Purpose: To assess the prevalence of apical periodontitis (AP), as determined by orthopantomograms (OPGs), and its correlation with the quality of root fillings and coronal restorations.

Materials and Methods: This cross-sectional study evaluated a random sample of 193 patients–112 (58%) females and 81 (42%) males–who presented as new patients at the Division of Endodontics. Digital OPGs were independently examined by two reliability-calibrated endodontists. The total number of teeth present, the location of the root canalfilled teeth, and the presence or absence of AP were recorded for each radiograph. The results were statistically analysed using the chi-square test followed by model building using multiple logistic regression.

Results: A total of 324 endodontically treated teeth from the 193 selected radiographs were analysed. The mean number of teeth per patient was 25.5�4.6, with an average of 1.64 root canal treatments per subject. Radiographically detected AP was associated with 190 (58.6%) root canal-treated teeth. The logistic model shows that the quality of endodontic treatment (adjusted odds ratio [ORa]= 1.82; 95% confidence interval [CI]: 1.40–3.17), status of coronal restoration (ORa= 1.77; 95% CI: 1.20–2.61) and the type of material used for coronal restorations (ORa= 1.39; 95% CI: 1.03–1.87) were significantly related to the periapical health of the teeth.

Conclusions: The quality of endodontic treatment, status of coronal restoration and the type of coronal restorative material were found to be the most important factors influencing the health of periradicular tissue.