Effect of repair material thickness on shade matching quality of composite resin

Abstract Aim: In vitro study to investigate the effect of repair material thickness of Omnichroma single shaded nanofilled composite resin on the shade matching quality of composite resin. Materials and methods: Forty discs were prepared from ENA Hri composite material with 2 mm dentin (shade D2) and 1 mm enamel (shade E2) as a base material using a custom-made Teflon mold. All the specimens were stored in artificial saliva at 37°C for 28 days. The specimens ( N = 40) were randomly divided into four equal groups ( n = 10) according to type and thickness of repair material, as follows: group I (repaired with 1 mm thickness of ENA Hri composite), group II (repaired with 0.5 mm thickness of Omnichroma), group III (repaired with 1 mm thickness of Omnichroma), and group IV (repaired with 1.5 mm thickness of Omnichroma). The color of all repaired specimens was recorded by vita easy shade V at the baseline and after 500 thermocycles. All data was collected, tabulated, and statistical analysis using statistical package for social science (SPSS, version 26). Results: The highest ΔE value was found in group I followed by groups II, III, and the lowest ΔE value was recorded in group IV. There was statistical significant differences for ΔE values between the four tested groups ( P = 0.001). Tukey’s test revealed a statistical significant difference between group I versus groups II, III, and IV at ( P < 0.001) and no statistical significant difference was recorded among groups II, III, and IV. Conclusion: The color matching of the repaired composite resin with Omnichroma was better than the repaired with the same base composite material. Different thicknesses of the currently used repair material (Omnichroma) had no significant effect on its shade matching quality.