Porosity study of the carbonated hydroxyapatite cement / 中国矫形外科杂志

ABSTRACT

[Objective] To compose carbonated hydroxyapatite cement with chemica l materials,and by adding the pore agent to develop a new bone substitute,which can be solidified in situ to form porous carbonated hydroxyapatite.[Method](1)A new type of carbonated hydroxyapatite cement(CHC)was prepared.The powder of cement was composed of calcium carbonate,tricalcium phosphate and calcium phosphate dibasic.The liquids were prepared by 0.2mol/L sodium phosphate buffer,solide phase to liquid phase was 1g to 0.4 ml;(2)To prepare an in situ setting porous carbonated hydroxyapatite cement,add the pore agent into the powder of cement,pore generate CO2 during situ setting of cement;(3)The chemcial composition,chemcial constitution mechanical property,setting time,interval porosity of the PCHA were tested.and then the physio-chemical character,manipulatity,histocompatibility were evaluated.[Result]Addition of pore agent could succeed to prepare a new bone substitute which could set in situ and transform into porous carbonated hydroxyapatite.The setting time was 13~15 minutes which was suitable to clinical application.The pore size and porosity character could be controlled by adjustment of the component.The checking results demonstrated that the self-setting composition of this cement was carbonated hydroxyapatite which was similar with the mineral phase of natural cancellous bone,the carbonic acid radical was 5.6% in the solidify production.Contain of the porosity was 36% with interconnect pore,the compressive strength was 5.6?2.2 MPa which was equal to strength of cancellous bone,and the cytotoxicity tests showed an exellent biocompatibility.[Conclusion]The porous carbonated hydroxyapatite cement is a good bone substitute which seems to be the cancellous bone with good porosities,exellent biocompatibility.