Implant survival after surgical treatment of early apical peri-implantitis: An ambispective cohort study covering a 20-year period

Purpose: To describe implant survival at least 1 year after the surgical treatment of early apical peri-implantitis (EAP) and explore potential risk factors of failure of such treatment. Materials and methods: An ambispective cohort study was conducted, involving all patients in whom EAP was detected and surgically treated between 1996 and 2016. Reporting followed the STROBE guidelines. The time from implant placement (IP) to EAP surgery (EAPS), the diagnostic stage and intraoperative variables (location, apical lesion in the tooth being replaced, mesial and distal tooth-implant distance measured at the apex, periapical surgery of the adjacent tooth, guided bone regeneration, implant resection, explantation) were recorded to determine their impact upon treatment outcome. Results: The initial sample consisted of 58 implants in 46 patients. The mean time from IP to EAPS was 21.7 ± 10.1 days. At the time of surgery, eight implants presented mobility and were explanted. The final sample consisted of 50 implants in 39 patients evaluated for implant survival after surgical treatment. A cumulative survival rate of 78.3% was recorded. The mean survival time of the EAP treated implants was 85.4 months (standard deviation [SD] 5.94). The diagnostic stage (P 0.001) and the existence of a previous periapical lesion in the tooth being replaced (P = 0.022) had a significant influence upon implant survival. Conclusions: The cumulative survival rate was 78.3%, with a mean survival time of 85.4 months. The diagnostic stage of EAP and the presence of a lesion in the tooth being replaced significantly influenced the survival of implants with EAP subjected to surgical treatment. Palabras clave: early peri-implantitis, follow-up, implant failure, implant periapical lesion, retrograde peri-implantitis, treatment survival Conflict-of-interest statement: The authors declare no conflicts of interest related to this study. *First and second authors claim equal authorship.