Investigation of water absorption and water solubility ofnew generation bulk-fill composite resins

Aim: The aim of this study was to examine the water sorption and water solubility values of new generation bulk-fill composites after aging in distilled water, in comparison with conventional and bulk-fill composites. Materials and Methods: Samples were prepared in the form of 8mm diameter and 2mm thickness discs using a traditional microhybrid composite (Filtek™ Z250), a traditional flowable composite (Filtek™ Supreme Flowable), two different high viscosity bulk-fill composites (Tetric Powerfill, Filtek™ One Bulk Fill), and two different low viscosity bulk-fill composites (Tetric Powerflow, Filtek™ Bulk Fill Flowable). The samples were polymerized using BluePhase PowerCure polymerization device in standard mode (1200 mW/cm2 ) for 10 seconds. Subsequently, additional two groups were prepared from Tetric Powerfill and Tetric Powerflow composites, and polymerized for 3 seconds using the same device in its Powercure mode (3050 mW/cm2 ). A total of 104 samples were prepared, with 13 samples in each group. The levels of water sorption, solubility and mass change percentages were measured according to ISO 4049:2009 spesifications. Data were analyzed using two-way ANOVA and post hoc Tukey's test. Results: Tetric Powerflow 10s group exhibited the lowest water sorption values among all tested groups, while the highest water sorption values were observed in the Filtek One Bulk Fill group. There was no statistically significant difference in water sorption and solubility values at 10s and 3s groups of Tetric Powerfill and Tetric Powerflow composites. The weight change percentages of all composite groups increased until the 30th day. Conclusion: Tetric Powerfill and Tetric Powerflow composites exhibited lower water sorption than the other tested groups. These composites did not show any disadvantage in terms of water sorption and solubility when the polymerization time was shortened to 3 seconds in Powercure mode.