The Association between Environmental Tobacco Smoke and Permanent Dental Caries in Nonsmoking Korean Adults: Korean National Health and Nutrition Examination Survey 2008–2011

Background: Active smoking is closely associated with the prevalence of periodontal diseases and with incidences of fewer remaining teeth. Although environmental tobacco smoke (ETS) can deteriorate oral health, very few studies have investigated the effects of ETS on dental decay. This study aimed to examine whether exposure to ETS was associated with occurrence of permanent teeth caries among nonsmoking Korean adults. Methods: We used the cross-sectional data from the Korean National Health and Nutrition Examination Survey (2008–2011) of 2,984 nonsmoking adults aged 19–49 years, who had undergone dental examinations as well as urine cotinine level measurement. Self-reported information on smoking habits and exposure to ETS was obtained using a standardized questionnaire. We defined exposure to ETS as urine cotinine levels of 10–50 ng/mL. The odds ratio (OR) of exposure to ETS was calculated using multivariate logistic regression analysis. Results: Most of the participants (91.3%) had had permanent caries in at least 1 tooth, and 84.5% had cotinine levels consistent with ETS. Elevated urinary cotinine level was significantly associated with permanent teeth decay (OR=1.501; 95% confidence interval [CI], 1.044–2.157) after adjusting for sex, daily frequency of tooth brushing, and perceived oral health status. This relationship persisted even after further adjusting for age, education, and household income level (OR=1.544; 95% CI, 1.068–2.231). Conclusion: Exposure to ETS increases the risk of permanent teeth caries among nonsmoking adults. Reduction of ETS exposure is important for prevention of many medical problems, as well as for promotion of oral health.