Characterization of melt-derived 45S5 and sol-gel-derived 58S bioactive glasses

The ability of bioactive glasses to form a bond to living bone and also to stimulate bone-cell proliferation depends on the chemical composition and on the surface texture of the glasses. In this work, the differences in physical properties between the melt-derived 45S5 and sol-gel-derived 58S Bioglass powders of various particle-size ranges were studied. The powders were characterized for particle-size distribution by laser spectrometry, for specific surface area and porosity by nitrogen sorption analysis, and for morphological features by scanning electron microscopy. Melt-derived 45S5 powders exhibited a low-porosity texture with surface area in the range 0.15-2.7 m(2)/g. In contrast, the sol-gel-derived powders exhibited a highly mesoporous texture, with surface area in the range of 126.5-164.7 m(2)/g and a large fraction of 6-9 nm pore sizes. These differences in texture, as well as variations in chemical composition, account for significant changes in the resorption and in vivo responses.