Low temperature fabrication of high strength porous calcium phosphate and the evaluation of the osteoconductivity.

Porous NaO(2)-MgO-CaO-P(2)O(5) bioglass doped beta-tri-calcium phosphate (beta-TCP) bioceramic possessing high mechanical properties and well pore structure with high porosity and high pore connectivity has been prepared through dipping method with the porous polyurethane as the pore forming template. The sintering mechanism and the mechanical properties of the bioglass doped beta-TCP scaffold have been investigated by the X-ray diffraction (XRD) analysis, Scanning electron microscope (SEM) and thermal differential analysis (DTA). The scaffold's in vivo osteoconductivity has been evaluated by implantation of scaffolds into the femurs of New Zealand rabbits. The results show that the porous structure can achieve the densification process at a low temperature about 950 degrees C by a solid solution sintering mechanism and hence dense macropore scaffold with a compressive strength of 4.32 MPa when the porosity is 75% has been obtained. The in vivo test shows that the Na(2)O-MgO-CaO-P(2)O(5) bioglass doped porous beta-TCP bioceramic has a relatively fast bone formation after implantation; after 1 month implantation new deposited bone tissue has been detected on the strut of the porous scaffold and degraded particles also has been found on the surface of the new formed bone. After 6 months implantation the porous scaffold has been thoroughly covered with new formed bone. Results show that the Na(2)O-MgO-CaO-P(2)O(5) bioglass doped porous beta-TCP bioceramic is potential bone tissue engineering scaffold for orthopedic use.