CHARACTERISTICS OF PLASMA-SPRAYED BIOACTIVE GLASS COATINGS ON TI-6AL-4V ALLOY - AN IN-VITRO STUDY

Conventional bioactive glasses, in bulk form, are being considered as biomaterials in prosthetic applications. In this study, a new attempt was made to coat bioactive glasses on Ti-6A1-4V by plasma spraying. Th is method will coat the bioactive glass coatings (BGCs) onto metal sub strate, potentially combining the excellent mechanical strength of met al and biocompatibility of bioactive glass. Analysis by X-ray diffract ometry (XRD) of the BGCs, revealed that the amorphous structure of gla ss was preserved. BGCs were soaked in simulated body fluid (SBF) to ev aluate their properties in vitro. After soaking in SBF for 1 day, prec ipitation of fiber structure was observed on the surface of the BGCs. After 2 and more days, the surface of the BGCs was completely covered with precipitates. The precipitates, identified as the apatite phase b y XRD, contained carbonate and hydroxyl functional groups detected by Fourier transform IR reflection (FTIR) spectroscopy. After soaking for 16 days, a thin layer of about 10 FM, rich in calcium and phosphorus but poor in silicon, was observed on the surface of the BGCs. The comp osition of the Ca-P rich layer was consistent with the apatite structu re identified by various methods, but the apatite layer was significan tly thicker than reported in bulk form. The formation of an apatite ph ase surface has been suggested to be indicative of biocompatibility. A ll findings in this study indicated the formation of apatite on the su rface of plasma-sprayed BGCs, and this material is expected to be bioc ompatible in vivo.