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 degreesC 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/cm(3), and compressive strength value of sigma(avr) = 83.03 +/- 33 MPa were achieved by sintering at 1200 degreesC with the addition of 10 wt.% bioglass in HA. This effect can be attributed to formation of Ca-5(PO4)(2)SiO4 based phases whereas increasing the sintering temperature also resulted in formation of Na2HPO4 7H(2)O phases which is responsible for decreasing mechanical properties. (C) 2003 Elsevier Ltd and Techna S.r.l. All rights reserved.