Antibacterial Activity and Optical Behavior for Restoration of Micro and Nano Dental Fillers Using Functional Graphene Nanosheets with Polymethyl Methacrylate

Polymer-based graphene nanocomposites significantly impact dental filler materials and antibacterial applications. Polymethyl methacrylate (PMMA) was used to improve the properties of nano and hybrid-dental fillings reinforced using synthesis graphene oxide (GO). Developed acoustic-solution-sonication-casting procedures were used to fabricate the new PMMA-dental filler-GO nanocomposites and the morphology, structure, optical properties, and antibacterial activity of samples were investigated. Fourier transforms infrared (FTIR) exposed good interaction among the PMMA, filling, and GO nanosheets. Scanning electron microscopy (SEM) and optical microscope (OPM) images revealed homogeneous samples and fine dispersion with improved morphology and overcoming cavities and cracks in the samples. The incorporation of PMMA and PMMA-GO in the nanocomposites showed promising properties: Absorption peak presented at 320 nm of samples enhanced from 0.8 (N1) to 0.98 (N3) for nano-fillers and from 0.7 (H1) to 0.97 (H3) for hybrid-fillers. Bandgap reduction from 3.35 (N1) to 3.15 (N3) for nano-fillers and from 3.10 (H1) to 2.75 (H3) for hybrid-fillers in allowed indirect transition, whereas it reduced from 3.38 (N1) to 3.00 (N3) for nano-fillers and from 3.05 (H1) to 2.75 (H3) for hybrid-fillers in forbidden indirect transition after the contribution of PMMA and GO nanosheets. The inhibition zone of the Klebsiella bacteria significantly expanded from 17 to 23 mm for nano-fillers and from 16 to 22 mm for hybrid-fillers. Nanofillers nanocomposites presented better properties and inhabitances zone diameter of antibacterial compared with non-reinforced dental fillers.