Smoking, a weak predictor of periodontitis in older adults

Background: The impact of smoking habits on periodontal conditions in older subjects is poorly studied. Aims: To assess if a history of smoking is associated with chronic periodontitis and medical history in older subjects. Material and Methods: The medical and dental history was collected from 1084 subjects 60-75 years of age. Smoking history information was obtained from self-reports. Periodontal variables [clinical probing depth (PD)>= 5.0 mm, clinical attachment levels (CALs) >= 4.0 mm], and radiographic evidence of alveolar bone loss were assessed. Results: 60.5% had never smoked (NS), 32.0% were former smokers (FS) (mean smoke years: 26.1 years, SD +/- 13.1), and 7.5% were current smokers (CS) (mean smoke years 38.0 years, (SD +/- 12.1). The proportional distribution of CAL >= 4.0 mm differed significantly by smoking status (NS and CS groups) (mean difference: 12.1%, 95% confidence interval (CI): 1.5-22.6, p < 0.02). The Mantel-Haenszel common odds ratio between smoking status (CS+FS) and periodontitis (> 20% bone loss) was 1.3 (p < 0.09, 95% CI: 0.9-2.0) and changed to 1.8 (p < 0.02, 95% CI: 1.3-2.7) with 30 years of smoking as cutoff. A weak correlation between number of years of smoking and CAL >= 4.0 mm was demonstrated (r(2) values 0.05 and 0.07) for FS and CS, respectively. Binary logistic forward (Wald) regression analysis demonstrated that the evidence of carotid calcification, current smoking status, gender (male), and the number of remaining teeth were explanatory to alveolar bone loss. Conclusions: A clinically significant impact on periodontal conditions may require 30 years of smoking or more. Tooth loss, radiographic evidence of carotid calcification, current smoking status, and male gender can predictably be associated with alveolar bone loss in older subjects.