Abstract: Objective: To analyze the effect of ceramic thickness on the color matching of ceramic veneers. Methods: Thirty-six artificial teeth (right maxillary central incisors, A2 shade, Endura, Shofu, Japan) were prepared following the veneer preparation protocol. An improved lithium-disilicate pressed glass ceramic materials (A2 shade, HT and LT Blocks, IPS e.max Press, Ivoclar Vivadent) were used to fabricate the 0.50 mm, 0.75 mm and 1.00 mm thick veneers at the body section. The ceramic veneer specimens were bonded on the corresponding artificial teeth with resin cement (TR shade, RelyX^TM Veneer, 3M, USA), respectively. The color parameters of ceramic veneer specimens were measured by a clinical spectrophotometer (Crystaleye, Olympus, Japan). The color differences (ΔE) of ceramic veneer specimens and A2 shade tab (Vita Classical Shade Guide, Vita Zahnfabrik, Germany) and C*_ab values were calculated. Results: The ΔE values ranged from 2.17 to 6.60. The ΔE values were less than 3.3 at the body and cervical section of veneer when the 0.75 mm and 1.0 mm thick ceramic veneers were fabricated by HT blocks. Two-way ANOVA showed that the ΔE values were significantly affected by the ceramic thickness and the sections of ceramic veneers (P<0.001). Conclusion: The color parameters of ceramic veneers were significantly influenced by the ceramic thickness. With the increasing of ceramic thickness, the values of HT ceramic veneer specimens increased and the chroma values decreased. Moreover, LT veneers exhibited a higher chroma and lower brightness.

Key words: Ceramic veneer , Resin cement, Resin artificial tooth, Color difference