Structural analysis of hydroxyapatite bioactive glass composite coatings obtained by plasma spray processing

Bioactive materials such as hydroxyapatite (HA) are used as coatings on metallic implants, producing a conjugate with better performance. The coatings are in general obtained by a plasma spray process. In this work the structural properties of composite coatings hydroxyapatite/bioactive glass (HA/BG) as well as coatings of the pure materials are measured. The coatings were obtained by plasma spraying mixtures of the powders Bioglass(R) and HA, in different proportions. The process parameters, are current and primary/secondary gas ratios, were also varied. X-ray diffraction (XRD), infrared spectroscopy and scanning electron microscopy (SEM) measurements were made of the coatings. The in vitro bioactivity of the different coatings was also evaluated. The results showed that Bioglass(R) addition to the coating powders increased the dissolution rates and rate of formation of a HA film on the surface of the coatings, thus increasing its in vitro bioactivity compared to pure HA coatings. (C) 1999 Elsevier Science B.V. All rights reserved.