Abstract Background: Antimicrobial nanoparticles can be an effective strategy to decrease demineralization and white spot lesions associated with orthodontic treatment by coating the surfaces of the used appliances. Objectives: As an antimicrobial agent, chlorhexidine hexametaphosphate nanoparticles can be used to coat orthodontic brackets to measure the release of chlorhexidine and assess its antibacterial activity. Materials and Methods: The nanoparticles were produced by mixing aqueous solutions of sodium hexametaphosphate and chlorhexidine digluconate. A release test was conducted using artificial saliva for 60 days. Antibacterial assays were performed against Streptococcus mutans and Lactobacillus acidophilus . This experimental study was conducted on 360 orthodontic brackets. Stainless steel and ceramic brackets were coated with 5 mM chlorhexidine hexametaphosphate nanoparticles. Results: Chlorhexidine hexametaphosphate nanoparticles-coated brackets showed continued release of chlorhexidine over 60 days. The release rates were significantly different between coated stainless steel and ceramic brackets on day 1 ( P = 0.002). More chlorhexidine was released from coated stainless steel than coated ceramic brackets in the next few days, although not significantly. In the antibacterial assay, bacteria were inhibited by coated brackets. Inhibitory zones around coated stainless steel brackets were significantly larger than those around coated ceramic brackets. Conclusion: Chlorhexidine hexametaphosphate as antimicrobial nanoparticles is a promising coating for orthodontic brackets, providing sustained chlorhexidine release and bacterial growth inhibition.
Al-Fadhily et al. (Thu,) studied this question.