Influence of Material Type, Thickness, and Cement Type on Optical Properties of CAD/CAM Laminate Restorations

Aim: The long-term success of laminate restorations depends not only on their mechanical strength but also on the stability of their optical properties. This study aimed to evaluate the effects of CAD/CAM material type, thickness, and cement type on color change (ΔE00) and translucency parameter differences (ΔTP) of laminate restorations after UV aging.Materials and Methods: A total of 200 specimens were prepared from five different CAD/CAM materials (CEREC feldspathic block, Cerasmart block, Vita Enamic block, Lava Ultimate block, and Grandio CAD/CAM block) and two thicknesses (0.7 mm and 1.2 mm). Specimens were divided according to cement type (dual-cure and light-cure). Color measurements (L*, a*, b*) were performed before and after UV aging, and color and translucency differences (ΔE00 and ΔTP) were calculated using the CIEDE2000 formula. UV aging was applied as an artificial aging procedure and was not included as an independent variable in the statistical analysis. Data were analyzed using three-way ANOVA according to material type, thickness, and cement type (p < 0.05).Results: Material type significantly influenced color changes (ΔE00) and the translucency parameter differences (ΔTP). Among the tested groups, the CEREC block (1.1 ± 0.3) demonstrated the least color change. In contrast, the Lava Ultimate block (12.7 ± 0.5) exhibited the most significant color change (p < 0.05). The lowest ΔTP differences were observed for Lava Ultimate block (-0.2 ± 0.2), Vita Enamic (-0.3 ± 0.4), and Cerasmart (-0.1 ± 0.4) (p < 0.05).Conclusion: All groups exhibited color changes that exceeded both the perceptibility and clinical acceptability thresholds. Changes observed after UV aging indicated a decrease in translucency. Among the evaluated factors, material type was identified as the most critical factor affecting ΔE00 values, while specimen thickness was the main determinant of ΔTP.