Purpose: The purpose of this study is to evaluate the changes in lightness, chroma, and hue of two types of zirconia, IPS e.max ZirCAD prime and IPS e.max ZirCAD prime esthetic, and lithium disilicate, HT and LT, under the influence of different light sources, daylight, incandescent light, fluorescent light, and LED.

Materials and Methods: Four types of materials were tested: two zirconia variants (IPS e.max ZirCAD Prime and Prime Esthetic) and two lithium disilicate types (IPS e.max CAD LT and HT). Twelve crowns for each material were made using CAD-CAM technology, with a control natural tooth (extracted maxillary central incisor) for comparison. Crowns were digitally designed and milled and then sintered according to manufacturer guidelines. The crowns were polished and glazed before color matching tests were conducted under controlled lighting conditions using a polarized camera setup. The color of the test crown samples, and the natural tooth were assessed by measuring their L*, a*, b* values, which represent color attributes, using a grid to ensure consistent analysis. Photographs were taken, and the data was analyzed using ANOVA to assess differences in color between the crowns and the natural tooth under varying light conditions. Statistical significance was set at p<0.05. Results: A two-way ANOVA was conducted to evaluate the effects of ceramic type and lighting conditions (incandescent, daylight, fluorescent, LED) on color differences (ΔL*, Δa*, and Δb*) across the incisal, midfacial, and cervical regions. Significant differences in ΔL* were observed across ceramic types, with LT and HT lithium disilicate showing higher values compared to Prime Esthetic and Prime zirconia (P < 0.05). Similar results were found for Δa* and Δb*, with lithium disilicate materials showing lower Δa* and Δb* values compared to zirconia types (P < 0.05). Lighting conditions had minimal effect on all color parameters, with no significant interactions between ceramic type and light (P > 0.32). These findings suggest that ceramic type is the primary factor influencing color changes, with lighting conditions playing a minor role. Conclusions: The main findings across all areas (incisal, midfacial, cervical) indicate that ceramic type significantly affects the ΔL*, Δa*, and Δb* values, with lighting conditions generally having little to no impact. The most notable differences were observed between HT and LT lithium disilicate and prime esthetic zirconia, with prime zirconia often showing the lowest values in multiple measures.