Objectives: The purpose of this study was to investigate the effect of prolonged chemical challenges on water sorption, solubility, and roughness of a silorane-based material when compared to methacrylate-based composites.
Methods: Initial roughness and mass were registered for specimens (n=24) fabricated from methacrylate (Filtek Z250, 3M ESPE; Filtek Z350XT, 3M ESPE; Master Fill, Biodinâmica) or silorane-based (Filtek P90, 3M ESPE) composites. The volume of all specimens was also calculated. Specimens were divided in four groups (n=6) and individually stored at 37°C in 0.02N citric acid, 0.02N phosphoric acid, 75% ethanol or distilled water for 7, 14, 21, and 180 days, when new measurements were performed. Subsequently, specimens were dehydrated until a constant mass was obtained. Water sorption and solubility were calculated after 180 days of immersion in the different solutions. Data were submitted to two-way analysis of variance or analysis of variance for repeated measures, and Tukey’s multiple comparison test (a=0.05).

Results: The silorane-based composite was the roughest (p<0.001) composite (Ra=0.06±0.01) when compared to the other investigated materials (Ra=0.05±0.01). Significant differences in water sorption and solubility were detected amongst the investigated composites (p<0.001). The silorane-based composite demonstrated low water sorption (with similar values to Filtek Z250 and Filtek Z350XT) and low solubility (with similar values to Filtek Z250) after prolonged immersion in the different solutions. The immersion solution had no significant influence in roughness (p=0.569) or solubility (p=0.766) of the investigated materials. However, ethanol resulted in significantly higher water sorption for the investigated materials (p<0.001) when compared to citric acid, phosphoric acid, and water.

Conclusions: The silorane-based composite demonstrated low water sorption and solubility, but increased roughness, when compared to the methacrylate-based resins. No effect of the immersion solution was noticed on roughness or solubility, but influenced water sorption of the investigated materials.

This abstract is based on research that was funded entirely or partially by an outside source: North of Paraná University and private funds supported this study. Authors acknowledge the donation of the investigated materials by 3M ESPE and Biodinâmica