Influence of Technical Quality and Coronal Restoration on Periapical Health of Root Canal Treatment Performed by Malaysian Undergraduate Students

Introduction: Root canal treatment (RCT) and its coronal restoration should be regularly assessed to ensure a successful treatment outcome. The aim of the current study is to evaluate the relationship between the obturation technical quality and coronal restoration in the clinical and radiographic outcome of RCT provided by Malaysian undergraduate students. Materials and Methods: A total of 143 root-treated teeth from 136 patients were evaluated through clinical examinations and periapical radiographs with a mean follow-up period of 2.4 (standard deviation = 1.59) years. The quality of the coronal restoration was classified according to modified United States Public Health Service criteria and the technical quality of the obturation was assessed based on two variables: length and density. Periapical status was evaluated according to periapical index scores. Results: About 64% of the teeth were classified as healthy with a significant reduction of apical periodontitis from 70.3% preoperatively to 36% at reassessment (P < 0.001). About 92.1% of obturation was of acceptable length, whereas 5% underfilled and 2.9% overfilled. Teeth with acceptable obturation length were five times less likely associated with apical periodontitis than the inadequately filled ones. 90% of canals had adequate obturation density with no significant association to apical periodontitis. Teeth restored with intracoronal restorations had 50% more chance of developing apical periodontitis. Inadequately restored teeth and teeth with poor obturation quality were associated with three times more likely apical periodontitis occurrence. The quality of endodontic treatment and the coronal restoration significantly influenced the periapical status (P < 0.001). Conclusion: The radiographic obturation quality and coronal restorations of the RCTs performed by the undergraduate students in a Malaysian public dental school were acceptable in 63.8% of cases with a 64% favorable outcome.