title: [Effect of premix schedule on crystal formation of compound calcium phosphate cements].
abstract: OBJECTIVE
  To investigate the effect of premix schedule on crystal formation of self-hardening calcium phosphate cements (CPC).
  
  
  METHODS
  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).
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  The premix schedule affects the crystal formation and phase transition, which may affect its biocompatibility and bioactivities in vivo.
authors.affiliation: Department of Stomatology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei Province, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Li-Yun
authors.initials: LY
authors.lastname: Yao
authors.forename: Bin
authors.initials: B
authors.lastname: Zhou
authors.forename: Jing
authors.initials: J
authors.lastname: Mao
mesh_terms: D001843:Bone Cements; D002130:Calcium Phosphates / Q000737:chemistry*; D048271:Chitosan; D003738:Dental Cements; D014961:X-Ray Diffraction
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates; D003738:Dental Cements; C485830:tetracalcium phosphate; D048271:Chitosan; C020243:calcium phosphate