Incidence of peri-implant mucositis and peri-implantitis in patients with a maxillary overdenture: A sub-analysis of two prospective studies with a 10-year follow-up period

Background: Though studies on maxillary overdentures show satisfying results on implant survival, patient-related outcomes and prosthetic complications, the epidemiology of peri-implant diseases in this specific group of patients has hardly been reported. While the general patient-level prevalence of peri-implant mucositis and peri-implantitis are estimated at ~45% and ~20%, respectively, the risk of developing these diseases within a specific period is less clear. To fully appreciate the epidemiology of peri-implant diseases, more long-term data on incidence of peri-implant diseases are needed.

Purpose: The purpose of this sub-analysis of two prospective studies was to assess the incidence of peri-implant mucositis and peri-implantitis in fully edentulous patients with implant-retained maxillary overdentures during a 10-year follow-up period.

Materials and methods: One hundred and sixteen patients treated with implant-supported maxillary overdentures were available from two clinical trials. Data on biological complications, clinical and radiographical parameters were collected for 106 patients at 5-year, for 82 patients at 10-year follow-up. The incidence was calculated following the consensus of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. Extent and severity then were calculated to enable an appropriate epidemiological description of peri-implantitis.

Results: The patient-level incidence of peri-implant mucositis was 37.7% after 5 years and 64.6% after 10 years whereas the patient-level incidence of peri-implantitis was 10.4% after 5 years and 19.5% after 10 years. After 10 years, the extent of peri-implant mucositis and peri-implantitis is 52.8% and 43.8%, respectively. In terms of severity, 26.5% of all affected implants suffered from >3 mm bone loss and 17.6% of all affected implants was lost.

Conclusion: Three of five fully edentulous patients with implant-supported maxillary overdentures experience peri-implant mucositis after 10 years. Peri-implantitis occurs in one of five patients after 10 years. In spite of these incidence rates, implant survival remains high.