title: Bone density at implant sites and its relationship to assessment of bone quality and treatment outcome.
abstract: OBJECTIVE
  To investigate the relationship between bone mineral density (BMD) before implant placement, implant stability measures at implant placement, and marginal bone loss of immediately loaded implants after 1 year in situ.
  
  
  METHODS
  Consecutively recruited patients received Straumann SLActive implants loaded with fixed provisional prostheses within 24 hours. BMD was measured from computed tomographic images before implant placement. Alveolar bone quality was assessed during surgery. Implant stability-both rotational and as measured with resonance frequency analysis-and marginal bone height were assessed at implant placement and after 1 year. The Pearson correlation coefficient was used to calculate correlations, and significance was considered when P < .05.
  
  
  RESULTS
  Twenty-one patients received 137 implants (87 in maxillae and 50 in mandibles). BMD was significantly correlated with bone quality classification in both arches (P < .001). Mean BMD was also significantly correlated with stability values (P < .001). Mean marginal bone loss at implant surfaces differed, but not significantly, at the 1-year follow-up, regardless of BMD values (P = .086) and measured stability (rotational stability P = .34, resonance frequency analysis P = .43) at implant placement.
  
  
  CONCLUSIONS
  Within the limits of this study, it can be concluded that computed tomographic examination can be used as a preoperative method to assess jawbone density before implant placement, since density values correlate with prevailing methods of measuring implant stability. However, in the short time perspective of 1 year, there were no differences in survival rates or changes in marginal bone level between implants placed in bone tissue of different density.
authors.affiliation: goran.bergkvist@ptj.se
authors.forename: Göran
authors.initials: G
authors.lastname: Bergkvist
authors.forename: Kwang-Joon
authors.initials: KJ
authors.lastname: Koh
authors.forename: Sten
authors.initials: S
authors.lastname: Sahlholm
authors.forename: Eva
authors.initials: E
authors.lastname: Klintström
authors.forename: Christina
authors.initials: C
authors.lastname: Lindh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging; D000539:Alveolar Process / Q000473:pathology*; D015519:Bone Density / Q000502:physiology*; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007430:Intraoperative Care; D007575:Jaw, Edentulous / Q000473:pathology / Q000601:surgery; D007576:Jaw, Edentulous, Partially / Q000473:pathology / Q000601:surgery; D008297:Male; D008334:Mandible / Q000473:pathology / Q000601:surgery; D008437:Maxilla / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology*; D011300:Preoperative Care; D012399:Rotation; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014732:Vibration
chemical_list: D015921:Dental Implants