Effect of thickness and material shade on the color masking ability of laminate veneers

The aim of this study was to investigate the shade masking ability of laminate veneers made from 4 different CAD/CAM materials. To mimic the discolored tooth, C2 shade of Filtek Z550 composite resin was used. A stainless steel mold containing 12x14 mm slots with 4 mm thickness was used to prepare 150 substrates. Shade of the substrates was measured with VITA Easyshade spectrophotometer. Laminate veneer samples of 0.3 mm, 0.5 mm and 0.8 mm layers were cut with a low-speed diamond disc from IPS e.max CAD MT and LT (EMX_MT, EMX-LT), IPS Empress CAD (EMP), Celtra DUO LT (CD), VITA Suprinity T (VS) blocs. Substrates and laminate veneers were cemented using Variolink II light curing resin cement. During the procedure, a 1 kg weight was placed on top of the veneer. After 20 seconds the weight was removed and the excess cement was cleared away. The shade of the samples was measured again. The difference between two shades was calculated using the ΔE formula. The statistical analyses were performed by Pearson Correlation Analysis, One-way ANOVA, Tukey HDS and Tamhane's T2 test (p<0.05). According to the results, thickness and shade masking ability of all materials except VS were in positive correlation. Lowest ΔE values in every thickness was shown by VS. EMX-MT shows the highest ΔE value in 0.3 mm and CD in 0.5 mm and 0.8 mm. In all materials, ΔL is increased with thickness. This study targets to be a guide for clinicians about masking dark-colored teeth with laminate veneers. Anahtar Kelimeler: renkleşmiş dişler, lamina vener, porselen, estetik dişhekimliği, CADCAM