Bibliogr. s. e400-e401

Purpose: The purpose of this study was a retrospective cross-sectional study of the Polish subpopulation, performed to evaluate the quality of endodontic treatment (ET) and the condition of the periapical tissues of permanent teeth based on cone-beam computed tomography (CBCT) images. Material and methods: The retrospective study included a group of patients who underwent CBCT at the University Dental Clinic of the Pomeranian Medical University in Szczecin. An endodontically treated tooth index (ETTI) was used to evaluate ET. Once apical periodontitis was recognised, the size, extent, and ratio of adjacent anatomical structures were assessed using the complex periapical index (COPI). Results: Analysis of the CBCT images showed that ET was performed in 9.9% of the teeth examined, of which 52.7% of the canals were treated correctly, while 28.1% of the root canals were found to be underfilled, 6.8% were overfilled, 9.3% of the root canals were not obturated at all, and in 3.1% of the teeth examined, the filling material was only visible in the pulp chamber. Apical periodontitis was observed in 6% of all teeth examined, while the percentage of teeth following ET was 38.5%. Conclusions: The quality of the ET provided to the Polish subpopulation is unsatisfactory. Lack of root canal filling homogeneity is a significant risk factor for ET failure. Improper ET and poor quality of crown restoration after ET have an impact on the increased risk of occurrence, size, degree of root coverage, and extent of inflammatory periapical lesions in relation to adjacent anatomical structures.