RESUMO
Introduction: Apical periodontitis is an inflammatory disease of the periradicular tissues caused by microbial (re)contamination of the root canal system. Due to its direct relationship to the quality of endodontic treatment, it is extremely important to carry out longitudinal and cross-sectional studies, following-up treatments carried out in universities. Aim: To evaluate the success rate of endodontic treatments performed by undergraduate students of the University of Southern Santa Catarina - UNISUL, Pedra Branca, between August 2015 and July 2017. Materials and Methods: One hundred twenty-four patients with endodontic treatment were contacted. Of these, only 27 attended for treatment follow-up, adding up to a total of 32 treatments analyzed. All teeth were clinically and radiographically evaluated, and the potential indicators related to endodontic treatment success or failure were analyzed. The frequencies of each criterion were calculated, and the data analyzed using the Chi-Square test (α = 5%). Results: 9 cases (28.13%) were considered failure, either because they were associated with symptoms or because there was a periapical alteration. In addition, 88.88% of the failure cases had temporary restorative material. Association was observed only between the number of root canals and symptoms (P = 0.049). Two of the 3 treated teeth with multiple root canals showed symptoms at the follow-up. The endodontic success rate was 71.87%. Conclusion: The success rate of the 32 endodontic treatments performed by undergraduate students from UNISUL was 71.87%.