Characterization of Ti biomedical implant surfaces modified by physical vapour deposition coating

Abstract

Bone fracture and osteoarthritis are common health issues in modern society. Surgical insertion of artificial implants is essential for managing acute osteoarthritis and repair of severely fractured bones. The surface topography of bioimplants is sensitive to osteointegration and bacteria adhesion. In this work, the surface topography of Ti-6Al-4V bioimplant is modified by laser texturing and titanium nitridesilver (TiN-Ag) thin film coating on plain and textured implant samples. The surface texturing was carried out using Nanosecond Nd-YAG laser. The TiN-Ag coating on the implant surface was performed by DC magnetron sputtering process. The characterization of the modified and as polished implant surfaces was carried out by confocal microscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis. The composition of the coated sample and the coating thickness was evaluated using SEM-EDS analysis. The quantification of water contact angle, to assess the hydrophobic or hydrophilic behaviour, was performed using the Kruss's drop shape analyzer. The results revealed that the laser textured samples are characterized by increased roughness with crystalline rutile phase of TiO2 and hydrophilic behaviour. XPS analysis showed that the element vanadium has vanished from all the modified surfaces. Further, it can be concluded that the textured-coated sample would exhibit superior osteogenic and antibacterial behaviour due to the presence of TiN, Ag and rutile and anatase phase of TiO2 together with the increased surface roughness.

Keywords: Biomedical implants, Ti6-Al-4V, surface modification, laser texturing, TiN-Ag nanocomposite coating, DC magnetron sputtering, surface characterization.