A retrospective cohort study of metal-cast resin- bonded fixed dental prostheses after at least 16 years

Purpose: This retrospective cohort study evaluated metal-cast silan-coated three-unit resin-bonded fixed dental prostheses (RBFDPs) after at least 16 years and identified covariates affecting the survival. Materials and methods: A total of 37 patients with 42 RBFDPs placed by one operator between 1986 and 1993 were recalled and invited for a clinical examination in conjunction with scrutiny of clinical records. Results: Thirteen RBFDPs were lost to follow-up after an average of 58.5 months (SD = 39.4) and considered unaccounted for, 10 failed prior to the research recall and had a survival of 130.2 months (SD = 68.3), and 19 were still in function with a mean survival of 236.2 months (SD = 24.7). The estimated, cumulative survival via Kaplan-Meier analysis of the total number of 43 RBFDPs resulted in 95% (SE = 4%) survival after 5 years, 88% (SE = 6%) after 10 years and 66% (SE = 9%) after 20 years. No covariates were found having a significant effect on the survival rates. Conclusions: RBFDPs have an acceptable clinical survival although lower than conventional FDPs and single implants. They should therefore be considered as a temporary provision, as a provision for geriatric or medically-compromised patients because of the simplicity of the provision, as a less expensive alternative, and for patients where the amount of bone loss impedes the use of dental implants. Keywords: Maryland bridge, prosthetic complications, prosthetic survival, resin-bonded bridge, resin-bonded fixed dental prosthesis