Association Between Dental Caries Prevalence and Stress Levels in Japanese Children

Introduction Early life stress (ELS) caused by abuse and bullying has increased dramatically, however, effective means for accurate detection have not been found. Some decades ago, an association between stress and dental caries was suggested. However, even now, stress is not recognized widely as a potential risk factor for caries. Therefore, the purpose of this study was to verify the possible effects of stress by comparing them to the effects of saliva factors and the microorganisms that pose a general caries risk. Methods We conducted cross-sectional observation research on 30 children with mental problems, diagnosed as ‘stressed,’ and 30 age-matched unstressed children in the same elementary school. An oral examination (dental caries diagnosis) and an oral environment survey (saliva test) were carried out in 2007. Further, the concentration and activity of salivary stress proteins were measured. All variables were statistically analyzed using the Mann-Whitney U test, correlation, and multivariate analysis. Results The dental caries experience ratio was significantly higher in the stress group, and only the concentration of CgA, a salivary stress protein, showed a significant difference. Unexpectedly, we did not detect any differences in the rates and counts of cariogenic bacteria or salivary buffering activity. Binomial logistic regression analysis only showed significance in the presence or absence of ELS. Conclusion Stress factors may have a stronger influence on caries development in the stress group than in the general caries risk. Therefore, long-term stress, causing changes in the children's bodies, might hint at important factors leading to the development of dental caries.