title: Marginal bone loss at implants: a retrospective, long-term follow-up of turned Brånemark System implants.
abstract: BACKGROUND
  Lately, presence of progressive bone loss around oral implants has been discussed.
  
  
  OBJECTIVE
  The aim of this study was to report in a large patient group with different prosthetic restorations marginal bone level and its change as measured in radiographs obtained from prosthesis insertion up to a maximum 20 years in service. Further, it also aimed to study the impact of gender, age, jaw, prosthetic restoration, and calendar year of surgery.
  
  
  METHODS
  Out of 1,716 patients recorded for clinical examination during 1999, 1,346 patients (78.4%) could be identified. A total of 640 patients (3,462 originally installed Brånemark System implants, Nobel Biocare, Göteborg, Sweden) with a follow-up of >or=5 years were included in the study, while patients with continuous overdentures and augmentation procedures were not. Distance between the fixture/abutment junction (FAJ) and the marginal bone level was recorded.
  
  
  RESULTS
  The number of implants with a mean bone level of >or=3 mm below FAJ increased from 2.8% at prosthesis insertion to 5.6% at year 1, and 10.8% after 5 years. Corresponding values after 10, 15, and 20 years were 15.2, 17.2, and 23.5%, respectively. Implant-based bone loss was as a mean 0.8 mm (SD 0.8) after 5 years, followed by only minor average changes. Mean bone loss on patient level followed a similar pattern. Disregarding follow-up time, altogether 183 implants (107 patients) showed a bone loss >or=3 mm from prosthesis insertion to last examination. Significantly larger bone loss was found the older the patient was at surgery and for lower jaw implants.
  
  
  CONCLUSIONS
  Marginal bone support at Brånemark implants was with few exceptions stable over years.
authors.affiliation: Department of Oral Radiology, Postgraduate Dental Education Center, Orebro, Sweden. solweig.sunden.pikner@orebroll.se
authors.forename: Solweig Sundén
authors.initials: SS
authors.lastname: Pikner
authors.forename: Kerstin
authors.initials: K
authors.lastname: Gröndahl
authors.forename: Torsten
authors.initials: T
authors.lastname: Jemt
authors.forename: Bertil
authors.initials: B
authors.lastname: Friberg
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000453:epidemiology*; D003442:Crowns / Q000706:statistics & numerical data; D000044:Dental Abutments / Q000706:statistics & numerical data; D015921:Dental Implants / Q000706:statistics & numerical data*; D017267:Dental Prosthesis Design / Q000706:statistics & numerical data*; D019094:Dental Prosthesis, Implant-Supported / Q000706:statistics & numerical data; D019232:Dental Restoration Failure; D003824:Denture, Complete / Q000706:statistics & numerical data; D003829:Denture, Partial / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D056948:Orthognathic Surgical Procedures; D012189:Retrospective Studies; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology
chemical_list: D015921:Dental Implants