Effect of shade and opacity on color differences and translucency of resin composite veneers over lighter and darker substrates.

To evaluate color differences (ΔE₀₀) and translucency parameters (TP) from mono, bi, and trilayer resin composite veneers using different opacities and shades of resin composite over lighter and darker simulated tooth-colored substrates. Mono, bi, and trilayer veneers (1.5 mm) (n = 12) were made using two shades (A1 and A2) and three opacities (enamel, body, and dentin) of resin composite over simulated lighter (A1) and darker (C4, and C4+) tooth-colored substrates. CIEDE2000 formula was used to calculate ΔE₀₀ considering simulated tooth-colored substrate versus opacities in distinct mono, bi, and trilayer combinations of resin composite over the simulated tooth-colored substrate. The TP was calculated using color coordinates measured over standard white and black backgrounds. Differences in ΔE₀₀ and TP values were calculated with a Three-way Analysis of Variance followed by Tukey's post-hoc test. A1E and A1B monolayer veneers showed similar TP values. Significantly higher ΔE₀₀ values were observed over darker (C4 and C4+), and lower over lighter (A1) simulated tooth-colored substrate. Bilayer and trilayer veneers using dentin opacity provided similar ΔE₀₀ values over the darker tooth-colored substrate. Distinct shades and opacities of resin composite layer combinations over lighter and darker tooth-colored substrates significantly affected TP and ΔE₀₀ values. A1 shade and dentin opacity of monolayer resin composite veneers yielded higher ΔE₀₀ values over darker tooth-colored substrates. [ABSTRACT FROM AUTHOR]