Staining Analysis of Resin Cements and Effects on Veneer Restorations

Objectives: To determine and analyse color and translucency changes of resin cements and lithium disilicate veneer restorations, as well as sorption and solubility of cements following staining.
Methods: Ten cylindrical specimens (10x2mm) were prepared of G-Cem One (GC), RelyX Universal (3M), Panavia V5 (Kuraray), Variolink Esthetic (Ivoclar). Another set of LiSi veneers were cemented to G-aenial Universal Injectable composite as dentine base (GC) (N=10/group). Color and translucency parameter (TP) were determined initially and after staining in black tea for 72h using a spectrophotometer and calculated using CIEDE2000 formula. Sorption and solubility of resin cements (N=5/group) was tested following the same conditions and calculated using the mass/volume formulae. Data were analysed using one-way ANOVA and Tukey’s post-hoc test, correlation and regression analyses (a=0.05).
Results: ΔE₀₀ of cements ranged between 9.1±2.9 (G-Cem) and 15.4±1.5 (Panavia). G-Cem and RelyX showed lower ΔE₀₀ than Variolink and Panavia (p<0.001). Comparable ΔTP₀₀ was observed for G-Cem, Variolink and Panavia (range -2.1±0.9 and -3.6±1.6)(p>0.05), whilst ΔTP₀₀ of RelyX significantly increased (2.6±2.1, p<0.001). ΔE₀₀ of veneer restorations cemented with different cements ranged from 2.7±0.5 (G-Cem) to 3.9±0.7 (Panavia)(p<0.05). TP decreased after staining with no significant differences between groups (p>0.05). Initial TP positively correlated with ΔE₀₀ of cements (Pearson r=0.67, regression equation Y=0.8398*X+4.101) and ΔE₀₀ of cemented veneer restorations (Pearson r=0.41, regression equation Y=0.1360*X+1.844)(p<0.05). ΔE₀₀ of cements positively correlated with ΔE₀₀ of cemented veneer restorations (Pearson r=0.48, p=0.0016, regression equation Y=0.1284*X+1.592). Highest sorption was observed for RelyX (0.0336±0.0024mg/mm3) and highest solubility for Variolink (0.0117±0.0028mg/mm3). No significant correlation was established between sorption or solubility and ΔE₀₀ of cements and veneer restorations (p>0.05).
Conclusions: Resin cements affected color and translucency differences of cemented veneer restorations after staining. Color differences of cements and veneer restorations depended on initial translucency of the tested cements but not on their sorption and solubility.