Influence of Smoking Habits on the Prevalence of Dental Caries: A Register-Based Cohort Study

Objective This study aimed to evaluate the influence of smoking habit on the prevalence of dental caries lesions in a follow-up study. Materials and Methods A total of 3,675 patients (2,186 females and 1,489 males) with an average age of 51.4 years were included. Outcome measures were the incidence of dental caries defined as incipient noncavitated, microcavitated, or cavitated lesions which had been diagnosed through clinical observation with mouth mirror and probe examination evaluating change of texture, translucency, and color; radiographic examination through bitewing radiographs; or secondary caries through placement of a new restoration during the follow-up of the study. Statistical Analysis Cumulative survival (time elapsed with absence of dental caries) was estimated through the Kaplan–Meier product limit estimator with comparison of survival curves (log-rank test). A multivariable Cox proportional hazards regression model was used to evaluate the effect of smoking on the incidence of dental caries lesions when controlled to age, gender, systemic status, frequency of dental hygiene appointments, and socioeconomic status. The significance level was set at 5%. Results Eight hundred sixty-three patients developed caries (23.5% incidence rate). The cumulative survival estimation was 81.8% and 48% survival rate for nonsmokers and smokers, respectively ( p < 0.001), with an average of 13.5 months between the healthy and diseased state diagnosis. Smokers registered a hazard ratio for dental caries lesions of 1.32 ( p = 0.001) when controlled for the other variables of interest. Conclusion Within the limitations of this study, it was concluded that smoking habit might be a predictor for dental caries.