[Effect of premix schedule on crystal formation of compound calcium phosphate cements]

To investigate the effect of premix schedule on crystal formation of self-hardening calcium phosphate cements (CPC).

CPC were prepared by mixing cement powders of tetracalcium phosphate(TTCP) with a cement liquid of phosphate acid saline solution. TTC-CPC, chitosan-CPC and chitosan-TTC-CPC were investigated with different premix schedules. The crystal formation was investigated by X-ray diffraction(XRD) and field scanning electron microscope(FSEM).

TTC and chitosan both affected the phase transition and crystal character in CPC. Chitosan, as organic additive, regulated the regular crystal formation and inhibited the phase transition of TTCP into OCP.

The premix schedule affects the crystal formation and phase transition, which may affect its biocompatibility and bioactivities in vivo.