Multivariate analyses of factors influencing the longevity of fixed partial dentures, retainers, and abutments

In logistic regression models, variables were studied for possible influence on the longevity of fixed partial dentures, retainers, and abutments. The type of dental material was the most critical variable for change or removal of fixed partial dentures. Cantilever extension indicated no substantial increased risk of change or removal for the fixed partial dentures. The risk of removal for an abutment was influenced by the following variables: endodontic treatment, distal terminal position, placement in the mandible, and advanced marginal bone loss. Several variables were stronger multivariately than bivariately and this indicated that a combination of risk factors may be the most detrimental for the longevity of the restorations.