Computational and experimental study of dental resin composites with high filler content

Nanocomposites have been used in various industries due to their excellent properties. For some of them, high filler content (over 50 wt%) is beneficial to improving their performances. This study aims to explore the network model construction and properties of high filler content dental resin composites (DRCs). An improved multistep dynamic cross-linking procedure was proposed and firstly applied to construct the reasonable molecular model of high filler content DRCs. The predicted elastic modulus and stress-strain results of DRCs with different nanofiller contents show that the DRCs with a 70 wt% filler content have the most excellent mechanical properties. Furthermore, the dynamic property study indicates that the diffusion coefficient of matrices firstly decreased and then increased with the nanofiller content increasing from 0 to 80 wt%, reaching the lowest value at 70 wt%. The migration of resin matrices can be limited by nanofillers at the content within 70 wt%. However, when the filler content is excessively high (80 wt%), the stability of matrices is destroyed and the fractional free volume of DRCs sharply increases, resulting in a decrease of mechanical properties of DRCs. The findings of this study deepen the understanding of structures and properties of DRCs at the atomic/molecular scales. [GRAPHICS]