Corrosion resistance and antibacterial activity of Ti-N-O coatings deposited on dental titanium alloy

Abstract

Abstract The corrosion resistance and antibacterial activity of dental metal materials are important service performances. In this paper, the TiN and Ti-N-O coatings with different chemical compositions were deposited on Ti6Al4V alloy by physical vapor deposition (PVD). The phase structure, surface morphology and elemental distribution of the Ti-N-O coatings were characterized by XRD, XPS, SEM and EPMA. The electrochemical corrosion behavior of the Ti-N-O coatings in acidic and fluoride-containing artificial saliva was investigated. The antibacterial activity of the coated Ti alloy was evaluated by an in vitro antibacterial test. The results show that with increasing O2 flow rate in the reaction atmosphere, the phase compositions of the Ti-N-O coatings gradually change from TiN to TiNxOy, Ti2O3, TiO2 and Ti3O5. The Ti-N-O coatings show good passivation behavior. Particularly, when the ratio of N2 and O2 flow rate is 2:1, the corrosion current density of the Ti-N-O coated specimen in acid (pH\xa0=\xa05.2) solution is only 6.0\xa0×\xa010−8 A/cm2. In an acidic solution containing 0.1% NaF, the passivation potential of the Ti-N-O coatings exceeds +1.0\xa0V, and the corrosion resistance is exceeds that of a TiN coating. When the ratio of N2 and O2 flow rate is 1:1, the antibacterial rate of the Ti-N-O coating against Staphylococcus aureus approaches 90%.