Modification of the Oxidized Surface of Titanium to Impart of Bioactivity

Clinical practice has shown that the effectiveness of titanium implants increases significantly when biocompatible bioactive coatings are applied to their surface, which provide a strong bond between the implant and native bone by forming a biologically active layer of hydroxyapatite on the implant surface.

In this study ceramic-like polyoxide coatings on titanium were modified with a nanostructured sol-gel film, containing calcium, silicate and phosphate ions, which imparted hydrophilicity, solubility, roughness, adsorption activity to the surface, and increased the content of calcium and phosphate ions on the surface.

Due to new properties the surface showed bioactivity in vitro experiment. The experimental samples with a two-layer coating (polyoxide layer and sol-gel film) were kept in cell-free simulated body fluid (SBF) for 4 weeks. During experiment, the pH of the solution changed within the alkaline reaction, which contributed to the crystallization of calcium phosphates. On the surface of the samples, the content of calcium and phosphorus ions increased, and hydroxyapatite crystals formed.

Keywords: Titanium implants; Surface modification; Sol-gel film; Bioactivity