Formation of a high-strength bioactive glass-ceramic in the system MgO-CaO-SiO2-P2O5

Abstract
Formation of a high-strength bioactive glass-ceramic in the system MgO-CaO-SiO2-P2O5 was investigated by observing the microstructure of the crystallized products. Crystallization of the parent glass in a bulk form led to the occurrence of large cracks in the crystallized product. This was attributed to the precipitation of fibrousβ-wollastonite crystals growing perpendicular to the outer surfaces of the glass after uniform precipitation of fine oxyapatite/fluoroapatite crystals. On the other hand, crystallization of the same glass in a powder compact led to the formation of a crack-free dense crystallized product due to uniform precipitation of both apatite and wollastonite fine crystals throughout the glass article. The uniform precipitation of the wollastonite crystals was attributed to the simultaneous formation of fine crystals in the individual glass particles.