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en: 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.

en: Hygiene

ja: Hygiene


en: 2-methacryloyloxyethyl phosphorylcholine polymer treatment prevents Candida albicans biofilm formation on acrylic resin

en: 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.

en: Journal of Prosthodontic Research

ja: Journal of Prosthodontic Research


en: Treatment outcomes of implant-assisted removable partial denture with distal extension based on the Kennedy classification and attachment type: a systematic review

en: 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.

en: International Journal of Implant Dentistry


en: Objective Assessment of Poor Oral Hygiene Using the ATP Swab Test in the Elderly

ja: 高齢者におけるATP拭き取り検査による口腔衛生状態不良の客観的評価

en:
 Purpose:The purpose of this study was to evaluate the assessment of poor oral hygiene using the ATP swab test.

 Method:A total of 102 consecutive elderly outpatients aged ≥65 years who visited for maintenance were enrolled between October 2019 and April 2020. The evaluation of poor oral hygiene included measurements of:Tongue Coating Index(TCI), number of bacteria by a rapid oral bacterial detection device(Bacterial Counter DU-AA01NP-H;Panasonic Health Care, Japan), and amount of ATP+AMP by the ATP swab test(Lumitester;Kikkoman, Japan). The specimens were a gargle solution rinsed with 10 mL of water for 5 seconds as soon as the patients came to the hospital or a cotton swab wiped on the tongue dorsum. The subjective assessment of hygiene of the oral mucosa and dentures was rated on a 5-point scale.

 Results:In the assessment of tongue dorsum hygiene, the number of bacteria and the amount of ATP+AMP were significantly correlated with TCI. There was also a significant correlation between the number of bacteria and the amount of ATP+AMP.

 Conclusion:The results of this study suggested that the ATP swab test might be used to objectively assess overall poor oral hygiene, including food residues.

ja:
 目的:ATP拭き取り検査キットを用いた口腔衛生状態不良の評価方法について，口腔機能低下症で示された評価法と比較し検討することを目的とした．

 方法:2019年10月から2020年4月までの間に徳島大学病院歯科にてメンテナンスを行っている高齢者102名に対し，残存歯数の測定および口腔衛生状態不良の検査を行った．口腔衛生状態不良の検査では，舌苔付着度(Tongue Coating Index，TCI)，細菌数測定装置による細菌数測定，およびATP拭き取り検査キットによるATP+AMP量の測定を行った．被検体は来院時すぐに10 mLの水で5秒間含嗽を行って吐き出した含嗽溶液と綿棒で舌背部を拭ったものとした．また，口腔内の衛生状態の包括評価として，5段階で口腔粘膜および義歯の主観的評価を行った．

 結果:舌背部の測定に関して，ATP拭き取り検査値とTCIにおけるSpearmanの順位相関係数は0.374(p<0.001)，TCIと細菌数における相関係数は0.429(p<0.001)，細菌数とATP拭き取り検査値における相関係数は0.388(p<0.001)であった．また，包括評価に関して，口腔粘膜の衛生状態とATP拭き取り検査(舌背部)，ATP拭き取り検査(含嗽溶液)，TCI，細菌数(含嗽溶液)との相関係数はそれぞれ-0.257(p＝0.009)，-0.274(p＝0.005)，-0.209(p＝0.035)，-0.321(p＝0.001)であった．義歯の衛生状態とATP拭き取り検査値(含嗽溶液)，TCIとの相関係数はそれぞれ-0.317(p＝0.001)，-0.232(p＝0.019)であった．

 結論:ATP拭き取り検査キットによる測定は，食物残渣などを含む総合的な口腔衛生状態不良を客観的に評価できる可能性が示唆された．

en: Japanese Journal of Gerodontology

ja: 老年歯科医学


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

en: Dentistry Journal

ja: Dentistry Journal


en: アルコール含有義歯安定剤であるホームリライナーが呼気中アルコール濃度へ与える影響の評価

en: Annals of Japan Prosthodontic Society

ja: 日本補綴歯科学会誌


en: Effect of the temperature of water on ultrasonic denture cleaning

en: 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.

en: Journal of Oral Science

ja: Journal of Oral Science


en: Comparison between two assessment tests for oral hygiene: adenosine triphosphate + adenosine monophosphate swab test and bacteria number counting by dielectrophoretic impedance measurement


en: Duplicate complete dentures made by general digital devices: Evaluation of material properties and clinical trial

ja: 汎用デジタル機器を用いて製作した複製義歯:材料特性と臨床評価

en:
Purpose: The purpose of this study was to investigate the validity of the process of duplicating complete dentures using general digital devices through the following tests: cytotoxicity test of materials used, adhesion test of materials to a silicone impression material and a self-curing resin, and questionnaires to operators on duplicate dentures in clinical situations.

Methods: The cell viability of mouse fibroblast-like cells in acrylonitrile- butadiene-styrene (ABS) and polylactic acid (PLA) were evaluated as a cytotoxicity test. The tensile strength between the silicone impression material/self-curing resin and ABS/PLA specimen was measured as adhesive strength using a universal testing machine. Six practitioners who used duplicate PLA complete dentures in 7 patients were asked to evaluate the duplicate denture using the original questionnaire.

Results: The cytotoxicity test showed that the cell viabilities in ABS and PLA were similar to that in acrylic resin at the cell culture times of 24, 48 and 72 hours. The adhesion test showed that the adhesive strength between the ABS/PLA and silicone impression material was significantly lower than that between the conventional self-curing resin and silicone impression material. Although the adhesive strength between the PLA and self-curing resin was low, there was no significant difference between the ABS and self-curing resin. The results of the questionnaire showed that the duplicate denture made of PLA would be of similar value compared to the conventional duplicate denture made of acrylic resin.

Conclusions: The present study suggests that the duplicate complete dentures made by our proposed digital process are clinically effective.

ja:
目的:われわれが提案した汎用デジタル機器を用いた複製義歯製作法の有用性を示すために，使用するアクリロニトリル-ブタジエン-スチレン(ABS)共重合樹脂，ポリ乳酸(PLA)樹脂の細胞毒性試験，シリコーン印象材および常温重合レジンとの接着試験，使用感に関する主観的評価を行った．

方法:細胞毒性試験では，ABS樹脂とPLA樹脂の浸漬液を用いてマウスの線維芽細胞様細胞の細胞生存率を測定した．接着試験では，専用の保持体にそれぞれの試験片を固定し，シリコーン印象材および常温重合レジンを圧接した後に，万能試験機を用いて引張試験を行った．使用感の評価には，専用の評価票を作成し，PLA製の複製義歯を使用する術者に回答させた．

結果:細胞毒性試験では，ABS樹脂，PLA樹脂ともに72時間までの細胞生存率の低下は認められなかった．接着試験では，トレー用レジンと比較して両試料ともにシリコーン印象材への接着強さは低かった．常温重合レジンとの接着強さでは，PLA樹脂は低かったが，ABS樹脂では従来のトレー用レジンと同等の接着強さであった．術者による複製義歯使用感の評価結果としては，従来のアクリルレジン製の義歯とほとんど変わらない評価が得られた．

結論:三次元プリンターで製作した複製義歯における材料的，臨床的評価から本術式の有効性が示唆された．


en: MiR-494-3p induced by compressive force inhibits cell proliferation in MC3T3-E1 cells.

en: 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.

en: Journal of Bioscience and Bioengineering


en: インプラント上部構造における前装材破折と主機能部位との関連について

ja: インプラント上部構造における前装材破折と主機能部位との関連について

en: Journal of Japanese Society of Oral Implantology

ja: 日本口腔インプラント学会誌


en: 補綴装置および歯の延命のために(Part 6) 力のコントロール 力を受ける生体側の観点から


en: Oral factors affecting titanium elution and corrosion: an in vitro study using simulated body fluid.

en: 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.

en: PLoS ONE

ja: PLoS ONE


en: Recording of individual identification information on dental prostheses using fluorescent material and ultraviolet light

en: 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.

en: The International Journal of Prosthodontics


en: 磁性アタッチメントを用いたミニインプラントオーバーデンチャーにおける力学解析

ja: 磁性アタッチメントを用いたミニインプラントオーバーデンチャーにおける力学解析

ja: 日本口腔インプラント学会誌