Evaluation of Mechanical Performance and Antibacterial Efficacy of Alumina‐Silver Nanoparticle‐Reinforced Bioepoxy for Dentistry

Abstract

The lack of mechanical and antibacterial characteristics of most dental resins impedes their broader applications in dentistry. Therefore, this study aimed to enhance biocompatibility and mechanical and antibacterial features of bioepoxy (BE) to be used in dentistry. The properties of BE were assessed prior to and after reinforcing with several loading of nanoalumina (Al2O3)/nanosilver (AgNPs) particles. The mechanical characteristics were evaluated using three‐point bending and Izod impact tests. The morphologies and surface roughness of pristine BE and nanoalumina/nanosilver‐reinforced BE composites were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The influence of these additives on the BE antibacterial properties were evaluated using the agar diffusion approach. The flexural strengths of the modified BE composites with nanoalumina/nanosilver particles were higher than those for additive‐free BE, and their values were considerably dependent on filler loading. The impact strength and flexural strength of composite materials were greater at hybrid reinforcement loading of 2 wt%. At such ratio, an increase of approximately 33.8% was obtained in the flexural strength compared with that of blank BE. On the other hand, the incorporation of higher proportions of nanoparticles led to a decrease in overall properties of composites, yet they were higher than that of additive‐free BE. The flexural strength for the composite containing 0.5 wt% AgNPs and 3.5 wt% Al2O3 was higher than the value stated for the nanoparticles‐free BE by 18.7%. Furthermore, the composite comprising 0.5 wt% of each of the nanoparticles had a great ability to alleviate the spreading of Staphylococcus aureus and Escherichia coli when compared with the resin and composites with other formula. For instance, the diameter of inhibition zone (DIZ) against Staphylococcus aureus of the aforementioned composite increased about 16% than that of additive‐free BE. All these features make this composite system a promising candidate in biomedical applications especially in dental related applications.