Color Adjustment Potential of Simplified-Shade Resin Composites to Different Shades of Surrounding Cavity

Objectives: This study investigates the color adjustment potential (CAP) of three simplified-shade resin composites placed in three different shades of a surrounding composite.
Methods: Fifteen Dual-shade resin composite specimens (n=5) were prepared using an outer control shade (Filtek Z350XT in shades XWB, A2B, and A4B). The inner tested shade was filled with Clearfil APX ES2 (CF), Omnichroma (OM), and Charisma Topaz One (TO). Thirty Single-shade specimens (n=5) were also created for all control and tested resin composites. Color evaluation was performed using a reflectance spectrophotometer, measuring a 1-mm circular area at the center of each specimen. Data were analyzed statistically with a significance level set at p < 0.05.
Results: The CAP of all tested groups exhibited positive values. For the XW surrounding shade, CF showed the lowest CAP (0.13 ± 0.06), while OM (0.49 ± 0.04) and TO (0.36 ± 0.05) displayed significantly higher CAP values. In the A2 surrounding shade, CF had a CAP of 0.32 ± 0.19, which was significantly lower than OM (0.80 ± 0.03) and TO (0.87 ± 0.05). Similarly, for the A4 surrounding shade, CF demonstrated the lowest CAP (0.25 ± 0.04), while OM (0.74 ± 0.02) and TO (0.79 ± 0.04) exhibited significantly higher CAP values. OM and TO consistently blended better with A2 and A4 surrounding shades than with XW. Across all surrounding shades, OM and TO demonstrated similar CAP values, both of which were higher than those of CF.
Conclusions: The color adjustment potential of simplified-shade resin composites is influenced by the type of resin composite and the color of the surrounding cavity.