Color matching ability of single-shade resin-based composites: an in vitro study

Single-shade resin-based composites (RBCs) are marketed as matching a wide range of tooth shades, although supporting evidence remains limited. This in vitro study evaluated the color-matching ability of Omnichroma (OMN), Vittra APS Unique (VTR), and Charisma Diamond One (DIA) against four shade backgrounds. Molds were fabricated from a conventional composite in A1, B1, JE, and BW shades, and standardized cavities were restored with each RBC (n = 15; 180 specimens). Color was measured using a clinical spectrophotometer. Two CIEDE2000 (ΔE₀₀) outcomes were calculated: polymerization-induced color change and the difference between the background mold and restored specimen. Data were analyzed using two-way ANOVA, followed by Welch's ANOVA and Games–Howell tests. Polymerization-induced ΔE₀₀ ranged from 3.31 to 10.18, differed among materials in three of the four shade backgrounds ( p < 0.001), and exceeded the perceptibility (0.8) and acceptability (1.8) thresholds in all groups. Only VTR against JE produced clinically acceptable matching (1.29 ± 0.24), although the difference remained perceptible. All other combinations exceeded the acceptability threshold. Color matching was material- and background-dependent and poorest against the most chromatic backgrounds, indicating that universal color matching should not be assumed under the tested conditions.