Assessing shade matching capability of Omnichroma, a single shade composite in posterior restorations: an in vitro study.

Recent composites are being developed to simplify shade matching in composite restorations. Only a limited amount of research has been conducted to determine the optical performance of this newly introduced composite in this area. This study investigated the Omnichroma (OMN) color matching (a single shade composite within type-I restorations) via simulated clinical cavities. A total of 72 frames were created by occupying the mold with Estelite Sigma Quick (ES) of A1, A2, and A3 shades (n = 24). Each shade of composite frame was divided into three subgroups (n = 8) according to cavity dimension (width = 2, 3, and 4 mm/depth = 2 mm). Cavities were filled with Omnichroma. Color parameters were calculated based on CIEDE2000 (DeltaE00) using a non-contact spectrophotometer. Finally, the data were analyzed using a two-way ANOVA (the Tukey HSD test) (P = 0.05). The surrounding frame color significantly affected the color-matching capacity of OMN (P < 0.0001). Groups A1 and A3 showed the lowest and highest amounts of DeltaE00, respectively. The cavity width also influenced the color-matching ability of OMN (P < 0.0001) significantly. According to the results, 4 mm cavity width showed the lowest amount of DeltaE00, and 2 mm showed the highest amount. Monochromatic composites (OMN) did not match colors well in Class I cavities in posterior teeth. In cases of teeth with less chromatic surroundings, OMN matched shades better. OMN could better match shades in posterior teeth with wider cavities.