A retrospective cohort study on peri-implant complications in implants up to 10 years of functional loading in periodontally compromised patients

Background: Prevalence of peri-implantitis is directly proportional to the time of functional loading. The aim of this retrospective study was to assess the survival and success rates as well as the incidence of peri-implantitis among patients with a history of periodontitis and among implants. Material and Methods: We evaluated clinical records of periodontally compromised patients treated between January 1998 and July 2002, with implants enrolled in a supportive periodontal and peri-implant treatment (SPT) follow-up programme. The following assessment indexes during follow up were recorded: suppuration on probing, modified bleeding on probing (mBoP), probing depth (PD), implant mobility, bone changes and criteria of success of Albrektsson. Results: Clinical data of 475 patients with 1,991 implants were analysed for a period of 10 years of functional loading. The survival and success rates were 91.8% and 75.4%, respectively, and the cumulative incidence of peri-implantitis among patients was 24.4%. The survival rate was 96.1%, and the success rate was 83.7% among implants. The incidence of peri-implantitis exhibited a peak rate after the seventh year (2.1%). The prevalence of peri-implantitis increased from 3.2% to 9.7% between five and ten years of follow-up, and the peri-implantitis rate among implants was 12.9% after ten years of functional loading. Conclusions: Peri-implantitis begins to appear more frequently after the fifth year of functional loading, especially between the seventh and eighth years of function.