Comparative survival analysis of endodontic Re-treatment versus implant Re-implantation: A 7-year retrospective cohort study

Objective: The primary objective of this study was to conduct a robust, comparative survival analysis of endodontic re-treatment versus implant re-implantation in a real-world patient cohort. A secondary objective was to identify patient-specific demographic and systemic health factors that act as independent predictors of treatment failure for these secondary procedures. Methods: This retrospective cohort study utilized a de-identified database of patient records from a university dental clinic spanning 2010 to 2016. A final sample of 1850 procedures was identified and assigned to an Endodontic Re-treatment Cohort (n = 1250) or an Implant Re-implantation Cohort (n = 600). Cohort assignment was based on standardized sequences of American Dental Association (ADA) Current Dental Terminology (CDT) codes. Survival distributions were compared using the Kaplan-Meier method with the log-rank test. A multivariable Cox proportional hazards regression model was constructed to assess the independent effect of the treatment modality on failure risk while adjusting for all collected covariates. A two-sided p-value < 0.05 was the threshold for statistical significance. Results: Baseline characteristics differed significantly between the cohorts. Patients in the Implant Re-implantation Cohort were older (mean age 65.1 vs 58.9 years, p < 0.001) and had a higher prevalence of tobacco use (36.2% vs 25.0%, p < 0.001) and diabetes (29.5% vs 16.1%, p < 0.001). In the multivariable Cox regression model, after adjusting for all confounding variables, the treatment modality was no longer a statistically significant predictor of failure (Adjusted Hazard Ratio [aHR] for implant re-implantation = 1.25; 95% Confidence Interval [CI]: 0.98–1.60; p = 0.08). The model identified several independent predictors of failure, including diabetes (aHR = 2.50; 95% CI: 1.95–3.21; p < 0.001), tobacco use (aHR = 1.85; 95% CI: 1.42–2.41; p < 0.001), age per decade (aHR = 1.18; 95% CI: 1.05–1.33; p = 0.006), and treatment in the maxillary arch (aHR = 1.45; 95% CI: 1.12–1.88; p = 0.005). Conclusions: After adjusting for significant differences in patient baseline health, this study found no statistically significant difference in the long-term survival rates between endodontic re-treatment and implant re-implantation. The most significant determinants of treatment failure were patient-related factors, particularly diabetes and tobacco use, rather than the choice of the re-treatment procedure itself. Clinical significance: The results of this study indicate that the long-term survival of secondary interventions—whether endodontic re-treatment for a failing tooth or re-implantation for a failed implant—is heavily influenced by patient-specific risk factors. Clinicians should prioritize a comprehensive risk assessment, focusing on systemic health and behavioral factors, to determine the prognosis of either salvage attempt.