Influence of Alumina Nanoparticles on the Mechanical Properties of a Bioresin Composite

A significant part of the research and production activities is represented in the field of bioengineering by the biomaterials used in hard tissue restorations. They are of great interest in dental science, intending to improve technological aspects, monitoring their biological responses to the living organisms, but also to redesign economic aspects, beginning with the choice of raw materials. In the present work, light-curing composite biomaterials were made from a composite polymer matrix consisting of specific concentrations of bisphenol A-glycidyl methacrylate base monomer (Bis-GMA), a mixture of two co-monomers, triethylene glycol dimethacrylate and ethoxylated bisphenol A-dimethacrylate (TEGDMA/BisEMA), and two alumina nanopowder concentrations (5 wt.% and 10 wt.%). These materials were mechanically tested for flexural strength and compressive strength. The structural analysis of these materials consisted of SEM microscopy and EDX elementary mapping. In order to extract 3D projections of sample surfaces, but also to produce indicative values of their roughness, the SEM micrographs were processed with open-source software. In order to observe a clear evolution of the mentioned properties, the composite biomaterials were compared with materials formed only with the Bis-GMA/TEGDMA/BisEMA composite, and with a commercial composite resin, Filtek™ Supreme Ultra Universal Restorative, also. The findings showed an increase in the mechanical properties of the materials manufactured concerning the concentration of nanoparticles of aluminum. EDX analyzes confirmed the good homogeneity of nanoparticles in the polymer matrix. Mechanical properties of the manufactured nanocomposite biomaterials were reported 28.8 % higher than the control biomaterial. The comparison results with the commercial resin composite are encouraging.