Full-arch prostheses from translucent zirconia: Accuracy of fit

AbstractObjectives m of this study was to evaluate the marginal and internal fit of single crowns, compared to 14-unit frameworks made of translucent yttria-stabilized zirconia. We hypothesized that there is an influence of the type of restoration on the marginal and internal fit. s teeth (FDI locations 17, 15, 13, 11, 21, 23, 25 and 27) of a typodont maxillary model were provided with a chamfer preparation to accommodate a 14-unit prosthesis or four single crowns (SCs). Ten 14-unit fixed dental prostheses (FDPs) and 40 single crowns were fabricated using a computer aided design (CAD)/computer aided manufacturing (CAM) system with pre-sintered translucent yttria-stabilized zirconia blanks. The restorations were cemented onto twenty master dies, which were sectioned into four pieces each. Then, the marginal and internal fits were examined using a binocular microscope. In order to detect the differences between the two types of restorations a non-parameteric test (Mann–Whitney-U) was carried out; to detect differences between the abutment teeth and the abutment surfaces non-parametric tests (Kruskal–Wallis) and pairwise post hoc analyses (Mann–Whitney-U) were performed after testing data for normal distribution (method according to Shapiro–Wilk). Level of significance was set at 5%. s an (SD) marginal opening gap dimensions were 18 μm (14) for the single crowns and 29 μm (27) for the 14-unit FDPs (p < 0.001). Abutment 21 of the FDPs showed statistical differences concerning the location of the teeth in both marginal and internal fit (p < 0.001). The measured gaps (types I–IV) revealed statistical differences between all types, when comparing SCs to the FDPs (p < 0.001). icance crowns showed significantly better accuracy of fit, compared to the 14-unit FDPs. However, both restorations showed clinically acceptable marginal and internal fit.