Yilmaz B, et al. - The effect of porcelain layering was assessed on the marginal fit of CAD-CAM–fabricated complete-arch implant-supported, screw-retained fixed dental prostheses (FDPs) with pre-sintered zirconia frameworks with titanium in this trial. A significant effect was obtained on the marginal fit of CAD-CAM–fabricated complete-arch implant-supported, screw-retained FDPs with partially sintered zirconia frameworks due to porcelain layering. Except for the layered zirconia framework, 3D marginal discrepancy mean values for all groups were within clinically acceptable limits (<120 μm).