Fabrication of porous calcium phosphates

Calcium phosphates of medical interest are hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP). They have been increasingly used in porous form, as bone filling and bone substitute with better biocompatibility than that of the other ceramic implants. Dicalcium phosphate dihydrate (DCPD) and anhydrous dicalcium phosphate (DCPA) powders produced in our laboratory were each mixed with CaCO3, pressed into shape and sintered in air at temperatures of 1200 and 1250 °C, respectively. The chemical characteristics of the porous specimens were determined using X-ray diffraction (XRD) and infrared spectroscopy (IR), while the physical characteristics were determined using scanning electron microscopy (SEM), mercury porosimetry and Archimedesʹ method and the mechanical characteristics by an Instron-type testing machine. The porous specimens obtained are high purity HA and HA–TCP composite with the following properties: interconnected micro- (<5 μm) to mesoporous (>20 μm) structure, compressive and flexural strengths of 26–78 and 8–17 MPa, respectively.