The Influence of Varying Dentin and Enamel Layer Thicknesses of Two Nanohybrid Resin Composites, on Color Match of Composite Resins and Lithium Disilicate Dental Ceramics

Abstract

Background. The process of shade matching is one of the most challenging steps in esthetic dentistry but the information available involving color matching between various dental materials is limited. The aim of this study was to evaluate the influence of varying dentin and enamel layer thicknesses of two nanohybrid resin composites, on color match of composite resins and lithium disilicate dental ceramics. Methods. 26 total specimens of nano-composite resins, Opallis and Vittra (FGM) were produced, using two-layered technique with different thickness ratios of enamel and dentin composites (A2) and total thickness of 1.2 mm. 13 discs of same thicknesses of lithium disilicate dental ceramic, IPS e.max press LT A2 (low translucency) were also made. Color was measured with a Spectrophotometer. Differences in color (ΔE00) and translucency parameter (TP) of composite and ceramic specimens were calculated. The data were analyzed using multi-factor ANOVA test, followed by Tukey’s HSD test (p<0.05). Results. ΔE00 for various areas of composites and ceramic showed that the color difference was not clinically acceptable in any areas of neither of the composites (ΔE00>2.25). But ΔE00 between the two composites was in the clinically acceptable range (ΔE00<2.25). The mean TP value of IPS e.max press, was greater than Vittra and less than Opallis. Conclusion. In similar thicknesses, composites in no enamel/dentin thickness ratios, could not successfully simulate the color and translucency of an IPS e.max press ceramic.