title: The association between selected risk indicators and severity of peri-implantitis using mixed model analyses.
abstract: OBJECTIVE
  The aim of the study was to assess possible risk indicators for peri-implantitis at different levels of severity using multi-level analyses.
  
  
  METHODS
  One hundred and nine subjects attended the examination, 69 females and 40 males. Mean time of implants in function was 8.4 years (standard deviation 4.6) (subject level). The participants were examined clinically and radiographically. Information regarding general health and habits was gathered, with special emphasis on smoking, oral hygiene and susceptibility to periodontitis. The relation between possible risk indicators and the following features were assessed: • Detectable peri-implantitis: detectable radiographic bone loss (>0.4 mm) and inflammation • Overt peri-implantitis: radiographic peri-implant bone loss 2.0 mm and bleeding on probing /suppuration at pocket probing depth 4 mm.
  
  
  RESULTS
  Multi-level statistical analyses identified location in the maxilla as risk indicator for detectable peri-implantitis. Regarding overt peri-implantitis, gender (male) and history of periodontitis were identified as risk indicators.
  
  
  CONCLUSIONS
  Individuals with a history of periodontitis were prone to peri-implantitis, peri-implant bone loss ≥ 2.0 mm and overt in the present study. No association was found between smoking and peri-implant disease in the present study population.
authors.affiliation: Institute of Clinical Dentistry, University of Oslo, Oslo, Norway. oddcko@odont.uio.no
authors.forename: Odd Carsten
authors.initials: OC
authors.lastname: Koldsland
authors.forename: Anne Aamdal
authors.initials: AA
authors.lastname: Scheie
authors.forename: Anne Merete
authors.initials: AM
authors.lastname: Aass
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000145:classification*; D015921:Dental Implants; D003774:Dental Plaque Index; D004198:Disease Susceptibility; D005260:Female; D005884:Gingival Hemorrhage / Q000145:classification; D015438:Health Behavior; D006304:Health Status; D006801:Humans; D008297:Male; D008437:Maxilla / Q000473:pathology; D008875:Middle Aged; D015233:Models, Statistical; D009910:Oral Hygiene; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000145:classification; D010518:Periodontitis / Q000145:classification* / Q000000981:diagnostic imaging; D011859:Radiography; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking; D016388:Tooth Loss / Q000145:classification; D055815:Young Adult
chemical_list: D015921:Dental Implants