Compositional dependence of in-vitro bioactivity in sodium calcium borate glasses

Borate glasses with composition xCaO (100-x) B2O3 (20 <= x <= 50), where x is in mole percent) and 50CaO center dot 45B(2)O(3) center dot 5Na(2)O have been prepared using conventional melt quench technique. Samples were submerged in simulating body fluid solution (SBF) at 37 degrees C for various periods of time. After storage the samples were analyzed in order to investigate if a surface layer of hydroxyl carbonate apatite layer (HCA layer/Ca-P layer) had formed. The analysis technique used included Fourier-Transform Infrared Spectroscopy (FTIR). The rate of HCA layer formation on the surface of exposed glass samples is determined by FTIR, percentage weight loss measurements of glass samples in SBF and variation of pH of SBF as a function of time. Increase in calcium content in the glass matrix has shown to decrease the rate of HCA formation on glass surfaces. The borate glass with x = 20 has shown HCA layer formation on glass surface within two days of dipping. The bone like apatite formation of glass surface demonstrates the potential of glass for integration with bone. (C) 2009 Elsevier Ltd. All rights reserved.