Processing and characterization of bioglass reinforced hydroxyapatite composites

The improvement of mechanical properties of HA with reinforcement of 5 and 10 wt.% bioglass (45S5) for different sintering temperatures was studied. Naturally produced HA from human teeth is sintered with the addition of 5 wt.% and 10 wt.% bioglass at 1200 and 1300 °C for 4 h. The microhardness measurements, density and compression tests were performed and microstructural characterizations were carried out by scanning electron microscopy and X-ray diffraction analysis in order to find the optimum sintering temperature. Finally average hardness value of 383±60 HV, average density of 2.72±0.01 g/cm³, and compressive strength value of σ_avr = 83.03±33 MPa were achieved by sintering at 1200 °C with the addition of 10 wt.% bioglass in HA. This effect can be attributed to formation of Ca₅(PO₄)₂SiO₄ based phases whereas increasing the sintering temperature also resulted in formation of Na₂HPO₄ 7H₂O phases which is responsible for decreasing mechanical properties.