Is the quality of root canal filling obtained by cone-beam computed tomography associated with periapical lesions? A systematic review and meta-analysis

Aim To evaluate the influence of root canal filling quality on periapical lesion status using cone-beam computed tomography (CBCT). Materials and Methods The bibliographic search was conducted in electronic databases of PubMed, Embase, Scopus, and Web of Science without restrictions related to the year of publication and language. Inclusion criteria were prospective or retrospective cohort studies that followed periapical pathosis for, at least, 1 year. Three reviewers independently evaluated the eligibility for inclusion, extracted data, and assessed the risk of bias. The quality of the studies was based on the Newcastle–Ottawa Scale. This meta-analysis was performed to evaluate the quality of treatment by the homogeneity and apical extension of the filling. Results Of the 1179 studies initially recovered, six cohort studies were included, out of which four were considered with a low risk of bias. The results showed that the absence of gaps in the filling reduced the chance of unhealed periapical lesions by 2.39 times (RR = 2.39; 95% CI: 1.62–3.53; p < 0.00001; I 2 = 55%). An apical filling extension of 0–2 mm below the apex also contributed significantly to the absence of unhealed periapical lesions (RR = 1.49; 95% CI: 1.15–1.94; p = 0.003; I 2 = 2%). Conclusion The homogeneity and apical extension of the filling influenced the presence of unhealed periapical lesions in endodontically treated teeth evaluated using CBCT. Clinical relevance Apical extension of the filling ranging between 0 and 2 mm short of the apical foramen and the homogeneity of the filling without gaps are directly related to the success rate of root canal treatment.