Efficacy evaluation with stratified randomized controlled study of foam dentifrice containing isodecyl galactosides in older adults

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.


A case of full-mouth reconstruction with amelioration of an irregular occlusal plane for Eichner Classification C1

すれ違い咬合に対して咬合平面を是正し全顎的な補綴治療を行った症例


Relationship between vertical hyoid bone position and swallowing function in older adults.

JOF may affect swallowing function in older males with lowered hyoid bone position.


Evaluation of the effect of reducing metal artifacts in multi-detector CT imaging of zirconia and titanium implants

Zirconia oral implants produce larger artifacts on computed tomography (CT) compared to titanium oral implants. This study aimed to compare the effectiveness of metal artifact reduction (MAR) software and dual-energy (DE) methods, which are used in multi-detector CT (MDCT) to reduce the artifacts produced by titanium and zirconia oral implants. Oral implants were placed in the lower right second premolar and second molar regions of an acrylic mandible model and evaluated using MDCT. For MAR, Single Energy Metal Artifact Reaction (SEMAR) images were obtained, and for DE, images were obtained at 135 keV. The evaluation was based on 21 regions of interest (ROIs) with sides of 2.8 mm, set at 15, 25, and 35 mm from the center (the lower-right first premolar), with 65°, 90°, 115°, and 145° angles set on the buccal and lingual sides. The evaluation was based on an Artifact Index (AI). The lingual aspect of the AI tended to be larger compared to the buccal aspect, regardless of the image-processing method. In addition, the SEMAR method tended to have a greater artifact reduction effect than the DE method. The distortion of the mandibular model and occurrence of new artifacts were confirmed using SEMAR. SEMAR had higher artifact reduction effects on metal artifacts than the DE method. Although SEMAR and dual-energy methods can effectively reduce metal artifacts, they also cause false images and areas that cannot be observed. Therefore, diagnostic and treatment planning, including imaging, is essential before artifact reduction processing.


Effective use of an extraoral vacuum in preventing the dispersal of particulate matter from metal dental materials.

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.


Effect of denture adhesives on masticatory performance: Multicenter randomized controlled trial.


Can Measurement of Ultrasonic Echo Intensity Predict Physical Frailty in Older Adults?

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.


Effects of denture adhesives on denture retention and occlusal forces in complete denture wearers: A multicenter, randomized controlled trial.

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.


Measurement of ultrasonic echo intensity predicts the mass and strength of the tongue muscles in the elderly

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.


Does Masticatory Ability Contribute to Nutritional Status in Older Individuals?

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.

International Journal of Environmental Research and Public Health


Reliability of screening methods to diagnose oral dryness and evaluate saliva secretion


Effect of denture adhesives on oral moisture: A multicenter randomized controlled trial

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.


Geniohyoid muscle affects directly masticatory function: Evaluation using a decision tree analysis

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.

The International Journal of Prosthodontics


Tongue thickness and its clinical significance


Changes in food bolus texture during mastication

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.


Characterization of Swallowing Sound: Preliminary Investigation of Normal Subjects

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.


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

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.


Hardness, cohesiveness, and adhesiveness of oral moisturizers and denture adhesives: selection criteria for denture wearers.

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.


End points and assessments in esthetic dental treatment.

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.