Surface Modification and In Vitro Characterization of Cp-Ti and Ti-5Al-2Nb-1Ta Alloy in Simulated Body Fluid

Ti and its alloys are widely used in manufacturing orthopedic implants as prostheses for joint replacement because of their high corrosion resistance and excellent biocompatibility. However, they lack in bone-bonding ability and leads to higher rate of osteolysis and subsequent loosening of implants. In order to enhance the bone-bonding ability of these alloys, various surface-modification techniques are generally employed. The present investigation is mainly concerned with the surface modification of Cp-Ti and Ti-5Al-2Nb-1Ta alloy using a mixture of alkali and hydrogen peroxide followed by subsequent heat treatment to produce a porous gel layer with anatase structure, which enhances osseointegration. The morphological behavior was examined by x-ray diffractometer (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) coupled with energy dispersive x-ray analysis (EDX). The in vitro characterization of all the specimens was evaluated by immersing the specimens in simulated body fluid solution to assess the apatite formation over the metal surface. The apatite formation was confirmed by XRD, SEM-EDX, and Fourier transform infrared spectroscopy (FT-IR). Further, the electrochemical corrosion behaviors of both the untreated and treated specimens were evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy. The results revealed that the surface-modified and heat-treated specimens exhibited higher corrosion resistance and excellent biocompatibility when compared to the chemical and untreated specimens.