Evaluation of color matching of single-shade resin composites with different background shades: an in vitro study

Contemporary single-shade resin composites claim to match all 16 VITA Classical shades using a single universal shade, simplifying clinical procedures and reducing technique sensitivity. This study aims to comparatively evaluate the color-matching potential of various single-shade resin composites against different background shades simulated using conventional resin composites. Four single-shade resin composites-Omnichroma, Zenchroma, Clearfil Majesty ES-2 Universal, and Vittra APS Unique-were evaluated against three conventional background shades (A1, A2, A3; G-aenial, GC). Color measurements were conducted using a spectrophotometer, and color differences (ΔE₀₀) were calculated according to the CIEDE2000 formula. Visual assessments were performed by independent observers, and CAP-I and CAP-V values were determined accordingly. Statistical analysis was carried out using a two-way and three-way analysis of variance (ANOVA) at a significance level of α = 0.05. Material type and background shade had a significant effect on both CAP-I and CAP-V values (p < 0.05). ΔE₀₀ values tended to increase from A1 to A3 in all composites. Zenchroma exhibited the lowest CAP-V at A1, while Omnichroma showed the highest at A3. The color-matching potential of the tested materials depends on both the type of composite and the background shade. Among the materials studied, Vittra APS Unique demonstrated the highest color-matching potential and the most noticeable shade adaptation. These findings may guide material selection in clinical practice. The color-matching performance of single-shade composites depends on the material and background shade, directly influencing material selection in esthetic restorations.