Color Match of Single-Shade Versus Multi-Shade Resin Composites: A Systematic Review With Meta-Analysis.

Objective: To address the following PICOS question: Can single-shade resin composites achieve a color match comparable to multi-shade composites in tooth restoration?

Materials and methods: A comprehensive search was conducted across multiple electronic databases to identify in vitro and clinical studies evaluating the color match in tooth restoration, in terms of CIELAB (ΔE_ab) and/or CIEDE2000 (ΔE₀₀) color differences metrics, using single-shade and multi-shade composites. The risk of bias was assessed using the Quality Assessment Tool For In Vitro Studies (QUIN Tool), while the revised Cochrane Collaboration's tool (RoB 2) was employed for randomized controlled clinical trials (RCTs). Meta-analyses were performed using RevMan to compare ΔE_ab and ΔE₀₀ values between single-shade and multi-shade composites (p < 0.05).

Results: After initial screening, 15 in vitro studies and 4 RCTs met the inclusion criteria for qualitative synthesis, with 8 in vitro studies selected for quantitative analysis. The majority of in vitro studies were classified as medium risk of bias, while RCTs were ranked as low risk of bias. Meta-analyses performed on in vitro studies revealed that single-shade composites exhibited statistically significant higher color differences with the surrounding tooth structure compared to multi-shade composites, for both ΔE_ab and ΔE₀₀ (p < 0.05). However, RCTs usually reported promising outcomes for single-shade materials.

Conclusions: This systematic review concluded that multi-shade composites provide a more accurate color match between tooth and direct restoration than single-shade materials when evaluated by instrumental analysis in laboratory settings.

Clinical significance: Multi-shade composites exhibit superior color match properties in laboratory studies. However, single-shade composites are a promising alternative when observed visually in clinical settings.