Influences of reinforcing agents on properties of biphasic calcium phosphate ceramics

To improve biphasic calcium phosphate (BCP) ceramic strength, well known biocompatible and strong ceramics such as SiO2, ZrO2 and TiO2 were added to BCP with hydroxyapatite/tricalcium phosphate ratios of 70:30 (BCP7030). SiO2, ZrO2 and TiO2 powders with 2, 5 and 10 wt-% each were mixed with the BCP7030 powder. X-ray diffractometry and scanning electron microscopy (SEM) were used to determine the crystal structures and morphology of the sintered samples respectively. The physical properties and flexural strength of the samples were measured. Cell proliferation and differentiation of osteoblast-like Saos-2 cells cultured on BCP ceramics were determined by Alamar Blue assay and alkaline phosphatase expression respectively. Finally, SEM was performed to investigate the cell morphology on the surfaces of the specimens. The BCP7030 sample with 10 wt-%TiO2 displayed an optimum bending strength of ∼61 MPa and showed the strongest enhancement of cell proliferation and differentiation among all tested reinforcing agents.