Does translucency influence cure efficiency and color stability of resin-based composites?

Abstract

Objective: To determine if material's translucency influences the cure efficiency and color stability of resin-based composites (RBCs).

Methods: Four commercially-available RBCs indicated for aesthetic restorations were selected in different translucent/opaque shades: IPS Empress Direct (IED) A3 Dentin, A3 Enamel, Trans 20, and Trans 30; Filtek Z350 XT (FZX) A3D, A3B, A3E, and CT; Estelite ∑ Quick (EQ) OA3, A3, and CE; and Opallis (OP) DA3, EA3, and T-Neutral. Color was obtained in the L'C'h' system at three distinct periods: 24h after photoactivation (baseline), after 30d of water storage (WS), and after 30d of coffee storage (CS). The translucency parameter (TP) of each RBC was calculated at baseline. The degree of CC conversion (DC) was obtained by Fourier-transform infrared spectroscopy at 0.05mm (top) and 2mm (bottom) surfaces; the cure efficiency considered the bottom/top ratio. The CIEDE2000 color difference (ΔE₀₀) was calculated considering the WS-baseline and CS-baseline values. Data were submitted to two-way ANOVA and Tukey's post-hoc test (α=0.05). Pearson's tests were used to analyze the correlations between TP and DC, and between TP and ΔE₀₀.

Results: For all RBCs, cure efficiency was not affected by materials' translucency. A positive, significant correlation was observed between TP and DC at the bottom surface for FZX only. For all RBCs, the higher the TP, the higher the ΔE₀₀. The ΔE₀₀ was higher after CS than after WS, except for EQ A3. Positive correlation between TP and ΔE₀₀ were observed for all materials.

Conclusion: The translucency did not influence the cure efficiency but affected the color stability for all RBCs.

Clinical significance: High-translucent RBCs presented lower color stability and should be used carefully.

Keywords: Hydrolysis; Opacity; Staining.