Current status of dental journals published by Japanese organization.

The publication status of dental journals in Japan was examined, with a focus on metrics such as Journal Impact Factor (JIF), Eigenfactor, Article Influence Score, and percentage of open access. A total of 18 journals published by Japanese dental organizations were identified in the Journal Citation Reports (JCR), with JIF values ranging from 0.4 to 6.6. The highest JIF was observed in The Japanese Dental Science Review. Additionally, 16 journals were not listed on the JCR. The authors explored the implications of these findings on the visibility and impact of Japanese dental research, and discussed the potential benefits of embracing open-access publications for greater global dissemination. This study highlighted the opportunities for journals to enhance their international recognition by meeting the criteria for JIF inclusion and embracing open-access publications. By adopting effective publication strategies, the dental community in Japan will be able to contribute to the advancement of dentistry globally, ensuring broader accessibility and recognition of its research contributions.

Application of one-piece endodontic crowns fabricated with CAD-CAM system to molars.

Computer-aided design-computer-aided manufacturing (CAD-CAM) systems have been widely used as a fabrication method for restorations because of their high efficiency and accuracy, which significantly reduces fabrication time. However, molars with insufficient clearance or short clinical crown lengths require retention holes or grooves on the preparation, making it difficult to replicate the shapes with the CAM milling system. In these cases, restorations using the lost-wax method are selected. This article focuses on one-piece endodontic crowns (endocrowns) fabricated with a CAD-CAM system (CAD-CAM endocrowns), in which their posts and crowns are integrated. Articles from July 2012 to August 2023 were searched in PubMed with the keyword "endocrown". This review discusses the application of CAD-CAM endocrowns to molars from the viewpoint of model experiment (fracture resistance, adaptation) and clinical research. This technique, which allows margins and internal gaps to be set within the clinically acceptable range, is reported to be an effective way of restoring molars with high survival rates in clinical research.

Usage of English prosthodontic terms 2019 in Japan.

The use of a uniform terminology is important to avoid misunderstanding of concepts or procedures in discussion. The usage of English prosthodontic terms in Japan was investigated in the current study. English prosthodontic terms listed in The Glossary of Prosthodontic Terms edited by the Japan Prosthodontic Society (GPTJ-5) were compared to those in The Glossary of Prosthodontic Terms ninth edition (GPT-9). A small number of terms labeled as objectionable in GPT-9 were listed in GPTJ-5. This might indicate that it takes a long time to replace terms that are used widely.

Bonding of resin luting materials to titanium and titanium alloy.

Recently in Japan, due to the increased prices of palladium and gold, cast titanium restorations have been included in the Japanese national health insurance system. The purpose of this review was to survey the available literature on titanium bonding systems, focusing on the adhesive monomer in the luting agent in order to expand the application of resin-bonded fixed prostheses made of titanium or titanium alloys. It was found that adhesive monomers are effective for bonding to titanium, and provide results equal to the procedures of silanization and tribochemical silica coating. A primer or a luting agent, including 10-methacryloyloxydecyl dihydrogen phosphate (MDP), methacryloyloxyalkyl thiophosphate derivative (MEPS), 6-methacryloxyhexyl phosphonoacetate (6-MHPA), and 4-methacryloyloxyethl trimellitate anhydride (4-META) promotes bonding characteristics between titanium and the resin material.

Education and licensure of dental technicians.

The Japanese Health, Labour, and Welfare Ministry in 2020 identified the following issues for training and recruitment of dental technicians: early involvement of students in dental practice and dental laboratory work, a curriculum in line with the times, and an extension of the years of training. This paper investigates the education and qualifications of dental technicians in other countries to discuss these issues. The survey method was to use the database PubMed to search the literature since 2001 using the keywords "dental technician," "education," and license" to collect literature related to the pre-graduate education of dental technicians. Information on educational institutions was also included in the survey. The results showed that the countries that introduced joint education between dental technicians and dentists into their educational programs, and the examinations and years of training required for each certification varied from country to country. The curriculum for dental technicians in Japan changed from a time-based to a credit-based system on April 1, 2018. The credit system is characterized by the possibility of each training institution actively engaging in flexible curriculum organization. Dental technician education programs in other countries can provide a valuable reference for each training institute to demonstrate its uniqueness.

Medication-related osteonecrosis of the jaw after tooth extraction in patients receiving pharmaceutical treatment for osteoporosis: A retrospective cohort study.

Background/purpose: Bone resorption inhibitors, such as bisphosphonates (BPs) and anti-receptor activator of nuclear factor kappa B ligand antibodies (denosumab; Dmab), are used to treat osteoporosis and effectively reduce the risk of fracture. However, medication-related osteonecrosis of the jaw (MRONJ) has been reported as a rare adverse effect. Invasive tooth extraction procedures are reportedly a factor in the development of MRONJ. In this study, we aimed to retrospectively observe and clinically examine the effect of medication status on MRONJ development after tooth extraction in patients receiving drug treatment for osteoporosis. Materials and methods: This study was conducted among patients who visited our hospital between December 2015 and December 2021. We collected and analyzed the medical information of patients who underwent dental extractions while using osteoporosis medications, including oral and injectable BPs and Dmab. Results: Among antiresorptive medication users, 40 patients (70 teeth) underwent extraction. The mean duration of BP/Dmab use was 40.4 months, and the mean duration of drug holiday was 6.9 months. MRONJ after tooth extraction was not seen in BP users, but we observed two cases in Dmab users. A significant difference in MRONJ development was confirmed with the use of injectable compared with oral medication administration (odds ratio＝5.01). Conclusion: The use of injectable bone resorption inhibitors was associated with a higher risk of developing MRONJ. The route of administration, duration of medication, and withdrawal period should be carefully considered to prevent MRONJ after tooth extraction.

Bonding behavior and chemical and mechanical properties of silver-based dental alloys.

This article presents a review of silver-based dental alloys, with a focus on their bonding behavior and their chemical and mechanical properties. The most effective pretreatment for bonding silver-based alloys involves alumina air-abrasion followed by the application of a metal adhesive primer containing both the vinyl-thione monomer and a hydrophobic phosphate monomer. Silver-based alloys are readily sulfurized, making it clinically important to limit their use to cast post and core restorations to avoid direct exposure to salivary components. Fracture of the post and core restorations can be prevented by reinforcing their mechanical properties by applying the cast joining technique with tougher metals.

Direct bonded fixed partial denture with an artificial denture tooth as a pontic.

Background: The present review aimed to investigate the feasibility and clinical effectiveness of a direct bonded fixed partial denture (DBFPD) based on available literature. The efficiency of a DBFPD is mainly affected by the type of artificial denture tooth, the type of luting agent, and the adhesive preparation. Methods: The parameters were reviewed based on the in vitro and in vivo studies conducted. An acrylic resin tooth or a composite resin tooth for removable dentures should be used as the artificial tooth for the pontic. Results: Considering the luting agent, a methyl methacrylate-based resin luting agent, which has low mechanical strength but is capable of plastic deformation and could sustain for a long time, should be used. Appropriate pre-adhesive treatment should be performed on both the artificial and abutment teeth. The cases in which a DBFPD can be applied are limited to one missing anterior tooth, as long as it is not overstressed. Patient cooperation in cases of occlusion seems to be another prerequisite. Conclusion: Knowledge and selection of the material and case indications are essential, and patient cooperation is pertinent in studying the long-term prognosis of a DBFPD.

Fabrication of titanium restoration by means of calcium aluminate-bonded magnesia investment material and one-chamber arc casting apparatus.

Cast titanium restoration for molars has high biocompatibility and is covered by the Japanese national health insurance. Titanium casting requires specific investment material and casting apparatus. A cast restoration for the mandibular left second molar was fabricated using titanium in this study. A wax pattern fabricated on a definitive cast was invested in calcium aluminate-bonded magnesia investment material. Titanium was cast using an argon gas pressure one-chamber casting apparatus. No defects were observed on the surface and the hole was clearly reproduced. A smooth surface on the restoration was obtained by polishing at low speed. Reproductivity and polishing properties of the titanium restoration fabricated in this study were comparable to those of conventional dental metal restorations.

Saliva-based PCR tests for SARS-CoV-2 detection.

The outbreak of novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. Nasopharyngeal swabs are widely used in polymerase chain reaction (PCR) test to detect SARS-CoV-2. However, the collection of nasopharyngeal swabs has a series of drawbacks concerning exposure of healthcare staff, difficulty in collection, and discomfort of patients. Therefore, an alternative noninvasive sample for diagnostic of emerging viral diseases is required. The usefulness of saliva screening tests is compared to conventional swab tests in this report. The results suggest that saliva could be a reliable sample for detecting SARS-CoV-2.

Fabrication systems for restorations and fixed dental prostheses made of titanium and titanium alloys.

PURPOSE: In recent years, the application of restorations and fixed dental prostheses to molars by computer-aided design-computer-aided manufacturing (CAD/CAM) with composite resin has been increasing. Titanium and titanium alloy having a high tissue affinity and good biocompatibility are suitable for cases where CAD/CAM fabrications are inadequate, such as allergic reaction to metal. Many studies have reported methods of production with titanium and titanium alloys. The purpose of this review is to survey the clinical application of titanium and titanium alloy restorations and fixed dental prostheses with various fabrication systems. STUDY SELECTION: A literature search in PubMed was performed for various fabrication systems of titanium and titanium alloy from 2010 through 2019. The search keywords were "titanium", "titanium alloy", "CAD/CAM", "cast", "fabrication system", "marginal gap", "internal gap", and "clinical performance". Only relevant studies are summarized and discussed in this review. RESULTS: With any fabrication system, titanium and titanium alloy restorations and fixed dental prostheses fabricated with various systems were within the clinically acceptable ranges of marginal gap and internal fit. Additionally, these restorations were considered to have less effect on the periodontal issues. Although metal-ceramic restoration has clinical performance problems, such as ceramic fracture, fabrications with only titanium and titanium alloy were reported to have good clinical performance. CONCLUSIONS: Regardless of the fabrication system, titanium and titanium alloy restorations and fixed dental prostheses can be applied clinically. Titanium and titanium alloys are thought to be a promising alternative to the dental metals currently used.

An analysis of the current condition of the medical insurance system in Japan.

The social security system, including the national health insurance system, in Japan has been maintained at a world-class level since 1974. However, an increase in the number of elderly people, and a decrease in the working generation, caused by a declining birthrate, represents a serious issue for the system both in the present and future. This report analyzes the key problems in the current insurance system and also considers how they can be handled in the future.

Application of titanium and titanium alloys to fixed dental prostheses.

PURPOSE: Titanium and titanium alloys are one of the main metallic materials in the medical and dental fields because of their biocompatibility. In this review, the application of titanium and its alloys as the substitute materials for Ag-Pd-Au alloy in the casting of fixed dental prostheses was examined. STUDY SELECTION: A reference search was performed through PubMed based on the keywords titanium, titanium alloy, and dental casting. Other relevant references were obtained from the citation in the articles. RESULTS: The dental casting technology for titanium has already been developed for clinical use, which enables the use of appropriate casting machines and investment materials for titanium and its alloys available commercially. The mechanical properties, castability, and corrosion resistance of titanium and titanium alloys were reported to be comparable or superior to the conventional dental alloys. Clinical researches reported that titanium and Ti-6Al-7Nb alloy casings showed suitable quality for clinical application. CONCLUSION: Titanium and its alloys can be the substitute materials for Ag-Pd-Au alloy, and should be considered worthy of qualifying for the dental insurance coverage.

Use of digital impression systems with intraoral scanners for fabricating restorations and fixed dental prostheses.

Accurate impressions are essential in fabri-cating dental restorations and fixed dental prostheses. During the last decade, digital impression systems have improved substantially. This review discusses the accuracy of digital impression systems for fabrication of dental restorations and fixed dental prostheses. A literature search in PubMed was performed for the period from July 2010 through June 2017. The search keywords were Cerec, digital impression, direct digitalization, indirect digitalization, and intraoral scanner. Only relevant studies are summarized and discussed in this review. In general, the latest systems have considerably reduced the time required for impression making, and the accuracy and marginal fit of digital impression systems have recently improved. Restorations and fixed dental prostheses fabricated with currently available digital impression systems and intraoral scanners exhibit clinically acceptable ranges of marginal gap in both direct and indirect procedures.