Effects of Luting Composites on the Resultant Colors of Ceramic Veneers to Intended Shade Tab.

PURPOSE: To investigate the color differences of ceramic veneers and the intended shade tab, and evaluate the effects of luting composites on the resultant colors of ceramic veneers.

MATERIALS AND METHODS: Pressable leucite-reinforced feldspathic ceramic discs (IPS e.max), with nominal shade A3, were fabricated with thicknesses of 1.0 mm, 0.7 mm, and 0.5 mm (n = 10/ thickness). The ceramic specimens were cemented onto a composite background (shade Dentin) using a veneer adhesive system with five colors of luting composites (RelyX). The colors of the veneer (veneer/luting/background complexes) and corresponding shade tab (A3, Vitapan) were measured using a spectrophotometer, and subsequently converted to CIE L*a*b* values. Color differences (△E) between each complex and the shade tab were calculated and analyzed with two-way ANOVA. Tukey's multiple comparisons were used to evaluate the effects of luting composites on the △E values.

RESULTS: The means of color differences between ceramic veneers and intended shade tab were 2.50 ± 0.38, 3.17 ± 0.48, and 3.84 ± 0.63 for the 1.0 mm, 0.7 mm, and 0.5 mm thicknesses, respectively. △E values were significantly affected by the veneer thickness and the luting composite color (p < 0.001). Tukey's multiple comparison results revealed no significant differences among the luting composites in the thickness of 1.0 mm and 0.7 mm.

CONCLUSIONS: The color matching of ceramic veneers to the intended shade tab was not achieved in the 0.7 mm and 0.5 mm veneer thicknesses, whichever colors of the luting composites were used.