A Retrospective Comparison of Endodontically Treated Teeth to Single Implants

Objectives: Nowadays when a tooth with large decay, limited tooth structure, and/or a significant periapical lesion is eligible for root canal therapy, more and more clinicians elect to replace this tooth with a single implant. However, there is limited evidence directly supporting which treatment has better clinical outcomes. This study aims to compare the survival rate of single implant therapy to initial endodontic treatment in a university-based cohort.
Methods: Patients who received treatment in 1996-2016 were randomly selected into two groups: the single implant group (IP) and the initial endodontic treatment group (ED) (n=199, 202 respectively). Information about each of the subjects was extracted from the electronic health record system, Axium. Cumulative survival rates were calculated using the Kaplan-Meier method. Univariate analyses were performed for each covariate to identify its association with survival.
Results: The mean follow-up periods were 31.7±25.6 and 39.2±35.8 months for IP and ED respectively. One-year, three-year, and five-year cumulative survival rates were 98.4% [95% confidence interval (CI): 95.2, 99.5], 98.4% [CI: 95.2, 99.5], and 98.4% [CI: 95.2, 99.4] in IP and 98.3% [CI: 94.6, 99.4], 97.6% [CI: 93.7, 99.1] and 94.33% [CI: 86.6, 97.7] in ED. Implant length (p=0.01, hazard ratio: 0.13, CI: [0.03, 0.64]) was significantly associated with implant survival. Maintenance visit (p=0.02, hazard ratio: 1.09, CI: [1.01, 1.17]) and lesion size change (p=0.047, hazard ratio: 0.42, CI: [0.18, 0.99]) were significantly associated with endodontic survival. The IP group had 1% (2/199) implants with surgical intervention and 3% (6/199) with progressive bone loss>2mm.The ED group had 3% (6/202) teeth with retreatments and 12.5% (12/96) with enlarged lesion size.
Conclusions: Single implant had higher cumulative survival rates than single endodontically treated tooth without statistical significance. The endodontically treated tooth had higher risks of having biological complications and receiving interventions than an implant.