Prevalence and correlates of common mental disorders among dental students in Brazil.

This study aimed to estimate prevalence of common mental disorders (CMD) and associated factors among dental students. In this cross-sectional study, 230 students answered a questionnaire and instruments to assess CMD (Self Reporting Questionnaire-20), hazardous alcohol consumption (Alcohol Use Disorder Identification Test), social support (Social Support Scale), perceptions of academic life (Dundee Ready Education Environment Measure), coping (Ways of Coping Inventory) and resilience (Resilience Scale). Bivariate analysis was conducted using the Chi-Square and Mann-Whitney tests. Logistic regression included all explanatory variableswith p<0.20 in the bivariate analysis, besides sex and academic year. The explanatory variables were analyzed in five successive blocks (backward-stepwise), until all variables presented statistical significance in the final model (p<0.05). The prevalence of CMD was 45.2% (95%CI: 38.7-51.6), with no significant differences between sexes. Students with no extracurricular activities, who had negatively self- assessed their health status and their academic performance, were about four times more likely to present CMD, followed by receiving psychological or psychiatric treatment during university (AOR: 2.65; 95%CI: 1.1-6.1) and those with high scores for confrontive coping (AOR: 1.20; 95%CI: 1.0-1.4). Resilience was a protective factor for CMD among dental students (AOR: 0.93; 95%CI: 0.9-1.0). Aspects related to academic performance, health status and confrontive coping strategies were risk factors to students' mental health. Individuals with high levels of resilience showed lower prevalence of CMD. Further prospective studies could contribute to understanding the role of resilience among this population.

Stress-related salivary proteins affect the production of volatile sulfur compounds by oral bacteria.

OBJECTIVE: To determine whether stress-related substances and sex hormones influence the growth and in vitro production of volatile sulfur compounds (VSCs) by Solobacterium moorei and Fusobacterium nucleatum. MATERIALS AND METHODS: Bacteria growth and VSCs production were evaluated in the presence of alpha-amylase, beta-defensin-2, mucin, estradiol, and progesterone. Growth was evaluated by colony counting, and the production of the VSCs hydrogen sulfide (H2 S) and methyl mercaptan (CH3 SH) was measured using the Oral Chroma™ instrument. RESULTS: Mucin induced the production of H2 S by both bacteria, but had a slight inhibitory effect on CH3 SH production by F. nucleatum. It also increased the viability of F. nucleatum. Alpha-amylase increased H2 S production by S. moorei and CH3 SH production by F. nucleatum, but had no effect on H2 S production by F. nucleatum. No substance altered the viability of S. moorei. No effects of beta-defensin-2, estradiol, or progesterone were observed. CONCLUSION: The salivary stress-related proteins mucin and alpha-amylase altered VSCs production by F. nucleatum and S. moorei, favoring H2 S production. These findings are a step toward understanding the relation between stress and increased amounts of H2 S.