Color Match of Single-Shade and Group-Shade Resin Composites: A Visual and Instrumental Analysis

Clinical Snapshot

Key Findings

• P Value: p < 0.05 for single-shade vs group-shade comparisons within each subgroup

• Effect Size: Single-shade showed higher ΔE00 values than group-shade across all subgroups at T1

• Primary Outcome: ΔE00 color difference between tooth and restoration

• Nnt Or Sensitivity: Dark teeth showed highest ΔE00 with single-shade (8.24 ± 1.85) vs light teeth (5.65 ± 2.24)

• Confidence Interval: Not reported

Clinical Application

Both materials are commercially available and technique-sensitive procedures are standard in restorative dentistry Both Omnichroma and SimpliShade are available in Australia; findings relevant to TGA-approved dental materials and standard restorative protocols Patients requiring posterior composite restorations, particularly those with varying tooth shades

Abstract

OBJECTIVE: Single-shade materials are favored for simplifying clinical workflows without compromising the esthetics of restorations, although evidence supporting their use remains limited. Therefore, this laboratory evaluated color match of single-shade versus group-shade resin composites. METHODS: Sixty sound human molars were divided into three subgroups (n = 20), based on the tooth-shade correspondence for the tested group-shade resin composite: L (light) including A1, B1, B2, C1 and D2; M (medium) including A2, A3, C2, D3 and D4, and D (dark) including A3.5, A4, B3, B4, C3 and C4 shaded teeth. Standardized class V cavities (4 × 4 × 2 mm) were prepared. Half of the specimens within each subgroup were restored with single-shade (Omnichroma), while the other half was restored with group-shade resin composite (SimpliShade). Tooth/restoration ΔE00 color differences were calculated at 24 hours (T1), and after seven days (T2) by a spectrophotometer (VITA Easyshade V). A visual analysis was performed after 14 days (T3). Also, a novel computer vision algorithm (CVA) analysis, was employed to evaluate color match at three weeks (T4). Student's t-test was used to compare the two groups within each subgroup and time point and one-way ANOVA was used to compare the values between subgroups, within each group and time point. RESULTS: Instrumental analysis at T1 showed higher mean ΔE00 for single-shade compared to group-shade resin composites (p < 0.05), within each subgroup. Within single-shade specimens, significantly higher mean ΔE00 differences were found at T2 between D (8.24 ± 1.85) vs L (5.65 ± 2.24) (p = 0.007) and M (6.49 ± 2.5) (p = 0.03). Within group-shade specimens, a significant difference was found between L (4.16 ± 2.19) and M (2.17 ± 1.05) at T1 (p = 0.034). Visual analysis reported a significant difference (p = 0.0153) between L-group shade (1.03 ± 1.04) and L-single shade (1.97 ± 0.78) restorations (p = 0.0153). No significant differences were detected when CVA analysis was employed. CONCLUSIONS: Overall, group-shade showed better color match than single-shade resin composites, especially when spectrophotometric and visual evaluation were employed.

References

1. 1.Checchi, V., Cavani, F., Vistola, M., Forabosco, E., Generali, L., Del Giovane, C., & Josic, U. (2026). Color match of single-shade and group-shade resin composites: A visual and instrumental analysis. Operative Dentistry. https://doi.org/10.2341/24-114-L