Background: Dental claims data have been used for epidemiological studies without establishing the validity of the recorded diagnoses or procedures. The present study aimed to examine the accuracy of diagnoses, procedures, operation time, and the number of teeth recorded in dental claims data. Methods: We reviewed the charts of 200 patients who visited and 100 patients who were hospitalized in the Department of General Dentistry, Orthodontics, and Oral and Maxillofacial Surgery in an academic hospital between August 2012 and December 2017. The sensitivity and specificity of the dental claims data for five diseases and 15 procedures were evaluated. We assessed the difference in the number of teeth and duration of general anesthesia between claims data and chart reviews. Results: Sensitivity was more than 86% for six out of seven diagnoses except for pericoronitis (67%). Specificity ranged from 72% (periodontal disease) to 100% (oral cancer for inpatient). The sensitivity of procedures ranged from 10% (scaling for inpatient) to 100%, and the specificity ranged from 6% (food intake on the day of the surgery) to 100%. The mean (standard deviation [SD]) number of teeth in the chart review was 22.6 (6.8), and in the dental claims was 21.6 (8.6). The mean (SD) operation time was 171.2 (120.3) minutes, while the duration of general anesthesia was 270.9 (171.3) minutes. Conclusions: The present study is the first study to validate dental claims data, and indicates the extent of usefulness of each diagnosis and procedure for future dental research using administrative data.

Sustainable human resource is one of the main issues in healthcare delivery and the way hospital dentists work has a significant impact on oral and dental healthcare services. This study is the first large-scale nationwide survey aiming to investigate the working hours including the working environment among hospital dentists in Japan. A total of 2914 hospital dentists responded to self-administered questionnaires from general hospitals (GHs) and medical educational institutions (MEIs) across the country. Among full-time dentists, the younger generation (i.e., those in their 20s and 30s) of both male and female dentists working in GHs engage in over 40 h of in-hospital clinical practice per week, apart from their self-learning hours. In contrast, the middle-aged dentists (i.e., those in their 40s and 50s) at MEIs work for more than 50 h on average due to the added teaching and research responsibilities. In a multiple logistic regression model using “more than 60 h of work per week” as the dependent variable, higher ORs (Odds Ratios) were found in males (OR = 1.83, 95%CI 1.50–2.22), MEIs (OR = 1.92, 1.52–2.42), and individuals specializing in dental and oral surgery (OR = 1.85, 1.47–2.32). Task-shifting was requested by 22.6% of the respondents for preventive care and dental guidance. Only a few male dentists experienced taking a parental leave and the peak distribution of working hours was shorter for females working in GHs. The support for child-rearing in the work environment is still insufficient and a consensus on the involvement of male dentists in childcare is needed.

The provision of oral health care services is one of the global challenges under the realization of universal health coverage in many countries. Despite the increasing importance of oral health care in an aging society, the disparities in the provision of oral care in Japan have not been clarified. Therefore, this study investigated the status of oral and dental care provision using the National Database of Health Insurance Claims and Specific Health Checkups (NDB) at the level of prefectures and secondary medical care areas. Additionally, a multiple regression model was applied to identify the influence of human resources in oral care services and economic factors on the standardized claims data ratio (SCR) of total dental receipts. The results showed that the total amount of oral care provided tended to be higher in metropolitan areas, with bimodal peaks in children aged 5–9 and adults in their 70s. The SCR for dental caries showed little difference nationally, but SCR for periodontal disease tended to be higher in prefectures including metropolitan areas. In a multiple regression model, the number of dentists and prefectural income per capita influenced the SCR of total dental receipts. In secondary medical care areas, some depopulated areas are supplemented by adjacent areas. These results suggest that oral health care services in the national health insurance system are generally well provided; however, they are likely to be influenced by human resources and economic disparities, and regional differences may occur in the care of periodontal diseases.

Few studies have evaluated gender differences in young dentists’ career focusing on career breaks and return to work. We created a cohort dataset for dentists registered in 2006 using the national survey between 2006–2016 (men, 1680; women, 984), and examined the work setting of dentists by gender 10 years after registration. The proportion of dentists on career break increased each survey year, and was more pronounced in women than in men (2006 to 2016, men, 11.2% to 14.2%; women, 7.9% to 31.0%). The proportion of those who had career breaks between 2006–2016 was 44.8% in men and 62.9% in women. In the multiple logistic regression for examining the associations between those who returned to work compared to those working continuously, in women, the odds ratios (OR) were significantly higher in those working in dental clinics (owner, OR: 5.39; employee, OR: 3.10), and those working part-time (OR: 2.07); however, in men, there was no significant association with part-time work. These results suggest during early career phase, female dentists are more likely than males to take career breaks and choose part-time on returning. These gender differences should be considered for ensuring adequate workforce in dentistry in the future.

The corrosion and tarnish behaviors of two Au-based casting alloys (ISO type 1 and type 4 Au alloys) and their constituent pure metals, Au, Ag, Cu, Pt, and Pd in a polyvinylpyrrolidone-iodine solution were examined. The two Au alloys actively corroded, and the main anodic reaction for both was dissolution of Au as AuI₂⁻. The amount of Au released from the ISO type 1 Au alloy was significantly larger than that from the ISO type 4 Au alloy (P<0.05). Visible light spectrophotometry revealed that the type 1 alloy exhibited higher susceptibility to tarnishing than the type 4 alloy. The corrosion forms of the two Au alloys were found to be completely different, i.e., the type 1 alloy exhibited the corrosion attack over the entire exposed surface with a little irregularity whereas the type 4 alloy exhibited typical intergranular corrosion, which was caused by local cells produced by segregation of Pd and Pt.

Objectives: Administrative claims databases are increasingly used in dental research. However, inconsistencies in data coverage and the lack of a global overview remain as challenges. This review aimed to summarize worldwide studies using dental administrative claims databases, focusing on research questions, methodologies, and findings to identify key trends and knowledge gaps. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses extension for Scoping Reviews (PRISMA‐ScR), we conducted a scoping review of studies using dental administrative claims data published between January 2010 and December 2025. We structured the review question using the Population‐Concept‐Context framework. The original search through April 2022, as registered in PROSPERO, was updated in April 2026 using the same search strategy and eligibility criteria. We searched PubMed, Ovid MEDLINE, Ichushi‐Web, CiNii, Scopus, and Web of Science databases. Two reviewers independently screened the records, and disagreements were resolved by consensus. Cohort and case–control studies were critically appraised using the Newcastle–Ottawa Scale (NOS) to characterize the methodological quality of the mapped literature. Results: Following screening, 472 studies met the eligibility criteria. Most studies originated from the United States and Taiwan, indicating marked geographical concentration; the updated search added Switzerland and New Zealand. Research topics included treatment effectiveness, the epidemiology of rare conditions, healthcare utilization, and policy evaluation. Common limitations were insufficient clinical detail, variable data quality, and limited generalizability. Conclusions: This review highlights the expanding use of administrative claims databases in dental research and their inherent limitations. Future research should prioritize validating claims‐based diagnosis and procedure codes and linking claims data with clinical records.