A comparison study on bioactivity and antibacterial properties of Ag-, Cu- and Zn- deposited oxide coatings produced on titanium

Abstract

The aim of this study was to create antimicrobial and bioactive surfaces on the commercial pure titanium (cp-Ti) surface for dental and orthopedic applications. Antibacterial and bioactive silver (Ag)-, copper (Cu)- and zinc (Zn)-based TiO2 with thicknesses of 1, 3 and 5 nm coatings were produced on cp-Ti surfaces via micro arc oxidation (MAO) and thermal evaporation (PVD-TE) techniques. The TiO2, brookite-TiO2 and rutile-TiO2 phases were detected on MAO treated cp-Ti plates and PVD-TE coated MAO surfaces. The surfaces were porous and rough owing to the presence of micro sparks that occurred through the MAO process. However, the surface morphology was not altered at post-coating PVD-TE process although the surface chemistry changed. The Ti, O, Si, Ag, Cu and Zn were homogeneously distributed through the surface and were observed on thin film-coated surfaces. The surfaces of MAO treated cp-Ti plates showed hydrophilic properties, while the thin film-coated MAO surfaces indicated hydrophobic properties. To investigate the bioactivities of Ag-, Cu- and Zn- deposited oxide coatings produced on titanium; all samples were soaked into 1.0X simulated body fluid (SBF) for 14 days at 36.5 degrees C. Whlie Cu surfaces showed better bioactivity properties compared to Ag, Zn surfaces revealed the best bioactivity. The antibacterial activities of plain MAO and Ag-, Cu- and Zn-coated MAO surfaces were evaluated against Escherichia coli and Staphylococcus aureus the colony counting method. Antibacterial studies concluded that Ag, Cu and Zn deposition effectively improved the antibacterial properties of MAO surface. When the coated thin film were compared, it was observed that Ag possessed the most effective antibacterial property against E. coli and S. aureus. Additionally, Zn-based coating revealed better antibacterial efficiency compared to Cu-based coating.