Nafion/ZrO2 Modified NiTi Orthodontic Wire: Preparation, Material Characterization, and Corrosion Studies

Background: Nickel-titanium (NiTi) orthodontic wires are widely used in dental corrective procedures due to their high mechanical properties and cost-effectiveness. However, they are prone to oral corrosion, leading to mechanical deterioration, aesthetic issues, and potential health concerns. Objective: This study aims to improve the corrosion resistance and durability of NiTi orthodontic wires by employing zirconium dioxide (ZrO2) and Nafion coating with the goal of enhancing wire performance. Methods: Two types of NiTi wires were evaluated: a standard, unmodified wire as a control and another wire treated with electrodeposited ZrO2 film and Nafion (Naf) coating. Surface analysis was conducted using various techniques, including Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray Spectroscopy (EDX) analysis. Results: The uncoated NiTi wire exhibited a corrosion rate of 4.436× 10^-1 mm/year, whereas the NAF/ZrO2-coated NiTi wire showed a corrosion rate of 4.068× 10^-1 mm/year, indicating that the NAF/ZrO2 coating acted as a protective layer. Additionally, the ZrO2 layer provided poor electrical conductivity, resulting in slightly higher impedance compared to bare NiTi. The coating served as a barrier, which significantly enhanced corrosion resistance and improved the wire lifespan. Conclusion: Electro-modification through ZrO2 deposition and Nafion coating significantly improved the corrosion resistance and overall durability of NiTi orthodontic wires, offering a promising advancement for their use in dental orthodontics. This study underscores the potential of ZrO2 and Nafion coating to enhance the corrosion resistance and longevity of NiTi orthodontic wires.