title: A 7-year prospective radiographic evaluation of marginal bone level around two different implant systems: a randomized clinical trial.
abstract: OBJECTIVE
  The aim of this study was to evaluate the change in marginal bone level radiographically around two different implant systems after 7 years of use.
  
  
  METHODS
  Twenty fully edentulous patients were included in the study and randomly assigned to two treatment groups of machined surface implants (Brånemark, n = 40) and rough-surface implants (Xive, n = 40). The implants were early loaded with individual bar-retained overdentures. All patients were treated by the same surgeon and the same prosthodontist. Clinical and radiographic examinations were conducted at the time of implant loading (baseline) and annually for up to 7 years of use. Measurements to the nearest 0.1 mm were taken at the mesial and distal site, and the average values were calculated for each implant. A three-level mixed-effect analysis of covariance (ANOVA) was used to test the significance of the mean marginal bone change in the two implant groups.
  
  
  RESULTS
  The study population consisted of 15 women (75%) and five men (25%) with an average age of 61.6 years. A total of 79 of 80 implants integrated successfully. n = 1 Brånemark implant failed after 3 weeks. There was a significant difference (P < 0.001) between the two implant systems at the baseline measurements (0.14 mm Brånemark vs. 0.39 mm Xive) and a highly significant difference for the annual bone loss (0.07 mm [Brånemark] vs. 0.18 mm [Xive], P < 0.001).
  
  
  CONCLUSIONS
  Both the implant systems are clinically satisfying. Nevertheless, the Brånemark group showed a better radiological performance than the Xive group.
authors.affiliation: Clinical Department of Restorative and Prosthetic Dentistry, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Doris
authors.initials: D
authors.lastname: Burtscher
authors.affiliation: Clinical Department of Oral and Maxillofacial Surgery, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Norer
authors.affiliation: Clinical Department of Oral and Maxillofacial Surgery, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Dalla Torre
authors.affiliation: Clinical Department of Restorative and Prosthetic Dentistry, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Beier
authors.affiliation: Clinical Department of Restorative and Prosthetic Dentistry, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Katharina
authors.initials: K
authors.lastname: Schubert
authors.affiliation: Clinical Department of Restorative and Prosthetic Dentistry, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Grunert
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging* / Q000209:etiology*; D003757:Dental Implantation / Q000295:instrumentation / Q000379:methods; D015921:Dental Implants / Q000009:adverse effects; D017267:Dental Prosthesis Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography / Q000379:methods
chemical_list: D015921:Dental Implants
keywords: Brånemark; Xive; implant; machined surface; marginal bone level; radiographic