Porcelain application and simulation of firing cycle: effect on marginal misfit of implantsupported frameworks

Abstract

Aim: Success of implant-supported prostheses is related to the frameworks’ passive fit, hence inaccuracies can generate stress, leading to bone resorption and rehabilitation failure. This study evaluated misfit levels of implant-supported frameworks after different coverage treatments. Methods: Twenty commercially pure titanium (CP Ti) frameworks were manufactured with 5 Branemark type multi-unit abutments. Frameworks were distributed in two groups as follows: G1 - porcelain application (n=10); G2 - porcelain firing cycle simulation (n=10). Using a traveling microscope, marginal misfit was measured before and after undertaking the techniques, following the single-screw test protocol. All data were submitted to ANOVA and Tukey’s test (p<0.05). Results: Initial marginal misfit values were not significantly different, but both groups presented significantly higher misfit values after treatment: G1: 233.99 µm (p=0.0003); G2: 119.75 µm (p<0.0001). In addition, G1 presented higher misfit than G2 (p<0.0001). Conclusions: Porcelain application promoted significantly higher increase of misfit, which indicates that such procedure should be considered on misfit analysis of implant-supported prostheses.