Effect of alumina particles loading on the mechanical properties of light-cured dental resin composites

The purpose of this study is to evaluate the effect of alumina (Al2O3) loading on the mechanical properties of dental resin composites (DRCs). The DRCs were prepared based on Al2O3 particles and bisphenol A-glycidyl methacrylate (Bis-GMA) was used as the base monomer. The silane-treated Al2O3 particles were mixed with the resin matrix in proportions of 40, 50, and 60 wt%, respectively. Resin matrix without filler was used as the control sample. The Vickers hardness (HV) and flexural modulus (FM) of the DRCs mixed with Al2O3 particles were found to be superior compared to the control sample; the values increased from 14.4 to 23.5 kg/mm2 and 1.5 to 5.7 GPa, respectively. However, the flexural strength (FS) values of DRCs were slightly decreased as the filler loading increased i.e. from 84.5 to 74.2 MPa. The results also revealed statistically significant increases in the HV and FM. On the other hand, FS values showed significant decrease when filler loading was increased (P < 0.05).