Shade matching and blending capabilities of a new single-shade composite: an in vivo study

Demand for direct esthetic restorations is high, but shade matching can be challenging. Some manufacturers claim that a single product is able to match all colors of the human dentition, eliminating shade matching challenges. This in vivo study, which followed the International Commission on Illumination's (CIE) CIEDE2000 color difference standard (ΔE₀₀), aimed to quantify the shade matching and blending capabilities of a single-shade composite (Omnichroma PLT) used as a direct veneer. A color difference of ΔE₀₀ ≤ 1.8 was set as the acceptability threshold. Ten participants with an unrestored and noncarious maxillary left central incisor were enrolled in the study. Direct spectrophotometric measurements (CIE L*a*b*) were made on the tooth and then on composite cured on the tooth. Consistency in measurements and composite resin placement were attained through the use of a specially designed jig. A digital photograph was then taken with the composite in place, and colorimetric software was used to obtain the L*a*b* values at the most incisal and cervical edges of the restoration. These values were compared to those of the natural tooth structure immediately adjacent to the composite resin. The ΔE₀₀ scores were calculated to determine the composite's ability to match the tooth shade beneath it (ΔE_m) and to blend with the incisal (ΔE_i) and cervical (ΔE_c) tooth shades. Mean scores for ΔE_m, ΔE_i, and ΔE_c were calculated, and an independent t test (α = 0.05) was used to compare means for ΔE_i and ΔE_c. The mean (SD) ΔE₀₀ values were 6.16 (2.38), 3.90 (2.47), and 6.84 (1.80) for ΔE_m, ΔE_i, and ΔE_c, respectively. A statistically significant difference (P = 0.008) was observed between ΔE_i and ΔE_c. As a direct veneer, the tested composite did not meet the acceptability threshold for any ΔE₀₀ measurement; however, it was better at matching the incisal third of the tooth than it was the other thirds. More in vivo studies are needed to verify and expand on these results.