Optical Properties of Novel Resin Matrix Ceramic Systems at Different Thicknesses

Objectives: The purpose of this study was to investigate the effect of material and thickness on the translucency parameters (TP) and opalescence parameters (OP) for resin matrix ceramic blocks. Materials and Methods: 90 disc-shaped specimens (8 mm diameter and A2 shade, High Translucency) were fabricated from Vita Enamic, Lava Ultimate and GC Cerasmart resin-matrix ceramic blocks and prepared to thicknesses of 0.5 mm, 1 mm and 1.5 mm (n=10).  A dental spectrophotometer (VITA Easyshade Advance) was used to calculate the TP and OP. All specimens were placed on white and black backgrounds. The color measurements were repeated three times for each of the specimens and the mean values of L, a and b were calculated. Data were analyzed by a two-way analysis of variance (ANOVA) and Tukey’s test. Results: For the 0.5 mm thickness groups, GC Cerasmart had the highest and Vita Enamic had the lowest TP values. For the 1 mm thickness groups, GC Cerasmart had the highest TP, whereas Vita Enamic had the lowest TP. For the 1.5 mm thickness groups, Lava Ultimate had the highest TP, whereas Vita Enamic had the lowest TP. For the 0.5 mm thickness groups, Vita Enamic, and GC Cerasmart had the highest and lowest OP, respectively. The OP values in the 1 mm thickness group of Vita Enamic groups were higher than the GC Cerasmart and Lava Ultimate groups. The OP values in the 1.5 mm thickness group Lava Ultimate group were higher than the GC Cerasmart and Vita Enamic groups. In all groups, the OP values showed an increase in parallel with the increase in thicknesses, in contrast, the TP values showed a decrease. Conclusions: Type and thickness of the resin matrix ceramics affect the optical properties of the materials.