The effect of defined stresses on cantilevered prostheses attached to osseointegrated implants was assessed by finite element analysis. The effect of stress on a cantilever, consisting of a ductile alloy in contact with a brittle polymer, was demonstrated to be complex. The distribution of applied stresses also influenced the results. Possible fracture and distortion of both materials were demonstrated. Finite element analysis is a particularly useful system for predicting stress behavior and can be employed to produce an optimal prosthetic design that reduces the potential for clinical failure.