Treatment Outcome in Patients With Peri-Implantitis in a Periodontal Clinic: A Retrospective Study

Background: The number of placed implants has grown during the past decade, and the prevalence of peri-implantitis has increased. The purpose of the present study is to investigate the treatment outcome of peri-implantitis and to identify factors influencing the treatment success rate. Methods: The study was conducted as a retrospective longitudinal study on a referral population. The material included 382 implants with peri-implantitis in 150 patients. Peri-implantitis was defined as presence of pocket depths >= 5 mm, bleeding at probing and/or suppuration, and the presence of implant radiographic bone loss >= 3 mm or bone loss comprising at least three threads of the implant. Variance analyses, chi(2) analyses, and logistic regression analysis were used for data analyses. Results: The mean age of the participants at baseline was found to be 64 years (range: 22 to 87 years). The mean +/- SD follow-up time was 26 +/- 20 months, and the mean time between implant installation and baseline was 6.4 years (range: 1 to 20 years). Periodontal flap surgery with osteoplasty was the most common type of therapy (47%), and regenerative surgery procedures with bone substitute materials were chosen in 20% of the cases. The mean success rate at patient level was 69%. The results of the logistic regression analyses showed that the success rate was significantly lower for individuals with the diagnosis of severe periodontitis, severe marginal bone loss around the implants, poor oral hygiene, and low compliance. Conclusion: The effectiveness of the peri-implantitis therapy was impaired by severe periodontitis, severe marginal bone loss around the implants, poor oral hygiene, and low compliance.