External cervical resorption – Treatment outcomes and determinants: A retrospective cohort study with up to 10 years of follow‐up

To assess long‐term external cervical resorption (ECR) treatment outcomes in relation to both local and treatment‐related determinants.

Information was available for 76 patients (98 teeth) who were diagnosed with ECR during the period from 2008 to 2018 at the University of British Columbia graduate endodontics clinic. The ECR patients were followed up, and a clinical and radiographic examination was conducted. Chi‐square test compared failure rates amongst different subgroups. The survival analysis was used to evaluate the overall ECR survival/failure rates in relation to several local and treatment‐related determinants.

Overall, 67 patients (89 teeth) were followed up. The mean follow‐up time was 3.9 years, and the minimum was 1 year. Twenty‐four teeth failed (19 extracted, 5 not functional), and the overall probability of failure was 50.0% 8 years after the diagnosis. Significant (p < .05) local ECR determinants were tooth location and the Heithersay classification, and treatment‐related determinants were root canal treatment (RCT) and the ECR repair combined with RCT. Treatment outcomes for Heithersay class 1 and 2 cases were better than for class 3 and 4 cases.

Higher failure rates were associated with posterior tooth location and higher Heithersay class, whilst RCT and ECR repair combined with RCT were associated with lower failure rates.