Influence of the thickness of enamel layer on overall color of composite restoration using different polychromatic composite resins

Abstract

The purpose of this study was to calculate and study the color components (Chroma and Value) and translucency of resin composites at different thicknesses. Method: resin composites shade A1 were used in this study; Filtek Z350 XT 3M (FT), Harmonize Kerr (HK), and Empress Direct Ivoclar Vivadent (ED). All samples were fabricated with same dentin thickness of 2mm, while the enamel samples were prepared in two thickness; 0.5mm and 1mm. Transparency parameter evaluation was done by measuring the CIELAB parameters of each sample once against white background and once against black. ∆E was used to evaluate the change in color of composite resin at different thicknesses. One-way ANOVA and Tukey HSD test were used to analyze the descriptive statistics. Pearson correlation coefficient was used to conclude a relation between thickness and chroma; and thickness and value. Results: There was a significant difference in translucency in all composite groups at enamel thickness 0.5 and 1mm. ∆E showed significant difference when comparing group FT with ED and HK, but no significant difference when comparing groups ED and HK. As for chroma, groups ED and FT showed a decrease in chroma as thickness increased and the results were significant at (p<0.05), while groups HK showed increase in chroma but the results were insignificant. Conclusion: As thickness increases the translucency and chroma of the composite resin decreases.