Enhancement of the mechanical and antibacterial properties of Bis-GMA/TEGDMA dental composite incorporated with ZnO/CS and Si/PMMA core-shell nanostructures

In this study, Si/PMMA and ZnO/CS core-shell structures were synthesized as inorganic fillers and added to a bisphenol A diglycidyl dimethacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) (50%/50%) commercial dental composite at a weight percentage (wt%) of 0.1-1.0% to simultaneously improve the mechanical and antibacterial properties of the composite. The prepared composites were characterized using dynamic light scattering (DLS), zeta potential (?-potential), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), ultraviolet-visible spectrophotometer (UV-Vis), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). The mechanical properties, including flexural strength and flexural modulus, of the composite were investigated by three-point bending tests. Additionally, the antibacterial activity against the Staphylococcus aureus (S. aureus) bacteria strain was evaluated using the colony-forming unit method to assess the antibacterial effect of the novel composite. As a result, the Bis-GMA/TEGDMA-Si/PMMA/ZnO/CS dental composite, reinforced with 0.1 wt% Si/PMMA and 0.5 wt% ZnO/CS, exhibited a 46% improvement in flexural strength and a 56% improvement in flexural modulus compared to pristine Bis-GMA/TEGDMA. Moreover, the novel Bis-GMA/TEGDMA-Si/PMMA/ZnO/CS dental composite showed a 95% reduction in bacterial growth against the S. aureus bacteria strain.