Effect of cyclic loading and casting technique over marginal fit, stress and detorque in multi-unit implant-supported prostheses

Abstract

The aim of this study is to evaluate the influence of the obtainment method of prosthetic components and the effect of cyclic loading in the detorque of the prosthetic screws, and in the marginal misfit and stress of the prosthesis-implant system. Metal prosthetic frameworks will be manufactured simulating three-element fixed-partial prostheses supported by two implants or complete fixed prostheses supported by five implants. The frameworks will be waxed with entirely calcinable plastic cylinders or premachined metalloplastic cylinders. After waxed, the frameworks will be randomly distributed into the evaluation groups (n=10). Three groups with entirely calcinable components and three groups with overcastted components will be obtained for each framework design evaluated. Individual models will be manufactured for each framework. Framework marginal misfit and screw detorque will be evaluated in these models, before and after cyclic loading is performed (1 million cycles, 2Hz, 130N). Stress analyses will be performed using both strain gauge and finite element methods. The results obtained will be submitted to exploratory analysis, and the appropriate statistical tests will be applied. (AU)