Rheological properties of an injectable calcium phosphate bone cement and their relationship with the phase evolution

An injectable calcium phosphate bone cement was prepared by combining amorphous calcium phosphate (ACP) and dicalcium phosphate dihydrate (DCPD) for use in non-invasive surgery in this work. The effect of the conserving time on the viscosity, yield stress and injectability of the calcium phosphate cement (CPC) pastes were studied. The results showed that as the conserving time of the pastes prolonged, the viscosity and the yield stress of the pastes increased exponentially, and the injectability of the pastes decreased. This resulted from the transformation of DCPD and ACP into hydroxyapatite via hydration reaction. The results also indicated that the pastes still exhibited good injectability in even 15 min after preparation of the CPC pastes.