara, Tomoya koda, Takashi Matsuda, Mio Kitamura, Yasuhiko Shirayama and Tetsuo Ichikawa : Biopsychosocial consideration of Ikigai in older adults in Japan through a cross-sectional study., Geriatrics, 9, 3, 78, 2024.
(要約)
-a Japanese concept that includes elements such as life's purpose and meaning-has been reported to be associated with various systemic health conditions, such as the risk of developing physical dysfunction or death in older adults. However, there are no reports that comprehensively examine the psychological and social aspects of . We attempted to clarify the characteristics of by examining it from a biopsychosocial model using physical, psychological, and social perspectives through a cross-sectional study on sarcopenia, frailty and healthy life expectancy in a hilly and mountainous area of Japan. Koyadaira in Mima City, which is located in a hilly and mountainous region on Shikoku Island in Japan, was targeted. This cross-sectional study included 105 outpatients aged 65 and over, with an average age of 79.02 ± 6.91 years. (self-rating score on a scale of 0 (no ) to 5 (the highest )) participants' level of physical activity (the Physical Activity Scale for the Elderly, PASE), degree of depression (the Geriatric Depression-15 Scale, GDS-15), cognitive function (the Mini-Mental State Examination, MMSE) and social isolation (the abbreviated Lubben Social Network Scale, LSNS-6) was assessed. Significant positive correlations were found between PASE and MMSE. The LSNS-6 significantly correlated with the MMSE and GDS-15. In a path model, out of four paths from PASE, GDS-15, MMSE, and LSNS-6 to , the path from the GDS-15 alone was significant (correlation coefficient -0.271, < 0.01). The adaptability of this model was good. This study indicates that depressive status has a large impact on , along with physical, cognitive, and social conditions; thus, it is appropriate to consider that an affective psychological status, such as depressive symptoms, is a fundamental condition for having .
Adityakrisna Putra Yoshi Wigianto, Megumi Watanabe, Yuki Iwawaki, Takaharu Goto, Tamaki Otsuki and Tetsuo Ichikawa : Antimicrobial Efficacy of a Portable UV-C-Based Coating Activation Device against Candida albicans Biofilm and SARS-CoV-2 as an Additional Feature: An In Vitro Study., Hygiene, 4, 1, 93-102, 2024.
Yukako Masutomi, Takaharu Goto and Tetsuo Ichikawa : Mouth breathing reduces oral function in adolescence, Scientific Reports, 14, 1, 3810, 2024.
(要約)
Although humans breathe naturally through the nostrils, mouth breathing in children has recently gathered attention. In this study, we hypothesized that tongue function and its related maxillofacial morphology would affect breathing in adolescence. To verify this hypothesis, we examined the association between breathing patterns, including mouth and nasal breathing; oral functions, including tongue motor function; and craniofacial morphology during adolescence, which has not been investigated till date. C3-H, which indicates the anteroposterior position of the hyoid bone in relation to the third cervical vertebra, was significantly smaller in mouth-breathers than in nasal-breathers. Lip-closing force, tongue pressure, and masticatory efficiency were lower in the order of nasal-breathers, oronasal-breathers, and mouth-breathers, and the values for mouth-breathers were significantly lower than those for nasal-breathers. Tongue pressure alone was identified as a significant independent variable, with an odds ratio of 1.063 (95% confidence interval, 1.006-1.123; p < 0.05). Our results indicate a relationship between mouth breathing and the lip-closing force, tongue pressure, and masticatory efficiency, as well as the significance of tongue pressure on mouth breathing in adolescents. The findings highlight the importance of clarifying the pathophysiology of mouth breathing and its underlying causes.
Takaharu Goto, Takahiro Kishimoto, Shinji Fujiwara, Yasuhiko Shirayama and Tetsuo Ichikawa : Social frailty as a predictor of all-cause mortality and functional disability: a systematic review and meta-analysis, Scientific Reports, 14, 1, 3410, 2024.
(要約)
The association between social frailty and adverse health outcomes, especially mortality and functional disability, which are essential health outcomes, has not been systematically summarized or meta-analyzed. In this study, we conducted a systematic review and meta-analysis of the impact of social frailty on all-cause mortality and functional disability, while addressing the components of social frailty. In this study, social frailty was operationally defined in alignment with the previous literature, as follows: "a state of increased vulnerability to the interactive back-and-forth of the community, including general resources, social resources, social behaviors, and needs." Hazard ratios or odds ratios described in each selected literature were used as the meta-analytic results. Considering the impact of social frailty on all-cause mortality, the hazard ratio was 1.96 (95% CI 1.20-3.19), indicating a significant association between the two but high heterogeneity. The hazard and odds ratios for the impact of social frailty on functional disability were 1.43 (95% CI 1.20-1.69) and 2.06 (95% CI 1.55-2.74), respectively. A significant association was found between social frailty and functional disability; both hazard and odds ratios were found, and low heterogeneity between these articles was observed. These results highlight the importance of assessing social frailty using more standardized methods and examining its effects on various health outcomes.
Megumi Watanabe, Lipei Liu and Tetsuo Ichikawa : Are Allergy-Induced Implant Failures Actually Hypersensitivity Reactions to Titanium? A Literature Review., Dentistry Journal, 11, 11, 263, 2023.
(要約)
This literature review was performed to assess whether implant failures are associated with titanium allergy. An electronic search of the MEDLINE/PubMed, Cochrane Library, and Scopus databases up to April 2021 was conducted, and the obtained articles were independently assessed by two reviewers. Articles describing cases of implant failure in which the cause of implant failure was only identified as allergy were included. Twelve studies were included. Eight studies identified Ti allergy by clinical examinations, of which four used patch tests, three used the lymphocyte transformation test (LTT)/memory lymphocyte immunostimulation assay (MELISA), and one used both tests. Nine studies reported cases of titanium hypersensitivity in combination with other systemic allergy-related disorders, with eight cases also showing positive results for Ni, Hg, Cr, and Co hypersensitivity. Ten papers reported the improvement of symptoms after the removal of the Ti implants and their replacement with zirconia implants, and two of these papers showed good results. Cases of probable titanium allergy included those with true titanium allergies and those with a potentially different cause. However, the differentiation of these cases is difficult. Since no definitive method has been established for diagnosing titanium allergy, a comprehensive diagnosis based on the clinical course and clinical examination using a patch test/LTT/MELISA is necessary. Implant treatment should be performed with caution in patients with any preoperative allergies.
Hideki Suito, Keiko Fujimoto, Takaharu Goto, Kan Nagao, Hidehiko Hosoki and Tetsuo Ichikawa : Effective use of an extraoral vacuum in preventing the dispersal of particulate matter from metal dental materials., Journal of Occupational Health, 65, 1, e12412, 2023.
(要約)
When dentists adjust prostheses at the dental chairside, particulate matter (PM) from the dental material is dispersed. Little is known about the effective use of an extraoral vacuum (EOV) in preventing PM dispersal. This study aimed to evaluate the effective use of an EOV in preventing the dispersal of metal PM in dental offices. The following experimental conditions were planned: the distance from the EOV to the metallic materials (50, 100, 150, and 200 mm), the horizontal angle between the long axis of the micromotor handpiece and EOV (0°, 45°, and 90°), and the operating time of the EOV (during grinding, during grinding and 1 min thereafter, during grinding and the preceding 1 min, 1 min before and after grinding, and during grinding). Carborundum and silicone points were used for grinding and PM dispersal. Diameters (0.3, 0.5, 1.0, and 3.0 μm) were measured using a laser particle counter. Depending on the instrument used to grind, there were undetectable PMs of different diameters (Carborundum point: 0.3 and 0.5 μm, Silicone point: 0.3 μm). PMNs were reduced as the distance from the EOV to metal materials decreased. Operating the EOV before grinding along the long axis of the micromotor handpiece was effective in reducing the PMNs. PMNs dispersed when grinding metals were effectively reduced by positioning the EOV closer to the grinding surface (within 150 mm) along the long axis of the micromotor handpiece and operating the EOV before grinding.
Kan Nagao, Keiko Fujimoto, Hideki Suito, Takaharu Goto, Yuichi Ishida, Megumi Watanabe and Tetsuo Ichikawa : Effect of Palatal Augmentation Prosthesis on Speech and Swallowing in Tongue Dysfunction:A Literature Review, Journal of Oral Health and Biosciences, 35, 2, 39-46, 2023.
(要約)
Purpose: Palatal augmentation prosthesis (PAP) is used on patients with dysphagia and dysarthria. While several studies have evaluated the effects of PAP, evidence regarding the adaptation criteria, effects, and limitations of PAP are not well organized. This review aims to summarize its functions, limitations, and applications. Procedure: To investigate the adaptation criteria, effects, and limitations of PAP, we searched the English language literature published in PubMed from its inception through April 20, 2022. The leading search terms included ``palatal augmentation prosthesis.'' Main findings: The primary search used keywords that reflected 31 studies. Finally, nine cross-sectional studies and nine case reports were selected for full-text assessment after applying the inclusion criteria. Eleven studies described the efficacy of speech function: two for motility factors and nine for organic factors (with overlap). Thirteen studies described the effectiveness of swallowing function, four related to motility factors, and ten for organic factors (with overlap). Several studies have demonstrated that PAP effectively restores articulation and swallowing in patients with impaired tongue function after glossectomy for oropharyngeal cancer, sequelae of cranial nerve disease, or neuromuscular disease. However, few papers describe the scope of glossectomy and tongue movement restrictions, so it is impossible to describe the adaptation criteria, effects, and limitations. In this review, most case reports and cross-sectional studies did not provide information on the fabrication methods of PAP or the dentistsʼ experience. Thus, the effect of bias on palatal morphology in PAP patients remains unclear. Conclusions: The number of patients with dysarthria and dysphagia is increasing worldwide, similar to what is already occurring in Japan. Therefore, additional high-quality studies on the effects of PAP are required.
(キーワード)
Palatal augmentation prosthesis / Tongue dysfunction / Literature review
Yoshihiro Tagami, Keiko Fujimoto, Takaharu Goto, Hideki Suito, Kan Nagao and Tetsuo Ichikawa : Can Measurement of Ultrasonic Echo Intensity Predict Physical Frailty in Older Adults?, Diagnostics, 13, 4, 675, 2023.
(要約)
Echo intensity (EI) of the tongue in ultrasonography is an easy and quantitative assessment of tongue function. Elucidating the relationship between EI and frailty, is expected to aid in the early detection of frailty and oral hypofunction in older adults. We assessed tongue function and frailty in older outpatients visiting a hospital. The subjects were 101 individuals aged 65 or older (35 men and 66 women, mean age 76.4 ± 7.0 years). Tongue pressure and EI were measured as assessments of tongue function and grip strength, and Kihon Checklist (KCL) scores were measured as assessments of frailty. In women, a significant correlation was not found between the mean EI and grip strength, whereas a significant correlation was noted between each score of the KCL and the mean EI; the scores increased as the mean EI increased. A significant positive correlation was found between tongue pressure and grip strength, but no significant correlation was observed between tongue pressure and the KCL scores. In men, no significant correlation was found between tongue assessments and frailty, except for a significant positive correlation between tongue pressure and grip strength. The results of this study suggest that EI of the tongue is positively associated with physical frailty in women and may be useful for early detection of physical frailty status.
Yasufumi Nishikawa, Yoritoki Tomotake, Hiromichi Kawano, Koji Naruishi, Jun-ichi Kido, Yuka Hiroshima, Akikazu Murakami, Tetsuo Ichikawa and Hiromichi Yumoto : Effects of Candidalysin Derived from Candida albicans on the Expression of Pro-Inflammatory Mediators in Human Gingival Fibroblasts, International Journal of Molecular Sciences, 24, 4, 3256, 2023.
Application of cream-type denture adhesives effectively improves the denture retention and occlusal force in complete denture wearers with a moderate degree of difficulty during edentulism treatment.
Takahiro Kishimoto, Takaharu Goto and Tetsuo Ichikawa : Stress Reduction Effects during Block-Tapping Task of Jaw in Healthy Participants: Functional Near-Infrared Spectroscopy (fNIRS) Measurements of Prefrontal Cortex Activity, Brain Sciences, 12, 12, 1711, 2022.
(要約)
The purpose of this study was to explore the influence of simple jaw opening and closing task of chewing movements on the activities of the prefrontal cortex (PFC) from the viewpoint of stress reduction. We measured cerebral blood flow (CBF) in the PFC during a block-tapping task of the jaw in healthy participants. Eleven young healthy individuals with normal dentition (7 males and 4 females, mean age 28.0 ± 3.7 years) volunteered for this study. CBF was measured using a wearable, functional near-infrared spectroscopy device. Measurements were taken using the central incisors and first molars at interocclusal distances of 5 and 10 mm. The participants were asked to bite a hard/soft block. CBF in all conditions showed limited variability or decreasing trend compared to resting state before the task. The main effect was observed for interocclusal distance ( = 0.008), and there were no significant differences for measurement area of the PFC, tooth type, and material type. An interaction was found between tooth type and material type. In conclusion, these results suggest that simple and rhythmical chewing motion has an effect of reducing CBF in the PFC and resting the PFC, which is an especially notable aspect of periodontal sensory information in the molar.
Kenji Maekawa, Tomoko Ikeuchi, Shoji Shinkai, Hirohiko Hirano, Masahiro Ryu, Katsushi Tamaki, Hirofumi Yatani, Takuo Kuboki, Aya Kimura-Ono, Takeshi Kikutani, Takashi Suganuma, Yasunori Ayukawa, Tomoya Gonda, Toru Ogawa, Masanori Fujisawa, Shoichi Ishigaki, Yutaka Watanabe, Akihiko Kitamura, Yu Taniguchi, Yoshinori Fujiwara, Ayako Edahiro, Yuki Ohara, Junichi Furuya, Junko Nakajima, Kento Umeki, Kentaro Igarashi, Yasuhiro Horibe, Yoshihiro Kugimiya, Yasuhiko Kawai, Hideo Matsumura, Tetsuo Ichikawa, Shuji Ohkawa and Kazuyoshi Baba : Impact of number of functional teeth on independence of Japanese older adults., Geriatrics & Gerontology International, 22, 12, 1032-1039, 2022.
(要約)
To examine the relationship between the number of present and functional teeth at baseline and future incidence of loss of independence. Participants were community-dwelling older individuals who participated in a comprehensive geriatric health examination conducted in Kusatsu town, Japan, between 2009 and 2015. The primary endpoint was the incidence of loss of independence among participants, defined as the first certification of long-term care insurance in Japan. The numbers of present and functional teeth at baseline were determined via an oral examination. Demographics, clinical variables (e.g., history of chronic diseases and psychosocial factors), blood nutritional markers, physical functions, and perceived masticatory function were assessed. This study included 1121 individuals, and 205 individuals suffered from loss of independence during the follow-up period. Kaplan-Meier estimates of loss of independence for participants with smaller numbers of present and functional teeth were significantly greater than for those with larger numbers of teeth. Cox proportional hazard analyses indicated that a smaller number of present teeth was not a significant risk factor after adjusting for demographic characteristics. However, the number of functional teeth was a significant risk factor after the adjustment (hazard ratio: 1.975 [1.168-3.340]). Additionally, higher hazard ratios were observed in other adjusted models, but they were not statistically significant. The number of functional teeth may be more closely related to the future incidence of loss of independence than the number of present teeth. This novel finding suggests that prosthodontic rehabilitation for tooth loss possibly prevents the future incidence of this life-event. Geriatr Gerontol Int 2022; 22: 1032-1039.
(キーワード)
Humans / Aged / Japan / Tooth Loss / Certification / Independent Living / Insurance, Long-Term Care
Adityakrisna Putra Yoshi Wigianto, Yuichi Ishida, Yuki Iwawaki, Takaharu Goto, Megumi Watanabe, Kazumitsu Sekine, Kenichi Hamada, Keiji Murakami, Hideki Fujii and Tetsuo Ichikawa : 2-methacryloyloxyethyl phosphorylcholine polymer treatment prevents Candida albicans biofilm formation on acrylic resin, Journal of Prosthodontic Research, 67, 3, 384-391, 2022.
(要約)
We aimed to evaluate the effectiveness of photoreactive 2-methacryloyloxyethyl phosphorylcholine (MPC) in inhibiting Candida albicans biofilm formation on polymethyl methacrylate (PMMA) and assess its mechanism and need for re-application by evaluating its interaction with salivary mucin and durability during temperature changes. PMMA discs were used as specimens. The MPC coating was applied using the spray and cure technique for the treatment groups, whereas no coating was applied to the control. The MPC treatment (MT) groups were further differentiated based on the number of thermal cycles involved (0, 1000, 2500, and 5000). The optical density was measured to assess mucin adsorption (MA). Contact angle (CA) was calculated to evaluate surface hydrophilicity. The presence of MPC components on the PMMA surface was assessed using X-ray photoelectron spectroscopy (XPS). C. albicans biofilms were evaluated qualitatively (scanning electron microscope images) and quantitatively (colony-forming units (CFUs)). Statistical analysis was conducted using two-way analysis of variance and Tukey's multiple comparison test. MA rate and CA increased significantly in the MT groups, which exhibited significantly fewer CFUs and thinner biofilms than those of the control group. Based on the XPS, MA, and CFU evaluations, the durability and efficacy of the MPC coating were considered stable up to 2500 thermal cycles. Additionally, a significant interaction was observed between mucin concentration and MPC efficacy. The photoreactive MPC coating, which was resistant to temperature changes for approximately 3 months, effectively prevented C. albicans biofilm formation by modifying surface hydrophilicity and increasing mucin adsorption.
Lipei Liu, Megumi Watanabe, Norikazu Minami, Mohammad Fadyl Yunizar and Tetsuo Ichikawa : Semaphorin 3A: A potential target for prevention and treatment of nickel allergy, Communications Biology, 5, 1, 671, 2022.
(要約)
Metal allergy is one of the typical immune disorders encountered during the application of dental/medical materials and has a highly complex pathogenic mechanism. Semaphorin 3A (Sema3A), a member of the semaphorin family, is reported to be involved in various immune disorders. However, its role in metal allergy has not been clarified yet. Herein, we show that Sema3A expression was upregulated in nickel (Ni) allergy-induced mouse ear tissue and in NiCl-stimulated mouse keratinocytes. Moreover, Sema3A regulated tumor necrosis factor-alpha production and mitogen-activated protein kinase activation in keratinocytes. The specific deletion of Sema3A in keratinocytes did not affect immune cell infiltration but reduced edema and ear swelling; it also impeded Th1 responses to cause a slight alleviation in Ni allergy in mice. Our results demonstrate that Sema3A promotes the development of metal allergy and should be explored as a potential target for the prevention and treatment of metal allergy.
Lipei Liu, Megumi Watanabe, Norikazu Minami, Mohammad Fadyl Yunizar and Tetsuo Ichikawa : Dendritic Cells Directly Recognize Nickel Ions as an Antigen during the Development, Journal of Oral Health and Biosciences, 34, 2, 40, 2022.
Adityakrisna Putra Yoshi Wigianto, Yuichi Ishida, Takashi Matsuda, Takaharu Goto, Megumi Watanabe and Tetsuo Ichikawa : Novel Magnetic Attachment System Manufactured Using High-Frequency Heat Treatment and Stamp Technique: Introduction and Basic Performance, Dentistry Journal, 10, 5, 75, 2022.
(要約)
Recently, a novel magnetic attachment with extremely low cost and high performance was developed. This article aims to introduce a novel magnetic attachment and to evaluate its basic eligibility for denture retention in clinical practice. The novel magnetic attachment system used in this study was the direct-bonding root-keeper-type Magteeth™ MT800 (MagneDesign, Nagoya, Japan). The retentive force without displacement (position 0) and after horizontal displacement to positions 0.5, 1, 1.5, 2, 2.5, and 3 mm were measured. The values relative to the retentive force without displacement were gradually decreased to 82.7 ± 16.3%, 68.8 ± 17.1%, 62.4 ± 15%, 47.2 ± 13.1%, 35.7 ± 9.9%, and 20.7 ± 6.5%, respectively. The retentive force and magnetic field strength did not change significantly after the load test (100 N load, 10,000 times). No new gap between the metal and resin was found in the root keeper- and magnet assembly-embedded blocks after the load test. Some scratches on magnetic assembly and root keeper surface, while no change in the resin texture after the load test were observed. Based on the findings of this preliminary study, this novel low-cost magnetic attachment exhibited favorable retention, strength, and durability for clinical use.
Mohammad Fadyl Yunizar, Megumi Watanabe and Tetsuo Ichikawa : Current development status of additive manufacturing technologies for fabricating removable partial denture frameworks: a literature review, International Journal of Computerized Dentistry, 25, 1, 57-70, 2022.
(要約)
The aim of the present study was to review the current development status of additive manufacturing (AM) technology for fabricating frameworks for removable partial dentures (RPDs) considering fit accuracy, surface condition, and mechanical strength. A search of the databases of MEDLINE, Cochrane Library, and Science Direct was conducted using definite keywords ("removable partial denture" or "framework" or "dental prosthesis design") and ("additive manufacturing technology" or "rapid prototyping" or "3D-printing"). A total of 23 articles were selected according to certain inclusion criteria. The direct AM techniques were applied to manufacture metal RPD frameworks consisting of selective laser melting (SLM), selective laser sintering (SLS), and metal binder jetting (MBJ). The SLM technique showed a good surface and mechanical strength, but low accuracy. The SLS technique showed higher accuracy than indirect AM, but further studies are required. The MBJ technique showed lower accuracy and a rougher surface than the conventional method. AM techniques can produce RPD frameworks within the acceptable range for clinical practice; however, more clinical studies are needed.
Mohammad Fadyl Yunizar, Megumi Watanabe, Lipei Liu, Norikazu Minami and Tetsuo Ichikawa : Metal Allergy Mediates the Development of Oral Lichen Planus via TSLP-TSLPR Signaling, Journal of Clinical Medicine, 11, 3, 519, 2022.
(要約)
Metal allergy is a T-cell-mediated delayed type of hypersensitive reaction. The pathogenetic mechanisms underlying the allergy are unclear, although the condition has been reported to be related to oral lichen planus (OLP), despite an absence of immunological studies to support this relationship. In this study, histopathological samples of OLP patients were examined to compare the metal allergy-positive and -negative groups, with a focus on the network of epidermal keratinocytes and T cells induced by thymic stromal lymphopoietin (TSLP) and its receptor, TSLPR. Infiltration of T cells into the epithelium was revealed to be higher in the OLP lesions of metal allergy-positive patients than in those of metal allergy-negative patients. Moreover, TSLP-TSLPR signaling and TNF-α production were higher in the epithelial tissue samples of the metal allergy-positive patients than in the metal allergy-negative patients. Metal allergy is associated with both increased expressions of TSLP in keratinocytes and increased TNF-α levels in the epithelium. We propose that this would promote the accumulation of T cells at the lesion site, contributing to the formation of the disease. These results suggest that metal allergy may be an aggravating factor in the pathogenesis of OLP.
Tetsuo Ichikawa, Takaharu Goto, Takahiro Kishimoto, Yuichi Ishida and Megumi Watanabe : Does Prosthodontic Treatment Improve the Nutrition Status in the Elderly? Literature Review, Journal of Food and Nutrition Research, 10, 1, 26-31, 2022.
Yoshihiro Tagami, Keiko Fujimoto, Takaharu Goto, Hideki Suito, Kan Nagao and Tetsuo Ichikawa : Measurement of ultrasonic echo intensity predicts the mass and strength of the tongue muscles in the elderly, Journal of Oral Science, 64, 1, 44-48, 2022.
(要約)
The purpose of this study was to investigate the relationship between the echo intensity (EI) on ultrasound images of the tongue, tongue thickness, and tongue pressure to examine the effectiveness of EI measurement for assessing the tongue function. A total of 100 elderly outpatients were enrolled. Tongue thickness and EI were measured using ultrasonography. The distance from mylohyoid muscle surface to dorsal surface of the tongue was measured for tongue thickness. Subsequently, this area was vertically divided into four areas: top of tongue dorsal side (DT), bottom of tongue dorsal side (DB), top of basal tongue side (BT), and bottom of basal tongue side (BB), and the EI was measured in each area. The mean EIs of DT and DB were lower than those of BT and BB. In the three areas apart from BB, the EI decreased with an increase in tongue thickness. In particular, a significant correlation between the EI in DB and tongue thickness was found. In all areas, the EI decreased with an increase in tongue pressure. The results of this study suggested that the measurement of EI could be an important indicator for assessing the tongue function in the elderly.
Wigianto Yoshi Putra Adityakrisna, Takaharu Goto, Yuki Iwawaki, Yuichi Ishida, Megumi Watanabe and Tetsuo Ichikawa : Treatment outcomes of implant-assisted removable partial denture with distal extension based on the Kennedy classification and attachment type: a systematic review, International Journal of Implant Dentistry, 7, 1, 111, 2021.
(要約)
Implant-assisted removable partial dentures (IARPDs) have recently become popular, but little information is available on the treatment outcomes based on the Kennedy classification and attachment types. The objective of this review was to evaluate the treatment outcomes of IARPD delivered for distal extension edentulous areas based on the differences in the Kennedy classification and attachment type. English-language clinical studies on IARPD published between January 1980 and February 2020 were collected from MEDLINE (via PubMed), the Cochrane Library (via the Cochrane Central Register of Controlled Trials), Scopus online database, and manual searching. Two reviewers selected the articles based on pre-determined inclusion and exclusion criteria, followed by data extraction and analysis. Eighty-one studies were selected after evaluating the titles and abstracts of 2410 papers. Nineteen studies were finally included after the perusal of the full text. Fourteen studies focused on Class I, 4 studies investigated both Class I and II, and only 1 study was conducted on Kennedy's class II. Eight types of attachments were reported. The ball attachment was the most frequently used attachment, which was employed in 8 of the included studies. The implant survival rate ranged from 91 to 100%. The reported marginal bone loss ranged from 0.3 mm to 2.30 mm. The patient satisfaction was higher with IARPD than with conventional RPDs or that before treatment. The results of prosthetic complications were heterogeneous and inconclusive. IARPD exhibited favorable clinical outcomes when used as a replacement for distal extension edentulous areas. The comparison between the clinical outcomes of Kennedy's class I and II was inconclusive owing to the lack of studies focusing on Kennedy Class II alone. The stud attachment was the most commonly used type in IARPDs. Overall, the different attachment systems did not influence the implant survival rate and patient satisfaction. Further high-quality studies are needed to investigate the attachment systems used in IARPD.
友竹 偉則, 川野 弘道, 西川 泰史, 武川 香織, 富永 賢, 市川 哲雄 : 徳島大学病院口腔インプラントセンターにおける新来患者の臨床統計, Journal of Oral Health and Biosciences, 33, 2, 39-44, 2021年.
(要約)
<b>Purpose:</b> Oral Implant Center established in April 2014 as specialized clinical section at Tokushima University Hospital. The aim of this study was to report a survey of new patients of preoperative registration at Oral Implant Center during the five years since its establishment.<br> <b>Subjects and methods:</b> Investigation of gender and age, chief complaint, details of treatment requests, sites of missing teeth, number of missing teeth, cause of tooth extraction, and treatment status for patients registered at Oral Implant Center from April 2014 to March 2019 were performed.<br> <b>Results:</b> Regarding the chief complaint, 605 (88.3%) patients consulted preoperatively for a request for implant treatment, and 80 (11.7%) consulted about complain of previous implant treatment or a request for continued maintenance. The average number of missing teeth for which treatment was requested was 3.8. The proportion of patients who wished to be treated for the number of missing teeth was 32.2% for missing one tooth, 56.1% for missing few teeth (2 to 6 teeth), 7.8% for missing many teeth (7 or more teeth) and edentulous 3.9%. As for the details of treatment requests of 80 patients who had already received implant treatment, 33 (41.3%) consulted on the improper superstructure, 29 (36.3%) wished to examine and treat peri-implantitis, 4 (5%) wished to remove the implant and 14 (17.5%) requested continued maintenance.<br> <b>Discussion and conclusion:</b> The number of new patients regarding implant treatment has been about the same each year, and it was reconfirmed that it was recognized as a treatment method for dental prostheses. In particular, many patients wished to receive implant treatment for a single tooth missing, suggesting that the patients also recognized the importance of preserving the remaining teeth. On the other hand, the number of patients complaining of previous implant treatment tends to increase, and it is necessary to consider future correspondence.
(キーワード)
Oral Implant Center / implant treatment / preoperative registration
<p><b>Purpose </b>To investigate the difference in improvement of oral health-related quality of life (OHR-QoL) depending on the oral and denture conditions of a complete denture wearer when using a cream or powder type denture adhesive in a 10-center parallel randomized clinical trial.</p><p><b>Methods </b>Two hundred edentulous subjects who wore complete dentures were allocated to each of the three groups according to denture adhesive type: cream, powder, and control (saline solution). The materials were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention were collected. OHR-QoL was assessed using the Japanese version of the modified Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT-J) scale for outcome. Multivariate analysis was used to investigate improvements in OHR-QoL according to participant characteristics among complete denture wearers using these materials.</p><p><b>Results </b>OHIP-EDENT-J scores were significantly decreased in all groups after the intervention (p < 0.05); however, there were no statistically significant differences among the groups. Multiple logistic regression analysis revealed a significant association between the vertical height of the maxillary and mandibular alveolar ridge and OHIP-EDENT-J scores in the cream-type denture adhesive group. In contrast, there were no significant association between participant characteristics and OHIP-EDENT-J scores in the powder-type adhesive and control groups.</p><p><b>Conclusions </b>The use of denture adhesives could improve OHR-QoL for complete denture wearers. The cream-type denture adhesives may be expected to improve OHR-QoL in patients with poor residual ridge conditions compared with patients with good residual ridge conditions.</p>
Keiko Fujimoto, Hideki Suito, Kan Nagao and Tetsuo Ichikawa : Does Masticatory Ability Contribute to Nutritional Status in Older Individuals?, International Journal of Environmental Research and Public Health, 17, 20, 2020.
(要約)
Mastication plays a primary role in the process of eating. Hence, compromised masticatory ability may affect the nutrition and quality of life, which are particularly important concerns among older individuals. It remains unclear how is the masticatory ability assessed regarding the nutritional status. We examined the effect of various oral factors on three masticatory ability tests conducted among older individuals. A total of 100 older individuals were enrolled in this study. Body mass index (BMI) as an indicator of nutritional status; and age, sex, and the number of occlusal and molar occlusal supports as clinical attributes were recorded. Three masticatory ability tests (masticatory efficiency, masticatory score, and satisfaction with mastication) were conducted, and tongue pressure, cheek pressure, and occlusal force were assessed as oral functions. A significant but weak correlation was found between masticatory efficiency and the masticatory score, but not between masticatory efficiency and satisfaction score. Objective masticatory efficiency was strongly associated with objective oral factors, whereas subjective assessments of masticatory ability (masticatory score and satisfaction score) were not. Furthermore, BMI was significantly associated with subjective assessments of masticatory ability but not with objective masticatory efficiency. Both subjective and objective assessments of masticatory ability, along with considerations of nutritional formulations, are required for the maintenance and improvement of nutritional status in older individuals.
(キーワード)
Aged / Female / Humans / Male / Mastication / Nutritional Status / Pressure / Quality of Life / Tongue
Takaharu Goto, Nobuaki Higaki, Takahiro Kishimoto, Yoritoki Tomotake and Tetsuo Ichikawa : Does periodontal tactile input uniquely increase cerebral blood flow in the prefrontal cortex?, Brain Sciences, 10, 8, E482, 2020.
(要約)
We previously studied the effect of peripheral sensory information from sensory periodontal ligament receptors on prefrontal cortex (PFC) activity. In the dental field, an alternative dental implant without periodontal sensation can be applied for missing teeth. In this study, we examine whether periodontal tactile input could increase cerebral blood flow (CBF) in the PFC against elderly patients with dental implants lacking periodontal tactile (implant group), elderly individuals with natural teeth (elderly group), and young individuals with natural teeth (young group). The experimental task of maintaining occlusal force as closed-loop stimulation was performed. Compared with the young group, the elderly group showed significantly lower CBF. Contrastingly, compared with the young group, the implant group showed significantly lower CBF. There were no significant differences between the elderly and implant groups. Regarding the mean occlusal force value, compared with the young group and the elderly group, the implant group had a numerically, but not significantly, larger occlusal force exceeding the directed range. In conclusion, the periodontal tactile input does not uniquely increase PFC activity. However, increased CBF in the PFC due to the periodontal tactile input in the posterior region requires existing attention behavior function in the PFC.
Y Nishi, T Nomura, M Murakami, Y Kawai, M Nishimura, H Kondo, Y Ito, A Tsuboi, G Hong, S Kimoto, A Gunji, A Suzuki, G Ohwada, S Minakuchi, Y Sato, T Suzuki, K Kimoto, N Hoshi, M Saita, Y Yoneyama, Y Sato, M Morokuma, J Okazaki, T Maeda, K Nakai, Tetsuo Ichikawa, Kan Nagao, Keiko Fujimoto, H Murata, T Kurogi, K Yoshida, T Hosoi and T Hamada : Effect of denture adhesives on oral moisture: A multicenter randomized controlled trial, Journal of Prosthodontic Research, 64, 3, 281-288, 2020.
(要約)
The purpose of this study was to investigate the effect of denture adhesives on oral moisture in a 10-center parallel randomized clinical trial. Two hundred edentulous subjects wearing complete dentures were allocated into three groups: cream-type adhesive, powder-type adhesive and control groups. The adhesives (and saline solution in the control group) were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention for eight meals over 4 days were obtained. For the main outcome, oral moisture was measured with a moisture checking device. Secondary outcomes were denture satisfaction, masticatory performance, denture retention, and occlusal force. In addition to between-group and within-group comparisons of oral moisture, investigations for secondary outcomes were undertaken in subgroups classified according to the degree of oral moisture at baseline (normal subgroup and dry mouth subgroup). Intention-to-treat analysis was also performed. Between-group and within-group comparisons of oral moisture showed no significant differences. The cream-type and powder-type denture adhesives were significantly effective in the dry mouth group for denture satisfaction ratings of ability to masticate, stability, retention, and comfort of mandibular dentures (p<0.05). The masticatory performance and retentive force of the dry mouth denture adhesive using groups were significantly improved after intervention (p<0.05). The oral moisture of complete denture wearers was not influenced by the use of denture adhesives. Our findings showed that denture adhesives improved subjective denture satisfaction, masticatory performance, and retention for complete denture patients with oral dryness.
Norikazu Minami, Megumi Watanabe, Lipei Liu, YUNIZAR Fadyl Mohammad and Tetsuo Ichikawa : Effect of Semaphorin7A during the Effector Phase of Nickel Allergy, Journal of Oral Health and Biosciences, 33, 1, 8-14, 2020.
Kenji Maekawa, Tomoko Ikeuchi, Shoji Shinkai, Hirohiko Hirano, Masahiro Ryu, Katsushi Tamaki, Hirofumi Yatani, Takuo Kuboki, Aya Kimura-Ono, Takeshi Kikutani, Takashi Suganuma, Yasunori Ayukawa, Tomoya Gonda, Toru Ogawa, Masanori Fujisawa, Shoichi Ishigaki, Yutaka Watanabe, Akihiko Kitamura, Yoshinori Fujiwara, Ayako Edahiro, Junichi Furuya, Junko Nakajima, Kento Umeki, Kentaro Igarashi, Yasuhiro Horibe, Yoshihiro Kugimiya, Yasuhiko Kawai, Hideo Matsumura, Tetsuo Ichikawa and Shuji Ohkawa : Number of functional teeth more strongly predicts all-cause mortality than number of present teeth in Japanese older adults., Geriatrics & Gerontology International, 20, 6, 607-614, 2020.
(要約)
Previous studies on the association between intraoral conditions and mortality in community-dwelling older individuals reported that fewer present teeth (PT) are significant risk factors for mortality. However, how the number of PT relative to the number of functional teeth (FT), including both present and rehabilitated teeth, influences mortality has not been investigated fully. This study examined the impact of the number of FT on mortality among community-dwelling Japanese older adults. This study was a retrospective, observational and population-based follow-up study, which examined 1188 older individuals who participated in an annual geriatric health examination from 2009 to 2015. The average follow-up period was 1697.0 774.5ays. The primary outcome was all-cause mortality at follow-up. The numbers of PT and FT of each participant were counted during an oral examination. In addition, demographics, clinical variables, blood nutrient markers, physical functions and perceived masticatory function were measured. Kaplan-Meier analysis, followed by a log-rank test, revealed that fewer PT (P < 0.001) and FT (P = 0.002) were significantly associated with a reduced survival rate. Cox's proportional hazard analysis indicated that the number of FT, but not the number of PT, was a significant independent mortality risk factor after adjusting for demographics, clinical variables, nutrient markers and physical functioning (P = 0.036, hazard ratio: 2.089). Current results suggest that the number of FT more strongly predicts all-cause mortality than the number of PT among community-dwelling older adults. Further studies are necessary to consider the confounding of socioeconomic status and disability status. Geriatr Gerontol Int 2020; : - .
(キーワード)
Aged / Aged, 80 and over / Diagnosis, Oral / Follow-Up Studies / Geriatric Assessment / Humans / Independent Living / Kaplan-Meier Estimate / Proportional Hazards Models / Retrospective Studies / Risk Factors / Tooth Loss
Tsukasa Hihara, Takaharu Goto and Tetsuo Ichikawa : Assessment of potential clinical cascade between oral hypofunction and physical frailty: Covariance structure analysis in a cross-sectional study, Journal of Oral Rehabilitation, 47, 1, 61-66, 2020.
(要約)
No report has yet examined the impact of oral hypofunction on physical frailty in relation to intra-relationships of physical frailty assessment items. The purpose of this study was to verify the potential of a clinical cascade between oral hypofunction and physical frailty, and especially to support the hypothesis that the influence of oral hypofunction on physical frailty is greater than the intra-relationships among elements of physical frailty and that sex differences significantly affect these relationships. The participants were 272 older adults (101 men and 171 women; mean age 75.1 ± 7.5 years). Maximum occlusal force (MOF) and oral dryness (OD), as indicators of oral hypofunction, and grip strength (GS) and walking speed (WS), as indicators of physical frailty, were measured. Mutual relationship of four variables was verified using covariance structure analysis. In men, three paths from MOF to WS and GS and from WS to GS were confirmed, and those from MOF to WS and from WS to GS were found to be significant (P < .01). In women, three paths from MOF to WS and GS and from WS to GS were also confirmed, as with the men, and those from MOF to WS and from MOF to GS were found to be significant (P < .01). Model adaptability was shown to be good for both men and women. The results suggest our hypothesis was verified, and it is expected that the early detection of oral hypofunction, that is MOF, may be important for assessing physical frailty, especially in women.
(キーワード)
Aged / Aged, 80 and over / Bite Force / Cross-Sectional Studies / Female / Frail Elderly / Frailty / Geriatric Assessment / Humans / Male
Tetsuo Ichikawa, Rudi Wigianto and Omar Maningo Rodis : Bibliography on Academic Exchanges of Tokushima University Faculty of Dentistry with Seven Indonesian Faculties, Journal of Oral Health and Biosciences, 32, 2, 41-47, 2020.
(要約)
Tokushima University Faculty of Dentistry has signed academic agreements with seven faculties in Indonesia, and joint international meetings between these Indonesian universities have been held biannually. Moreover, undergraduate student exchange programs have been executed every year with three faculties. Behind the development of these successful outcomes is a story of a large amount of effort by pioneers. The purpose of this article is to present the process and history of the academic exchanges of Tokushima University Faculty of Dentistry with Indonesian faculties at present and to discuss future exchange programs.
(キーワード)
徳島 (Tokushima) / Indonesia / Academic exchange / Dentistry
Kosuke Kurahashi, Takashi Matsuda, Yuichi Ishida and Tetsuo Ichikawa : Effect of polishing protocols on the surface roughness of polyetheretherketone., Journal of Oral Science, 62, 1, 40-42, 2020.
(要約)
The purpose of this study was to evaluate the influence of various polishing protocols on the surface roughness of polyetheretherketone (PEEK) and identify an effective polishing method of dental prostheses at the chairside. The PEEK specimens were assigned to seven groups with different protocols: no additional polishing (NT); polishing using a rubber point (C); polishing using "silky shine" (S); polishing using "aqua blue paste" (A); protocol C followed by protocol S (CS); protocol C followed by protocol A (CA); and protocol C followed by protocols S and A (CSA). The surface roughness (Sa and Ra) of the polished surfaces was measured. The surface roughness decreased in the following order of groups: NT, C, S, CS, CSA, CA, and A. In Groups C and S, wide deep pits formed by abrasive grains of SiC paper were observed, whereas only fine linear structures were observed on the surface in other groups. With respect to the polishing protocol of PEEK, clinically acceptable surface roughness was obtained using a soft polishing brush and agent for more than 3 min.
The prefrontal cortex (PFC) plays an important role in several cognitive functions, such as planning, decision making, and social behavior. We previously reported that periodontal sensory input significantly increases PFC activity during the motor task of maintaining occlusal (biting) force. However, the relationships between periodontal sensation, PFC activity, and the performance of motor tasks have not been evaluated in detail. Therefore, using functional near-infrared spectroscopy, we investigated PFC activity by monitoring changes in cerebral blood flow (CBF) to specific areas of the PFC that corresponded to changes in occlusal force generated during four different biting tasks: (1) occlusion with the central incisor with an interocclusal distance of 5 mm (BI-5 mm); or (2) 10 mm (BI-10 mm); (3) occlusion with the first molars with an interocclusal distance of 5 mm (BM-5 mm), or (4) 10 mm (BM-10 mm). Occlusion of molars generated increased PFC regional CBF as the interocclusal distance decreased (BM-10 mm vs BM-5 mm). No significant differences in CBF during occlusion of incisors were found when comparing 5 mm and 10 mm intercostal distances (BI-5 mm vs BI-10 mm). The mean occlusal force generated by BM-5 mm occlusion was significantly lower than that generated by BM-10 mm occlusion. Taken together, our results suggest that the PFC decreases efferent signaling to motor units, to reduce occlusal force generated when periodontal sensation, which is greater when the interocclusal distance is reduced, is primarily responsible for maintaining occlusal force in the absence of sensations from the temporomandibular joint and muscle spindles.
Tsukasa Hihara, Takaharu Goto and Tetsuo Ichikawa : Investigating eating behaviors and symptoms of oral frailty using questionnaires, Dentistry Journal, 7, 3, 66, 2019.
(要約)
A questionnaire survey was conducted to investigate eating behavior and the subjective symptoms of oral frailty, and to examine the relationship between them. A total of 744 subjects with ages over 65 years were included. The questionnaire comprised 18 question items indicating eating behavior and seven question items indicating oral frailty. All items were assessed according to 4 grades on a scale of 1 (not applicable) to 4 (applicable). The total score of oral frailty gradually increased with age. Regarding the scores for "eating recognition" and "eating habits", no changes were observed, however the scores for "eating action" demonstrated a decreasing tendency with age and the scores of 85 years age group was significantly lower than the 65-69, 70-74, and 75-79 years age groups. As a result of multiple regression analysis, among the significant independent variable, the scores of "I do not chew foods well" under the category of "eating action" showed the highest standard partial regression coefficients for dependent variable of symptoms of oral frailty. The significant association was found between the eating behavior and subjective symptoms of oral frailty, and this study suggests that the good chewing habit might be an important criterion for the prevention of oral frailty.
G Ohwada, S Minakuchi, Yuji Sato, A Tsuboi, Tetsuo Ichikawa, Kan Nagao and Keiko Fujimoto : Subjective Evaluation of Denture Adhesives: A Multicenter Randomized Controlled Trial., JDR Clinical and Translational Research, 5, 1, 50-61, 2019.
(要約)
Many reports show that denture adhesives improve the retention and stability of dentures. However, few randomized controlled trials have examined the effects of denture adhesives. This 10-center randomized controlled trial with parallel groups involving 200 edentulous patients wearing complete dentures aimed to evaluate the effects of short-term use of cream and powder denture adhesives. Patients were allocated into 2 cream- and powder-type adhesive groups and 1 control group. Intervention groups were treated with the 2 adhesives (1 each), and the control group received saline solution. Adhesive or control was applied to the denture-mucosal surface for 4 d, and data at baseline and after day 4 of intervention (i.e., 8 meals) were obtained. Patient satisfaction was evaluated with a 100-mm visual analog scale. Oral health-related quality of life was measured with the Japanese version of the Oral Health Impact Profile for Edentulous Patients. Perceived chewing ability was evaluated by a questionnaire regarding ease of chewing and swallowing food. Between-group comparisons were performed with Kruskal-Wallis tests with the Mann-Whitney test adjusted by Bonferroni correction. Within-group comparisons of pre- and postintervention measurements were performed with the Wilcoxon signed-rank test. Intention-to-treat analysis was also performed. Between-group comparisons showed no significant differences for general satisfaction or Oral Health Impact Profile for Edentulous Patients. However, significant differences in satisfaction with various denture functions with cream- and powder-type adhesives were seen in pre- and postintervention comparisons ( < 0.05). Significant differences were also observed for perceived chewing ability of hard foods ( < 0.05). These results suggest that although denture adhesives do not invariably improve denture function, they do affect subjective evaluations and possibly chewing of hard foods. Therefore, the effects of denture adhesive use are insufficient to resolve any fundamental dissatisfaction with dentures ( ClinicalTrials.gov NCT01712802 ). The results of this study suggest that denture adhesives should be applied under certain conditions; however, an appropriate diagnosis is important before application. These practice-based data provide information to establish evidence-based guidelines for applying denture adhesives.
To demonstrate the usefulness of a virtual reality device that authentically portrays the emotions of dementia patients and their families (VR Dementia Experience) for encouraging an understanding of and reducing and eliminating prejudice towards dementia patients among local residents. In Prefecture T, Town N, 85 residents of Neighborhood A were chosen as the intervention group, and 95 residents of Neighborhood B were chosen as the non-intervention group. The VR Dementia Experience was provided only to the residents of Neighborhood A. Residents of both neighborhoods completed a 35-item questionnaire regarding their degree of understanding and prejudice towards dementia patients before and after the intervention. Seventy-seven residents of Neighborhood A and 82 residents of Neighborhood B were analyzed. Their gender, age, and pre-intervention test baseline values were equivalent in the degree of understanding and prejudice. Significant increases were observed in 9 of 35 items for Neighborhood A residents (7 understanding-related, 2 prejudice-related) and 2 items for Neighborhood B residents (1 understanding-related, 1 prejudice-related). To ascertain the usefulness of the VR Dementia Experience, we compared the number of items with a significant increase: 9/35 (25.7%) in Neighborhood A and 2/35 (5.7%) in Neighborhood B. An effect (≥ 20%) was observed among the residents of Neighborhood A. Furthermore, after exposure to the VR Dementia Experience, the connection between understanding, prejudice, and dementia was strengthened among the residents of Neighborhood A compared to the residents of Neighborhood B. The VR Dementia Experience is a useful tool for encouraging an understanding of and reducing and eliminating prejudice towards dementia patients among local residents. However, to encourage the widespread usage of the technology, we should compare results with other public awareness campaigns as well as make improvements to the device and its VR content.
(キーワード)
認知症 (dementia) / vertual reality / local residents
Yuki Iwawaki, Takashi Matsuda, Kosuke Kurahashi, Tsuyoshi Honda, Takaharu Goto and Tetsuo Ichikawa : Effect of the temperature of water on ultrasonic denture cleaning, Journal of Oral Science, 61, 1, 140-145, 2019.
(要約)
Denture plaque is a biofilm composed of various microorganisms aggregated with saliva. Various denture cleansers and cleaning apparatuses have been developed and studied. However, the optimum water temperature for denture cleaning is unknown. Therefore, the present study investigated the effects of water temperature during ultrasonic denture cleaning. In vitro, resin disks with artificial Candida albicans biofilm were pressed onto Candida GE media after ultrasonic cleaning with water at different temperatures for 5 min. The media were subsequently cultured at 37°C for 24 h. The colonies formed were observed and colony areas were quantified using ImageJ software (US National Institutes of Health, Bethesda, MD, USA). In situ, the bacterial count and degree of cleanliness on the tissue surface of maxillary dentures were measured before and after ultrasonic cleaning with water at different temperatures for 5 min. Changes in bacterial counts and cleanliness were calculated for each temperature. The ratio of the area occupied by bacterial colonies in vitro and reduction rates in situ after cleaning with warm water were markedly less than those observed after cleaning with cold water. Therefore, ultrasonic denture cleaning with warm water is more effective.
(キーワード)
Bacteria / Biofilms / Candida albicans / Colony Count, Microbial / Culture Media / Dentures / Disinfection / Hot Temperature / Ultrasonic Waves / Water
Yuki Iwawaki, Muraoka Yuki, Higashiyama Hiroaki, Takahiro Kishimoto, Liu Lipei, Takaharu Goto and Tetsuo Ichikawa : Comparison between two assessment tests for oral hygiene: adenosine triphosphate + adenosine monophosphate swab test and bacteria number counting by dielectrophoretic impedance measurement, Dentistry Journal, 7, 1, 10, 2019.
Tetsuo Ichikawa, Kosuke Kurahashi, Lipei Liu, Takashi Matsuda and Yuichi Ishida : Use of a Polyetheretherketone Clasp Retainer for Removable Partial Denture: A Case Report, Dentistry Journal, 7, 1, 4, 2019.
(要約)
Clasp retainers made of metal alloys may be esthetically unappealing or cause allergic reactions. To investigate alternative materials, we used the nonfiller polyetheretherketone (PEEK) to fabricate the clasp retainer of a removable partial denture for the mandibular bilateral distal free-end abutment of an 84-year-old female. Two years later, few color and texture changes of PEEK were found macroscopically. The rest part and the clasp arm fitted well without any deformation. There were no particular occlusal or periodontal problems. Subjective satisfaction was expressed by both the practitioner and the patient.
Takuro Baba, Takaharu Goto, Keiko Fujimoto, Hideki Suito, Kazutomo Yagi, Kan Nagao and Tetsuo Ichikawa : Geniohyoid muscle affects directly masticatory function: Evaluation using a decision tree analysis, The International Journal of Prosthodontics, 31, 6, 569-572, 2018.
(要約)
To clarify the effect of geniohyoid (GH) muscle morphology and related function on masticatory ability using a decision-tree analysis. A total of 103 participants were enrolled. A cross-sectional area (CSA) of the GH muscle, neck circumference, body mass index, tongue pressure, jaw opening strength, and masticatory ability score were measured. The CSA of the GH muscle was selected as an independent variable for the first layer of the decision tree, with masticatory score as the dependent variable. These data suggest that the CSA of the GH muscle may have a large impact on the masticatory ability score when evaluating masticatory ability.
(キーワード)
Body Mass Index / Decision Trees / 女性 (female) / Humans / 男性 (male) / Mastication / Middle Aged / Muscle Strength / Neck Muscles / Pharyngeal Muscles / Pressure / Range of Motion, Articular
Yoshihito Naitou, Hiromichi Yumoto, K Hs Kumar, Takashi Matsuo, Katsuhiko Hirota, Yoichiro Miyake, Kan Nagao, Yoritoki Tomotake, R Jimbo and Tetsuo Ichikawa : Antifungal and Mechanical Properties of Tissue Conditioner Containing Plant-Derived Component, --- An In Vitro Study ---, Journal of Prosthodontics, 27, 7, 665-669, 2018.
(要約)
To evaluate the antifungal activity and mechanical properties of a novel antifungal tissue conditioner containing Juncus powder. Juncus powder was mixed with GC tissue conditioner at concentrations of 2.5%, 5.0%, and 10.0% by mass. The cylindrical specimens of Juncus-mixed tissue conditioner (dimensions: 10 mm in diameter and 2 and 6 mm in height for antimicrobial and mechanical tests, respectively) were prepared. The specimens placed on the bottom of the 24-well tissue culture plate were cultured with Candida albicans CAD1 for 2 and 4 days. The proliferation of the C. albicans in the wells was determined by measuring the optical density of fungal culture, and the surface of the specimens were also observed by scanning electron microscopy (SEM). To assess the mechanical properties of the specimens, the fluidity and hardness of Juncus-mixed tissue conditioner were measured using the methods certified according to ISO 10139-1. Juncus-mixed tissue conditioner significantly exhibited growth inhibitory effect in a Juncus concentration-dependent manner after both 2- and 4- day cultures. SEM observation showed that the amount of C. albicans on Juncus-mixed specimens drastically decreased, and biofilm formation was markedly inhibited. Moreover, both mechanical properties were found to be within the ranges regulated and specified by ISO. These findings demonstrated that the tissue conditioner including Juncus powder has a significant growth inhibitory effect against C. albicans, and it is suggested that the application of Juncus-mixed tissue conditioner may prevent denture stomatitis and oral candidiasis in denture wearers.
Keiko Fujimoto, Tsuyoshi Honda, Hideki Suito, Kan Nagao and Tetsuo Ichikawa : Tongue thickness and its clinical significance, Journal of Oral Health and Biosciences, 31, 1, 32-38, 2018.
Gantumur Chimeddulam, Keisuke Nishigawa, Yoshihito Naitou, Junhel Dalanon, S Afroz, Rika Hayama, Masamitsu Ohshima, Yoritoki Tomotake, Tetsuo Ichikawa and Yoshizo Matsuka : Radiographic investigation of the marginal bone loss on dental implants, a retrospective cohort study, Journal of Oral Health and Biosciences, 31, 1, 13-24, 2018.
(要約)
Background: During functional loading, the design of the dental implant may have an effect on the response of marginal bone.Objectives: The purpose of this study was to report the prevalence of peri-implantitis, and to compare radiographic parameters around Brånemark and Replace Select dental implants and evaluate whether disparities in the morphologic features of these two indistinct implant systems, particularly their abutment-implant attachment, had an influence on the health of surrounding tissues and marginal bone loss (MBL).Materials and Methods: Collection of data was done at the Department of Fixed Prosthodontics, the Department of Maxillo-Facial Prosthodontics, and Oral Implant Center of Tokushima University Hospital, in Tokushima, Japan; between March 2003 and followed until January 2017. Patients who have been treated with the Replace Select internal type implant and the Brånemark variety were selected as cohort. Marginal bone level measurements were evaluated via periapical and panoramic radiographs taken at regular follow-up visit. These dimensions were calculated, starting from the orientation mark at the implant abutment interface to the bottommost perceived contact area of marginal bone with the aforementioned implant system. The change in the level of bone was estimated by calculating the variation involving an initial reference value and the follow-up values.Results: An average loss of bone at 0.65 ± 1.51 mm (range 0.36 to 7.89 mm) in the Replace Select group was observed, while in the Brånemark group 0.7 ± 1.32 mm (range 0.62 to 8.64 mm) was observed. Spearman rank correlation exhibited a statistically significant positive correlation between progress of bone loss around implant body and interval from implantation in the Brånemark group, whereas in the Replace Select group it was not significant. The Brånemark group exhibited significant (P = 0.0269) negative correlation of MBL and its diameters, whereas the Replace Select group did not exhibit such correlation.Conclusion: Within the limits of this study, it can be concluded that deviations in the morphologic attributes of these two diverse implant systems had an influence on the health of surrounding tissues and MBL. The Brånemark implants showed a significant increase in MBL (> 1.8mm) as the time of placement elapses. This marked MBL was greater in females than males, in posterior than in anterior, and in the narrow platform implants than the regular platform implants or the wide platform implants. On the other hand, results suggested that this bone loss was greater in the mandible than the maxilla, in single-unit implant crowns than multiple implant restorations in the Replace Select group.
(キーワード)
dental implant / marginal bone loss / retrospective cohort study / implant design
Takuo Kuboki, Tetsuo Ichikawa, Kazuyoshi Baba, Masanori Fujisawa, Hironobu Sato, Hideki Aita, Shigeto Koyama, Masayuki Hideshima, Yuji Sato, Hiroyuki Wake, Aya Kimura-Ono, Kan Nagao, Yorika Kodaira, Katsushi Tamaki, Shinsuke Sadamori, Kazuhiro Tsuga, Yasuhiro Nishi, Takashi Sawase, Hisashi Koshino, Shinichi Masumi, Kaoru Sakurai, Kanji Ishibashi, Takashi Ohyama, Yasumasa Akagawa, Toshihiro Hirai, Keiichi Sasaki, Kiyoshi Koyano, Hirofumi Yatani and Hideo Matsumura : A multi-centered epidemiological study evaluating the validity of the treatment difficulty indices developed by the Japan Prosthodontic Society, Journal of Prosthodontic Research, 62, 2, 162-170, 2018.
(要約)
The Japan Prosthodontic Society developed a multi-axis assessment protocol to evaluate the complex variations in patients who need prosthodontic care, and to classify the level of treatment difficulty. A previous report found the protocol to be sufficiently reliable. The purpose of this multi-center cohort study was to evaluate the validity of this multi-axis assessment protocol. The treatment difficulty was evaluated using the multi-axis assessment protocol before starting prosthodontic treatment. The time required for active prosthodontic treatment, medical resources such as treatment cost, and changes in the oral health-related QOL before and after treatment, were evaluated after treatment completion. The construct validity of this protocol was assessed by the correlation between the dentist's pre-operative subjective assessment of the treatment difficulty, and the level of difficulty determined by this protocol. The predictive validity was assessed estimating the correlations between a "comprehensive level of treatment difficulty" based on the four axes of this protocol and total treatment cost, total treatment time, and changes in the oral health-related QOL before and after treatment. The construct validity of this protocol was well documented except for psychological assessment. Regarding the predictive validity, the comprehensive level of treatment difficulty assessed before treatment was significantly correlated with the three surrogate endpoints known to be related to the treatment difficulty (total treatment cost, treatment time, and improvement in the oral health-related QOL). To further clarify the validity of the protocol according to patients' oral condition, a subgroup analysis by defects was performed. Analyses revealed that treatment difficulty assessment before treatment was significantly related to one or two surrogate endpoints in the fully edentulous patients and the partially edentulous patients. No significant relationship was observed in the patients with mixture of full/partial edentulism and the patients with teeth problems, possibly due to the small sample size in these groups. This study revealed that the multi-axis assessment protocol was sufficiently valid to predict the level of treatment difficulty in prosthodontic care in patients with fully edentulous defects and with partially edentulous defects.
(キーワード)
Cohort Studies / Forecasting / Humans / Japan / Mouth, Edentulous / Oral Health / Process Assessment (Health Care) / Prosthodontics / Quality of Life / Societies, Dental / Time Factors
Sachie Wada, Takaharu Goto, Keiko Fujimoto, Megumi Watanabe, Kan Nagao, Atsuko Nakamichi and Tetsuo Ichikawa : Changes in food bolus texture during mastication, Journal of Texture Studies, 48, 2, 171-177, 2017.
(要約)
The purpose of this study was to survey the changes that occur in bolus texture from intake to swallowing during the mastication process for four types of food materials and to identify how texture is related to the number of chews. We recruited 15 young Japanese participants for this study. The subjects were asked to spit the food bolus just before swallowing when eating four different foods: cracker, boiled rice, hard gelatine gel, and soft gelatine gel. Three physical properties (hardness, adhesiveness, and cohesiveness) were measured in the bolus after being chewed for 25, 50, 75, 100, and 125% of the normal number of chews. Occlusal force and pressure as well as stimulated whole saliva volume were also measured. Extensive variation in the number of chews existed between subjects, but minimal intra-subject variation was observed. Hardness was observed to decrease, whereas cohesiveness and adhesiveness increased in a chew-dependent manner for the cracker, soft gelatine gel, and hard gelatine gel, but not boiled rice. Bolus texture appears to be largely related to the number of chews. Hardness also tended to be influenced by occlusion. The adhesiveness and hardness of the boiled rice were also greatly influenced by saliva volume and occlusal force, respectively. Hardness is an important rheological factor in food bolus texture and likely plays a significant role in determining the appropriate number of chews. Adhesiveness and cohesiveness appear to be secondary factors in this process. We propose a model of oral processing for application in determining the appropriate number of chews for an individual. Hardness appears to be an important rheological factor in food bolus texture, with adhesiveness and cohesiveness being secondary aspects. When food is hard or difficult to swallow, chewing behavior will likely be more influenced by the perception of bolus texture.
(キーワード)
food bolus texture / mastication / number of chews / oral processing
Kosuke Kurahashi, Takashi Matsuda, Takaharu Goto, Yuichi Ishida, Teruaki Ito and Tetsuo Ichikawa : Duplication of complete dentures using general-purpose handheld optical scanner and 3-dimensional printer: Introduction and clinical considerations, Journal of Prosthodontic Research, 61, 1, 81-86, 2017.
(要約)
To introduce a new clinical procedure for fabricating duplicates of complete dentures by bite pressure impression using digital technology, and to discuss its clinical significance. The denture is placed on a rotary table and the 3-dimensional form of the denture is digitized using a general-purpose handheld optical scanner. The duplicate denture is made of polylactic acid by a 3-dimensional printer using the 3-dimensional data. This procedure has the advantages of wasting less material, employing less human power, decreasing treatment time at the chair side, lowering the rates of contamination, and being readily fabricated at the time of the treatment visit.
Yoshizo Matsuka, Yoshiyuki Hagiwara, Katsushi Tamaki, Hisahiro Takeuchi, Masanori Fujisawa, Takahiro Ono, Yoshihiro Tsukiyama, Kan Nagao, Kazuhiro Tsuga, Hideki Aita, Hisatomo Kondo, Kenji Fueki, Hiroaki Tsukasaki, Keisuke Nishigawa, Shogo Ozawa, Rika Kuwatsuru, Hajime Minakuchi, Toshimitsu Iinuma, Takashi Matsuura, Kanji Ishibashi, Shigehisa Fujii, Toshihiro Hirai, Keiichi Sasaki, Hirofumi Yatani, Yoshimasa Igarashi, Yuji Sato, Tetsuo Ichikawa, Tetsuo Yamamori, Takuo Kuboki, Kazuyoshi Baba, Kiyoshi Koyano, Hironobu Sato and Matsumura Hideo : Reliability and validity of the patient disability-oriented diagnostic nomenclature system for prosthetic dentistry, Journal of Prosthodontic Research, 61, 1, 20-33, 2017.
(要約)
The Japan Prosthodontic Society (JPS) has proposed a new diagnostic nomenclature system (DNS), based on pathogenesis and etiology, to facilitate and improve prosthodontic treatment. This system specifies patient disability and the causative factor (i.e. "B (disability) caused by A (causative factor)"). The purpose of this study was to examine the reliability and validity of this DNS. The JPS Clinical Guideline Committee assessed mock patient charts and formulated disease names using the new DNS. Fifty validators, comprising prosthodontic specialists and dental residents, made diagnoses using the same patient charts. Reliability was evaluated as the consistency of the disease names among the validators, and validity was evaluated using the concordance rate of the disease names with the reference disease names. Krippendorff's α was 0.378 among all validators, 0.370 among prosthodontic specialists, and 0.401 among dental hospital residents. Krippendorff's α for 10 validators (3 specialists and 7 residents) with higher concordance rates was 0.524. Two validators (1 specialist and 1 resident) with the highest concordance rates had a Krippendorff's α of 0.648. Common disease names had higher concordance rates, while uncommon disease names showed lower concordance rates. These rates did not show correlation with clinical experience of the validator or time taken to devise the disease name. High reliability was not found among all validators; however, validators with higher concordance rates showed better reliability. Furthermore, common disease names had higher concordance rates. These findings indicate that the new DNS for prosthodontic dentistry exhibits clinically acceptable reliability and validity.
Tsuyoshi Honda, Takuro Baba, Keiko Fujimoto, Takaharu Goto, Kan Nagao, Masafumi Harada, Eiichi Honda and Tetsuo Ichikawa : Characterization of Swallowing Sound: Preliminary Investigation of Normal Subjects, PLoS ONE, 11, 12, e0168187, 2016.
(要約)
The purpose of this study was to characterize the swallowing sound and identify the process of sound generation during swallowing in young healthy adults. Thirty-three healthy volunteers were enrolled and allocated into three experimental groups. In experiment 1, a microphone was attached to one of eight cervical sites in 20 subjects, participants swallowed 5 ml water, and the sound waveform was recorded. In experiment 2, 10 subjects swallowed either 0, 5, 10, or 15 ml water during audio recording. In addition, participants consumed the 5 ml bolus in two different cervical postures. In experiment 3, the sound waveform and videofluoroscopy were simultaneously recorded while the three participants consumed 5 ml iopamidol solution. The duration and peak intensity ratio of the waveform were analyzed in all experimental groups. The acoustic analysis of the waveforms and videofluoroscopy suggested that the swallowing sound could be divided into three periods, each associated with a stage of the swallowing movement: the oral phase comprising posterior tongue and hyoid bone movement; the pharyngeal phase comprising larynx movement, hyoid bone elevation, epiglottis closure, and passage of the bolus through the esophagus orifice; and the repositioning phase comprising the return of the hyoid bone and larynx to their resting positions, and reopening of the epiglottis. Acoustic analysis of swallowing sounds and videofluoroscopy suggests that the swallowing sound could be divided into three periods associated with each process of the swallowing movement: the oral phase comprising the posterior movement of the tongue and hyoid bone; the pharyngeal phase comprising the laryngeal movement, hyoid bone elevation, epiglottis closure, and the bolus passage to the esophagus orifice; and the repositioning phase comprising the repositioning of the hyoid bone and larynx, and reopening of the epiglottis.
(キーワード)
Acoustics / Adult / Deglutition / Deglutition Disorders / Epiglottis / Esophagus / Female / Fluoroscopy / Healthy Volunteers / Humans / Hyoid Bone / Iopamidol / Larynx / Male / Pharynx / Posture / Sound / Video Recording / Water / Young Adult
Takaharu Goto, Nobuaki Higaki, Kazutomo Yagi, Yuichi Ishida, Megumi Watanabe, Kan Nagao and Tetsuo Ichikawa : An innovative masticatory efficiency test using odor intensity in the mouth as a target marker: a feasibility study, Journal of Oral Rehabilitation, 43, 12, 883-888, 2016.
(要約)
A large number of studies have reported the findings for masticatory efficiency tests; however, some objective masticatory efficiency tests have a drawback, in that subjects are required to spit out the test material. This study examined the possibility of a masticatory efficiency test that evaluates the intensity of odours released when chewing an odour compound-containing material. A total of 20 volunteers were used in this study. The odour intensity in the breath after chewing a gum was measured by portable odour sensor device. The odour intensity after chewing the gum was measured over four chewing durations and at four intervals between spitting out and measurement of the odour intensity. The volume of stimulated saliva was measured by calculating the difference in the weight of the gauze before and after chewing to examine the effect of saliva flow. With an increase in chewing duration, odour intensity reduced. The odour intensity was the highest immediately after chewing. There was a positive correlation between odour intensity and gummy jelly-related masticatory efficiency test value (G-METV), which was significant for 10-s chewing. The regression equation was calculated from three objective variables of odour intensity and G-METV as dependent variable. Pearson's correlation coefficient between G-METV and the odour intensity-related masticatory efficiency value (O-METV) was 0·68. The coefficient of variation of O-METV was significantly lower than that of G-METV. These results suggest that the masticatory performance can be estimated by measuring the odour intensity immediately after chewing food containing odour compounds for 10 s.
Katsuhiko Hirota, Hiromichi Yumoto, B Sapaar, Takashi Matsuo, Tetsuo Ichikawa and Yoichiro Miyake : Pathogenic factors in Candida biofilm-related infectious diseases., Journal of Applied Microbiology, 122, 2, 321-330, 2016.
(要約)
Candida albicans is a commonly found member of the human microflora and is a major human opportunistic fungal pathogen. A perturbation of the microbiome can lead to infectious diseases caused by various micro-organisms, including C. albicans. Moreover, the interactions between C. albicans and bacteria are considered to play critical roles in human health. The major biological feature of C. albicans, which impacts human health, resides in its ability to form biofilms. In particular, the extracellular matrix (ECM) of Candida biofilm plays a multifaceted role and therefore may be considered as a highly attractive target to combat biofilm-related infectious diseases. In addition, extracellular DNA (eDNA) also plays a crucial role in Candida biofilm formation and its structural integrity and induces the morphological transition from yeast to the hyphal growth form during C. albicans biofilm development. This review focuses on pathogenic factors such as eDNA in Candida biofilm formation and its ECM production and provides meaningful information for future studies to develop a novel strategy to battle infectious diseases elicited by Candida-formed biofilm.
Nobuaki Higaki, Takaharu Goto and Tetsuo Ichikawa : Periodontal tactile input activates the prefrontal cortex, Scientific Reports, 6, 36893, 2016.
(要約)
The prefrontal cortex (PFC) plays a role in complex cognitive behavioural planning, decision-making, and social behaviours. However, the effects of sensory integration during motor tasks on PFC activation have not been studied to date. Therefore, we investigated the effect of peripheral sensory information and external information on PFC activation using functional near-infrared spectroscopy (fNIRS). Cerebral blood flow (CBF) was increased around bilateral Brodmann areas 46 and 10 during visual and auditory information integration during an occlusal force (biting) task. After local anesthesia, CBF values were significantly decreased, but occlusal force was similar. In conclusion, the effects of peripheral sensory information from the periodontal ligament and external information have minimal impacts on occlusal force maintenance but are important for PFC activation.
Suguru Kimoto, Yasuhiko Kawai, Atsuko Gunji, Hisatomo Kondo, Taro Nomura, Tomohiko Murakami, Akito Tsuboi, Guang Hong, Shunsuke Minakuchi, Yusuke Sato, Gaku Ohwada, Tetsuya Suzuki, Katsuhiko Kimoto, Noriyuki Hoshi, Makiko Saita, Yoshikazu Yoneyama, Yohei Sato, Masakazu Morokuma, Joji Okazaki, Takeshi Maeda, Kenichiro Nakai, Tetsuo Ichikawa, Kan Nagao, Keiko Fujimoto, Hiroshi Murata, Tadafumi Kurogi, Kazuhiro Yoshida, Masahiro Nishimura, Yasuhiro Nishi, Mamoru Murakami, Toshio Hosoi and Taizo Hamada : Study protocol for a multi-center, randomized controlled trial to develop Japanese denture adhesive guidelines for patients with complete dentures: The Denture Adhesive Guideline trial: Study protocol for a randomized controlled trial, Trials, 17, 1, 506, 2016.
(要約)
Denture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability. However, many dentists in Japan are hesitant to acknowledge denture adhesives in daily practice because of the stereotype that dentures should be inherently stable, without the aid of adhesives. The aim of this study is to verify the efficacy of denture adhesives to establish guidelines for Japanese users. The null hypothesis is that the application of denture adhesives, including the cream and powder types, or a control (isotonic sodium chloride solution) would not produce different outcomes nor would they differentially improve the set outcomes between baseline and day 4 post-application. This ten-center, randomized controlled trial with parallel groups is ongoing. Three hundred edentulous patients with complete dentures will be allocated to three groups (cream-type adhesive, powder-type adhesive, and control groups). The participants will wear their dentures with the denture adhesive for 4 days, including during eight meals (three breakfasts, two lunches, and three dinners). The baseline measurements and final measurements for the denture adhesives will be performed on the first day and after breakfast on the fourth day. The primary outcome is a general satisfaction rating for the denture. The secondary outcomes are denture satisfaction ratings for various denture functions, occlusal bite force, resistance to dislodgement, masticatory performance, perceived chewing ability, and oral health-related quality of life. Between-subjects comparisons among the three groups and within-subjects comparisons of the pre- and post-intervention measurements will be performed. Furthermore, a multiple regression analysis will be performed. The main analyses will be based on the intention-to-treat principle. A sample size of 100 subjects per group, including an assumed dropout rate of 10 %, will be required to achieve 80 % power with a 5 % alpha level. This randomized clinical trial will provide information about denture adhesives to complete denture wearers, prosthodontic educators, and dentists in Japan. We believe this new evidence on denture adhesive use from Japan will aid dentists in their daily practice even in other countries. ClinicalTrials.gov NCT01712802 . Registered on 17 October 2012.
(キーワード)
全部床義歯 (complete dentures) / Denture adhesive / Edentulism / Masticatory performance / Occlusal bite force / Oral health-related quality of life / Retentive force
Yuichi Ishida, Kumer Kiran, Takaharu Goto, Megumi Watanabe, Wigianto Rudi, Kan Nagao and Tetsuo Ichikawa : Magnet-retained two-mini-implant overdenture: Clinical and mechanical consideration., Dentistry Journal, 4, 4, 35, 2016.
(要約)
Two-implant overdentures have become the accepted treatment for restoring mandibular edentulism. The dimensions of regular implants sometimes limit their use, such as in the case of narrow ridges. Mini-implants with reduced diameters (less than 3.0 mm) enable insertion into narrow ridges. A magnet-retained two-mini-implant overdenture system was developed and is described in this paper. Additionally, we describe a clinical mandibular procedure using the system and evaluate its biomechanical performance.
Keiko Fujimoto, Norikazu Minami, Takaharu Goto, Yuichi Ishida, Megumi Watanabe, Kan Nagao and Tetsuo Ichikawa : Hardness, cohesiveness, and adhesiveness of oral moisturizers and denture adhesives: selection criteria for denture wearers., Dentistry Journal, 4, 4, 34, 2016.
(要約)
The mechanical properties of seven denture adhesives and eight oral moisturizers, all of which are commercially available, were evaluated using a texture pro le analysis. A new assessment chart is proposed for the selection criteria of denture adhesive and oral moisturizers using a radar chart with three axes: hardness, cohesiveness, and adhesiveness.
Takashi Matsuda, Takaharu Goto, Kazutomo Yagi, Toshiya Kashiwabara and Tetsuo Ichikawa : Part-digitizing system of impression and interocclusal record for complete denture fabrication, Journal of Prosthodontics, 25, 6, 503-509, 2016.
(要約)
Few studies have reported the application of digital technology to removable dentures, particularly for the process of impression and interocclusal recording for complete denture fabrication. This article describes a part-digitizing system of impression and interocclusal records for complete denture fabrication. The denture foundation area in an edentulous mouth, including the border areas and residual ridge, is outlined by tracing the surfaces with a 3-D pen-type digitizer. Specialized trays for final impressions and interocclusal records were generated using computer-aided design and manufactured using the digital data. Final impression and interocclusal records were carried out using these specialized trays. The computer-aided method using preliminary digital impressions and specialized trays would be feasible for clinical use for complete denture fabrication.
市川 哲雄, 友竹 偉則, 田島 登誉子, 内藤 禎人, 清水 裕次, 石田 雄一 : グラスファイバーで補強された高強度コンポジットレジンを用いた3ユニットブリッジ治療について(原著論文), Journal of Oral Health and Biosciences, 28, 2, 55-62, 2016年.
(要約)
Mechanical strength to withstand occlusal force is required to the crown restorations of molars. Ag-Pd-Au alloy has been used as the acceptable material of the National Health Insurance system in Japan. However, the metallic color of prosthesis does not meet the aesthetic requirements of the patients, and there is also a problem to the provider side of the treatment that the price fluctuation is large by soaring material costs. A fiber reinforced metal-less bridge is proposed to resolve these problems and we began clinical application of this prosthetic treatment from September, 2012 on the approval of Tokushima University Hospital ethics committee. So far, six patients have been treated with 8 fiber reinforced bridges, and this treatment in Tokushima University Hospital was approved in Shikoku Regional Bureau of Health and Welfare as the advanced medical. We have followed the treatment for a maximum of more than two years, and it has been passed successfully with patient's satisfaction. Slightly problems which were caused in the hybrid resin material, could be easily solved by the direct procedures. This clinical results in short term suggested that the fiber reinforced metalless bridge have a sufficiently high therapeutic effect as a prosthetic method.
Widyasri Prananingrum, Yoshihito Naito, Silvia Galli, Jiyoung Bae, Kazumitsu Sekine, Kenichi Hamada, Yoritoki Tomotake, Ann Wennerberg, Ryo Jimbo and Tetsuo Ichikawa : Bone ingrowth of various porous titanium scaffolds produced by a moldless and space holder technique: An in vivo study in rabbits, Biomedical Materials, 11, 1, 015012, 2016.
(要約)
Porous titanium has long been desired as a bone substitute material because of its ability to reduce the stress shielding in supporting bone. In order to achieve the various pore structures, we have evolved a moldless process combined with a space holder technique to fabricate porous titanium. This study aims to evaluate which pore size is most suitable for bone regeneration using our process. The mixture comprising Ti powder, wax binder and PMMA spacer was prepared manually at 70 °C which depended on the mixing ratio of each group. Group 1 had an average pore size of 60 μm, group 2 had a maximum pore size of 100 μm, group 3 had a maximum pore size of 200 μm and group 4 had a maximum pore size of 600 μm. These specimens were implanted into rabbit calvaria for three and 20 weeks. Thereafter, histomorphometrical evaluation was performed. In the histomorphometrical evaluation after three weeks, the group with a 600 μm pore size showed a tendency to greater bone ingrowth. However, after 20 weeks the group with a pore size of 100 μm showed significantly greater bone ingrowth than the other groups. This study suggested that bone regeneration into porous titanium scaffolds is pore size-dependent, while bone ingrowth was most prominent for the group with 100 μm-sized pores after 20 weeks in vivo.
(キーワード)
animal study / biomaterials / bone substitutes / histological analysis
Takashi Matsuda, Takaharu Goto, Kosuke Kurahashi, Toshiya Kashiwabara, Megumi Watanabe, Yoritoki Tomotake, Kan Nagao and Tetsuo Ichikawa : Digital assessment of preliminary impression accuracy for edentulous jaws: Comparisons of 3-dimensional surfaces between study and working casts, Journal of Prosthodontic Research, 60, 3, 206-212, 2016.
(要約)
The aim of this study was to compare 3-dimensional surfaces of study and working casts for edentulous jaws and to evaluate the accuracy of preliminary impressions with a view to the future application of digital dentistry for edentulous jaws. Forty edentulous volunteers were serially recruited. Nine dentists took preliminary and final impressions in a routine clinical work-up. The study and working casts were digitized using a dental 3-dimensional scanner. The two surface images were superimposed through a least-square algorithm using imaging software and compared qualitatively. Furthermore, the surface of each jaw was divided into 6 sections, and the difference between the 2 images was quantitatively evaluated. Overall inspection showed that the difference around residual ridges was small and that around borders were large. The mean differences in the upper and lower jaws were 0.26mm and 0.45mm, respectively. The maximum values of the differences showed that the upward change mainly occurred in the anterior residual ridge, and the downward change mainly in the posterior border seal, and the labial and buccal vestibules, whereas every border of final impression was shortened in the lower jaw. The accuracy in all areas except the border, which forms the foundation, was estimated to be less than 0.25mm. Using digital technology, we here showed the overall and sectional accuracy of the preliminary impression for edentulous jaws. In our clinic, preliminary impressions have been made using an alginate material while ensuring that the requisite impression area was covered.
Takashi Matsuda, Takaharu Goto, Kosuke Kurahashi, Toshiya Kashiwabara and Tetsuo Ichikawa : Development of a digital impression procedure using photogrammetry for complete denture fabrication, International Journal of Computerized Dentistry, 19, 3, 193-202, 2016.
(要約)
We developed an innovative procedure for digitizing maxillary edentulous residual ridges with a photogrammetric system capable of estimating three-dimensional (3D) digital forms from multiple two-dimensional (2D) digital images. The aim of this study was to validate the effectiveness of the photogrammetric system. Impressions of the maxillary residual ridges of five edentulous patients were taken with four kinds of procedures: three conventional impression procedures and the photogrammetric system. Plaster models were fabricated from conventional impressions and digitized with a 3D scanner. Two 3D forms out of four forms were superimposed with 3D inspection software, and differences were evaluated using a least squares best fit algorithm. The in vitro experiment suggested that better imaging conditions were in the horizontal range of ± 15 degrees and at a vertical angle of 45 degrees. The mean difference between the photogrammetric image (Form A) and the image taken from conventional preliminarily impression (Form C) was 0.52 ± 0.22 mm. The mean difference between the image taken of final impression through a special tray (Form B) and Form C was 0.26 ± 0.06 mm. The mean difference between the image taken from conventional final impression (Form D) and Form C was 0.25 ± 0.07 mm. The difference between Forms A and C was significantly larger than the differences between Forms B and C and between Forms D and C. The results of this study suggest that obtaining digital impressions of edentulous residual ridges using a photogrammetric system is feasible and available for clinical use.
Yuki Iwawaki, Noriko Mizusawa, Takeo Iwata, Nobuaki Higaki, Takaharu Goto, Megumi Watanabe, Yoritoki Tomotake, Tetsuo Ichikawa and Katsuhiko Yoshimoto : MiR-494-3p induced by compressive force inhibits cell proliferation in MC3T3-E1 cells., Journal of Bioscience and Bioengineering, 120, 4, 456-462, 2015.
(要約)
Mechanical stimuli regulate fundamental cell processes such as proliferation, differentiation, and morphogenesis. We attempted to identify microRNA (miRNA) whose expression is changed during compressive treatment in MC3T3-E1, a pre-osteoblastic cell line. Microarray analysis followed by reverse transcription-quantitative polymerase chain reaction revealed that compressive force at 294 Pa for 24 h in MC3T3-E1 cells increased levels of miR-494-3p, miR-146a-5p, miR-210-3p, and miR-1247-3p. Among these miRNAs, miR-494-3p was found to inhibit cell proliferation in MC3T3-E1 cells. Furthermore, cells subjected to compressive force showed slower cell growth compared with control cells. Levels of mRNA for fibroblast growth factor receptor 2 (FGFR2) and Rho-associated coiled-coil kinase 1 (ROCK1), which were predicted to be targets of miR-494-3p, were decreased by compressive force or overexpression of miR-494-3p mimics in MC3T3-E1 cells. Furthermore, binding sites of miR-494-3p within 3'-untranslated regions of Fgfr2 and Rock1 were determined using luciferase reporter assay. In conclusion, compressive force affected expressions of several miRNAs including miR-494-3p in MC3T3-E1 cells. Compressive force might inhibit cell proliferation in osteoblasts by up-regulating miR-494-3p followed by FGFR2 and ROCK1 gene repressions.
Tsuyoshi Honda, Keiko Fujimoto, Takuro Baba, Kan Nagao, Akira Takahashi and Tetsuo Ichikawa : Swallowing sound waveform and its clinical significance: Evaluation using ultrasonography, Journal of Oral Health and Biosciences, 28, 1, 21-27, 2015.
(要約)
Background: Cervical auscultation is a technique frequently used for the screening of dysphagia. However, this method is difficult to evaluate objectively and it is unclear how sound is generated during the swallowing process. The aim of this study was to analyze the waveform of swallowing sound and clarify the sound production process using recordings of swallowing sounds and ultrasound images (USI), performed simultaneously.Materials and Methods: Commercial natural spring water and natural carbonated water were used in experiments 1 and 2, respectively. In experiment 1, a microphone was attached to the skin of the neck of 20 young participants and swallowing sounds were recorded and analyzed. In experiment 2, swallowing processes in three participants were recorded by a medical ultrasonography apparatus. The ultrasonic probe was placed on the skin over one of the thyroid cartilages or the thyroid gland.Results: The swallowing sound wave (SSW) was divided into three sectional periods. The mean duration of the first, second, and third SSW was 210 ± 147 ms, 458 ± 113 ms, and 91 ± 61 ms, respectively. The mean intensity ratio of the first, second, and third SSW was 7.8 ± 5.2, 29.2 ± 16.5,and 5.8 ± 5.1, respectively. When the ultrasonic probe was placed on the skin over one of the thyroid cartilages, in the phase between the production of the second SSW and the silent period, the USI revealed an accumulation of swallowed material around the valleculae and oropharynx. In the silent period of the second SSW, the swallowed material accumulated around the hypopharynx. When the ultrasonic probe was placed on the skin over the thyroid gland, in the silent period of the second SSW, the USI revealed that the swallowed material had passed through esophagus.Conclusion: Waveform and USI findings from this study suggest that swallowing sound can be divided into three sectional periods: an oral phase, a pharyngeal phase, and a repositioning phase.
Yuichi Ishida, Keiko Fujimoto, Nobuaki Higaki, Takaharu Goto and Tetsuo Ichikawa : End points and assessments in esthetic dental treatment., Journal of Prosthodontic Research, 59, 4, 229-235, 2015.
(要約)
There are two key considerations for successful esthetic dental treatments. This article systematically describes the two key considerations: the end points of esthetic dental treatments and assessments of esthetic outcomes, which are also important for acquiring clinical skill in esthetic dental treatments. The end point and assessment of esthetic dental treatment were discussed through literature reviews and clinical practices. Before designing a treatment plan, the end point of dental treatment should be established. The section entitled "End point of esthetic dental treatment" discusses treatments for maxillary anterior teeth and the restoration of facial profile with prostheses. The process of assessing treatment outcomes entitled "Assessments of esthetic dental treatment" discusses objective and subjective evaluation methods. Practitioners should reach an agreement regarding desired end points with patients through medical interviews, and continuing improvements and developments of esthetic assessments are required to raise the therapeutic level of esthetic dental treatments.
Takaharu Goto, Atsuko Nakamichi, Megumi Watanabe, Kan Nagao, Miwa Matsuyama and Tetsuo Ichikawa : Influence of food volume per mouthful on chewing and bolus properties, Physiology & Behavior, 141, 58-62, 2015.
(要約)
Behaviors relating to food intake, i.e., speed of chewing, number of chews, and bite size, are important for decreasing energy intake, which might reduce excess body weight and thus metabolic risk. This study aimed at investigating the influence of mouthful volume on the number of chews and food bolus properties in addition to clarifying appropriate eating behaviors related to mouthful volume. Fifteen young Japanese women volunteered to participate. The subjects were asked to spit the food bolus in a glass dish just before swallowing when eating 3 different foods: boiled rice, fish sausage, and peanuts. The 3 physical properties of solidity, adhesiveness, and cohesiveness were measured in the bolus, and the number of chews was noted. The number of chews significantly increased with increasing mouthful volume with all 3 foods; conversely, the number of chews per unit of food weight (g) decreased significantly with boiled rice and fish sausage. Trends were observed for solidity and cohesiveness, which varied with increasing mouthful volumes. Decreased mouthful volume resulted in a greater number of chews per weight of food and more appropriate bolus properties; therefore, a change in mouthful volume could be a useful behavior modification for regulation of energy intake.
(キーワード)
Eating / Energy Intake / Feeding Behavior / Female / Food / Humans / Mastication / Young Adult
松田 岳, 後藤 崇晴, 柏原 稔也, 市川 哲雄 : 無歯顎補綴における咬合平面設定に関する文献考察, Journal of Oral Health and Biosciences, 28, 1, 13-19, 2015年.
(要約)
The maxillomandibular registration is one of important processes to achieve patientsatisfaction with the function and esthetics for complete denture fabrication. Over the years, clinical decision of vertical and horizontal jaw relationship has been mainly discussed in the maxillomandibular registration. With regard to the occlusal plane setting, many clinicians have believed to decide the occlusal plane parallel to Camper's plane, however there is little information on the effect of occlusal plane setting on clinical meanings and outcome. The aim of this study is to analyze published literature focusing on the occlusal plane and the related oral function and esthetics, and to clarify clinical implications of occlusal plane setting. Two databases, "PubMed" and "Japana Centra Revuo Medicina" were searched to retrieve research papers focusing on the occlusal plane.Seventy four papers were selected from the database, and they were reviewed.Literature reviews suggests that many landmarks were described on the occlusal plane setting for edentulous patients; and Camper's plane has been most frequently referred, showed a good result in function, but not always good in esthetics. The influence of occlusal plane setting on clinical results: oral function, esthetics, denture stability, and patient satisfaction after denture delivery has to be examined.
Takaharu Goto, Kan Nagao, Yuichi Ishida, Yoritoki Tomotake and Tetsuo Ichikawa : Influence of female attachment installation load on movement and resultant forces in implant overdentures, Journal of Prosthodontics, 24, 2, 156-163, 2015.
(要約)
This in vitro study investigated the effect of attachment installation conditions on the load transfer and denture movements of implant overdentures, and aims to clarify the differences among the three types of attachments, namely ball, Locator, and magnet attachments. Three types of attachments, namely ball, Locator, and magnetic attachments were used. An acrylic resin mandibular edentulous model with two implants placed in the bilateral canine regions and removable overdenture were prepared. The two implants and bilateral molar ridges were connected to three-axis load-cell transducers, and a universal testing machine was used to apply a 50 N vertical force to each site of the occlusal table in the first molar region. The denture movement was measured using a G(2) motion sensor. Three installation conditions, namely, the application of 0, 50, and 100 N loads were used to install each attachment on the denture base. The load transfer and denture movement were then evaluated. The resultant force decreased with increasing installation load for all attachments. In particular, the resultant force on implants on the loading side of the Locator attachment significantly decreased when the installation load was increased from 0 to 50 N, and that for magnetic attachment significantly decreased when the installation load was increased from 50 to 100 N. For the residual ridges on the loading side, the direction of the forces for all attachments changed to downward with increasing installation load. Furthermore, the yaw Euler angle increased with increasing installation load for the magnetic attachment. Subject to the limitations of this study, the use of any installation load greater than 0 N is recommended for the installation of ball and Locator attachments on a denture base. Regarding magnetic attachments, our results also recommend installation on a denture base using any installation load greater than 0 N, and suggest that the resultant force acting on the implant can be decreased by increasing the installation load; however, a large installation load of 100 N should be avoided when installing the attachment on the denture base to avoid increasing the denture movement.
中道 敦子, 後藤 崇晴, 市川 哲雄 : 一口量に着目した食行動評価:YN食行動質問票の有効性, Journal of Oral Health and Biosciences, 27, 2, 71-80, 2015年.
(要約)
We created a simple questionnaire to promote better eating habits and behavioral modification for the prevention and improvement of metabolic syndrome, examined its reliability and validity, and finally, assessed its effectiveness. A questionnaire, comprising of eighteen items to promote behavioral modification, was prepared comprising of three factors, "dietary recognition" , "eating habits" and "eating action" and was developed based on data from 125 students at the Faculty of Dentistry, The University of Tokushima. Furthermore, to assess the effectiveness of this version of the questionnaire, we conducted a survey on 845 health-care providers in Tokushima Prefecture and Hyogo Prefecture. The results confirmed a relatively high internal consistency with a Cronbach's alpha coefficient of 0.735–0.762 for the three factors. The questionnaire scores in the "obese" group with a body mass index of 25 or higher were high for all three factors and a significant difference was noted between the "normal" and "thin" groups under the category of "dietary awareness" . Moreover, trends between men and women; and between age groups were ascertained, therefore suggesting that this questionnaire is effective in assessing eating behavior associated with obesity.
Nobuaki Higaki, Takaharu Goto, Yuichi Ishida, Megumi Watanabe, Yoritoki Tomotake and Tetsuo Ichikawa : Do sensation differences exist between dental implants and natural teeth?: a meta-analysis., Clinical Oral Implants Research, 25, 11, 1307-1310, 2014.
(要約)
The purpose of this systematic review was to survey evidence pertaining to the sensation differences between natural teeth and osseointegrated dental implants. Using the MEDLINE (online PubMed) database, Cochrane Library, and Scientific Citation index, we performed a systematic search of articles. We used the following search terms: "perception or sensation and dental implant." The systematic review of the extracted articles was performed to see the sensation differences between natural teeth and dental implants. A total of six studies on oral sensation, "tactile sensibility," and "thickness discrimination" were included in the meta-analysis. As to the "tactile sensibility", all studies indicated the threshold levels of the implants were about 4-20 times higher than that of natural teeth. The tactile sensibility of an implant was significantly higher than that of a natural tooth, with an standardized mean difference (SMD) of 8.3619 (95% CI, 6.3920-10.3317) and a P < 0.0001. As to the "thickness discrimination", all studies indicated the threshold levels of implants were about 1.2-2.3 times higher than that of natural teeth. The thickness discrimination was significantly higher than that of natural teeth with an SMD of 1.2368 (95% CI, 0.8699-1.6038) and a P < 0.0001. This meta-analysis suggested that both tactile sensibility and thickness discrimination thresholds of implants were significantly higher than those of natural teeth. This meta-analysis reconfirms that sensation differences between dental implants and natural teeth exist.
Yoshihito Naitou, Ryo Jimbo, Matthew S Bryington, Stefan Vandeweghe, Bruno Chrcanovic, Nick Tovar, Tetsuo Ichikawa, Coelho G. Paulo and Ann Wennerberg : The Influence of 1α.25-Dihydroxyvitamin D3 Coating on Implant Osseointegration in the Rabbit Tibia, Journal of Oral & Maxillofacial Research, 5, 3, e3, 2014.
(要約)
This study aims to evaluate bone response to an implant surface modified by 1α,25-dihydroxyvitamin D3 [1.25-(OH)2D3] in vivo and the potential link between 1.25-(OH) 2D3 surface concentration and bone response. Twenty-eight implants were divided into 4 groups (1 uncoated control, 3 groups coated with 1.25-(OH)2D3 in concentrations of 10(-8), 10(-7) and 10(-6) M respectively), placed in the rabbit tibia for 6 weeks. Topographical analyses were carried out on coated and uncoated discs using interferometer and atomic-force-microscope (AFM). Twenty-eight implants were histologically observed (bone-to-implant-contact [BIC] and new-bone-area [NBA]). The results showed that the 1.25-(OH)2D3 coated implants presented a tendency to osseointegrate better than the non-coated surfaces, the differences were not significant (P > 0.05). The effect of 1.25-(OH)2D3 coating to implants suggested possible dose dependent effects, however no statistical differences could be found. It is thought that the base substrate topography (turned) could not sustain sufficient amount of 1.25-(OH)2D3 enough to present significant biologic responses. Thus, development a base substrate that can sustain 1.25-(OH)2D3 for a long period is necessary in future studies.
Atsuko Nakamichi, Miwa Matsuyama and Tetsuo Ichikawa : Relationship between mouthful volume and number of chews in young Japanese females, Appetite, 83, 327-332, 2014.
(要約)
Objective: Modification of eating behavior in Japan is promoted to prevent overweight and obesity, but the effects of such modifications are unclear. This study aimed to clarify the inter- and intra-individual relationship between bite size and number of chews of food. Design and methods: Subjects comprised of 50 young healthy Japanese women (mean age 19.5 years). Food materials were boiled rice and apple. First, the average bite size and the number of chews per mouthful of food were calculated across the study cohort. The number of chews was counted by the subjects themselves and then self-reported. Correlation between the individual one-bite volume and the number of chews per volume was analyzed using Spearman's rank correlation coefficient. Second, the number of chews for three different sized bites of food (half of one bite, one bite, and one-and-a-half bites) were calculated as a prospective observational study. The number of chews for each of the three volumes of food was compared using one way ANOVA with Bonferroni correction. Results: For both food types, there was a negative correlation between individual mouthful volume and number of chews for both food materials. The number of chews per volume decreased as bite sizes increased. Conclusion: This study demonstrated an inter- and intra-individual relationship between bite size and the number of chews and suggested that smaller bite sizes were associated with more chews per volume of food.
(キーワード)
Mouthful volume / Chewing / Eating behavior / Health promotion
Ashrin Nur Meinar, Rieko Arakaki, Akiko Yamada, Tomoyuki Kondo, Mie Kurosawa, Yasusei Kudo, Megumi Watanabe, Tetsuo Ichikawa, Yoshio Hayashi and Naozumi Ishimaru : A critical role for thymic stromal lymphopoietin in nickel-induced allergy in mice., The Journal of Immunology, 192, 9, 4025-4031, 2014.
(要約)
Ni is the most frequent cause of contact allergy induced by metals. However, the underlying mechanism of this induction is unknown. Our previous research demonstrates that activation of dendritic cells (DCs) through p38MAPK/MKK6 is required for Ni-induced allergy in mice. In the current study, we investigated the cellular and molecular mechanisms underlying Ni-induced allergy using a mouse model that involves injecting Ni into the ear, with or without Freund's incomplete or complete adjuvants. Nickel had greater potential to cause allergic reactions compared with palladium and gold. Among the proteins expressed at higher levels in mice with Ni-induced allergy, we focused on thymic stromal lymphopoietin (TSLP), which is produced in abundance by keratinocytes. We detected increased expression of the TSLP receptor (TSLPR) in DCs from cervical lymph nodes of mice with Ni-induced allergy, suggesting that DCs in ear tissues were activated through TSLPR signaling induced by keratinocyte-derived TSLP. Furthermore, delayed-type hypersensitivity reactions in mice with Ni-induced allergy were decreased significantly by injection of a Tslp-short interfering RNA along with atelocollagen in the ear skin. These results suggest that Ni allergy may be triggered by a TSLP/TSLPR-mediated interaction between epithelial and immune cells.
B Sapaar, A Nur, Katsuhiko Hirota, Hiromichi Yumoto, Keiji Murakami, T Amoh, Takashi Matsuo, Tetsuo Ichikawa and Yoichiro Miyake : Effects of extracellular DNA from Candida albicans and pneumonia-related pathogens on Candida biofilm formation and hyphal transformation., Journal of Applied Microbiology, 116, 6, 1531-1542, 2014.
(要約)
The aim of this study was to investigate the effects of genomic DNA purified from Candida albicans and pneumonia-related pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, on in vitro biofilm formation and morphological change of 3 Candida species (C. albicans, C. glabrata, and C. tropicalis). Biofilm formation was evaluated by the crystal violet assay and colony-forming unit counts. Morphological characteristics of biofilms were evaluated by scanning electron microscopy and fluorescence microscopy. Addition of DNA at a low concentration (<1·0 μg ml(-1)) significantly increased biofilm mass of all three Candida species. In contrast, the addition of DNA at a high concentration (10 μg ml(-1)) decreased the biofilm mass. Interestingly, the formation of hyphae in a dense network of yeast cells was observed in C. albicans biofilms exposed to a low concentration of DNA (<1·0 μg ml(-1)). These findings demonstrated that extracellular DNA (eDNA) plays a crucial role in Candida biofilm formation and suggested that eDNA may induce the morphological transition from yeast to hyphal growth form during C. albicans biofilm development. A novel therapy targeting eDNA may be applicable for Candida infection to decrease biofilm formation and hyphal formation.
Yoshihito Naitou, Takayuki Terukina, Silvia Galli, Yusuke Kozai, Stefan Vandeweghe, Tatsuaki Tagami, Tetsuya Ozeki, Tetsuo Ichikawa, Paulo G. Coelho and Ryo Jimbo : The effect of simvastatin-loaded polymeric microspheres in a critical size bone defect in the rabbit calvaria., International Journal of Pharmaceutics, 461, 1-2, 157-162, 2014.
(要約)
The present study describes the development of a microsphere capsule based on polylactide-co-glycolide (PLGA) loaded with simvastatin that was subsequently incorporated into synthetic bone cement. The osteogenic effect of simvastatin-loaded bone cement was in a critical sized defect in vivo to test the hypothesis the biologic response would be different depending on the dosage of simvastatin applied to bone cement. Our results showed that simvastatin loaded PLGA microspheres can be successfully obtained through O/W emulsion/solvent evaporation method with appropriate morphologic characteristics and high encapsulation efficiency for incorporation in bone cements. The biodegradable characteristic of the microspheres successfully presented a slow release and the duration of the release lasted for more than 1 month. The in vivo experiment revealed that the microspheres containing simvastatin significantly enhanced bone formation in the rabbit calvaria critical size defect.
(キーワード)
Implant dentistry / biomaterials / drug deliverly system
Many studies on surface modifications of titanium have been performed in an attempt to accelerate osseointegration. Recently, anatase titanium dioxide has been found to act as a photocatalyst that expresses antibiotic properties and exhibits hydrophilicity after ultraviolet exposure. A blue-violet semiconductor laser (BV-LD) has been developed as near-ultraviolet light. The purpose of this study was to investigate the effects of exposure to this BV-LD on surface modifications of titanium with the goal of enhancing osteoconductive and antibacterial properties. The surfaces of pure commercial titanium were polished with #800 waterproof polishing papers and were treated with anatase titania solution. Specimens were exposed using BV-LD (λ = 405 nm) or an ultraviolet light-emitting diode (UV-LED, λ = 365 nm) at 6 mW/cm(2) for 3 h. The surface modification was evaluated physically and biologically using the following parameters or tests: surface roughness, surface temperature during exposure, X-ray diffraction (XRD) analysis, contact angle, methylene blue degradation tests, adherence of Porphyromonas gingivalis, osteoblast and fibroblast proliferation, and histological examination after implantation in rats. No significant changes were found in the surface roughness or XRD profiles after exposure. BV-LD exposure did not raise the surface temperature of titanium. The contact angle was significantly decreased, and methylene blue was significantly degraded. The number of attached P. gingivalis organisms was significantly reduced after BV-LD exposure compared to that in the no exposure group. New bone was observed around exposed specimens in the histological evaluation, and both the bone-to-specimen contact ratio and the new bone area increased significantly in exposed groups. This study suggested that exposure of titanium to BV-LD can enhance the osteoconductivity of the titanium surface and induce antibacterial properties, similar to the properties observed following exposure to UV-LED.
Kan Nagao, Takaharu Goto, Yuichi Ishida, Tetsuo Ichikawa, M Hideshima, H Koshino, K Hoshiai and Y Umekawa : Should Occlusal Pressure be Applied in Fixing Magnet Assenmlies to Denture? An Evaluation using the Delphi Technique, The Journal of the Japanese Sociaty of Magnetic Applications in Dentistry, 22, 2, 43-46, 2013.
109.
Takaharu Goto, Yuichi Ishida, Kan Nagao and Tetsuo Ichikawa : Long-term follow-up case reports on the use of magnetic attachment as intracoronal/extracoronal attachments, The Journal of the Japanese Sociaty of Magnetic Applications in Dentistry, 22, 2, 12-14, 2013.
The purpose of this study was to evaluate stress analysis of a magnet-retained mini-implant overdenture on an in vitro mandibular model. Mini implants less than 3.0 mm in diameter have been used as not only provisional use, but also permanent use to support overdentures.<br/>Four mini implants (MagDen Fixture MFI4010RF, Shinwon Dental, Seoul, Korea) were placed in edentulous regions between bilateral canines in an acrylic resin mandibular model and the abutments (MagDen Keeper MFK4020, Shinwon Dental, Seoul, Korea) for magnet attachments were used. Seven strain gauges were attached on the resin surface around the right side of two mini implants. The surface of the model was covered with silicone impression material to simulate oral mucosa and an experimental complete denture was placed on the model. A vertical force of 50 N was applied to either one of the premolar, first molar and second molar of the experimental denture using a universal testing machine. <br/>When four mini implants were supported, compressive strains were caused at the lingual side of the distal mini implant. The more posterior the loading point was, the lower the strain around the implant was generally. Although tensile strain was caused at the buccal side of the mesial mini implant, it decreased at the moment when compressive strain arose. When four implants were supported, the strain around the mini implants was distributed more evenly than those in the two implant-supported ones. The influence of implant positioning was examined by removing either two mesial or two distal attachments in the four mini implants. The maximum strain in two mesial implant-supported attachments was smaller than that in two distal implant-supported attachments.
(キーワード)
mini implant / stress analysis / magnetic attachment / overdenture / strain
Hideki Suito, Yuki Iwawaki, Takaharu Goto, Yoritoki Tomotake and Tetsuo Ichikawa : Oral factors affecting titanium elution and corrosion: an in vitro study using simulated body fluid., PLoS ONE, 8, 6, e66052, 2013.
(要約)
Ti, which is biocompatible and resistant to corrosion, is widely used for dental implants, particularly in patients allergic to other materials. However, numerous studies have reported on Ti allergy and the in vitro corrosion of Ti. This study investigated the conditions that promote the elution of Ti ions from Ti implants. Specimens of commercially pure Ti, pure nickel, a magnetic alloy, and a gold alloy were tested. Each specimen was immersed in a simulated body fluid (SBF) whose pH value was controlled (2.0, 3.0, 5.0, 7.4, and 9.0) using either hydrochloric or lactic acid. The parameters investigated were the following: duration of immersion, pH of the SBF, contact with a dissimilar metal, and mechanical stimulus. The amounts of Ti ions eluted were measured using a polarized Zeeman atomic absorption spectrophotometer. Eluted Ti ions were detected after 24 h (pH of 2.0 and 3.0) and after 48 h (pH of 9.0). However, even after 4 weeks, eluted Ti ions were not detected in SBF solutions with pH values of 5.0 and 7.4. Ti elution was affected by immersion time, pH, acid type, mechanical stimulus, and contact with a dissimilar metal. Elution of Ti ions in a Candida albicans culture medium was observed after 72 h. Elution of Ti ions in the SBF was influenced by its pH and by crevice corrosion. The results of this study elucidate the conditions that lead to the elution of Ti ions in humans, which results in implant corrosion and Ti allergy.
Yoshihito Naitou, Jiyon Be, Yoritoki Tomotake, Kenichi Hamada, Kenzo Asaoka and Tetsuo Ichikawa : Formability and mechanical properties of porous titanium produced by a moldless process, Journal of Biomedical Materials Research. Part B, Applied Biomaterials, 101, 6, 1090-1094, 2013.
(要約)
Tailor-made porous titanium implants show great promise in both orthopedic and dental applications. However, traditional powder metallurgical processes require a high-cost mold, making them economically unviable for producing unique devices. In this study, a mixture of titanium powder and an inlay wax binder was developed for moldless forming and sintering. The formability of the mixture, the dimensional changes after sintering, and the physical and mechanical properties of the sintered porous titanium were evaluated. A 90:10 wt % mixture of Ti powder and wax binder was created manually at 70°C. After debindering, the specimen was sintered in Ar at 1100°C without any mold for 1, 5, and 10 h. The shrinkage, porosity, absorption ratio, bending and compressive strength, and elastic modulus were measured. The bending strength (135-356 MPa), compression strength (178-1226 MPa), and elastic modulus (24-54 GPa) increased with sintering time; the shrinkage also increased, whereas the porosity (from 37.1 to 29.7%) and absorption ratio decreased. The high formability of the binder/metal powder mixture presents a clear advantage for fabricating tailor-made bone and hard tissue substitution units. Moreover, the sintered compacts showed high strength and an elastic modulus comparable to that of cortical bone.
Yoshihito Naitou, Ashrin N. Meinar, Yuki Iwawaki, Toshiya Kashiwabara, Takaharu Goto, Teruaki Ito, Tetsuro Sakuma and Tetsuo Ichikawa : Recording of individual identification information on dental prostheses using fluorescent material and ultraviolet light, The International Journal of Prosthodontics, 26, 2, 172-174, 2013.
(要約)
The placement of individual identification on a prosthesis is very important for forensic dentistry and traceability. This article describes the unique naming/labeling of dentures with information for individual identification using a method in which information is invisible under natural light but visible under ultraviolet light-emitting diode/black light exposure. The use of laser beam machining with this method will enable the recording of a large amount of information.
As the connection mechanism between the superstructure and implant, the cement-retained type and screw-retained type are mainly used. The choice of a screw-retained versus a cement-retained superstructure is a complex and comprehensive decision involving many points of consideration. On the other hand, various retained methods that is complementary with each retained type have been proposed. In this article, various retained types which have been reported in the literatures and developed by us, were systematically assorted from the standpoints of retreivability, and the advantages were pointed out showing case photographs. This systematical information would help the selection of retained type of the superstructure.
Takaharu Goto, Hidenobu Nishinaka, Toshiya Kashiwabara, Kan Nagao and Tetsuo Ichikawa : Main occluding area in partially edentulous patients: changes before and after implant treatment, Journal of Oral Rehabilitation, 39, 9, 677-683, 2012.
(要約)
The 'main occluding area', the location where food crushing occurs during the first stroke of mastication, is reported to be an important concept; however, it is currently limited to findings in individuals with normal dentition. The purpose of this study was to assess the changes in the location, area and bite force of the main occluding area before and after implant treatments. We enrolled 50 partially edentulous and 22 normally dentate subjects. To identify the location of the main occluding area, each subject was instructed to freely bite once on a dental stopping using the partially edentulous side or the normally dentate area. The location, occluding contact area and bite force of the main occluding area before and after the implant treatments were analysed. The main occluding area was located at a reproducible location in the partially edentulous and normally dentate subjects. This location was principally the first molar region, and for the partially edentulous patients with missing teeth in the molar regions, it moved from the premolar region to the first molar region after treatment. The occluding contact area and bite force for the main occluding area increased (P < 0·05) after the implant treatment in the partially edentulous patients with missing teeth in the molar regions. These results suggest that the main occluding area can be restored to the first molar region after implant treatment and may be an important factor in the assessment of prosthodontic treatment.
Jing Li, Katsuhiko Hirota, Takaharu Goto, Hiromichi Yumoto, Yoichiro Miyake and Tetsuo Ichikawa : Biofilm formation of Candida albicans on implant overdenture materials and its removal., Journal of Dentistry, 40, 8, 686-692, 2012.
(要約)
The purposes of this study were to clarify the surface characteristics of various implant overdenture materials and the capabilities of Candida albicans adherence and biofilm formation on these surfaces, and to investigate the role of salivary mucin in biofilm formation. Seven commonly used implant and restorative materials were assessed. The surface roughness averages of all materials were limited to 0.07-0.10μm. Contact angles and salivary mucin absorption were measured. After 90-min initial adhesion and 2-day biofilm formation, the amounts of C. albicans were determined by counting colony-forming units and the morphological characteristics were observed by scanning electron microscopy (SEM). The effects of saliva coating and the influences of material surface property on initial adhesion, biofilm formation and its removability were analysed by univariate two-way analysis of variance and multiple linear regression analysis. Surface contact angle of materials, the index of hydrophobicity, was found to be correlated positively with initial adhesion and biofilm formation of C. albicans. A negative correlation between mucin absorption and removability of Candida biofilm indicates that mucin plays an important role in biofilm formation and its rigidity. SEM observation also revealed fewer Candida cells on saliva-coated Ti than on saliva-coated hydroxyapatite or acrylic resin. The materials with different hydrophobic property and compositions display diverse manners of salivary mucin absorption, initial adhesion and biofilm formation. The hydrophobic materials encourage enhanced initial adhesion, subsequently resulting in the active biofilm formation. Mucin has decisive effects on Candida immobilization and biofilm development on the materials. Surface hydrophilic property and composition of materials and salivary proteins, especially mucin, affect the process of Candida biofilm formation and influence the amount and rigidity of formed biofilm. The present data may be applied as a reference for selecting materials in implant overdenture treatment from a microbiological point of view.
Seiko Hongama, Kan Nagao, Sachie Toko, Kyuma Tanida, Masatake Akutagawa, Yohsuke Kinouchi and Tetsuo Ichikawa : MI sensor-aided screening system for assessing swallowing dysfunction: Application to the repetitive saliva-swallowing test, Journal of Prosthodontic Research, 56, 1, 53-57, 2012.
(要約)
Assessment of swallowing dysfunction, particularly the risk of aspiration, is extremely important to clinicians because it provides crucial information for preventing morbidity and mortality from dysphagia. The purpose of this study was to describe a magneto-impedance sensor-aided screening system (MISS) for assessing swallowing function and clarify its effectiveness with the repetitive saliva-swallowing test (RSST). An MI sensor attached to the skin over the sternum detected the distance from a magnet attached to the skin over the thyroid cartilage during swallowing as the change of magnetic fields. The MISS was validated by videofluoroscopic and videoendoscopic observations. Further, the swallowing behavior of 93 individuals was assessed by using the MISS and then analyzed with the RSST. Swallowing behavior can be recorded and investigated objectively by signal inspection in the MISS compared with the conventional methods. The MISS is a simple and straightforward method for recording and safe because of dry swallow. The MISS system was validated by using simultaneous recordings with videofluoroscopic or videoendoscopic examinations, and compared with the conventional RSST method. The MISS combined with the RSST is an effective screening test for swallowing function.
(キーワード)
Adult / Aged / Aged, 80 and over / Deglutition / Deglutition Disorders / Electric Impedance / Female / Humans / Magnets / Male / Middle Aged / Prosthodontics / Saliva / Young Adult
Tetsuo Ichikawa, Kan Nagao and Takaharu Goto : Alternative Decision Making Considerations in Prosthodontics, The International Journal of Prosthodontics, 25, 3, 260-261, 2012.
Chen Rong Jian, Yoritoki Tomotake, Megumi Watanabe, Yuichi Ishida, Kan Nagao and Tetsuo Ichikawa : Telescopic Magnetic Attachment for Implant-Supported Denture: Evaluation of Splint Effect, The International Journal of Oral & Maxillofacial Implants, 26, 3, 657-664, 2011.
(要約)
Retrievability, connecting strength, and ease of laboratory work are important but conflicting prerequisites for the success of an implant superstructure, particularly with regard to immediate function. To resolve this issue, a telescopic magnetic attachment system has been developed for implant-supported removable dentures. The splinting effect of the attachment was evaluated for stress distribution and elevation with an in vitro model of three implants in an edentulous mandible. Two types of telescopic magnetic attachments were prepared; the inclination angles of the axial wall of the abutment were 2.5 and 6.0 degrees. Three types of three-unit superstructures--a screw-retained superstructure and two telescopic magnet-retained superstructures--were fabricated. Static loads of 24.5, 49, and 98 N were applied vertically at three loading points on one side of each occlusal table. The elevation was measured as the height at which the magnet-retained superstructure detached from the abutment (on the other side of the prosthesis). In addition, by means of strain gauges, the stress distribution around the implants was evaluated and compared among the superstructures with the same three loads applied at six different points. The magnet-retained superstructure with the axial wall inclined at 2.5 degrees did not detach from the abutment. The differences in stress distribution between the screw-retained and magnet-retained superstructures with a 2.5-degree inclination were found to be statistically insignificant. The magnet-retained superstructure with a 6-degree inclination detached from the abutment, and the stress was concentrated during loading to a cantilever site. Because of its stress distribution and elevation, the new telescopic magnetic attachment, which has properties such as splinting the implants, ease of fabrication, and retrievability, is expected to be a viable alternative for the retention of implant-supported removable dentures.
Megumi Watanabe, Naozumi Ishimaru, Meinar Nur Ashrin, Rieko Arakaki, Akiko Yamada, Tetsuo Ichikawa and Yoshio Hayashi : A Novel DC Therapy with Manipulation of MKK6 Gene on Nickel Allergy in Mice, PLoS ONE, 6, 4, E19017, 2011.
(要約)
BACKGROUND: Although the activation of dermal dendritic cells (DCs) or Langerhans cells (LCs) via p38 mitogen-activated protein kinase (MAPK) plays a crucial role in the pathogenesis of metal allergy, the in vivo molecular mechanisms have not been identified and a possible therapeutic strategy using the control of dermal DCs or LCs has not been established. In this study, we focused on dermal DCs to define the in vivo mechanisms of metal allergy pathogenesis in a mouse nickel (Ni) allergy model. The effects of DC therapy on Ni allergic responses were also investigated. METHODS AND FINDING: The activation of dermal DCs via p38 MAPK triggered a T cell-mediated allergic immune response in this model. In the MAPK signaling cascade in DCs, Ni potently phosphorylated MAP kinase kinase 6 (MKK6) following increased DC activation. Ni-stimulated DCs could prime T cell activation to induce Ni allergy. Interestingly, when MKK6 gene-transfected DCs were transferred into the model mice, a more pronounced allergic reaction was observed. In addition, injection of short interfering (si) RNA targeting the MKK6 gene protected against a hypersensitivity reaction after Ni immunization. The cooperative action between T cell activation and MKK6-mediated DC activation by Ni played an important role in the development of Ni allergy. CONCLUSIONS: DC activation by Ni played an important role in the development of Ni allergy. Manipulating the MKK6 gene in DCs may be a good therapeutic strategy for dermal Ni allergy.
Hideki Suito, Yoritoki Tomotake, Megumi Watanabe, Daisuke Nagao, Yuichi Ishida and Tetsuo Ichikawa : Survival of immediate implant restoration: A retrospective study through 9-year-observation, Journal of Prosthodontic Research, 55, 3, 141-145, 2011.
(要約)
The purpose of this retrospective study was to assess the implant survival rate and the risk factors associated with implant failure in patients who had undergone immediate implant restoration. We performed a retrospective review and an outcome assessment of all patients who received immediate implant restoration between 2000 and 2010 in our department at Tokushima University Hospital. The patients were divided into groups on the basis of the predictor variables: age, gender, implant location, and number of implants per jaw. The cumulative implant survival rate in the paired groups was determined by using Kaplan-Meier analysis and the log-rank test. Cox proportional hazards model was subsequently used to identify exposures associated with implant failure. Using the Kaplan-Meier method, the survival rates at 1, 3, and 9 years were calculated to be 98.8%, 98.0%, and 94.7%, respectively. No statistically significant association was observed between the implant survival rates and the predictor variables: gender, age, location, and number of implants. Immediate implant restoration is a reliable prosthetic procedure with an acceptable survival rate compared to the conventional implant procedure.
Jian-Rong CHENJ, Kenji Oka, Takanori KAWANO, Takaharu Goto and Tetsuo Ichikawa : Carbon dioxide laser application enhances the effect of silane primer on the shear bone strength between porcelain and composite resin, Dental Materials Journal, 29, 6, 731-737, 2010.
(要約)
The purpose of this study was to evaluate the effect of carbon dioxide laser irradiation on the performance of silane coupling agent as an adhesion promoter. The carbon dioxide laser used in this study was Opelaser 03S II, which irradiated the silane coupling agent applied on the adhesive surface of porcelain. Before and after thermal cycling, shear bond strength was measured using a universal testing machine. Without primer treatment, most of the specimens failed adhesively before reaching the end of the thermal cycling period. For the specimens irradiated with carbon dioxide laser after primer treatment, their shear bond strengths before and after thermal cycling were higher than those treated with primer only -with a significantly pronounced difference between these two groups especially after thermal cycling. Therefore, a combined surface treatment which involved silane application followed by laser treatment was feasible and efficacious for chairside porcelain repair.
J Li, Katsuhiko Hirota, Hiromichi Yumoto, Takashi Matsuo, Yoichiro Miyake and Tetsuo Ichikawa : Enhanced germicidal effects of pulsed UV-LED irradiation on biofilms., Journal of Applied Microbiology, 109, 6, 2183-2190, 2010.
(要約)
The germicidal effects of UVA-LED irradiation (365 nm, 0·28 mW cm(-2) , in pulsed or continuous mode) on Candida albicans or Escherichia coli biofilms were evaluated by determining colony-forming units. The morphological change of microbial cells in biofilms was observed using scanning electron microscopy. After 5-min irradiation, over 90% of viable micro-organisms in biofilms had been killed, and pulsed irradiation (1-1000 Hz) had significantly greater germicidal ability than continuous irradiation. Pulsed irradiation (100 Hz, 60 min) almost completely killed micro-organisms in biofilm (>99·9%), and 20-min irradiation greatly damaged both microbial species. Interestingly, few hyphae were found in irradiated Candida biofilms. Moreover, mannitol treatment, a scavenger of hydroxyl radicals (OH(•) ), significantly protected viable micro-organisms in biofilms from UVA-LED irradiation.
Jing Li, Yoshihito Naitou, Jian-Rong Chen, Takaharu Goto, Yuichi Ishida, Takanori Kawano, Yoritoki Tomotake and Tetsuo Ichikawa : New glass polyalkenoate temporary cement for cement-retained implant restoration: Evaluation of elevation and retentive strength, Dental Materials Journal, 29, 5, 589-595, 2010.
(要約)
The purpose of this study was to evaluate four luting agents for cement-retained implant restorations in two aspects: post-cementation elevation of the superstructure and the retentive strength before and after thermocycling and mechanical cycling. The four evaluated luting agents were: new glass polyalkenoate hard-type (GH) and soft-type (GS) cements, polycarboxylate hard-type (HH) and soft-type (HS) cements. Elevation and retentive strength were measured using a CCD laser displacement sensor and a universal testing machine respectively. Elevation increased in this order: GH, GS, HH, and HS. Thermal and mechanical stresses significantly decreased retentive strength, and the mean values exhibited by GH were significantly higher than the other luting agents. The novel glass polyalkenoate cements (hard- and soft-type) experimentally prepared in the present study augured well as luting agents by virtue of their reduced film thickness and their excellent post-cementation retention and elevation.
Toshiya Kashiwabara, Takaharu Goto, Yutaka Sato, Yoritoki Tomotake, Kan Nagao and Tetsuo Ichikawa : A new method to prevent the corrosion of dental materials, during disinfection using functional water: Sacrificial protection, Journal of Prosthodontic Research, 54, 3, 147-149, 2010.
(要約)
This paper demonstrates a simple method using sacrificial protection for preventing the corrosion of dental metals. Dental metals are directly connected or/and wound with a pure commercial aluminum/zinc wire/plate with high ionization tendency, before their immersion into oxidizing functional water. Dental materials such as Co-Cr alloy wires, stainless steel, and Au-Ag-Pd alloys did not corrode when this method was used. Thus, this method is very simple and effective for preventing corrosion of dental metals during disinfection using functional water.
Yuka Yoshijima, Keiji Murakami, Shizuo Kayama, Dali Liu, Katsuhiko Hirota, Tetsuo Ichikawa and Yoichiro Miyake : Effect of substrate surface hydrophobicity on the adherence of yeast and hyphal Candida, Mycoses, 53, 3, 221-226, 2009.
(要約)
A biofilm composed of various microorganisms including Candida is found on denture surfaces and is likely to be involved in the etiology of denture-induced stomatitis. The purpose of this study was to examine the role of hydrophobic interactions in candidal adherence to acrylic surfaces, particularly that of the hyphal form of Candida albicans. Candida clinical isolates were used. Acrylic plates coated with carrageenan and hydrocolloid (Hitachi chemical, Tokyo, Japan) were used as a hydrophilic substratum. A microbial suspension was placed on each acrylic plate and incubated. All plates were washed in phosphate-buffered saline containing CaCl(2) and MgCl(2) [PBS (+)] and cells still adhering to the acrylic surface were collected by 0.25% trypsin treatment. Cell-surface hydrophobicity was estimated using a modification of the technique used to measure adherence to hydrocarbons. When the acrylic plates were coated with hydrophilic materials, the adherence of hydrophobic clinical isolates of Candida and the hydrophobic hyphal C. albicans decreased, whereas the adherence of non-hydrophobic Candida was not affected or increased. We suggest that hydrophilic coating of denture surfaces could be a potent method for reduction of the adherence of relatively hydrophobic fungal cells, particularly hyphal C. albicans, which causes denture stomatitis and related infections.
Razia Sultana, Kenichi Hamada, Tetsuo Ichikawa and Kenzo Asaoka : Effects of heat treatment on the bioactivity of surface-modified titanium in calcium solution, Bio-Medical Materials and Engineering, 19, 2-3, 193-204, 2009.
(要約)
The purpose of this study was to determine the effects of heat treatment on the bioactivity of hydrothermal-modified titanium in CaO solution for improved bioactivity by immersion in simulated body fluid (SBF). The hydrothermal treatment of titanium in CaO solution was performed at 121 degrees C at 0.2 MPa for 1 h in an autoclave followed by 1 h heat treatments at 200, 400, 600 and 800 degrees C simultaneously. The bioactivity of titanium was evaluated by hydroxyapatite precipitation during immersion in SBF. Surface microstructure changes after the heat treatments and immersion in SBF were determined by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Heat treatments at high temperatures (600 and 800 degrees C) promoted the synthesis of anatase, increased the thickness of the titanium oxide layer on the modified titanium surface and promoted the synthesis of calcium titanate, which possibly promoted the precipitation of apatite in SBF. The extent of precipitations increased with the time of immersion in SBF and the temperature of the heat treatment. Island-like deposits of needle-like crystals were observed only on the surface of the 600 and 800 degrees C heat-treated specimens after two or four week immersions in SBF. The results suggested that treatments of the surface of hydrothermal-treated titanium specimens at high temperatures (600 and 800 degrees C) could be effective for the surface modification of titanium as an implant material offering better osseointegration.
(キーワード)
Absorption / Biocompatible Materials / Body Fluids / Calcium / Crystallization / Hot Temperature / Materials Testing / Particle Size / Porosity / Solutions / Surface Properties / Titanium
Tetsuo Ichikawa, Osamu Ishida, Megumi Watanabe, Yoritoki Tomotake and Hua Wei : A new retrieval system for cement-retained implant superstructures., Journal of Prosthodontics, 17, 6, 487-489, 2008.
(要約)
This article discusses two methods for improving the retrievability of cement-retained implant superstructures. One method involves incorporating a removal screw in the superstructure and the second method uses a small dimple on the abutment, accessed through a vent in the superstructure.
Wei Hau, Yoritoki Tomotake, Kan Nagao and Tetsuo Ichikawa : Implant prostheses and adjacent tooth migration: preliminary retrospective survey using 3-dimensional occlusal analysis., The International Journal of Prosthodontics, 21, 4, 302-304, 2008.
(要約)
Occlusal force analysis was retrospectively evaluated to clarify the proximal contact loss after fixed implant prosthesis placement. Twenty-eight patients (55 prostheses) with fixed implant prostheses in the posterior region were divided into 2 groups: proximal contact loss and unchanged groups. The occlusal force and its distribution were 3-dimensionally measured using the Dental Prescale system. A high proportion of lingual and anterior component forces and high occlusal force distribution in the intercanine region were observed in the contact loss group. The high occlusal force of the adjacent tooth may enhance the mesial migration.
(キーワード)
Bite Force / Dental Prosthesis, Implant-Supported / Dental Stress Analysis / Humans / Malocclusion / Mesial Movement of Teeth / Retrospective Studies
(文献検索サイトへのリンク)
● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 18717086
Toshiya Kashiwabara, Yuka Yoshijima, Seiko Hongama, Kan Nagao, Katsuhiko Hirota and Tetsuo Ichikawa : Denture plaque microflora in geriatric inpatients and maxillary defect patients, Prosthodontic Research & Practice, 6, 3, 153-158, 2007.
(要約)
Purpose: The purpose of this study was to investigate denture plaque microflora of geriatric inpatients and maxillary defect patients from the standpoint of infection control in the elderly.Methods: Denture plaque was collected from 80 elderly subjects who were categorized into 3 groups: group A, 21 healthy complete denture wearers; group B, 49 complete denture wearers residing at a geriatric hospital; and group C, 10 complete denture wearers with maxillary defects. The microflora was investigated by counting the total number of microorganisms, including streptococci, staphylococci, and Candida spp.Results: The colony-forming unit (CFUs) count and incidence, particularly those of Candida spp., were significantly higher in group B (P<0.01). The CFUs of staphylococci were significantly higher in group C (P<0.01), and methicillin-resistant Staphylococcus aureus (MRSA) was observed in all Staphylococcus-positive patients. The CFUs of Candida spp. were significantly correlated to those of staphylococci (P<0.01).Conclusion: A high CFU count of Candida spp. and staphylococci (including MRSA) are characteristic of the microflora in geriatric inpatients and maxillary defect patients, respectively. This study supports the hypothesis that dentures might serve as potential reservoirs of organisms causing systemic infections.
Chen Jianrong, Kan Nagao, Yoritoki Tomotake and Tetsuo Ichikawa : Influence of a Vent Hole on the Retentive Force of a Cement-retained Superstructure before/after Thermocycling, Prosthodontic Research & Practice, 5, 3, 157-160, 2006.
(要約)
<B>Purpose:</B> The purpose of this study was to evaluate the influence of a vent hole on the retentive force of a cement-retained superstructure to an abutment.<BR><B>Methods:</B> The retentive force of superstructures with/without a vent hole, retained using one of two luting cements, was measured using a universal testing machine both before and after thermocycling<BR><B>Results:</B> The retentive force of the cement-retained superstructure with the vent hole was greater than that of the cement-retained superstructure without the vent hole. While the retentive force decreased significantly after thermocycling, the size of the vent hole had little influence on the retentive force.<BR><B>Conclusion:</B> It was concluded that placement of a vent hole in the superstructure is useful, with little adverse effect on the retentive force of the restoration.
(キーワード)
retentive force / cement-retained superstructure / vent hole / thermocycling
Chen Jain-rong, 岡 謙次, Hua Wei, 市川 哲雄 : Effect of surface treatment with commercial primers on tensile bone strength of auto-polymerizing resin to magnetic stainless steel, International Chinese Journal of Dentistry, 5, 1, 7-11, 2005年.
Hua Wei, Yoritoki Tomotake, Kan Nagao, Takafumi Ohguri, Daisuke Nagao and Tetsuo Ichikawa : In vitro Study of Stress Distribution on Additional Posterior Mandibular Implants, Prosthodontic Research & Practice, 3, 1, 84-91, 2004.
(要約)
Purpose : This in vitro study investigated the influence of implant splinting on stress distribution in two experimental implant-bone models.Materials and Methods : Two experimental implant-bone models simulated the original Brånemark model with four implants between the mental foramina and one additional implant placed on each side posterior to the mental foramen. The stress distribution on each implant in the models was examined by applying a static load to the superstructure. Three types of superstructures were studied to determine the effect of additional implants in the posterior region : 1) a metal superstructure supported by all six implants (Full dental arch ; Metal FDA) ; 2) the same type of superstructure made of resin instead of metal (Resin FDA) ; and 3) the metal superstructure supported by four anterior implants, with the conical abutments removed from the two posterior implants (Short dental arch ; Metal SDA).Results : Regardless of the type of superstructure tested, high stress was observed around each loaded implant. The highest stress was concentrated on the distal implants of the FDA compared to the stress on the anterior implants.Conclusion : The elevated stress concentration around the implants found in the present in vitro study is considered to be one of the reasons for the high failure rate of additional posterior mandibular implants.
(キーワード)
stress distribution / splinting / posterior installation of implant / mandibular distortion
Satoru Eguchi, Kikuji Yamashita, Hiroyuki Morimoto, Tetsuo Ichikawa, Nobuyoshi Nakajo and Seiichiro Kitamura : Extracellular matrix formed by MC3T3-E1 osteoblast-like cells cultured on titanium 2. Collagen fiber formation, Connective Tissue, 36, 1, 9-15, 2004.
(要約)
Many aspects of the structures formed between titanium and cells and the mechanism of the formation are still unknown. In order to clarify these issues, we analyzed the initial structures formed between titanium and MC3T3-E1 osteoblast-like cells cultured on titanium. The present results indicate that extracellular matrix containing collagen fibers formed at the surface of a calcined layer on the titanium. At first, a hemispherical body and a small secondary spherical structure formed at the surface, followed by more beads to form a string-of-beads structure. These string-of-beads collagen structures elongated and formed spirals. For the first time ever, we directly observed the structure of collagen fiber formed between cultured osteoblasts and titanium with microscopy. Here, we describe the formation mechanism of type I collagen fibers in extracellular bone matrix. Elucidation of the mechanism of collagen fiber formation will aid in the development of controlled tissue regeneration.
Kikuji Yamashita, Satoru Eguchi, Hiroyuki Morimoto, Takeo Hanawa, Tetsuo Ichikawa, Nobuyoshi Nakajo and Seiichiro Kitamura : Extracellular matrix formed by MC3T3-E1 osteoblast-like cells cultured on titanium 1. Anchor structure, Connective Tissue, 36, 1, 1-8, 2004.
(要約)
In order to clarify the structure of the extracellular matrix formed by osteoblasts in contact with titanium, we analyzed the structure formed by cultured clonal MC3T3-E1 osteoblasts on a calcified surface of commercial pure titanium, after exfoliating the cells from the surface of the titanium. Collagen fibers formed between neighboring cells and between cells and titanium, in the latter case with one tip of each collagen fiber bound to the cell and the other tip bound to the surface of the titanium embedded in the calcified layer. We called this structure an "anchor structure", because the collagen fibers embedded in the calcified layer anchor the cells to the titanium. This structure may be a reason for the useful biocompatibility between titanium and bone.
(キーワード)
MC3T3-E1 / 細胞外マトリックス (extracellular matrix) / チタン (titanium) / type I collagen / anchor structure
Purpose: Recently, laser welding has gained wide acceptance as a dental laboratory technique for bonding metals. We have previously reported a new technique for installing a magnetic keeper in the overdenture abutment coping using laser welding. In the present study, the influence of this technique on the attractive force and corrosion were evaluated.<BR>Methods: A commercially-available magnetic keeper and dental casting Au-Ag-Pd alloy were used. Specimens were prepared by one of the following procedures: original magnetic keeper only, conventional cast-on technique and laser welding technique. Attractive force between thedental magnetic assembly and magnetic keeper was measured using a self-made measuring device. The results were analyzed using the one-way ANOVA test. The external and inner surface of magnetic keepers and cross sections of specimens were observed using metal and stereoscopic microscopes before and after immersion of the specimens in 0.9% NaCl solution for 21 days.<BR>Results: There was no significant difference of attractive force between the conventional cast-on technique and laser welding technique. All of the specimens using the cast-on technique rusted in the corrosion test. Half of the specimens using the laser welding technique changed less, and no oxidized layer or corrosion was observed on the surface.<BR>Conclusions: Installation of magnetic keepers using laser welding is useful for increasing both attractive force and corrosion resistance.
Purpose: Misfit of superstructure-supported osseointegrated implants causes adverse stress in the prosthesis, components, and surrounding bone. A passive fit of the implant-supported prosthesis is essential for successful long-term osseointegration. Various clinical methods for evaluating the fit of implant-supported prostheses have been suggested. However, the methods have little scientific evidence to determine the acceptable fit. The present study evaluated the misfit of implant-supported prostheses by measuring the rotational angle/tightening torque in screwing the prosthesis on master models.<BR>Materials and Methods: Twenty-four implant-supported prostheses (3 single standing, 20 fixed partial, 1 full bridge) of fourteen patients were evaluated using a custom-made rotational angle/ tightening torque measuring apparatus on the master models. The influence of the order of tightening and unit number on the value was also evaluated.<BR>Results: The mean of the rotational angle/tightening torque was 2.6 (SD: 0.6) degree/Ncm in all prostheses. The value was significantly higher than that in the abutment screw as a control. The order of tightening and unit number did not significantly affect the values.<BR>Conclusions: The results suggest that measurements of rotational angle/tightening torque be useful for evaluating the fit of implant-supported prostheses. Misfit of the prostheses was below the level of acceptable fit.
Kan Nagao, Naoki Kitaoka, Fumiaki Kawano, Junji Komoda and Tetsuo Ichikawa : Influence of Changes in Occlusal Vertical Dimension on Tongue Pressure to Palate during Swallowing, Prosthodontic Research & Practice, 1, 1, 16-23, 2002.
(要約)
Purpose : The purpose of the present study was to examine the relationship of tongue pressure and changes in occlusal vertical dimension to swallowing.Materials and Methods : The volunteer subjects were four young male dentulous adults and eight elderly complete denture wearers. The tongue pressure to the palate was simultaneously recorded with electromyography (EMG) measurements of the suprahyoid muscles as the occlusal vertical dimension changed. The subjects were instructed to perform two actions : swallowing without any liquid or food (dry swallowing) and swallowing of 2 ml water (wet swallowing).Results : During dry swallowing, the maximum pressure decreased significantly as the vertical dimension increased in the young subjects. In the elderly, the maximum tongue pressure decreased monotonically as the vertical occlusion increased. The same results were clearly found for wet swallowing. Overall data suggested that the tongue pressure of the elderly group was lower and the duration of tongue pressure in wet swallowing was longer than that of the younger group.Conclusion : An increase of the vertical dimension decreased the tongue pressure to the palate, whereas a decrease of the vertical dimension affected the tongue pressure less. Tongue pressure is an important factor for the evaluation of tongue function, especially swallowing.
Seiko Hongama, Masatoshi Ishikawa, Fumiaki Kawano and Tetsuo Ichikawa : Complete denture with a removable palatal lift prosthesis, --- A case report and clinical evaluation ---, Quintessence International, 33, 9, 675-678, 2002.
(要約)
The palatal lift prosthesis is used to alleviate rhinopharyngeal closure dysfunction. It is generally problematical to use in edentulous patients, because the palatal lift prosthesis requires secure retention of the denture base and is difficult for the patient to retain while eating. This article describes the fabrication of a complete denture with a removable palatal lift prosthesis and a clinical evaluation of the denture's stability. A sprue pin and tube were used as a connecting attachment between the removable palatal lift prosthesis and the denture base. The force required for lifting the soft palate and the denture's stability were measured in the clinical evaluation. The prosthesis required an average retentive force of 0.26 N for each 1 mm of soft palate lift. The force required to dislodge the denture was measured with and without the palatal lift prosthesis in place. The force required to dislodge the conventional complete dentures of five healthy individuals was also measured as a reference. The denture was 24.4% less stable when the palatal lift prosthesis was in place and was generally easier to dislodge than were conventional dentures. This denture with a removable palatal lift prosthesis is useful for patients with dysfunction of the soft palate involving hypernasal speech who have difficulty in retaining the prosthesis while eating.
Purpose: Prevention of an infection, especially aspiration pneumonia, is an important theme in the elderly. We are pointing out risk that is causing an infection such as the aspiration pneumonia, and a denture acts as a reservoir of microorganisms. The aim of this study was to examine the relationship between denture plaque and pharyngeal microflora in the elderly, and the drug susceptibility of isolated <I>Candida</I> spp.<BR>Methods: We collected samples of denture plaque and pharyngeal plaque from elderly patients in a geriatric hospital and Tokushima University Dental Hospital (TUDH). The microflora was investigated by the detection of oral streptococci, staphylococci, <I>Candida</I> spp., <I>Pseudomonas aeruginosa, Escherichia coli</I> and coliforms, and MRSA. Isolated <I>Candida</I> spp. were measured for drug susceptibility.<BR>Results: The microflora of denture plaque was very similar to pharyngeal microflora. A higher incidence of most microorganisms was observed in the patients in TUDH compared with patients in the geriatric hospital. Staphylococci were detected from the patients who harbored <I>Candida</I> spp. All strains of <I>Candida</I> spp. appeared to be susceptible to amphotericin B. Some strains of <I>C. glabrata, C</I>.tropicalis, and <I>C. krusei</I> appeared to be less susceptible to fluconazole. Fluconazole-resistant <I>C. albicans</I> was not isolated.<BR>Conclusions: Denture plaque strongly influences the pharyngeal microflora in the elderly.
Ken'ichi Yokoyama, Tetsuo Ichikawa, Hiroki Murakami, Youji Miyamoto and Kenzo Asaoka : Fracture mechanisms of retrieved titanium screw thread in dental implant, Biomaterials, 23, 12, 2456-2465, 2002.
(要約)
Titanium and its alloy are increasingly attracting attention for use as biomaterials. However, delayed fracture of titanium dental implants has been reported, and factors affecting the acceleration of corrosion and fatigue have to be determined. The fractured surface of a retrieved titanium screw and metallurgical structures of a dental implant system were analyzed. The outer surface of the retrieved screw had a structure different from that of the as-received screw. It was confirmed that a shear crack initiated at the root of the thread and propagated into the inner section of the screw. Gas chromatography revealed that the retrieved screw had absorbed a higher amount of hydrogen than the as-received sample. The grain structure of a titanium screw, immersed in a solution known to induce hydrogen absorption, showed features similar to those of the retrieved screw. It was concluded that titanium in a biological environment absorbs hydrogen and this may be the reason for delayed fracture of a titanium implant.
Fumiaki Kawano, Takafumi Ohguri, Tetsuo Ichikawa, Iwate Mizuno and Akira Hasegawa : Shock Absorbability and Hardness of Commercially Available Denture Teeth, The International Journal of Prosthodontics, 15, 3, 243-247, 2002.
(要約)
Composite resin teeth are more widely used than porcelain or acrylic resin teeth in the fabrication of removable dentures because of their high fracture toughness and high abrasion resistance. The purpose of this study was to evaluate the shock absorbability of commercially available artificial posterior teeth by the free drop-ball test with an accelerometer and to evaluate the Vickers hardness at the surface. The tested artificial teeth included seven composite resin teeth, one acrylic resin tooth, and one porcelain tooth. Specimens were tested 50 hours after immersion in distilled water at 37 degrees C. The impact value and Vickers hardness were measured. A one-way analysis of variance was used to analyzed the data (P = .05). The composite resin teeth showed an intermediate impact value between that of the acrylic resin tooth and the porcelain tooth. Among the artificial teeth investigated, the porcelain tooth showed the highest impact value. A significant difference in the impact value was observed between the porcelain tooth and the composite resin and acrylic resin teeth. However, no significant difference was observed among the composite resin teeth tested. A significant correlation was found between the impact values and the Vickers hardness of the artificial teeth. The present findings suggest that composite resin teeth and acrylic resin teeth have a higher shock absorbability than porcelain teeth.
Yoritoki Tomotake, Tetsuo Ichikawa, Hideo Kanitani, Masahide Nakao and Naoki Kitaoka : Dynamics of bone marrow pressure with tapping of titanium and hydroxyapatite implants in rabbit, Clinical Oral Implants Research, 13, 2, 221-224, 2002.
(要約)
The purpose of the present study was to evaluate the difference in stress transfer between titanium (Ti) and hydroxyapatite (HA) by the measurement of bone marrow pressure using a catheter pressure transducer. Ti and HA implants were inserted in the tibiae of rabbits. A hole of 1 mm in diameter was drilled in the bone and a fine catheter pressure transducer was placed in the bone marrow through a tube. The top of the abutment was vertically tapped with an impulse hammer, and the acceleration signal from the hammer and pressure signal from the catheter pressure transducer were examined. The time of contact (impulse duration) recorded in the impulse with Ti and HA was 166+/-17 micro sec and 164 +/- 17 micro sec, respectively. Maximum bone marrow pressure (BMP) with Ti and HA was 54.2 +/- 32.6 and 47.5 +/- 10.0 mmHg, respectively. Variation of the BMP with Ti was significantly larger than that with HA (P < 0.05). A negative correlation coefficient between impulse duration and BMP was found. The results of the present study suggest that the stress transfer is different between Ti and HA implants using dynamics of the bone marrow pressure.
Screw tightening of the superstructure of osseointegrated implants often produces unsuitable strain on the prosthesis and surrounding bone The purpose of this study was to investigate the effects of screw tightening on surrounding bone in several conditions <br/> Three Steri-oss® implants were placed in an acrylic resin experimental model and a three-unit framework was fabricated on the implants The fit of the framework was judged excellent by laboratory microscopy Ten strain gauges were attached on the experimental model surface around the implants The strain was measured after every screw was tightened by a custom-designed torque controller Static and dynamic strain was recorded Each test was repeated five times under the same conditions <br/> The results were as follows:<br/> 1 The order of screw tightening affected stress distribution The distribution was unequal and asymmetrical to the implants <br/> 2 Staged tightening of the screws decreased the sum of all strains <br/> 3 Tightening torque does not affect stress distribution <br/> 4 Misfit of the abutment/superstructure joint increased the sum of all strains <br/> 5 Strain induced by tightening of the second or third implant was greater than that by tightening the first one
Purpose: The purpose of the present study was to evaluate the difference for stress transfer between titanium (Ti) and hydroxyapatite (HA) implants by measuring bone marrow pressure using a catheter pressure transducer, and then to clarify the relationship between the histological and biomechanical properties.<BR>Methods: Ti and HA implants were inserted in the tibiae of rabbits. About 10 weeks following implantation, a hole, 1mm in diameter, was drilled in the bone distal to the implant, and a fine catheter pressure transducer was placed in the bone marrow through a tube. After the abutment was connected to the implant, the top of the abutment was vertically tapped with an impulse hammer, and the acceleration signal from the hammer, and the pressure signal from the catheter pressure transducer, were examined. In addition, histological examination was performed on each implant.<BR>Results: Maximum bone marrow pressure (BMP) with Ti and HA was 117.4±54.8mmHg and 90.3±30.6mmHg, respectively. A significant difference was observed (p<0.05). Moreover, variation of the BMP with Ti was significantly larger than that with HA (p<0.05). A negative correlation coefficient between the time of contact recorded in the impulse and BMP was found with Ti. As to histological examination of the bone structure around several implants, no significant difference was found between Ti and HA implants.<BR>Conclusion: The results show that the stress transfer is different between Ti and HA implants, using dynamics of bone marrow pressure. Little relation was found between biomechanical properties and histological views. The present study suggests that the evaluation of osseointegration requires consideration of biomechanical properties.
Yoritoki Tomotake, Osamu Ishida, Hideo Kanitani and Tetsuo Ichikawa : Immediate implant-supported oral rehabilitation using a photocurable plastic skull model and laser welding: A technical Note of Screw Retained type: Part 1, The International Journal of Prosthodontics, 15, 3, 303-306, 2002.
(要約)
This article describes a new procedure for immediate implant-supported oral rehabilitation using a photocurable resin skull model and a laser-welding apparatus. Preoperatively, the framework was fabricated on a photocurable resin skull model produced from a CT scan and individually designed guide template. The implants were immediately placed using the guide template; laser welding connected the components of framework. Despite the custom-made prosthesis, the total treatment from implant placement to superstructure placement can be completed within only 1 day. This procedure for immediate implant-supported oral rehabilitation using a photocurable resin skull model and a laser-welding apparatus may be useful for any implant system and patient.
(キーワード)
TITANIUM FRAMEWORKS / EDENTULOUS JAW / PLACEMENT
(文献検索サイトへのリンク)
● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 12066496
Fumiaki Kawano, Takafumi Ohguri, Naoyuki Matsumoto and Tetsuo Ichikawa : Influence of thermal cycling in water on flexural strength of laboratory-processed composite resin, Journal of Oral Rehabilitation, 28, 8, 703-707, 2001.
(要約)
Recently a new generation of laboratory-processed composite resins containing submicron glass fillers was introduced, with claims of high strength. The purpose of this study was to evaluate the effect of thermal cycling in water on the flexural strength and hardness of several laboratory composite systems. The flexural strength of the new laboratory processed composite resins (Artglass [AG], Targis [TR] and Estenia [ES]) was significantly higher than that of conventional resins (Dentacolor [DC] and Cesead II [CS]). Thermocycling caused a reduction of the flexural strength but not a reduction of the hardness for most of materials tested. It was concluded that thermocycling affected the properties of the laboratory-processed hybrid type composite resin, ES, AG and TR. However, the changes of these properties were smaller than those of microfine type composite resin DC. Thus, ES, AG and TR may maintain better properties during service compared with DC.
Hideo Kanitani, Yoritoki Tomotake, Wigianto Rudi, Naeko Kawamoto and Tetsuo Ichikawa : Bone changes around hydroxyapatite and titanium implants after abutment placement in rabbits, --- observations using histological and three-dimensional examinations ---, The Journal of Oral Implantology, 26, 4, 251-256, 2000.
(要約)
We have previously developed a computer-aided system for examination of the three-dimensional bone structure around implants and observed the bone changes in the healing period after implant placement. This paper describes the bone changes around hydroxyapatite (HA) and titanium (Ti) implants after abutment placement using histological and three-dimensional examinations. Twenty-four HA and Ti implants were embedded in the tibias of adult male New Zealand white rabbits. After 8 weeks, the abutment had passed through periosteum and was placed under the skin. Rabbits were sacrificed 4 and 8 weeks following abutment placement. In conclusion, histological examination showed that, at 4 weeks after abutment placement, bone resorption around the implant neck was seen in both HA and Ti implants, and at 8 weeks, excessive bone formation was seen around the implant neck. Three-dimensional bone examination showed that abutment placement may affect bone formation and cause additional bone hypertrophy in the bone marrow area.
Archadian Nuryanti, Fumiaki Kawano, Takafumi Ohguri, Tetsuo Ichikawa and Naoyuki Matsumoto : Flexural strength of rebased denture polymers, Journal of Oral Rehabilitation, 27, 8, 690-696, 2000.
(要約)
The properties of denture base and reline resins may be affected by daily changes between room temperature and mouth temperature. The purpose of the study was to evaluate the effect of thermocycling on the flexural strength of the relined denture base polymer with reline resin. Three denture base resins, three hard reline resins and their combinations were tested. Fourteen specimens, 65x10x2.5 mm, were fabricated for each material. Polymer combination specimens were made using 1.5 mm hard reline resin on 1.0 mm cured denture base resins. Half of the specimens were stored for 50+/-2 h in distilled water at 37 degrees C, while the other half were thermocycled for 20 000 cycles between 4 and 60 degrees C. Three point bending tests were conducted on a universal testing machine at a cross-head speed of 0.5 cm/s. The flexural strengths were measured and a statistical analysis was performed on the data using three-way ANOVA (P<0.05). The results showed that the flexural strength of relined denture base polymer was significantly higher than that of hard reline polymer. Thermocycling did not affect the flexural strength of the relined denture base polymers, whereas the denture base polymer and reline polymer alone showed a decrease in strength after thermocycling.
(キーワード)
Acrylic Resins / Analysis of Variance / Denture Bases / Hot Temperature / Materials Testing / Pliability / Polymers / Polymethyl Methacrylate / Statistics, Nonparametric
Tetsuo Ichikawa, Hanawa Takao, Ukai Hidemi and Murakami Koichi : Three-dimensional bone response to commercially pure titanium, hydroxyapatite, and calcium-ion-mixing titanium in rabbits, The International Journal of Oral & Maxillofacial Implants, 15, 2, 231-238, 2000.
(要約)
Three-dimensional bone response to 3 biomaterials--commercially pure titanium (Ti), hydroxyapatite (HA), and calcium-ion-mixing titanium (Ca-Ti)--embedded in the tibiae of rabbits was examined chronologically. The rabbits were sacrificed at 2, 4, and 8 weeks after implantation, and the percent bone volume around each implant was calculated from the implant surface to each of 4 measurements: 36 microns, 0.25 mm, 0.5 mm, and 1.0 mm in 2 regions (cortical bone and bone marrow regions). Percent bone volume in the cortical bone was consistent, whereas in the bone marrow region, the percent bone volume varied according to implant material, implantation period, and distance from the implant surface. With Ti implants the percent increased gradually up to 8 weeks at each distance, whereas in HA and Ca-Ti implants the percent was largest at 4 weeks and increased closer to the surface. The percent with Ti implants was largest at 36 microns to 0.25 mm. Aspect of bone response to Ca-Ti was its position intermediate between those of HA and Ti. The decrease of the percent at 8 weeks was smaller than HA.
(キーワード)
Analysis of Variance / Animals / Biocompatible Materials / Bone Marrow / Bone and Bones / Calcium / Coated Materials, Biocompatible / Durapatite / Image Processing, Computer-Assisted / Male / Prostheses and Implants / Rabbits / Tibia / Time Factors / Titanium
(文献検索サイトへのリンク)
● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 10795455
Fumiaki Kawano, Takafumi Ohguri, Andrew Koran 3rd, Naoyuki Matsumoto and Tetsuo Ichikawa : Influence of lining design of three processed soft denture liners on cushioning effect, Journal of Oral Rehabilitation, 26, 12, 962-968, 1999.
(要約)
The purpose of this study was to evaluate the influence of the lining design of a soft denture liner on its cushioning effect, using a free drop test and an accelerometer. The peak instantaneous acceleration value was computed. The materials tested were SuperSoft(R) (SS), Kurepeet-Dough(R) (KD), and Molloplast-B(R) (MB). Soft denture liners 2 mm in thickness were placed in test denture bases using three different configurations. Specimens were tested at 24 h and at 180 days after storage in distilled water at 37 degrees C. A three-way ANOVA was used to analyse the data (P=0.05) and Tukey intervals were computed. It was found that all three materials were effective in reducing the impact force. The lining design that had the soft denture liner extended to the periphery of the denture base demonstrated the greatest shock absorbability of all the tested designs. A silicone denture liner using lining design 1 was the most effective in reducing the shock transmitted to the denture bases.
Takafumi Ohguri, Fumiaki Kawano, Tetsuo Ichikawa and Naoyuki Matsumoto : Influence of occlusal scheme on pressure distribution under complete denture, The International Journal of Prosthodontics, 12, 4, 353-358, 1999.
(要約)
The purpose of this study was to estimate which occlusion offers the best conditions of pressure distribution on the supporting structure under a complete denture when crushing food. Simulated maxillary and mandibular complete dentures with three different posterior occlusal schemes--fully balanced occlusion, lingualized occlusion, and monoplane occlusion--were fabricated. Eight pressure transducers were placed in the basal surface of a mandibular denture. The pressure distribution on the mandibular edentulous mouth model with 1.5-mm-thick artificial tissue under a complete denture was recorded when crushing three different foods: soft food (kamaboko), peanuts, and carrot. The mean pressure values at each measurement point and the force required for each test were compared using one-way analysis of variance with P < or = 0.05 representing statistical significance. The required force for crushing a soft food or carrot in the left molar region in monoplane occlusion was significantly larger than that required in fully balanced occlusion or lingualized occlusion. In crushing soft food, fully balanced occlusion showed significantly higher pressure values on the working side than in monoplane occlusion or lingualized occlusion. In crushing the carrot, the pressure values in fully balanced occlusion and in lingualized occlusion were significantly lower than those in monoplane occlusion. These results demonstrate that with fully balanced occlusion and lingualized occlusion a large occlusal force is not needed for crushing hard food, and the stress to the supporting tissues is smaller than with monoplane occlusion.
Rudi Wigianto, Tetsuo Ichikawa, Hideo Kanitani, Naeko Kawamoto, Naoyuki Matsumoto and Hiroshi Ishizuka : Three-dimensional bone structure around hydroxyapatite and titanium implants in rabbits, Clinical Oral Implants Research, 10, 3, 219-225, 1999.
(要約)
Long-term support of dental implants requires adequate bone thickness in the area surrounding the implant. A three-dimensional examination, including calculations of percent bone-implant contact and percent bone volume, was conducted to clarify the bone structure around pure titanium (Ti) and dense hydroxyapatite (HA) implants. The implants were installed in the tibiae of rabbits, and the bone structure was examined after 2, 4, 6 and 8 weeks. The bone formation following implantation differed in the cortical bone and cancellous bone areas. In the cortical bone area, the percent bone-implant contact and percent bone volume were comparatively consistent for both Ti and HA implants during the observation period. In the cancellous bone area, both findings were influenced by the implantation period, and the chronological bone structure in the cancellous bone area also differed between Ti and HA implants. The percent bone-implant contact and percent bone volume in the Ti implant increased over 8 weeks, whereas the dense HA implant increased for the first 4 weeks and then decreased. The implant materials, Ti and HA, affected the bone remodeling in the cancellous bone area.
(キーワード)
Analysis of Variance / Animals / Bone Density / Bone Remodeling / Computer Graphics / Dental Implantation, Endosseous / Durapatite / Image Processing, Computer-Assisted / Implants, Experimental / Male / Osseointegration / Rabbits / Tibia / Titanium
Fumiaki Kawano, Takao Hanawa, Kenji Oka, Yoritoki Tomotake, Kenzo Asaoka, Tetsuo Ichikawa and Naoyuki Matsumoto : Estimation of residual stress in dental porcelain by Laser-Raman spectroscopy, Dental Materials Journal, 17, 1, 41-50, 1998.
(要約)
Residual stress in the surface of dental porcelain was estimated using laser Raman spectroscopy. Sixteen different magnitudes of residual stress were generated in commercial porcelain disks by tempering, ion exchange, and slow cooling. The specimens were analyzed using a laser-Raman spectrometer with an Ar+ laser. The Raman shift of the largest peak near 500 cm-1 originating from silica was used as an indicator of the level of residual stress. For comparison, the residual stress in the specimen was estimated by the indentation micro-fracture method. The Raman shift of the porcelain increased with increasing residual stress at 3.7 x 10(-2) cm-1/MPa (R2 = 0.89). The increase in the Raman shift corresponded to the increase in compressive stress. In addition, the value of full width at half maximum on the peak corresponded to the residual stress (-1.57 x 10(-1) cm-1/MPa: R2 = 0.82). These results revealed that the increase of residual stress in porcelain clearly appears on the Raman spectrum as an increase in the Raman shift. It is thus feasible to estimate residual stress in porcelain by laser-Raman spectroscopy.
Tetsuo Ichikawa, Katsuhiko Hirota, H Kanitani, Yoichiro Miyake and N Matsumoto : In vitro adherence of Streptococcus constellatus to dense hydroxyapatite and titanium, Journal of Oral Rehabilitation, 25, 2, 125-127, 1998.
(要約)
Bacterial adherence to dense hydroxyapatite (HA) and titanium (Ti) rods was examined in vitro using Streptococcus constellatus ATCC27832. Streptoccus constellatus is associated with dental abscess and was isolated from the peri-implantitis. The dense HA was etched with 5% hydrofluoric acid for 0, 10, 20, 30, 40, and 50 s Adherence to the untreated dense HA was twice as high as the adherence to the Ti. The adherence to saliva-treated Ti was 13% higher than that to untreated Ti. The adherence was increased by acid-treatment of the dense HA, following a sigmoid curve from 20 to 50 s of treatment time. The dense HA has the capacity to receive more bacterial adherence than Ti and furthermore, the etched dense HA becomes more adherent.
Rudi Wigianto, Tetsuo Ichikawa, Hideo Kanitani, Masanobu Horiuchi, Naoyuki Matsumoto and Hiroshi Ishizuka : Three-dimensional examination of bone structure around hydroxyapatite implant using digital image processing, Journal of Biomedical Materials Research, 34, 2, 177-182, 1997.
(要約)
This study introduced a new method for three-dimensional (3D) examination of the bone structure around an implant and presented 3D bone-implant contact rates. A block of nondecalcified implant tissue was ground gradually at an interval of 80 micrograms for the collection of serial two-dimensional (2D) images. An image of the stained block surface was instantly recorded by a charge-couple device (CCD) camera and computer-aided system. A 3D model was reconstructed from 60-70 sheets of serial 2D images. The 3D bone structure around the implant was shown in perspective and displayed all sides of the implant. The bone-implant contact rate depended on the cutting position and direction in the specimen. The 3D model will be necessary and valuable for the biomechanical study of dynamic bone changes around implants.
(キーワード)
Animals / Bone Substitutes / Bone and Bones / Durapatite / Image Processing, Computer-Assisted / Male / Models, Biological / Prostheses and Implants / Rabbits
Tetsuo Ichikawa, Katsuhiko Hirota, Hideo Kanitani, Rudi Wigianto, Naeko Kawamoto, Naoyuki Matsumoto and Yoichiro Miyake : Rapid bone resorption adjacent to hydroxyapatite-coated implants, The Journal of Oral Implantology, 22, 3,4, 232-235, 1997.
(要約)
This paper describes rapid bone resorption in the peri-implantitis of HA implants based on both our clinical observations of and histological research on extracted dense hydroxyapatite (HA) implants. The surfaces of extracted HA implants were rough, although they were smooth at fixture placement. Plaque formed on the necks of the implants, whereas little plaque was seen on the bottoms. The plaque consisted of cocci and rods, including filamentous bacteria. Few spirochetes were observed. Although surrounding bone was formed rapidly around the HA implant, bone thickness gradually decreased compared with the titanium implant. These facts suggest that the rigid biointegration of HA with the thin surrounding bone--that is, the overstressing of the bone--causes rapid bone resorption rather than plaque accumulation on HA.
(キーワード)
Hydroxyapatite / Peri-implantitis / Bone Resorption / Overstressing
(文献検索サイトへのリンク)
● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 9524500
Tetsuo Ichikawa, Hideo Kanitani, Rudi Wigianto, Naeko Kawamoto, Masanobu Horiuchi and Naoyuki Matsumoto : Influence of bone quality in the stress distribution, --- An in vitro experiment ---, Clinical Oral Implants Research, 8, 1, 18-22, 1997.
(要約)
Adequate bone quality and stress distribution to the bone are of decisive importance for implant success. The purpose of this in vitro study was to investigate the influence of bone quality on the stress distribution using 2 implant-bone mimicking models, simulating compact and cancellous bone quality. The resin model was made of an acrylic resin only simulating compact bone quality. The hybrid model was made of 2 kinds of materials, acrylic resin covered with a 1-mm layer of urethane to simulate cancellous bone quality. An implant was embedded in each model, and the abutment and suprastructures were connected to the implant. A strain gauge was placed perpendicular to the implant on the surface of the model and a small accelerometer was attached to the abutment. When an impact load was applied to the suprastructure, both strain and acceleration were measured. Both abutment acceleration and surface strain in the hybrid model decreased rapidly as time progressed when compared to the resin model. Abutment accelerations in the resin model were significantly lower than those in the hybrid model. In the hybrid model, the strain increased as the loading site was moved closer to the strain gauge. The influence of loading sites on strain in the resin model was greater than in the hybrid model. Therefore, the occlusal stress was distributed more widely in the hybrid model than in the resin model. This may indicate that occlusal stress in compact bone may have a tendency to concentrate in particular regions.
(キーワード)
Acrylic Resins / Alveolar Process / Analysis of Variance / Bite Force / Bone Density / Dental Stress Analysis / Elasticity / Humans / Models, Structural / Urethane
Masanobu Horiuchi, Tetsuo Ichikawa, Miyuki Noda and Naoyuki Matsumoto : Use of inter-implant displacement to measure mandibular distortion during jaw movements in human subjects, Archives of Oral Biology, 42, 2, 185-188, 1997.
(要約)
It has been reported that the mandibular body and the dental arch distort during jaw movements because of contraction of the jaw muscles. In the present study the relative position between two biointegrated implants approx. 10 mm apart was measured during maximum opening and protrusive movements of the jaw using a magnetic sensor system. Mandibular distortion was evaluated as the change in the sensor signal. In all participants the distal implant deviated to the lingual side relative to the mesial implant and the deviation with jaw protrusion was larger than that with opening movement. The linear displacement of the two implants ranged from 8 to 25 microns during maximum opening and from 10 to 37 microns during jaw protrusion. Further investigation is required to establish the mechanism of this mandibular distortion, which may be of relevance to implant therapy.
Tetsuo Ichikawa, Masanobu Horiuchi, Rudi Wigianto and Naoyuki Matsumoto : In vitro study of mandibular implant-retained overdentures. The influence of stud attachment on load transfer to implant and soft tissue, The International Journal of Prosthodontics, 9, 4, 394-399, 1996.
(要約)
This study investigated the occlusal stress distribution to the implant and soft tissue for the implant-retained overdenture. The stress at the molar residual ridge and the strain around the implant were measured on an experimental resin cast using static and dynamic loading. The influence of connecting structures of stud attachments on stress distribution was discussed. The occlusal stress had a tendency to concentrate on the implant, especially in the areas distal to the implant. The modified magnetic attachment system, using a silicone-covered magnet, provided the optimal stress distribution.
Tetsuo Ichikawa, Junji Komoda, Masanobu Horiuchi and Naoyuki Matsumoto : Influence of alteration in the oral environment on speech production, Journal of Oral Rehabilitation, 22, 4, 295-299, 1995.
(要約)
We examined the influence on temporal aspects of three consonants, /k/, /c/ and /s/, of alterations in the oral environment produced by either palatal augmentation or by an increase in the vertical dimension of occlusion. Voice onset time (V.O.T.) for /k/ and /c/ was influenced more than aspiration time by the palatal augmentation. Consonant duration for /s/ was also influenced by palatal augmentation. Significant influence of an increase in vertical dimension on the timing was not recognized. Speech disorder caused by the malformation of palate seems to be more frequent than that caused by vertical dimension. Adaptation to prostheses would seem to be definitely concerned with orosensory feedback.
Masanobu Horiuchi, Tetsuo Ichikawa, Hideo Kanitani, Rudi Wigianto, Naeko Kawamoto and Naoyuki Matsumoto : Pilot-hole preparation for proper implant positioning and the enhancement of bone formation, The Journal of Oral Implantology, 21, 4, 318-324, 1995.
(要約)
We have demonstrated a new insertion technique, "pilot-hole preparation", for proper implant positioning. The purpose of this study was to investigate the histological and biomechanical efficacies of the technique. We analyzed the influence of implant position on the stress distribution to the bone by the two-dimensional finite element method (FEM). In addition, we studied the influence of the pre-operative pilot-hole preparation on the bone tissue in vivo using histological examination.
Hiroshi Terada, Hideaki Nagamune, Norifumi Morikawa and Tetsuo Ichikawa : The cyanine dye triS-C4(5) as a cationic uncoupler of oxidative phosphorylation: Interaction with mitochondria detected by derivative spectrophotometry, Cell Structure and Function, 8, 2, 161-170, 1983.
Lipei Liu, Megumi Watanabe and Tetsuo Ichikawa : Robotics in Dentistry: A Narrative Review, Dentistry Journal, 11, 3, 62, 2023.
(要約)
Robotics is progressing rapidly. The aim of this study was to provide a comprehensive overview of the basic and applied research status of robotics in dentistry and discusses its development and application prospects in several major professional fields of dentistry. A literature search was conducted on databases: MEDLINE, IEEE and Cochrane Library, using MeSH terms: ["robotics" and "dentistry"]. Forty-nine articles were eventually selected according to certain inclusion criteria. There were 12 studies on prosthodontics, reaching 24%; 11 studies were on dental implantology, accounting for 23%. Scholars from China published the most articles, followed by Japan and the United States. The number of articles published between 2011 and 2015 was the largest. With the advancement of science and technology, the applications of robots in dental medicine has promoted the development of intelligent, precise, and minimally invasive dental treatments. Currently, robots are used in basic and applied research in various specialized fields of dentistry. Automatic tooth-crown-preparation robots, tooth-arrangement robots, drilling robots, and orthodontic archwire-bending robots that meet clinical requirements have been developed. We believe that in the near future, robots will change the existing dental treatment model and guide new directions for further development.
We prepared career advancement program "Experience learning in medical team treatment" towards the second，third and fouth year students of dental school. This program consits of prior learningconcerned with 'Team treatment and Dental profession' and experience learning in medical team treatment at Tokushima University Hospital.The purpose of this program was to rouse career conciousness as a dentalprofession. This program provided students with career image which they want to be in the future. Besides，they were motivated to study more widely to approach their own image. In this paper，we evaluated theeffects of the program"The experience learning in medical team treatment" on career advancement ofdental school students. As a result，it is suggested that this program might be fruitful as career advancement on dental students.我々は歯学部学生のキャリア形成支援のための教育プログラム「チーム医療体験学習」を開発し，歯学部の2，3，4年次の学生を対象として実施した．本プログラムは，グループワークによる事前学習とチーム医療の現場体験を2つの柱とし，学生の歯科医療職としてのキャリア意識を強化することを目的とした．プログラム終了時のアンケートから，学生には歯科専門職としての将来の姿勢や目指す方向性が具体化すると同時に幅広い知識を身につけたいといった学習に対する動機付が強化されるなど明らかな教育成果が認められた．プログラム実施前後のアンケートの分析結果から， 「チーム医療体験学習」が歯学部学生のキャリア形成支援教育の手法として有効なプログラムである可能性が示唆された．
Kenji Oka, Fumiaki Kawano and Tetsuo Ichikawa : Effect of barium in porcelain on bonding strength of titanium-porcelain system., Dental Materials Journal, 15, 2, 111-120, 1996.
(要約)
The bonding strength to titanium, thermal expansion, and bending strength of glassy porcelain containing barium of 5, 10, and 15 mass% were estimated and compared with those of barium-free porcelain, to estimate the effect of barium content on bonding strength to titanium. The three different glassy porcelains containing barium were made by melting at 950 degrees C. The bonding strength of a commercial porcelain to titanium increased with the addition of barium. Bending strength and thermal expansion were not affected by the barium content. Therefore, the addition of barium to porcelain is effective for strengthening the bonding of porcelain to titanium.
Keiko Fujimoto, Hideki Suito, Kan Nagao and Tetsuo Ichikawa : Validity of Quantitative and Qualitative Assessments of Skeletal Muscles in the Lower Extremities Using Ultrasound Imaging: A Literature Review, Journal of Oral Health and Biosciences, 36, 2, 30-35, 2024.
(要約)
Purpose: To explore the use of ultrasound (US) for quantitative and qualitative assessment of muscles (especially the tongue) in dentistry, we performed investigations using muscles of the lower extremities. These muscles are often used to assess skeletal muscles in general. We aimed to determine whether there was a correlation between quantitative and qualitative assessments of lower extremity muscles using diagnostic US and computed tomography (CT) scans in adults.<br> Procedure: We conducted a search for English articles published in PubMed and Scopus from its inception up to October 18, 2022. We used a combination of the keywords ``muscle,'' ``ultrasonography,'' and ``computed tomography'' for the search. Additionally, we manually searched through relevant journals and search engines.<br> Main findings: After applying the inclusion criteria, we ultimately selected seven studies for inclusion in this review. These seven studies focused on muscle mass and involved ultrasonographic evaluations of muscle thickness and cross-sectional area as well as CT evaluations of muscle volume and cross-sectional area. Two studies also evaluated muscle quality using echo intensity (EI) for US assessment and CT values for CT assessment. In three of the seven studies, there was a significant correlation between the US and CT results. Three studies also determined an intraclass correlation coefficient (≥0.8 in all three) to determine the correlation between CT and US. In both studies that additionally assessed muscle quality, a strong correlation was observed between CT and US measurements.<br> Conclusion: Our results suggest that US can be used to perform high quality assessments of lower extremity muscles and muscle mass in healthy individuals and patients with mild or moderate disease. In the future, high quality research on the tongue is needed for application to the field of dentistry.
(キーワード)
ultrasonography / computed tomography / muscle mass / muscle quality
Takahiro Kishimoto, Takaharu Goto, Takashi Matsuda, Yuki Iwawaki and Tetsuo Ichikawa : Application of artificial intelligence in the dental field: A literature review., Journal of Prosthodontic Research, 66, 1, 19-28, Jan. 2022.
(要約)
Application of AI in the dental field has progressed; however, the criteria for evaluating the efficacy of AI have not been clarified. It is necessary to obtain better quality data for machine learning to achieve the effective diagnosis of lesions and suitable treatment planning.
白山 靖彦, 柳沢 志津子, 一ノ宮 実咲, 渡邉 彩, 竹内 祐子, 市川 哲雄, 後藤 崇晴, 藤原 真治 : 徳島県における地域包括ケアシステムの現状と課題 -美馬市木屋平の健康調査を通じて-, Journal of Oral Health and Biosciences, 33, 1, 24-27, 2020年6月.
(要約)
It is predicted that the population of Tokushima Prefecture will decrease to 550,000 by 2040, and 17 municipalities will disappear. For that reason, the community-based integrated care system (integrated care) must be further developed. The purpose of integrated care is the realization of "community development which you can continue to live as you are in the area where you are accustomed to living". To achieve this, not only medical and care, but also the utilization of new human resources and resources has been demanded. In Japan, based on the Sustainable Development Goals (SDGs), relevant laws and systems will be revised to achieve the agenda set forth by 2030, and it has been strongly suggested that it is necessary to participate the welfare area (Long-term care insurance) not only in medicine but also in dentistry.<br>In this paper, we discuss the current situation and issues of integrated care in Tokushima Prefecture, and discuss the future state in relation to the study of the Koyadaira district in Mima City, which is an area of disappearance.
(キーワード)
aging / population decline / community-based integrated care system
後藤 崇晴, 岩脇 有軌, 渡邉 恵, 永尾 寛, 市川 哲雄 : 補綴装置による個人認証システムに関する文献的考察, Journal of Oral Health and Biosciences, 27, 2, 21-27, 2015年2月.
(要約)
In disasters such as hydraulic bore, earthquakes and fire, the oral structure including the dental prostheses can provide identifying information. Over the years, many different personal identification system of dental prostheses have been reported. This present study analyzes the published literature offering the description of the personal identification system of dental prostheses.Two databases, "PubMed" and "Japana Centra Revuo Medicina" were searched to retrieve research papers referred to the personal identification system of dental prostheses. Twenty four papers were selected from the database with the criteria, and they were reviewed. This literature search showed that the personal identifications in three kinds of dental prostheses: removable denture, crown and implant were reported; and more papers on removable dentures were extracted compared to the crown and implant, however there is no high quality paper indicating that the structured methods for personal identification of dental prostheses is effective. A new method and common write format for personal identification are required to improve the present problems, and our systems using fluorescent material and ultraviolet light and femtosecond pulse laser-oriented recording system would be effective.
In-depth oral care toward severe human cases is crucial for the management of their general condition. As a matter of fact, maintenance of a good oral hygiene condition can reduce the risk for developing respiratory diseases such as aspiration pneumonia and ventilator-associated pneumonia. In September 2007, we initiated at Tokushima University Hospital Intensive Care Unit (ICU)a collaboration between nurses and medical doctors to provide professional oral care to patients. The aim of this activity was to establish a standardized protocol of oral care in order to reduce the risk for infectious disease complications for inpatients undergoing respiratory care. At the initial oral examination, the majority of patients in ICU had dry lips, and showed tongue coating and the presence of oral debris on tooth and oral mucosa surfaces. In addition, we sometimes observed ulcer formation on oral mucosa or tooth mobility, which are conditions that ICU members should pay an attention when fixing the endotracheal tube. Our professional oral care protocol reduced oral debris, dry mouth, and oral malodor to some extent in the majority of patients at ICU. An intensive collaboration between dental professionals with nurses and medical doctors, was favored through this activity. Our long-term objective is to contribute to the maintenance of general condition continuously as a member of multi-professional team.
(キーワード)
professional oral care / ventilator-associated pneumonia / VAP / ICU
In case of making complete dentures, we have to consider not only denture stability but also the restoration of aesthetics and function such as mastication and speech. However these are contradictory theoretically from the point of view of denture stability, and it is very difficult to satisfy both requirements in the case of a patient who has poor upper and lower alveolar ridges. We investigated the effect of artificial posterior teeth form and occlusal scheme on the distribution of pressure on supporting structures under complete dentures during mastication with upper and lower edentulous simulators. In this report, a guideline for the selection of occlusal scheme for complete dentures, based on our previous investigations, is described. The occlusal scheme remarkably affected the distribution of pressure under simulated complete dentures, as shown by comparing the distribution of pressure using two different occlusal schemes:fully balanced occlusion and lingualized occlusion. However other factors such as posterior teeth form and position affect the distribution of pressure as well, and are related to each other. Therefore, not only occlusal scheme but also posterior artificial teeth form has to be considered, and the form of posterior teeth should be carefully and comprehensively decided when making complete dentures.
Wigianto Yoshi Putra Adityakrisna, Yuichi Ishida and Tetsuo Ichikawa : Contemporary magnetic removable partial denture system utilizing ultra-thin magnetic attachment, Jul. 2024.
3.
Mohammad Fadyl Yunizar, Megumi Watanabe, Lipei Liu and Tetsuo Ichikawa : The pathogenesis of oral lichen planus related to metal reaction, International College of Prosthodontics, 19th Biennial Meeting, Sep. 2021.
4.
Lipei Liu, Megumi Watanabe, Mohammad Fadyl Yunizar and Tetsuo Ichikawa : Semaphorin3A Promotes the Development of Nickel Allergy, International College of Prosthodontics, 19th Biennial Meeting, virtual meeting, Sep. 2021.
5.
Takahiro Kishimoto, Takaharu Goto and Tetsuo Ichikawa : A novel three-dimensional face modeling using photogrammetry in dental chair-side, The 6th Biennial Joint Congress of CPS-JPS-KAP (Online), Feb. 2021.
6.
Takaharu Goto, Tsukasa Hihara, Keiko Fujimoto, Kan Nagao and Tetsuo Ichikawa : Sex difference of clinical cascade from oral hypofunction to physical frailty, The 7th Biennial Joint Congress of KAP-CPS-JPS, Mar. 2019.
7.
Takahiro Kishimoto, Takaharu Goto and Tetsuo Ichikawa : Neuroscientific evaluation of periodontal tactile with/without sensory integration task: comparison between incisor and molar teeth, 11th Biennial Congress of Asian Academy of Prosthodontics, Kuala Lumpur, Malaysia, Sep. 2018.
8.
Takaharu Goto, Tsukasa Hihara, Tagami Yoshihiro, Yuki Iwawaki, Kan Nagao and Tetsuo Ichikawa : Investigation with questionnaires on symptoms of physical frailty and eating behaviors, 11th Biennial Congress of Asian Academy of Prosthodontics, Kuala Lumpur, Malaysia, Sep. 2018.
9.
Tetsuo Ichikawa, Takaharu Goto, Tsukasa Hihara, Tagami Yoshihiro and Kan Nagao : A quantitative evaluation of oral frailty-physical frailty relationship model based on covariance structure analysis, 11th Biennial Congress of Asian Academy of Prosthodontics, Kuala Lumpur, Malaysia, Sep. 2018.
10.
Kazumitsu Sekine, Yoshihito Naitou, Tetsuo Ichikawa, Otto Baba and Kenichi Hamada : Development of structural and chemical enforcement of neointimal growth as the blood contacting surface for the vascular prosthesis, 45th European Society for Artificial Organs 2018 Congress, Madrid, Sep. 2018.
11.
Takaharu Goto, Hihara Tsukasa, Kishimoto Takahiro, Takashi Matsuda, Yuki Iwawaki, Kan Nagao and Tetsuo Ichikawa : Investigation with questionnaires on symptoms of oral frailty and eating behaviors: Importance of chewing, Biennial Joint Congress of JPS-CPS-KAP, Wenzhou, China, Oct. 2017.
12.
Tetsuo Ichikawa, Higaki Nobuaki, Takaharu Goto, Kishimoto Takahiro, Yuki Iwawaki, Takashi Matsuda, Ishida Yuichi and Watanabe Megumi : A comparison of the occlusal force-sustaining ability of natural and dental implant patients during a sensory integration task, Biennial Joint Congress of JPS-CPS-KAP, Wenzhou, China, Oct. 2017.
13.
Takaharu Goto and Tetsuo Ichikawa : Frailty and Oral Frailty in super-aging society: Physiological considerations and Prosthodontic Strategy, Biennial Joint Congress of JPS-CPS-KAP, Wenzhou, China, Oct. 2017.
14.
Takashi Matsuda, Kurahashi Kosuke, Ishida Yuichi, Takaharu Goto, Kan Nagao and Tetsuo Ichikawa : Part-digitizing system for complete denture fabrication using digital impression and specialized CAD/CAM tray, The 17th Biennial Meeting of International College of Prosthodontists, Santiago, Chile, Sep. 2017.
15.
Kishimoto Takahiro, Takaharu Goto and Tetsuo Ichikawa : Differences in prefrontal activities under sensory integration task: Comparison between incisor and molar teeth, The 17th Biennial Meeting of International College of Prosthodontists, Santiago, Chile, Sep. 2017.
16.
Takaharu Goto, Hihara Tsukasa, Kishimoto Takahiro, Takashi Matsuda and Tetsuo Ichikawa : Influence of solitary eating in the elderly on symptoms on Oral frailty and Physical frailty, The 17th Biennial Meeting of International College of Prosthodontists, Santiago, Chile, Sep. 2017.
17.
Megumi Watanabe and Tetsuo Ichikawa : The effect of ELF pulsed magnetic fields on osteoblast differentiation via MAP kinase pathways, International College of Prosthodontists, Sep. 2017.
18.
Junya Asano, Masatake Akutagawa, Takahiro Emoto, Yohsuke Kinouchi, Shinsuke Konaka, Fumio Shichijo, Yoshio Kaji, Kazuhiko Furukawa and Tetsuo Ichikawa : Automated repetitive saliva swallowing test using magnetic sensors, Abstracts book of the 16th International Conference on Biomedical Engineering, 124, Singapore, Dec. 2016.
19.
Prananingrum Widyasri, Yoshihito Naitou, Kazumitsu Sekine, Kenichi Hamada and Tetsuo Ichikawa : Application of porous titanium in tailored post-core systems using a moldless process: evaluation of the physical and mechanical properties with different particle sizes, International Dental Materials Congress 2016, Bali, Nov. 2016.
20.
Teruaki Ito, HAMID Abdul Rahimah and Tetsuo Ichikawa : Collaborative Design and Manufacturing of Prosthodontics Wire Clasp, Proceedings of the 23th ISPE International Conference on Concurrent Engineering, 421-428, Curitiba, Oct. 2016.
Prananingrum Widyasri, Yoritoki Tomotake, Yoshihito Naitou, Kazumitsu Sekine, Kenichi Hamada and Tetsuo Ichikawa : Sintering Time and Its Influence on Moldless-Processed Porous Titanium's Properties, 94th General Session and Exhibition of the International Association for Dental Research, Seoul, Jun. 2016.
22.
Yoshihito Naitou and Tetsuo Ichikawa : Potential bone forming properties of simvastatin loaded microspheres in a rabbit critical sized defect model 23th European association for osseointegration, Rome, Sep. 2015.
23.
Takaharu Goto, Yoritoki Tomotake, Yuichi Ishida, Nobuaki Higaki, Kan Nagao and Tetsuo Ichikawa : Functional Significance of the Main Occluding Area for Partially Edentulous, 16th Biennial Meeting of International College of Prosthodontists, Sep. 2015.
24.
Nobuaki Higaki, Takaharu Goto, Yuki Iwawaki, Kan Nagao and Tetsuo Ichikawa : Brain Function on Modulation of Occlusal Force and Sensory Integration, 16th Biennial Meeting of International College of Prosthodontists, Sep. 2015.
25.
Megumi Watanabe and Tetsuo Ichikawa : Magnetic Fields Enhanced Osteoblast Differentiation via ERK Pathways, 16th International College of Prosthodontics Biennial Meeting, Seoul, Sep. 2015.
26.
Shiori Nakamura, Nobuaki Higaki, Takaharu Goto, Kan Nagao and Tetsuo Ichikawa : Effect analysis of oral stimulation to prevent dementia focusing on the individual sensibility, 16th Biennial Meeting of International College of Prosthodontists, Sep. 2015.
27.
Kazutomo Yagi, AA Lowe, NT Ayas, JA Fleetham, Tetsuo Ichikawa and FR Fernanda : Parallel changes in the frequency of respiratory event and swallowing during sleep in obstructive sleep apnea patients with and without a mandibular advancement device, American Academy of Dental Sleep Medicine, 24th Annual Meeting,, Seattle, Jun. 2015.
28.
Kazumitsu Sekine, Jiyon Be, Yoshihito Naitou, Tetsuo Ichikawa and Kenichi Hamada : Development of micro-porous Titanium scaffold for promoting the early neointimal growth, Materials Today Asia 2014, Hong Kong, Dec. 2014.
29.
Takashi Matsuda, Takaharu Goto, Toshiya Kashiwabara, Kan Nagao and Tetsuo Ichikawa : Possibility of Complete Denture Fabrication using Digital Technology: the possibility of Contactless Digital Preliminary Impression, The 3rd ASEAN plus and TOKUSHIMA Joint International Conference on ``Strategic Achievement of Oral Sciences and Promotion of Quality of Life'', Makassar, Dec. 2014.
30.
Nobuaki Higaki, Takaharu Goto, Yuichi Ishida, Kan Nagao and Tetsuo Ichikawa : Effects of vibratory and gustatory stimulations on cerebral blood flows, The 3rd ASEAN plus and TOKUSHIMA Joint International Conference ``Strategic Achievement of Oral Sciences and Promotion of Quality of Life'', Makassar, Dec. 2014.
31.
Megumi Watanabe and Tetsuo Ichikawa : Extremely Low Frequency Pulsed Magnetic Fields Accelerate Osteoblast Differentiation, 3rd ASEAN plus and TOKUSHIMA Joint International Conference, Makassar, Dec. 2014.
32.
Yuki Iwawaki, Noriko Mizusawa, Yoritoki Tomotake, Tetsuo Ichikawa and Katsuhiko Yoshimoto : Mechanical stress - responsive microRNA, The 3rd ASEAN plus and TOKUSHIMA Joint International Conference, Makassar, Indonesia, Dec. 2014.
33.
Takaharu Goto, Yoritoki Tomotake, Yuichi Ishida, Nobuaki Higaki, Kan Nagao and Tetsuo Ichikawa : Clinical significance of the main occluding in prosthodontic treatment, The 3rd ASEAN plus and TOKUSHIMA Joint International Conference on ``Strategic Achievement of Oral Sciences and Promotion of Quality of Life'', Makassar, Dec. 2014.
34.
Tsuyoshi Honda, Keiko Fujimoto, Takuro Baba, Seiko Hongama, Kan Nagao and Tetsuo Ichikawa : Elucidation of swallowing Sound Production Mechanism Using Ultrasonography, Indonesian and Japan Prosthodontic Society JOINT MEETING, Bali, Nov. 2014.
35.
Takashi Matsuda, Tetsuo Ichikawa, Takaharu Goto, Toshiya Kashiwabara and Kan Nagao : Digital preliminary impression for complete denture fabrication, Indonesia Japan Prosthodontic Society JOINT MEETING, Bali, Oct. 2014.
36.
Kan Nagao, Takaharu Goto and Tetsuo Ichikawa : Which is better for complete denture wearers, fully balanced occlusion or lingualized occlusion, Indonesian and Japan Prosthodontic Society JOINT MEETING, Bali, Oct. 2014.
37.
Takaharu Goto, Yuichi Ishida, Megumi Watanabe, Yoritoki Tomotake, Kan Nagao and Tetsuo Ichikawa : Location of the main occluding area after implant treatment, 38th Annual Conference of The European Prosthodontic Association, Istanbul, Sep. 2014.
38.
Megumi Watanabe and Tetsuo Ichikawa : Analysis of Small GTPases in Keratinocytes during Nickel Allergy Development, 38th Annual Conference of The European Prosthodontic Association, Istanbul, Sep. 2014.
39.
Sachie Toko, Tetsuo Ichikawa, Atsuko Nakamichi, Tsuyoshi Honda and Kan Nagao : Properties of Food Bolus for Assessing Quality of Mastication, 38th Annual Conference of The European Prosthodontic Association, Istanbul, Sep. 2014.
40.
Teruaki Ito, Eiichi Honda, Tetsuo Ichikawa, Yohsuke Kinouchi, Masatake Akutagawa, Takahiro Emoto and Midori Yoshida : 1/F noise-fluctuated cozy lighting system for concentration improvement, Proceedings of the ASME 2014 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, 34335, 1-10, Buffalo, Aug. 2014.
Tetsuo Ichikawa : Pore size control of porous titanium bone substitution using moldless and space holder method The 9th Scientific Meeting of the Asian Academy of Osseointegration., Sapporo, Jul. 2014.
42.
Tetsuo Ichikawa : Application of resilient liner for attachment of implant - overdenture. The 9th Scientific Meeting of the Asian Academy of Osseointegration., Sapporo, Jul. 2014.
43.
Kazutomo Yagi, AA Lowe, NT Ayas, JA Fleetham, Tetsuo Ichikawa and FR Almeida : Postural movement of the mandible associated with inspiratory effort during sleep in obstructive sleep apnea patients., American Academy of Dental Sleep Medicine, 23rd Annual Meeting, Minneapolis, Jun. 2014.
44.
Kazumitsu Sekine, Jiyon Be, Yoshihito Naitou, Tetsuo Ichikawa and Kenichi Hamada : Fundamental studies of micro-porous titanium scaffold for obtaining the neointimal formation., Joint congress of 51st Annual Meeting of the Japanese Society for Artificial Organs and 5th Congress of the International Federation for Artificial Organs, Yokohama, Sep. 2013.
45.
Yuichi Ishida, Hideki Suito, Yoritoki Tomotake and Tetsuo Ichikawa : Prediction of prosthetic complications in the superstructure by assessing changes in the provisional restoration., The 15th Biennnial Meeting of International College of Prosthodontics, Turin, Sep. 2013.
46.
Yuichi Ishida, 水頭 英樹, Yoritoki Tomotake and Tetsuo Ichikawa : Prediction of prosthetic complications in the superstructure by assessing changes in the provisional restoration., The 15th Biennnial Meeting of International College of Prosthodontics, Turin, Sep. 2013.
47.
Takaharu Goto, Atsuko Nakamichi, Sachie Toko, Tsuyoshi Honda, Kan Nagao and Tetsuo Ichikawa : Assessments of Quality of mastication: Relationship between overall eating behavior and mastication, The 15th Biennial Meeting of International College of prosthodontics, Turin, Sep. 2013.
48.
Nobuaki Higaki, Takaharu Goto, Yuki Iwawaki, Kan Nagao and Tetsuo Ichikawa : Efficiency of oral stimulations on brain function activities: Evaluations using wearable near-infrared spectroscopy, The 15th Biennial Meeting of International College of prosthodontics, Turin, Sep. 2013.
49.
Osamu Isida, Yoritoki Tomotake and Tetsuo Ichikawa : The development of implant superstructures: especially considering the retrievability., Programs and Abstracts of Biennial Meeting of Asian Academy of Prosthodontics., 8, 135, Dec. 2012.
50.
Takaharu Goto, Yoritoki Tomotake and Tetsuo Ichikawa : Systematic literature review on sensation of osseointegrated implants., Programs and Abstracts of Biennial Meeting of Asian Academy of Prosthodontics., 8, 137, Dec. 2012.
51.
Yoritoki Tomotake, Takaharu Goto and Tetsuo Ichikawa : The Relationship between Main Occluding Area and Prosthetic Complains in Implant Superstructure., The 8th Biennial Meeting of Asian Academy of Prosthodontics, 8, 139, Chennai, Dec. 2012.
52.
Hideki Suito, Takaharu Goto, Yuki Iwawaki, Yoritoki Tomotake and Tetsuo Ichikawa : Oral factors affecting titanium elution and corrosion; in vitro study using SBF solution., ASEAN plus and TOKUSHIMA Joint International Conference"Strategic Achievement of Oral Sciences and Promotion of Quality of Life", Dec. 2012.
53.
Takaharu Goto, Nobuaki Higaki, Yoritoki Tomotake, Kan Nagao and Tetsuo Ichikawa : Sensation of osseointegrated implants: literature review and new neurophysiological approach, ASEAN plus and TOKUSHIMA Joint International Conference"Strategic Achievement of Oral Sciences and Promotion of Quality of Life", Dec. 2012.
54.
Takashi Matsuda, Takaharu Goto, Yuichi Ishida, Toshiya Kashiwabara, Kan Nagao and Tetsuo Ichikawa : A Trial of Complete Denture Fabrication using Digital Technology: in vitro Evaluation of digital impression, ASEAN plus and TOKUSHIMA Joint International Conference"Strategic Achievement of Oral Sciences and Promotion of Quality of Life", Yogyakarta, Dec. 2012.
55.
Sachie Toko, Hitoshi Higa, Tsuyoshi Honda, Seiko Hongama, Kan Nagao and Tetsuo Ichikawa : Changes in the physical properties of food bolus and mandibular movement during mastication, ASEAN plus and TOKUSHIMA Joint International Conference on "Strategic Achievement of Oral Sciences and Promotion of Quality of Life", Yogyakarta, Dec. 2012.
56.
Teruaki Ito, Hanumare C. Nevan, Tetsuo Ichikawa and Slocum H. Alexander : Expectation management in a global collaboration project using a deterministic design approach, Proceedings of the ASME 2012 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, 70296, 1-8, Chicago, Aug. 2012.
Yoshihito Naitou, Hideki Suito, Kenichi Hamada and Tetsuo Ichikawa : Fabrication of porous titanium using moldless and space holder technique, 90th General Session and Exhibition of the International Association for Dental Research, Iguase Falls, Brazil, Jun. 2012.
58.
Yoshihito Naitou, 水頭 英樹, Kenichi Hamada and Tetsuo Ichikawa : Fabrication of porous titanium using moldless and space holder technique, 90th General Session and Exhibition of the International Association for Dental Research, Iguase Falls, Brazil, Jun. 2012.
59.
Takaharu Goto, Takashi Matsuda, Yuichi Ishida, Toshiya Kashiwabara, Kan Nagao and Tetsuo Ichikawa : Digital dentistry in complete denture fabrication, --- Feasibility study ---, International Symposium on Oral Health Education and Research, Balikpapan, Dec. 2011.
60.
Yuki Iwawaki, Yoshihito Naitou, Li Jing, Kan Nagao and Tetsuo Ichikawa : The long-term change in properties of the anti-microbiological tissue conditioner containing Juncus powder, The 7th Biennial Meeting of AAP, Shanghai, Oct. 2011.
61.
Megumi Watanabe and Tetsuo Ichikawa : Extremely Low Frequency Pulsed Magnetic Fields Accelerate Osteoblast Differentiation, International College of Prosthodontics, Sep. 2011.
62.
Takaharu Goto, Kan Nagao, Yuichi Ishida, Yoritoki Tomotake and Tetsuo Ichikawa : Influence of Attachments On Load Transfer in Implant Overdentures: Effect Of Denture Rigidity, 14th Meeting of International College of Prosthodontists, Hawaii, Sep. 2011.
63.
Teruaki Ito, Masayoshi Taniguchi and Tetsuo Ichikawa : Regeneration of 3D profile line using a combination of photo images and target markers, Proceedings of the 18th ISPE International Conference on Concurrent Engineering, XXI, 293-300, Cambridge, MA, USA, Jul. 2011.
Ashrin Nur Meinar, Naozumi Ishimaru, Megumi Watanabe, Yoshio Hayashi and Tetsuo Ichikawa : Analysis of Molecular Mechanism for Pathogenesis of Metal Allergy, International Joint Symposium, The University of Tokushima-Niigata University-Gajah Mada University, Bali, Dec. 2010.
65.
Kenichi Hamada, Yoshihito Naitou, Daisuke Nagao, Yoritoki Tomotake, Tetsuo Ichikawa and Kenzo Asaoka : Properties of Porous Titanium using Moldless Process, International Joint Symposium on Oral Science, Denpasar, Dec. 2010.
66.
Takaharu Goto, Kan Nagao, Yuichi Ishida, Yoshihito Naitou, Yoritoki Tomotake and Tetsuo Ichikawa : Observation of the Main ccluding Area with Partually bentate, changes before/after Prosthetic Treatments., 6th Scientific Meeting Asian Academy of Osseointegration, Seoul, Nov. 2010.
67.
Takanori Kawano, Tetsuo Ichikawa, Yoshihito Naitou, Megumi Watanabe and Takaharu Goto : Surface Modification of Titanium by Blue-violet Semiconductor Laser and Ultraviolet Light Emitting Diode, 19th Annual Scientific Meeting European Assocoation for Osseintegration, Glasgow, Oct. 2010.
68.
Megumi Watanabe and Tetsuo Ichikawa : Extremely low frequency pulsed magnetic fields accelerate osteoblast differentiation, 19th Annual Scientific Meeting European Assocoation for Osseintegration, Glasgow, Oct. 2010.
69.
Yoshihito Naitou, Kenichi Hamada, Takaharu Goto, Megumi Watanabe, Daisuke Nagao, Yoritoki Tomotake and Tetsuo Ichikawa : Powder-size effect on biocompatibility of porous-titanium produced using moldless-process, 19th Annual Scientific Meeting European Assocoation for Osseintegration, Glasgow, Oct. 2010.
70.
Takaharu Goto, Kan Nagao, Yuichi Ishida, Yoshihito Naitou, Megumi Watanabe, Yoritoki Tomotake and Tetsuo Ichikawa : Influence of Attachments on Load Transfer in Implant Overdentures, 19th Annual Scientific Meeting European Assocoation for Osseintegration, Glasgow, Oct. 2010.
71.
A Kimura, H Arakawa, ES Hara, Yoshizo Matsuka, Tetsuo Ichikawa and T Kuboki : A newly-developed retrospective appraisal method for prosthodontic treatment efficacy, International Association for Dental Research, Barcelona, Jul. 2010.
72.
Kenichi Hamada, Yoshihito Naitou, Daisuke Nagao, Yoritoki Tomotake, Tetsuo Ichikawa and Kenzo Asaoka : Smart process of porous titanium for tailor-made medical and dental devices, Thermec (International Conference on Processing & Manufacturing of Advanced Materials) 2009, Berlin, Aug. 2009.
73.
Yoshihito Naitou, Daisuke Nagao, Yoritoki Tomotake, Kenichi Hamada, Kenzo Asaoka and Tetsuo Ichikawa : Bioactivity of porous titanium prodeced by a newly developing moldless process, 2nd International Symposium and Workshop "The future Direction of Oral Sciences in the 21st Century", Tokushima, Dec. 2007.
74.
Yutaka Sato, Teruaki Ishikawa, Eiichi Bando, Masanori Nakano, Tetsuo Ichikawa, Maki Hosoki and Shuji Shigemoto : Development of Real-time Monitor for Examination of Occlusal Harmony, 12th Meetings of the International College of Prosthodontists, 190, Fukuoka, Sep. 2007.
(要約)
(Purpose) In the case preparing teeth that guide lateral excursion, prosthodontists reproduce and record original lateral jaw movements on an adjustable articulator and make restorations. However, intra-oral occlusal quilibration before setting restorations is still difficult because there is no procedure to compare jaw movements before and after restoration at the chair-side. The purpose of the study was to develop a new computer-aided technique to record and display the.relationship between incisal point path and condylar point path as diagnostic examination in real-time. (Materials and Methods) Jaw motions were recorded by magnetic jaw-tracking device(CSIIi) with 3 µm accuracy is 3 micro meters. A new software which was developed with C++ class library (Trolltech Qt) and Graphic Library (Mesa), is capable to display 1) path of incisal and condylar points, and 2)the diagnostitic diagram of relationship between incisal path and balancing-side condylar path. We measured frame rate and delay-time of displaying jaw motions with 2.4GHz of computer-clock. (Results) Our software can visualize incisal and condylar path with 25 frames per second (FPS) and display with time lag of 265ms. Diagram can display the relationship between incisal path and balancing condylar path dynamically with 12.5 FPS. (Conclusion) Our system can record jaw movements and display diagnostic diagram immediately at the chair-side. The new technique visualizing the comparison of diagnostic data before and after treatment is useful in the examination of occlusal harmony.
(キーワード)
リアルタイムモニタ / 咬合調整 ()
75.
Yoshihito Naitou, Kenichi Hamada, Daisuke Nagao, Yoritoki Tomotake, Tetsuo Ichikawa and Kenzo Asaoka : Bioactivity of porous titanium produced using moldless process, 6th International Symposium on Titanium in Dentistry, Kyoto, Jul. 2007.
76.
Kenichi Hamada, Yoshihito Naitou, Daisuke Nagao, Yoritoki Tomotake, Tetsuo Ichikawa and Kenzo Asaoka : Moldless Process of Producing Porous Titanium for Dental Applications, 6th International Symposium on Titanium in Dentistry, Kyoto, Jun. 2007.
77.
Yoshihito Naitou, Daisuke Nagao, Tetsuo Ichikawa, Kenzo Asaoka and Kenichi Hamada : High formable porous titanium for biomedical applications, International Association for Dental Research, New Orleans, Mar. 2007.
78.
Yoshihito Naitou, Daisuke Nagao, Kenichi Hamada, Kenzo Asaoka and Tetsuo Ichikawa : High formability of newly developing biomedical porous titanium, 1st International Symposium and Workshop "The future Direction of Oral Sciences in the 21st Century", Awaji, Mar. 2007.
79.
Kenji Fujita, Akihiro Takita, Yoshio Hayasaki and Tetsuo Ichikawa : Data recording on a dental device using femtosecond laser processing with a surface detection system, 5th Internatinal Conference on Optics-photonics Design & Fabrication (ODF'06), 197-198, Nara, Dec. 2006.
80.
Keiji Fujita, Akihiro Takita, Tetsuo Ichikawa and Yoshio Hayasaki : Data recording on a dental device by use of a femtosecond laser for personal identification, The 9th International Conference on Optics Within Life Sciences (OWLS9), P1-2, Taipei, Nov. 2006.
81.
Daisuke Nagao, Katsuhiko Yoshimoto and Tetsuo Ichikawa : Compressing force induces Hsp25 in a mouse osteoblast-like cell line., IADR General Session & Exhibition, Brisbane, Jun. 2006.
82.
Daisuke Nagao, Katsuhiko Yoshimoto, Yoritoki Tomotake, Megumi Watanabe, Y Yoshijima and Tetsuo Ichikawa : Gene expression in a mouse osteoblast like cell line in response to compressing force., 11th International College of Prosthodontists, Crete, Greece, May 2005.
83.
Naoki Ohmura, Katsuhiko Hirota, Hiromichi Yumoto, Keiji Murakami, Hideo Kanitani, Toshiya Kashiwabara, Yoichiro Miyake and Tetsuo Ichikawa : Influence of denture plaque on the pharyngeal microflora, 80th General Session and Exhibition of the International Association for Dental Research, San Diego(USA), Mar. 2002.
84.
Kikuji Yamashita, Hiroyuki Morimoto, Masahide Nakao, Hidemi Ukai, Takao Hanawa, Tetsuo Ichikawa and Seiichiro Kitamura : Development of bio-integrated materials with intact extracellular matrix, The International Symposium on Bio-Integrated Materials and Tissue Engineering, 126-127, 2002.
Adityakrisna Yoshi Putra Wigianto, 後藤 崇晴, 岩脇 有軌, 市川 哲雄 : Germicidal efficacy of portable UV-C light against Candida albicans biofilm on PMMA and SARS-CoV-2, 日本義歯ケア学会第15回学術大会, 2023年1月.
Lipei Liu, Megumi Watanabe, Mohammad Fadyl Yunizar and Tetsuo Ichikawa : Semaphorin3A: A novel potential target for prevention and treatment of nickel allergy, 第50回日本免疫学会学術集会, Dec. 2021.
Ch. Gantumur, Keisuke Nishigawa, R. Hayama, Toyoko Tajima, Yoritoki Tomotake, Yoshihito Naitou, Tetsuo Ichikawa and Yoshizo Matsuka : Etiological investigation of the marginal bone loss on the peri-implant area: a retrospective cohort study, Tokushima University Bioscience Retreat, Sep. 2017.
Tetsuo Ichikawa : Analysis of Small GTPases in Keratinocytes during Nickel Allergy Development 38th Annual Conference of The European Prosthodontic Association, Sep. 2014.
関根 一光, 内藤 禎人, 市川 哲雄, 裵 志英, 浜田 賢一 : Development and evaluation of micro-porous titanium scaffold for promoting neointimal growth as the blood contacting surface, 第53回日本生体医工学会大会, 2014年6月.
Sapaar Bayarmagnai, Yoshihito Naitou, Takaharu Goto, Kan Nagao and Tetsuo Ichikawa : Loss of retentive force and per,manent deformation of polyethylene terephthalate and polyster clasps retainers, 平成25年度公益社団法人日本補綴歯科学会中国・四国支部学術大会, Sep. 2013.
Sapaar Bayarmagnai, Yoshihito Naitou, Takaharu Goto, Kan Nagao and Tetsuo Ichikawa : Extracellular DNA of Candida albicans and its effect on biofilm formation on denture base materials, 平成24年度 (社)日本補綴歯科学会中国・四国・九州合同学術大会, Sep. 2012.
Nur Meinar Ashrin, Megumi Watanabe, Rieko Arakaki, Akiko Yamada, Tetsuo Ichikawa, Yoshio Hayashi and Naozumi Ishimaru : Analysis of Immune Responess to Metal using Murine Nickel Allergy Model., Proceedings of the Japanese Society for Immunology, 40, 102, Nov. 2011.
Ashrin Nur Meinar, Megumi Watanabe and Tetsuo Ichikawa : Analysis of Molecular Mechanism for Pathogenesis of Nickel Allergy, 社団法人日本補綴歯科学会 第120回記念学術大会, May 2011.
T Goto, H Nishinaka, Toshiya Kashiwabara, Yoritoki Tomotake, Kan Nagao and Tetsuo Ichikawa : Significance of the Main Occluding Area in Implant Treatment, 社団法人日本補綴歯科学会 第120回記念学術大会, May 2011.
李 景, Yoshihito Naitou, Megumi Watanabe, Daisuke Nagao and Tetsuo Ichikawa : Characteristics of Candidal adherence and biofilm formation on materials used in the implant overdenture, 第40回日本口腔インプラント学会・学術大会, Sep. 2010.