A novel sample design for determining color compatibility between layered resin composite and vita shade guides.

Objective: To compare the color of double-layered (DL) resin-composite (RC) samples with variant enamel-thicknesses (ET) to their corresponding shade-tabs from VITA classical (VC) and 3D-Master (V3DM).
Methods: A2-DL samples (N = 30) fabricated using three pairs of custom-made molds with an ET of 0.5, 0.7, and 1.0 mm. Shades were selected according to the manufacturer's instructions of two RC brands: Clearfil-Majesty (CM), and Vita-l-essence (VL). A spectrophotometer measured CIE L*a*b* color parameters. We used ΔE ₀₀ to calculate color differences among DL samples, VC, and V3DM shade-tabs. The data were analyzed using Spearman correlation coefficient, one-way ANOVA, and Tukey test (∝=0.05).
Results: ΔE ₀₀ between DL samples A2 and 2M2 shade tabs were all greater than the predetermined 50:50% acceptability threshold (ΔE ₀₀ = 6.6-10.4). Depending on the shade tabs compared, the ΔE ₀₀ among CM and VL ET subgroups were statistically different (P < .001). ET and L* were negatively correlated for CM and VL. For CM, ΔE ₀₀ and L* correlated on the A2 shade tab, whereas for VL, ΔE ₀₀ , and ET correlated on the 2M2 shade tab (P < .05).
Conclusions: The DL samples produced unacceptable color matches to their corresponding shade. An enamel layer thickness of 0.7 mm corresponded to the lowest ΔE ₀₀ . The use of V3DM for RC shade selection should be investigated.
Clinical Significance: Understanding color interaction between RC layers is important to achieve consistent results in esthetic clinical procedures. The thickness of the enamel layer can critically alter the overall shade for a given RC shade and brand. This variation is difficult for the clinician to predict and negatively impacts patient satisfaction, increasing overall procedure costs, and decreasing efficiency. This color interaction study aims to facilitate consistency in shade reproduction.
(© 2019 Wiley Periodicals, Inc.)