Morphochemical characterization, microhardness, water sorption, and solubility of regular viscosity bulk fill and traditional composite resins.

Abstract

To evaluate the morphology of filler particles, chemical composition, microhardness (MH), water sorption (WSp), and solubility (WSl) of a regular viscosity bulk fill and traditional composite resins. Eighty samples (Ø:5 mm; height: 4 mm) were prepared according to the factors "composite" (Aura/SDI, FiltekZ250 XT/3M, Aura Bulk Fill/SDI, and Filtek Bulk Fill/3M) and "filling technique" (incremental and bulk) (n = 10). Vickers MH was measured on the top and bottom surfaces of each samples, and then WSp and WSl were obtained by means of mass gain and loss. Morphology of filler particles and chemical characteristics of composites were evaluated by scanning electron microscopy (SEM) and energy dispersity spectroscopy (EDS) in additional samples (n = 1/group). Data were analyzed using two- and three-way ANOVA and Tukey's tests (p < .05). No significant difference was found for WSp among the groups. Comparing composites in the incremental technique, Aura bulk fill composite showed lower WSI than the other materials and in the bulk fill technique, Filtek Bulk Fill showed the lowest value. Filtek Bulk Fill showed higher MH than the other composites on the bottom surface when samples were produced by bulk filling. The composites presented good physical properties, but the bulk fill ones showed better results for the bottom microhardness and solubility, although chemical elements and morphology were similar in general.