fabrication of tio2-al2o3-ha nanobiocomposite by sintering method and evalution of in vitro bioactivity for orthopedic applications

for the purposes of this study, hydroxyapatite (ha)-al2o3-tio2 nanobiocomposites with significant mechanical properties, biocompatibility and capability to form surface apatite were fabricated by cold pressing and sintering. samples were examined for their compressive strengths. the results of compression experiments showed that sample a (50 wt.% tio2-30 wt.% ha- 20 wt.% al2o3) was superior compared with sample b (30 wt.% tio2-50 wt.% ha- 20 wt.% al2o3). in addition, the examination of porosity in samples' surfaces showed that sample a has less prosity than sample b. in vitro bioactivity of the nanobiocomposites in a simulated body fluid (simulated body fluid (sbf)) was also investigated. after immersing the samples in the sbf solution for 7 days, sample b exhibited greater ability to form calcium phosphate compounds on the surface. in vitro studies showed that mg-67 osteoblast-like cells were attached and spread on the samples' surfaces. the results showed that cells proliferated in greater numbers on the b sample compared to the a sample. finally, x-ray diffraction (xrd) and scanning electron microscopic examinations, energy-dispersive x-ray analysis (edx), and fourier transform infrared spectroscopy (ftir) were performed in order to identify different phases, to study the microstructures, to determine concentration of different elements, and to identify the bonds formed in samples, respectively. to prevent the formation of microcracks and secondary phases, sintering operation was conducted at 1000 °c. based on the results obtained and considering desirable properties of samples, both nanobiocomposites can be used in dental implants and orthopedic applications.