Incidence Of Retrograde Peri-Implantitis In Sites With Previous Apical Surgeries: A Retrospective Study

Background Retrograde peri-implantitis (RPI) is a rapidly progressing periapical infection that forms around the implant apex. It is usually associated with sites adjacent to teeth with apical lesions; previous endodontic failures, retained root fragments, etc. This study aimed to study the incidence of RPI in sites with a history of apical surgeries. Methods Patients with sites treated for both apicoectomy and implant placement presenting to the University of Michigan School of Dentistry from 2001 to 2016 were screened. A total of 502 apicoectomies were performed, only 25 of these fit the predetermined eligibility criteria and were thus included in this retrospective analysis. Results Implants that were placed in sites with a previous apical surgery had a cumulative survival rate of 92%. The incidence of peri-implantitis was 8%, while the incidence of RPI was 20%. There was an increased trend for RPI in cases where the cause of extraction was persistent apical periodontitis (35.7%), but this increase didn't reach the level of statistical significance (P = 0.061). Conclusion Implants placed in sites with previous apical surgery are not at an increased risk of implant failure or RPI.