Is smoking a predictor of apical periodontitis?

OBJECTIVES: To evaluate the association between cigarette smoking and the frequency of apical periodontitis in female and male patients seeking treatment at the University of Basel (KREBS Project). MATERIALS AND METHODS: This cohort study included full-mouth periapical radiographs of 161 subjects, including 66 current smokers, 28 former smokers and 67 [corrected] individuals who had never smoked. The periapical region of all teeth was radiographically evaluated using the Periapical Index (PAI) score. Generalised linear mixed-effects models using the logit link were performed. RESULTS: The frequency of apical periodontitis differed based on gender and smoking status. Current male cigarette smokers with <10 or >/=10 pack years showed frequencies of apical periodontitis of 7.9 % and 7.5 %, [corrceted] respectively, compared to 4.1 % [corrected] in individuals who had never smoked. The corresponding data for female smokers were 5.8 % and 7.4 % [corrected] in smokers with <10 or >/=10 pack years, respectively, versus 5.2 % in individuals who had never smoked. The factors "prevalent coronal restoration" (p < 0.001), "prevalent root canal treatment" (p < 0.001) and "quality of root canal filling" (p < 0.001) were significant predictors for apical periodontitis. After adjustment for quality of root canal filling cigarette smoking was not associated with apical periodontitis in current female and male smokers with <10 or >/=10 pack years (p > 0.05). CONCLUSION: Smoking status did not predict apical periodontitis in females and males in this sample group. CLINICAL RELEVANCE: With respect to quality of root canal filling, tobacco use may not be a significant predictor for apical periodontitis.