Prevalence of peri-implant disease and risk indicators in a Japanese population with at least 3 years in function-A multicentre retrospective study.

OBJECTIVES: The aim of this study was to evaluate the prevalence of peri-implant disease and analyze risk indicators in Japanese subjects with ≥3 years of implant function. MATERIAL AND METHODS: Five hundred and forty-three subjects treated with 1,613 implants were evaluated. Information was collected about the patients' physical and dental history, as well as implant details. Peri-implant evaluation included probing depth, bleeding on probing (BoP), suppuration (Sup), and keratinized tissue width. Bone loss was calculated from intra-oral radiographs taken after 1 year and more than 3 years of function. Implants were classified into three groups: healthy, peri-implant mucositis (BoP without bone loss), and peri-implantitis (BoP and/or Sup with bone loss >1 mm). These data were analyzed by multivariable multinomial logistic regression. RESULTS: The prevalence of peri-implant mucositis and peri-implantitis at the subject level was 23.9% and 15.8%, respectively. An association was found between peri-implant mucositis and plaque control record (PCR) >20% and keratinized tissue width <2 mm. Peri-implantitis was associated with PCR >20%, smoking, insertion in the maxilla, and keratinized tissue width <2 mm. CONCLUSIONS: Within the limitations of this study, the prevalence of peri-implant diseases was elucidated in a Japanese population. Peri-implant mucositis was associated with poor oral hygiene and less keratinized tissue. Poor oral hygiene, smoking, insertion in the maxilla, and less keratinized tissue were risk indicators for peri-implantitis.

Longitudinal study on risk indicators for peri-implantitis using survival-time analysis.

PURPOSE: The purpose of this study was to evaluate the incidence of peri-implantitis and to identify potential associated risk indicators. METHODS: This longitudinal study included 477 patients treated with 1420 implants. Medical and dental histories were evaluated in all patients. The location, size, connection type, surgical protocol, use of prosthesis splinting and fixation type were evaluated for each implant. In peri-implant evaluation, minimum keratinized tissue width around implants, peri-implant probing depths, peri-implant bleeding and peri-implant suppuration were assessed. Bone resorption around implants was evaluated with intraoral radiographs at baseline and at follow-up examinations. The study endpoint was peri-implantitis, which was defined as the presence of bleeding on probing and/or suppuration with bone resorption >1mm, in accordance with previous studies. Data were analyzed with mixed-effects Cox models. RESULTS: Peri-implantitis occurred in 15.3% of patients and 9.2% of implants. The overall 5- and 10-year cumulative implant survival rates were 0.95 (95% confidence interval [CI]: 0.93-0.96) and 0.83 (95% CI: 0.8-0.87), respectively. Age (hazard ratio [HR]=0.94, 95% CI: 0.90-0.98, p<0.01), plaque control record >20% (HR=2.61, 95% CI: 1.02-6.67, p=0.04), maxillary placement (HR=1.90, 95% CI: 1.11-3.23, p=0.02) and number of occlusal supports (HR=0.87, 95% CI: 0.77-0.99, p=0.03) were significantly correlated with peri-implantitis development. CONCLUSIONS: Within the limitations of this longitudinal study on risk indicators for peri-implantitis, age, inadequate plaque control, insertion in the maxilla and less occlusal support of natural teeth correlated with peri-implantitis development.