In vitro degradation and apatite-formation of ZnO–CaO–SiO2–P2O5 glass–ceramics by substitution of zinc for calcium

Abstract

Abstract A series of CaSiO 3 –Ca 2 ZnSi 2 O 7 -based glass–ceramics of the type ZnO–CaO–SiO 2 –P 2 O 5 were successfully obtained by the partial substitution of calcium with zinc. The effect of zinc addition on structure, dissolution behavior and apatite-forming ability of the resultant glass–ceramics was comprehensively investigated by X-ray diffraction (XRD), thermogravimetric and differential scanning calorimetry (TG/DSC), and scanning electron microscopy coupled to an energy dispersive X-Ray spectrometer (EDS). The data revealed that the zinc addition favored the generation of Ca 2 ZnSi 2 O 7 and induced the formation of ZnSiO 4 and SiO 2 phases. In addition, the excessive content of these compounds led to the attendant loss in the dissolution rate and apatite-forming ability, indicating that the incorporation of zinc into CaSiO 3 is a promising route to regulate the dissolution and apatite formation of CaSiO 3 –Ca 2 ZnSi 2 O 7 - based bioceramics.