Implant failures before and after peri‐implantitis surgery: A retrospective study on 207 consecutively treated patients

PURPOSE: This study aimed to report implant failures before and after peri-implantitis surgery (P-IS) and to compare the pattern of implant failures with in untreated at-risk patients during the same period. MATERIALS AND METHODS: A total of 5628 untreated at-risk patients (7240 jaws) and 207 consecutively patients treated with P-IS (212 jaws) were included in two groups. Implants were placed and followed-up between 1986 and 2018. Cumulative survival rates (CSR) for patients treated with P-IS after 2003 were calculated before and after P-IS and compared with those for nontreated patients. RESULTS: The overall 15-year CSR was 91.2% (CI 95%; 90.5%-91.9%) and 68.5%, (CI 95%, 62.1%-75.5%) for untreated patients at risk and P-IS patients, respectively (P < .05). The 10-year CSR (baseline 1 year after implant surgery) was 97.2% (CI 95%, 95.2%-100%) for treated patients before P-IS which was comparable with that for untreated patients: 95.4% (CI 95%, 94.8%-97.7%). The corresponding 10-year CSR for P-IS patients after surgery was significantly lower (71.6%: CI 95%, 63.1%-81.3% (P < .05)). CONCLUSION: CSR for patients/jaws without implant failures was comparable between untreated and treated P-IS patients before, but lower for P-IS patients after P-IS (P < .05). A negative effect of P-IS on implant survival after treatment cannot be disregarded.