Radiographic Outcome of Endodontic Treatment of Teeth with Primary Apical Periodontitis: Results from a Postgraduate Clinic

Objective The aim of the study was to analyze factors influencing the radiographic outcome of first-time endodontic treatment of teeth with periapical lesions. Methods From March 2008 to October 2022, 804 cases of primary apical periodontitis with radiographically detectable lesions were treated conservatively by post-graduate students at the Department of Endodontics. 437 patients satisfied the inclusion criteria of having recall data at least 11 months after completion. Post-operative and control radiographs of the teeth were scored by the periapical index (PAI) adjusted to define strict and lenient criteria for success. Patients’ sex and age, the tooth treated, the number of visits, and several tooth- and treatment-related factors were registered and related to radiographic outcome in bivariate and regression, with actual p levels recorded. Results Overall success rate was 68 % by strict and 83 % by lenient criteria. In binary analyses high pre-operative PAI score, older age, poorer periodontal status, tooth type (anterior teeth and premolars), and higher number of visits were negatively related to outcome. Logistic regression analysis of the whole material confirmed an adverse effect on outcome by these factors. Conclusions Outcome of treatment of primary apical periodontitis by postgraduate students was negatively affected by higher preoperative PAI score, higher patients’ age, poorer periodontal status, and higher number of visits for completion.