Performance of the experimental resins and dental nanocomposites at varying deformation rates

Abstract

The aim of the present study was to evaluate the bi-axial flexural strength of experimental unfilled resins and resin-based composites at varying deformation rates following 1-week dry, 1-week wet, and 13-week wet storage regimes. A total of 270 disc-shaped specimens (12mm diameter, 1mm thickness) of either unfilled resins or experimental resin-based composites comprising of three groups (n=90) were fabricated. Three groups of each unfilled resin and resin-based composites (n=90) were stored for 1week under dry conditions, and at 1 and 13weeks under wet conditions (37±1°C) before testing. The bi-axial flexural strength of each unfilled resin and resin-based composites group was determined at a 0.1, 1, and 10mm/min deformation rate (n=30). The unfilled resins revealed a deformation rate dependence following all storage regimes; however, the addition of fillers in the unfilled resins modified such reliance following the 1-week dry and 13-week wet storage regimes. In contrast, a lower bi-axial flexural strength of the 1-week wet resin-based composites specimens at a 0.1mm/min deformation rate was identified. A lower bi-axial flexural strength of the 1-week wet resin-based composites specimens at a low deformation rate suggests that premature failure of resin-based composites restorations might occur in patients with parafunctional habits, such as bruxism.