Water sorption and solubility of different resin composites

Objectives: The aim of this study was to access the influences of particle type in water sorption (WS) and solubility (WSB) of different resin composites (RC). Methods: The tested materials were: APH, Z100 and Z250, Charisma, Fill Magic and Esthet X systems. For each material, eight specimens were prepared (1.5 x 0.5 mm) and photopolimerized by halogen lamp (400 mw/cm2). They were transferred to desiccators until a constant mass was obtained (m1), subsequently immersed in deionized water until no alteration was obtained (m2). Following, the specimens were reconditioned to constant mass in desiccators (m3). The volume (V) of each specimen was calculated (mm3). WS and WSB were determined using the equations (m2-m3/V) and (m3-m1/V), respectively. Data were subjected to one-way analysis of variance and Tukey test (p<0.05). Results: Z250 and Esthet X showed the highest and lowest values of WS, respectively. No statistical differences of WSB were verified for tested RCs. Conclusions: Despite of all the tested RCs were categorized as hybrid composites, they differ among them due to particle type, size and distribution. Thus particle characteristics influence the susceptibility of resin composites on water adverse effects and they may become prone to degradation over time.