Association of Passive Smoking with Dental Caries and Cotinine Biomarker among 8 to 12-Year-Old Children

Background: The present study was designed to determine the association of passive smoking with dental caries and cotinine biomarkers among 8-to 12-year-old children in Semnan, Iran. Methods: This cross sectional study was conducted on two groups of 8-12-year-old children exposed (n=100) and non-exposed to passive smoking (n=100) in Semnan (Iran). The sampling method was two-stage cluster sampling design. The data collection tool was a standard checklist consisted of demographic, laboratory and dental characteristics. The examinations were performed by a dentist on a dental unit and the dental indicators were measured for two groups. Also, salivary cotinine was measured and recorded using ELISA method by special cotinine kit (De salimetrics medi etc, USA). Univariate and Multivariable Logistic Regression models; and area under the ROC curve were used for data analysis by STATA 14 software. Results: Univariate logistic regression model showed a statistically significant difference between the groups, exposed and unexposed to passive smoking, in terms of the salivary cotinine level, age, sex , decayed, missing, and filled teeth (dmft) index, decayed, and filled teeth (dft) index and missing teeth (mt) (P-Value <= 0.20). However, multiple logistic regression model showed that the decayed, missing, and filled teeth (dmft) index were significantly correlated with passive smoking (OR=1.28; 95% CI: 1.05 - 1.38). Conclusion: This study revealed that the decay risk of the deciduous teeth is higher in children exposed to passive smoking; therefore, passive smoking should be considered in the implementation of programs to prevent tooth decay in children.