The role of smoking as a risk indicator for apical periodontitis and endodontic status: a cross-sectional study of a portuguese adult sample

This study aimed to determine whether smoking acts as an independent predictor of apical periodontitis and endodontic treatment in a Portuguese adult population. This retrospective cross-sectional study was conducted in accordance with the PROBE (Preferred Reporting items for OBservational studies in Endodontics) guidelines. A total of 1841 first-time patient records were analyzed and met the inclusion criteria. Smoking status and systemic conditions were obtained from self-reported medical histories, and periapical status was assessed on panoramic radiographs using the Periapical Index (PAI). All assessments were conducted by calibrated observers who were blinded to clinical information. Data were analysed using IBM SPSS Statistics (Version 30.0; IBM Corp.) with descriptive, bivariate and multivariate logistic regression models, reporting odds ratios (OR) with 95% confidence intervals (CI) and significance at p < 0.05. Smoking was significantly associated with apical periodontitis (OR = 2.46; 95% CI: 1.96-3.11; p < 0.001), but not with endodontic treatment. Other factors independently associated with apical periodontitis included older age, greater caries experience, fewer remaining teeth, hypertension, and the presence of at least one root-filled tooth (OR = 3.19; 95% CI: 2.49-4.09; p < 0.001). Apical periodontitis showed the strongest association with the presence of at least one root-filled tooth (OR = 3.13; 95% CI: 2.47-3.96; p < 0.001). In conclusion, smoking may be considered a risk indicator for apical periodontitis. The increased inflammatory burden associated with periapical lesions highlights the importance of oral-health-related factors and behavioral habits in determining periapical status.