Correlation between marginal misfit and strains around implants

Abstract

Stress induced to implants and bone tissue may be responsible for the tissue reabsorption and for the loss of the implant. Prostheses with minimum vertical misfit are required, believing in the creation of lower values of stress induced to implants. Therefore, there is no certainty about this correlation, once the literature does not show reliable results that can elucidate such aspect. Thus, the objective of this study was to evaluate if there is correlation between misfit and stress induced to implants after the screwing of titanium frameworks. Ten commercially pure titanium (Ti c.p.) frameworks were manufactured, by using a metallic master cast containing two implants connected to multi-unit conical abutments. For misfit evaluation, one-screw test measurement was performed with an optic microscope (120x). To evaluate stress induced to implants, strain gages connected to specific software were used. The misfit mean value was 118.07 (58.61 μm) and the stress mean value was 580.06 (253.93 gf). Pearson test was applied, showing no correlation between misfit and stress (-0.072) with p = 0.842. Vertical misfit and its level are not reliable indicators for the prognostic of the stress induced to osseointegrated implants.