Energy dispersive analysis (EDX) of a degradable bioactive-glass coating on Ti6Al4V in-vivo

The bioactive-glass coating of metallic substrates provides a gradually deg rading interface which can be used to favor the bony integration of the imp lant by the physiologic processes of bone turn-over and remodeling. Twelve New Zealand White rabbits, about 2700 g of weight, were operated by the sag ittal insertion of a bioactive-glass coated plate of Ti6Al4V. Retrievals we re performed at 4, 8 and 12 weeks. Undecalcified specimens were embedded in methyl-metacrylate and sectioned at 100 microns of thickness. Blocks were grinded and had an electroconductive coating to be examined by scanning ele ctron microscopy (SEM), back scattering electron microscopy (BSEM) and X-ra y energy dispersive spectroscopy microanalysis (EDX). EDX allows to evaluat e quantitatively the gradual process of coating degradation. Areas of 200 m icrons in square were analyzed at the interface between bone and coating to determine their elemental composition. Silicon was the key marker for the presence of the glass. Morphological analysis confirms that a tight apposit ion with bone can be obtained by utilizing the bioactive glass coating of m etal. Results of energy dispersive analysis support the mechanism of a grad ual degradation of the bioactive glass coating and its integration with bon e, since the presence of silicon can be documented within the newly formed bone after the coating has disappeared. (C) 2001 Kluwer Academic Publishers .