RESUMEN
INTRODUCTION: The aims of this study were to assess the survival and clinical success of patients with teeth with external cervical resorption (ECR) who underwent surgical repair, to assess the reliability of using 2 different classification systems for ECR (Heithersay 2-dimensional classification and Patel 3-dimensional classification), and to identify if a 3-dimensional classification is a viable alternative. METHODS: A retrospective study was performed in a teaching dental hospital in England. The inclusion criteria were limited to patients who underwent surgical management of ECR between 2015 and 2018. Both periapical radiographs and cone-beam computed tomographic scans of 13 patients were assessed by 2 independent dental practitioners using the Heithersay and Patel classifications. The same radiographic assessment of those records was then repeated 3 weeks later by 1 operator. These data were tested using the Cohen kappa analysis to determine inter- and intraobserver agreement. RESULTS: A total of 14 teeth affected with ECR were identified in 13 patients (6 women and 7 men) with a mean age of 41 years. The mean follow-up was 20 months. At follow-up, survival was noted in all cases; however, clinical success describing endodontic success, comprehensive restorative integrity, and arrest of the resorptive process was only met in 11 cases. Although helpful in describing the lesions, both classification systems displayed considerable limitations in predicting treatment outcome. A measure of Cohen kappa regarding interobserver reliability found the Heithersay classification to provide a moderate level of agreement (0.69), whereas the Patel classification provided a weak level of agreement (0.40). CONCLUSIONS: ECR is a complex, aggressive, and uncommon form of external resorption. The long-term success of the treatment is predictable but strictly related to careful case selection and operative skill. In reference to ECR classifications, ambiguity still exists between their distinctive categories, leading to moderate and weak levels of interobserver agreement. Further improvement is required to enhance their use in future research.