Objective: The purpose of the present study is to assess the water sorption, solubility and surface roughness of compomer and giomer restorative materials after storage in different immersion media.
Materials and Methods: Two resin-based restorative materials were selected for this study: Compomer (Twinky Star) and Giomer (Beautifil II). For water sorption and solubility, 6 disc-shaped specimens of each material were prepared according to manufacturers' instruction. Measurements were done by weighing the samples before and after immersion in distilled water for 28 days and after desiccation. Values were statistically analyzed using student-t test (P-Value <0.05). For surface roughness, 18 disc-shaped specimens of each material were divided into three subgroups according to the immersion media; Mirinda orange, milk and distilled water as the control. Specimens were kept immersed for 28 days. Average baseline and after immersion surface roughness measurements were recorded using a 3D digital image processing technique. Values were statistically analyzed using One-way ANOVA (P-Value <0.05)
Results: Twinky Star represented significant lower water sorption and solubility values (0.181 mg/mm3 and 0.179 mg/mm3) when compared to Beautifil II (0.208 mg/mm3 and 0.207 mg/mm3), respectively. No significant difference in the surface roughness values between both materials after the immersion in either distilled water, Mirinda orange or milk. Conclusions: The higher sorption and solubility of Beautifil II compared to Twinky Star might compromise its performance and longevity. Immersion of compomer and giomer in water and sugar-sweetened beverages may seriously reduce the durability of both materials . Mirinda orange could potentially erode both materials.