Orthodontic Adhesive Doped with Nano-Graphene Oxide: Physico-mechanical and Antimicrobial Properties

Abstract

Introduction: In fixed orthodontics, formation of white spot lesions, enamel demineralization, and tooth decay around appliances are common complications which mar the outcome. Aim: The aims of this study were the determination of the shear bond strength (SBS) and adhesive remnant index (ARI) of orthodontic adhesive doped with N-GO, as well as the assessment of antimicrobial activities of the modified orthodontic adhesive against Streptococcus mutans. Materials and methods: N-GO was characterized by a scanning electron microscope (SEM), Fourier transformation infrared (FTIR), X-ray diffraction (XRD), and Zeta potential. The SBS and ARI of modified orthodontics adhesive containing different concentrations of N-GO (0, 1, 2, 5, and 10 wt%) were then measured. The influences of adding N-GO on antimicrobial properties of orthodontic adhesive were determined against S. mutans by disc agar diffusion (DAD) testing and biofilm formation inhibition assay. Results: The SEM, FTIR, XRD, and Zeta potential analysis indicated the successful synthesis of N-GO. Orthodontics adhesive doped with 5 wt% N-GO showed the highest concentration of N-GO and SBS value (21.71±7.45 MPa, p<0.05) simultaneously with no significant differences in adhesive remnant index compared with the control group. SBS in the 1, 2, and 5% N-GO were significantly higher than that in 10% N-GO (p=0.025, p=0.036, p=0.041, respectively). The disinfection ability of the modified orthodontic adhesive doped with N-GO against S. mutans in the DAD and biofilm formation inhibition assays were positively associated with increased in N-GO concentrations (p<0.05). However, the 5 and 10 wt% N-GO showed a statistically significant decrease the CFU/mL of the test microorganisms in biofilm structures (p<0.05). Conclusions: It could be concluded that 5 wt% of N-GO can be considered as an orthodontic adhesive additive to reduce the microbial count and biofilm with no adverse effect on SBS and ARI.