Color match of high translucency monolithic zirconia restorations with different thicknesses and backgrounds

To assess the effects of ceramic thickness and background type on the color match of high translucency monolithic zirconia restorations.

Fifty A2 shade high translucency zirconia disk specimens with five different thicknesses (0.7, 0.9, 1.1, 1.4, 1.6 mm) were placed on 12 backgrounds: A1, A2, A3, A3.5, B1, and B2 shade composite resin, A3 shade zirconia, nonprecious gold-colored alloy, nickel-chromium alloy, amalgam, and A2 and A3 shade tooth. Color measurements were performed to determine the specimens' CIELab values. CIEDE2000 formula was used to determine ΔE₀₀ color differences between specimens and A2 VITA classical shade (target). The ΔE₀₀ values were compared with perceptibility (0.8) and acceptability (1.8) thresholds to assess color matches. Data were analyzed using repeated measures ANOVA, Bonferroni, and 1-sample t tests (P < .05).

Mean ΔE₀₀ values ranged between 1.3 and 5.7. Ceramic thickness, background type, and their interaction significantly affected the ΔE₀₀ (P < .001). Ceramic thicknesses of ≥1.1 mm with the A2 or A3 shade tooth background showed 0.8 < ΔE₀₀ ≤ 1.8 producing acceptable color matches.

High translucency monolithic zirconia restorations with a minimum thickness of 1.1 mm on tooth backgrounds could create acceptable color matches; however, with other backgrounds tested, they could not.

Ceramic thickness and background type affect the color of high translucency monolithic zirconia restorations. A minimum zirconia thickness of 1.1 mm and normal color tooth structures, as a background, are essential for achieving the acceptable color match of these restorations.