Surface Modification Of Orthodontic Arch Wire With Carboxymethyl Chitosan Via Adhesive Polydopamine For Improving Corrosion Resistance And Antibacterial Efficacy

Objective: Via polydopamine, CMC was immobilized on the surface of orthodontic stainless steel arch wires in this study. Electrochemical working station(CHI660C) was used to measure the corrosion of stainless steel arch wires. Microbial assay kit-WST was performed to measure bacterial adhesion of stainless steel arch wires. The security and stability of stainless steel arch wires were improved by this approach for clinical orthodontic use. Methods: Stainless steel arch wires in same size of 0.019×0.025 inch were used. By active group of polydopamine, carboxymethyl chitosan(CMC) were covalently grafted on the surface of arch wires. EDX and SEM were used to analyze the components and surface characteristics. Micro-hardness tester was used to test the hardness of arch wires. Electrochemical working station(CHI660C) was used to measure the corrosion of arch wires. Microbial assay kit-WST was performed to measure bacterial adhesion of arch wires. Results: C, N, O, Si, Cr, Mn, Fe were contained in decorated arch wire, Si, Cr, Mn, Fe in undecorated arch wire. The hardness between modified and unmodified arch wire had no statistical difference. By contrast with pristine arch wire, modified arch wire exhibited higher corrosion resistance and good antibacterial efficacy. Conclusion: Via polydopamine, grafting CMC, simple surface modification could improve corrosion resistance and inhibit bacterial adhesion without affecting mechanical performance for orthodontic arch wire, which was beneficial to orthodontic application.