Evaluation of Nanoparticle Tantalum Pentoxide Coatings on Nickel Titanium Alloy for Orthodontic Archwires (in Vitro Study)

Tantalum pentoxide (Ta2O5) thin films were deposited on Nickel Titanium Alloy (NiTi) substrates using DC magnetron reactive sputtering at a low temperature of about 100ºC, with a power input of 50 Watts. Advanced techniques such as X-ray diffraction, Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM) were employed to analyze the Ta2O5 coatings. The results revealed that these coatings displayed remarkable uniformity, with extremely low surface roughness (only 2.75 nanometers) and particles in the 15-30 nanometer range. Microhardness was also measured via nanoindentation. Beyond structural and morphological attributes, the study explored the suitability of Ta2O5-coated NiTi alloys for biomedical applications, particularly orthodontic archwires. Assessments covered corrosion resistance, biocompatibility, and nickel ion release in artificial saliva (AS) and simulated body fluid (SBF) solutions. The findings demonstrated enhanced electrochemical behavior, significantly improved corrosion resistance, enhanced biocompatibility, and lower nickel ion release for Ta2O5-coated NiTi alloys than uncoated ones. These benefits are attributed to the improved cohesiveness of the Ta2O5 coatings. In summary, sputtering Ta2O5 films onto NiTi alloys offers a promising avenue for biomedical surface modification. The exceptional uniformity and improved properties of Ta2O5-coated NiTi alloys position them as valuable candidates for orthodontic archwires and other biomedical devices, showcasing the potential of this method in advancing medical and dental technology materials.