Deposition of TiO₂/Polyhexamethylene Biguanide on Stainless Steel Wire for the Enhancement of Corrosion Resistance and Stability

Background: Orthodontic treatment relies on stainless steel (SS) wires to apply forces and torque to reposition teeth. However, SS wires are susceptible to wear and corrosion in the oral environment, necessitating improvements in their durability. Objective: This study explores the potential of a coating comprising titanium dioxide (TiO2) and polymethylene biguanide (PHMB) to enhance the corrosion resistance of SS wires. Methods: SS wires were coated with a solution containing PHMB and TiO2 using a drop-casting technique. Field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDAX), and electrochemical tests, including impedance spectroscopy and potentiodynamic polarization, were conducted to characterize the coated wires and evaluate their corrosion resistance. Results: FE-SEM, EDAX, and Emap analysis confirmed the presence and uniform deposition of PHMB/TiO2 onto the SS wire surface. Electrochemical tests revealed that the PHMB/TiO2- coated SS wires exhibited a significantly lower corrosion rate (7.08×10−6 mm/year) and higher corrosion resistance (562466 Ω) compared to bare SS. Conclusion: The PHMB/TiO2 coated SS wire exhibited high corrosion resistance and offered potential benefits for orthodontic treatments. Further research and optimization of this coating may help to improve the durability and reliability of orthodontic appliances.