Physico-mechanical properties, antimicrobial activities, and anti-biofilm potencies of orthodontic adhesive containing cerium oxide nanoparticles against Streptococcus mutans
Maryam Pourhajibagher, Abbas Bahador
Abstract
Introduction : White spot lesions around orthodontic brackets may lead to the formation of dental caries during and following fixed orthodontic treatment. Aim : This study aimed to evaluate the physico-mechanical properties and antimicrobial potencies of orthodontic adhesive doped with cerium oxide nanoparticles (CeO 2 -NPs) against Streptococcus mutans . Materials and methods : After synthesis and conformation of CeO 2 -NPs by transmission electron microscope (TEM), shear bond strength (SBS) and adhesive remnant index (ARI) of modified orthodontic adhesive containing different concentrations of CeO 2 -NPs (0, 1, 2, 5, and 10 wt%) were measured. The antimicrobial effects of modified orthodontic adhesive were evaluated by disk agar diffusion method and biofilm formation inhibition assay. Results : The pseudo-spherical shapes of CeO 2 -NPs were observed in TEM micrographs. The physico-mechanical finding showed that 5 wt% CeO 2 -NPs showed the highest concentration of CeO 2 -NPs and SBS value (18.21±9.06 MPa, p <0.05) simultaneously with no significant differences in ARI compared with the control group ( p >0.05). There was a significant reduction in cell viability of S. mutans with increasing CeO 2 -NPs concentration. The 3.1 Log 10 and 4.6 Log 10 reductions were observed in the count of treated S. mutans with 5 and 10 wt% CeO 2 -NPs, respectively ( p <0.05). Conclusions : Overall, an orthodontic adhesive containing 5 wt% CeO 2 -NPs had antimicrobial properties against S. mutans without adverse effects on SBS and ARI.