Study objectives Perfluoroalkyl acids (PFAAs) are a class of anthropogenic and persistent compounds that may impact some biological pathways related to oral health. The objective of our study was to estimate the relationship between dental caries prevalence and exposure to four PFAA: perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS) and perfluorooctane sulfonic acid (PFOS) in a nationally representative sample of US adolescents. Setting/Design We analysed cross-sectional data from the National Health and Nutrition Examination Survey from 1999 to 2012 for 12–19-year-old US adolescents. Participants Of 10 856 adolescents aged 12 to 19 years who had a dental examination, we included 2869 with laboratory measurements for serum PFAA concentrations and complete covariate data in our study. Primary and secondary outcome measures Dental caries prevalence was defined as the presence of decay or a restoration on any tooth surface, or the loss of a tooth due to tooth decay. We used multivariable logistic regression to estimate the covariate-adjusted association between serum PFAA concentrations and dental caries prevalence, accounting for the complex National Health and Nutrition Examination Survey design. Results Of 2869 adolescents, 59% had one or more dental caries. We observed no associations between the prevalence of dental caries and serum concentrations of PFOA, PFOS or PFHxS. The adjusted odds of caries were 21% (OR 0.79; 95% CI 0.63 to 1.01), 15% (OR 0.85; 95% CI 0.67 to 1.08) and 30% (OR 0.7; 95% CI 0.55 to 0.90) lower among adolescents in the 2nd, 3rd and 4th serum PFNA concentration quartiles compared to adolescents in the first quartile, respectively. The linear trend for this association was not statistically significant. Conclusion PFOA, PFOS and PFHxS were not associated with prevalence of dental caries. The prevalence of caries was reduced with increasing serum PFNA concentrations; however, these results should be interpreted cautiously given that we were unable to adjust for several factors related to oral health.

Objectives: Amid the COVID-19 pandemic, the transition to distance learning raised pertinent questions regarding advantages and challenges compared to traditional in-person learning. This study aimed to investigate dental students’ perceptions of distance learning throughout the pandemic, examining its impact on their education. Methods: This study employed a convergent mixed-methods design. Three online surveys were conducted in 2020, 2021, and 2022 to collect quantitative data. Additionally, qualitative semi-structured interviews were carried out in 2022. Interviews were recorded and transcribed; then, thematic analysis was performed following an inductive approach. Results: As perceived by the participants, distance learning entails advantages and challenges. Initially, they felt uncertainty and negativity about the new environment with distance learning. However, their perceptions shifted positively as they adapted, even after returning to hybrid and in-person modules. Furthermore, most participants felt that distance learning is better suited for didactic content. It was suggested that didactic courses contain approximately 25–50% of online methods. Conclusions: Distance learning has provided valuable opportunities to reinforce curricula and improve learning efficacy during the pandemic. Our findings suggest that a hybrid learning model that combines traditional and distance modules appears to be an effective approach for future dental education.

Self-assessment is key to improving the quality of work performed by dental professionals. The ability to accurately self-assess has been found to correlate with better clinical performance, making it an important skill for students to master during their dental education. Furthermore, studies conducted in dental schools across the world have shown that lower-performing students tend to overestimate their abilities compared to their peers. This study aimed to evaluate the self-assessment skills of dental students in pre-clinical operative dentistry and to investigate the impact of gender on these skills. Third-year undergraduate dental students (N = 335) took 2 pre-clinical practical exams: class II composite preparation and restoration. Students self-assessed each assignment using a standardized rubric, and 6 calibrated faculty members graded all procedures blindly and independently. The difference between students' self-assessment scores (S) and mean faculty grades (F) reflected the students' self-assessment skills and was referred to as the Student-Faculty (S-F) gap. A positive S-F gap indicates that students overestimate their work, while a negative S-F gap indicates that students underestimate their work. Data was stratified by gender and by faculty-determined student performance, and then statistically analyzed. The study demonstrated a statistically significant difference between faculty grades and students' self-assessment scores. Positive S-F gaps were observed across all procedures, indicating overestimation, with a mean S-F gap of 11.4 ±9.9%. A negative correlation was found between faculty grades and S-F gaps. Higher-performing students showed smaller S-F gaps (4.8 ±5.3%) compared to lower-performing students (21.2 ±9.68%). Furthermore, male students showed significantly higher S-F gaps (14.0 ±10.3%) compared to females (9.7 ±9.4%). Overestimation was more prevalent among lower-performing and male students compared to higher-performing and female students. Future investigations should consider exploring effective interventions and educational strategies aimed at improving students' self-awareness and their ability to accurately assess their performance.