A long-term retrospective analysis of single tooth implants and endodontic therapies in a university setting.

Background: This study aimed to compare survival of single tooth implants (SI) to teeth receiving initial endodontic treatment (IET), non-surgical (NET), and surgical endodontic retreatments (SET). The secondary aim was to determine success rate and identify factors associated with the survival and success of implant and endodontic treatments.

Methods: A retrospective cohort study using electronic health records (January 1st, 1995 to April 30th, 2017) was conducted. Every case that qualified for the study in SI (n = 321), NET (n = 211), and SET (n = 79) was included and cases in IET (n = 642) were selected at random and with a 2 to 1 case ratio to SI for data extraction efficiency. Statistical analyses were conducted to compare survival rates and estimate success rates between the four groups adjusting for confounders.

Results: The 3 year survival rates for SI, IET, NET, and SET were 99.0%, 92.1%, 90.5%, and 89.5% while the 5 year survival rates for SI, IET, NET, and SET were 99.0%, 87.6%, 84.4%, and 81.1%, respectively. Generally, the SI group had the highest survival rate and the SET group had the lowest survival rate. Short implants (≤8 mm) were significantly associated with implant failure (P < 0.01). Teeth with composite restoration had lower survival rates in IET and NET than other restorations (P < 0.01 and < 0.01).

Conclusion: Within the limitations of this study, single tooth implants and the endodontic treatments yielded predictable survival and success in the short term but the survival and success rates in endodontic treatments dropped more rapidly than single tooth implants during the longer follow-up period.