Water Sorption and Staining of Filtek Silorane and Methacrylate Composites

Objective: Water sorption and exogenic staining of composites are generally thought to be correlated. The recently introduced composite Filtek Silorane is based on a hydrophobic resin chemistry fundamentally different from methacrylate-based composites. The purpose of this study was to evaluate water sorption and exogenic staining of this new material in comparison to methacrylate composites and evaluate the correlation between these two parameters.

Methods: Specimens (Ø 15 mm, h 1.5 mm) were prepared of Filtek Silorane, TPH3, Esthet-X, Tetric Evoceram, Grandio, Premise Packable, Venus, ELS and Quixfil. Water sorption was determined according to ISO 4049. Exogenic staining was evaluated by immersion of specimens in brewed coffee (36°C, 7d, n=5). Color was determined before and after storage as L*a*b*-values (CIElab LAB SCAN, n=3). Delta-E values were calculated.

Results: Water sorption of Filtek Silorane was 8.14µg/mm3 (0.48µg/mm3) and was significantly lower than that of the methacrylate composites tested: 11.7µg/mm3(0.9µg/mm3) - 19.8µg/mm3(0.8 µg/mm3), ANOVA (p<0.05). Exogenic coffee staining of Filtek Silorane was Delta-E 0.88(0.18) and was also significantly lower than that of the methacrylate composites tested: 2.8(0.5) - 10.6(2.4), ANOVA (p<0.05). No direct correlation between water sorption and exogenic staining was observed (r=0.194).

Conclusion: This study indicates that the silorane-based material (Filtek Silorane) has lower water uptake and lower susceptibility to exogenic staining than methacrylate-based composites. However, within the limits of this study no direct correlation of water uptake and exogenic staining was observed.