Preparation, Characterization, and Assessment of Antimicrobial Properties of Silver-doped Hydroxyapatite Nanoparticles in Orthodontic Composite

Abstract

Aim: The incorporation of nanoparticles in orthodontic materials like composites and primers can be used to combat white spot lesions (WSLs), which is a common complication of orthodontic treatment. Silver-doped hydroxyapatite nanoparticles (AgHANps) have the potential to produce antibacterial effects against caries-causing bacteria in the oral cavity and can be applied for combating WSL when incorporated in orthodontic composites. Hence, the primary objective of this study is to characterize and assess the antibacterial properties of orthodontic composites containing AgHANps. Materials and Methods: The structure of the synthesized AgHANps was studied using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX), and Fourier transform infrared spectroscopy (FTIR). Commercially available orthodontic composite was incorporated with the prepared AgHANps. The agar-well diffusion method was used to investigate the AgHANps-incorporated composite’s antibacterial properties against Staphylococcus aureus ( S. aureus), Streptococcus mutans ( S. mutans), and Escherichia coli ( E. coli). ANOVA and Bonferroni post-hoc test was used to assess the differences in zones of inhibition (ZOI) between the groups with the p value set at .05. Results: The AgHANPs was prepared and characterized using EDAX and FTIR, which revealed the successful formation of the nanoparticles without any contaminants. After the integration of the AgHANps into the orthodontic composite, antimicrobial assessment showed statistically significant ZOI against S. aureus ( p = .003), S. mutans (0.001), and E. coli (0.003). The high concentration of the AgHANPS (40 μL) showed the largest ZOI against all the bacteria followed the control group and the low concentration (20 μL) group. Conclusion: The study shows the AgHANps incorporated orthodontic adhesive possess antimicrobial effect against S. aureus, S. mutans, and E. coli and the effect increases with the concentration of the nanoparticle.