title: Dental implant suprastructures using cobalt-chromium alloy compared with gold alloy framework veneered with ceramic or acrylic resin: a retrospective cohort study up to 18 years.
abstract: BACKGROUND
  An association between the long-term success and survival of implant-supported prostheses as a function of biomaterial combinations has not been established. The use of cast cobalt-chromium for the suprastructure framework may be an alternative to the conventional approach of using type 3 gold alloys.
  
  
  METHODS
  A retrospective chart audit of all patients who had received implant-supported fixed dental prostheses (FDP) before 1996 was identified in a private practice clinic. Data were recorded for FDPs made from four combinations of alloy frameworks and veneering material, i.e. type 3 gold and cobalt-chromium with ceramic or prefabricated acrylic teeth. The extracted data from the charts were subjected to explorative statistical tests including Kaplan-Meier survival analyses.
  
  
  RESULTS
  Patients (n=198) with 270 short and extensive FDPs supported entirely by 1117 implants were identified. The average follow-up observation periods varied between 4 and 220 months, with an average of 120 months. The success and survival, as well as event rates and types of biological and technical complications, were similar for implant-supported FDPs using cobalt-chromium and type 3 gold alloy frameworks veneered with ceramics or prefabricated acrylic teeth. An influence of the suprastructure biomaterial combination on the clinical performance of the individual supporting implants could not be established.
  
  
  CONCLUSIONS
  Implant-supported FDPs made from type 3 gold or cobalt-chromium frameworks and veneered with ceramic or prefabricated acrylic teeth demonstrate comparable clinical performance. The biomaterial combinations do not appear to influence the success or survival of the individual implants.
authors.affiliation: Prosthodontics Specialty Practice, Bergen, Norway. kyrre.teigen@arkentannlege.no
authors.forename: Kyrre
authors.initials: K
authors.lastname: Teigen
authors.forename: Asbjørn
authors.initials: A
authors.lastname: Jokstad
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry; D002858:Chromium Alloys / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D003776:Dental Porcelain / Q000737:chemistry; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003801:Dental Veneers; D005260:Female; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D008297:Male; D009664:Norway; D011183:Postoperative Complications; D012189:Retrospective Studies; D014885:Waxes / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D002858:Chromium Alloys; D015921:Dental Implants; D006047:Gold Alloys; D014885:Waxes; D003776:Dental Porcelain; C058237:Biodent; D003035:Cobalt; C036530:inzoma