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

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 cobaltchromium for the suprastructure framework may be an alternative to the conventional approach of using type 3 gold alloys. Materials and 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 cobaltchromium with ceramic or prefabricated acrylic teeth. The extracted data from the charts were subjected to explorative statistical tests including KaplanMeier 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 cobaltchromium 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 cobaltchromium 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. To cite this article:?Teigen K, Jokstad A. Dental implant suprastructures using cobaltchromium alloy compared with gold alloy framework veneered with ceramic or acrylic resin: a retrospective cohort study up to 18 years.?Clin. Oral Impl. Res. 23, 2012; 853860.?doi: 10.1111/j.1600-0501.2011.02211.x