Evaluation of shade correspondence between current monolithic CAD/CAM blocks and target shade tab by considering the influence of cement shade and restorative material thickness.

It was aimed to evaluate shade matching between novel CAD/CAM blocks and the A2 target shade tab by considering the influence of cement shade and restorative material thickness on the chromatic background. A total number of 120 rectangular-shaped specimens were subtracted from four different prefabricated CAD/CAM blocks [Vita Enamic (VE), Lava Ultimate (LU), GC Cerasmart (GC), and Vita Mark II (VMII)]. These specimens had thicknesses of 0.5 mm and 1.0 mm. Three different shades (A2, opaque, and translucent) of dual-polymerized resin cement were chosen. The dentin shade (A3.5) restorative composite foundation was incrementally fabricated in a silicon mold. For control group, the A2 shade tab of the Vitapan classical shade guide was used. Different restorative material-cement-foundation assemblies were generated with optic gel. Color readings were performed by using a clinical spectrophotometer, and CIEDE2000 (ΔE00) formula was used to assess color differences. Data were statistically analyzed (α = 0.05). With increasing thickness, color difference values decreased. Higher mean ΔE00 units were observed in all restorative material sub-groups for 0.5 mm thickness. In TR shade, no statistically significant difference was detected among the mean ΔE00 values of 0.5 mm-thick restorative materials. Color differences in groups 1.0 mm-opaque-LU and 1.0 mm-opaque-GC indicated perceptible but clinically acceptable values (0.8˂ΔE00 ≤ 1.8). The highest and lowest ΔE00 units were observed in the 0.5 mm-A2-VE group (ΔE00 = 7.07) and 1 mm-opaque-GC group (ΔE00 = 1.46), respectively. Luting cement shade, restorative material type, and thickness significantly influenced the resultant color of restoration. Opaque cement on dentin foundation exhibited lower color differences.