Clinical evidence for smoking as a risk factor for periodontitis

Objective: To assess the periodontal condition through the Community Periodontal Index and Loss of Attachment (WHO, 1997) and smoking status by means of a questionnaire in a representative adult rural population in southern Brazil. Periodontitis (P) was associated with smoking characteristics. Methods: Bivariate statistics analysis were used to associate smoking status with periodontal condition in a cross-sectional study comprising 165 dentate individuals, aged 35 to 66 years-old, submitted to oral clinical examination of six sites per tooth per sextants. Results: The prevalence of P (Probing depth≥4mm) in this population was 35.2% (58/165). Overall, 13.9% (23/165) had loss of attachment higher than 4mm. Among current-smokers (59/165), the mean years of exposure to smoking was 17, and 49% (29/59) consumed 10 or more cigarettes per day. Statistical analysis showed current-smokers had 11 times (95% confidence interval-CI=4.69-26.62) and former-smokers 9 times (CI=3.29-25.96) greater probabilities to have established P compared to never-smokers. The number of cigarettes (p=0.0005) and years of exposure (p=0013) were associated to an increased prevalence of P among current-smokers. Years of exposure to tobacco was a statistically significant risk factor for periodontal disease, with an increased odds ratio of 12.11 (CI=2.30-63.69) for P in patients smoking cigarettes for 10 years or more. Other socio-demographic variables, as gender and age, were not associated with P. Conclusion: The prevalence of P in this population was considered high. Cigarette smoking was strongly associated with P, and there was a relationship with duration and dose of smoking. These findings contributed to the evidence of smoking as an undoubtedly risk factor for periodontal diseases and support the importance of dose-response analysis on determining the strength of this association.