Effect of magnesium to the properties of sintered biphasic calcium phosphate (BCP) for bone regeneration

Biphasic calcium phosphate (mixture of HA and β-tricalcium phosphate) with incorporation of Mg2+ into calcium site were synthesized by precipitation method. The aim was to improve the mechanical properties for biomedical application. The as-synthesized powder was calcined at 600 °C and sintered at three different temperatures (900 °C, 1000 °C, 1100 °C) and characterized by several characterization techniques. The calcined sample was also being tested for this study since this is the optimum phase (60-70% HA: 40-30% β-TCP) present for BCP. Sintering was applied for densification purposes to give strength toward the BCP pellet body. By increasing sintering temperature, the compressive strength of sintered pellets had been improved from 2.15 to 8.47 MPa (BCP), 3.07 to 9.85 MPa (MgBCP) with decrease of porosity. Furthermore, the effect of Mg on phase formation found that it suppresses HA phase and favors β-TCP phase. This result was supported by the XRD phase analysis. Moreover, the addition of Mg as sintering additive enhanced densification and decreased porosity which led to higher compressive strength.