Color alteration with ceramic veneers according to the tooth type and preparation step: A clinical analysis

Statement of problem: Achieving accurate tooth color is important in esthetic dental treatments; however, clinical studies evaluating how ceramic veneer procedures affect color alterations are lacking. Purpose: The purpose of this clinical study was to assess the color alteration during treatment with ceramic veneers and to correlate these changes with the tooth treated and veneer thickness. Material and methods: Ten patients who underwent esthetic treatment were enrolled as participants. Color analysis with the VITA spectrophotometer was performed at baseline, after tooth preparation, immediately after cementation (Final 1), and after 6 to 12 months of follow-up (Final 2). Data of L∗, a∗, b∗, shade guide unit (SGU), ΔE_ab, ΔE₀₀, and variation in SGU (ΔSGU) were obtained. Thickness of the veneer was also recorded. Each participant was considered as a statistical block, and the mean results for each tooth (maxillary central incisors, lateral incisors, and canines) were presented. Data were evaluated by the mixed model for repeated measures and Tukey-Kramer post hoc test (L∗, a∗, b∗), generalized linear models (thickness, ΔE_ab, ΔE₀₀, SGU), Friedman test (ΔSGU), and the Pearson test was used to correlate veneer thickness and color change (ΔE_ab, ΔE₀₀, ΔSGU) (α=.05). Results: Among the teeth treated, no differences were found in ceramic thicknesses. The mean thickness was 1.03 mm for central incisors, 0.96 for lateral incisors, and 0.89 for canines. The b∗ values increased significantly after preparation and decreased after cementation (P<.001). For ΔE_ab, ΔE₀₀, and ΔSGU, there was no statistically significant difference between the types of tooth at each respective time of analysis (P>.05). Regardless of the tooth, a decrease in the SGU score was detected after cementation (P=.015). After tooth preparation, there was significant correlation (P<.05) between ceramic thickness and ΔSGU (r=0.36). Conclusions: Treatment with ceramic veneers resulted in color change, mainly with respect to the b∗ axis (yellow), producing objective differences in the ΔE analysis. Although ceramic thickness correlated with the VITA scale change (ΔSGU) after tooth wear or preparation, ceramic thickness did not differ among tooth types and did not correlate with changes in color parameters after cementation. (P>.05).