Evaluation of Water Sorption-solubility and Surface Roughness of Different Bulk Fill Composite Resins

Abstract

Objective: This study aimed to investigate and compare the water sorption (WS), solubility (SO) and surface roughness (SR) of four bulk fill resin-based composites (RBCs), a conventional flowable RBC and a conventional hybrid RBC. Materials and Methods: Disc-shaped specimens of 3 low-viscosity bulk fill RBCs (SureFil SDR flow, X-tra base, Filtek Bulk Fill flow), 1 high-viscosity bulk fill RBC (Tetric EvoCream Bulk Fill), 1 conventional low-viscosity flowable RBC (Filtek Ultimate flow) and 1 conventional hybrid RBC (Filtek Z250) (n=10) were prepared and immersed in distilled water for 28 days. Upon removal, specimens were weighed using an electronic scale to determine WS and SO based on weight gain/loss, and surface profilometry was performed to determine SR. Data were analyzed using one-way ANOVA and Tukey's post-hoc tests (p=0.05). Results: WS and SO showed significant, positive correlations (r=0.612; p<0.001), and both varied significantly among the materials, with WS and SO values of both high-filled and low-filled bulk fill RBCs lower than their conventional counterparts. Moreover, SR values of both bulk and conventional flowable low-fill RBCs were significantly lower in comparison to the high-fill RBCs (p<0.05). Conclusion: WS, SO and SR of RBCs are material-dependent and highly affected by filler loading and resin matrix composition. Bulk fill RBCs can be used in a large variety of clinical situations in line with the manufacturers' recommendations.