title: Prevalence of subjects with progressive bone loss at implants.
abstract: OBJECTIVE
  The aim of the present study was to assess the prevalence of subjects with progressive bone loss at implants with a function time of at least 5 years.
  
  
  METHODS
  Radiographs of 1346 patients who had attended annual follow-up visits at the Brånemark Clinic, Public Dental Services, Gothenburg, Sweden were retrieved. Six hundred and sixty-two subjects fulfilled the inclusion criteria. Thus, they all had been provided with implant-supported (Brånemark System) Nobel BioCare, Gothenburg, Sweden) fixed partial or complete dentures or single-tooth replacements with a documented function time in radiographs of at least 5 years. Implants that demonstrated progressive bone loss to a level of > or =3 threads of an implant were detected. The number of subjects who exhibited one or more implants with progressive bone loss to the threshold level was recorded.
  
  
  RESULTS
  Twenty-eight percent of 662 included subjects had one or more implants with progressive bone loss. A logistic regression analysis revealed that the individuals in this group carried a significantly larger number of implants than the subjects in whom no implants with progressive loss were detected (6 vs. 4.8). Furthermore, >30% of the subjects in the group with progressive bone loss had > or =3 identified implants and that about 33% of all such implants in this group exhibited extensive bone loss. Out of the total 3413 implants included in the study, 423 implants (12.4%) demonstrated progressive bone loss.
  
  
  CONCLUSIONS
  It is suggested that the prevalence of progressive bone loss at implants assessed from subject-based data is higher than that evaluated from implant-based data.
authors.affiliation: Department of Periodontology, The Sahlgrenska Academy at Göteborg University, Gothenburg, Sweden.
authors.forename: Christer
authors.initials: C
authors.lastname: Fransson
authors.forename: Ulf
authors.initials: U
authors.lastname: Lekholm
authors.forename: Torsten
authors.initials: T
authors.lastname: Jemt
authors.forename: Tord
authors.initials: T
authors.lastname: Berglundh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000453:epidemiology*; D015921:Dental Implants / Q000706:statistics & numerical data*; D019250:Dental Implants, Single-Tooth / Q000706:statistics & numerical data; D003824:Denture, Complete / Q000706:statistics & numerical data; D003830:Denture, Partial, Fixed / Q000706:statistics & numerical data; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D013548:Sweden / Q000453:epidemiology
chemical_list: D015921:Dental Implants