Thickness effect on optical behavior of monolithic zirconia

Achieving optimal esthetics in all-ceramic restorations remains a challenge due to variations in translucency and color influenced by material thickness. Therefore, this study aimed to evaluate the effect of thickness on the optical properties of monolithic zirconia compared to veneered zirconia. Fifty zirconia discs were fabricated in varying thicknesses (0.5, 1.0, 1.5, and 2.0 mm) and analyzed for color and translucency using a spectrophotometer. Veneered zirconia exhibited the highest lightness, while 0.5 mm monolithic zirconia appeared darkest with clinically unacceptable ΔE values. The 1.0 mm monolithic zirconia showed the closest match to veneered zirconia with acceptable color differences. Overall, increasing thickness reduced translucency, and a 1.0 mm thickness offered the most esthetically favorable balance for clinical applications.