Study of superficial properties of titanium treated by PIIID

Abstract

Chemical composition and topography of titanium surface are important factors to improve osteointegration. Surfaces with different roughness and chemical composition respond differently when in a biologic environment. In this work, calcium incorporation to Al2O3 sandblasted titanium surfaces has been achieved by Plasma Immersion Ion Implantation and Deposition (PIIID). Granulated calcium was sublimated by an electron beam at the same time as negative pulses (5 kV, 30 mu s and 400 Hz) were applied to titanium samples immersed in argon DC plasmas. During the on time of the pulses, positive ions in the plasma were implanted on the surface while between the pulses the surface was covered by a metallic calcium layer. Modified surfaces were characterized before and after soaking the samples in simulated body fluid (SBF), to evaluate the effect of the treatments on the titanium bioactivity. Morphology, composition and chemical structure were evaluated by scanning electron microscopy, energy dispersive and infrared absorption spectroscopies, respectively. Selected sample was also characterized by X-ray photoelectron spectroscopy. The results have shown that the concentrations of calcium and phosphorus, after the immersion in SBF, were larger on the plasma treated titanium samples if compared to the as-received material. Those elements can be present on the surface forming bioactive species such as CaTiO3, CaCO3 and hydroxyapatite (HA).