Microstructural, biological and mechanical investigations of hydroxyapatite-β-tricalcium phosphate composites doped with strontium and fluoride

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2016
Pourreza, Elmira
The aim of this study was to investigate the microstructure, mechanical and biological properties of biphasic hydroxyapatite--Tricalcium phosphate (HT) and HT substituted with constant fluoride (F−) and varying strontium (Sr2+) amounts. All the samples were synthesized via precipitation method and sintered at 1100°C for 1 h. It was observed that the relative density of the sintered strontium and fluoride doped HT slightly increased. For microstructural analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) examinations were performed. Remarkable amounts of β-TCP and CaO phases were detected in XRD analysis which could be due to the Ca/P ratio less than 1.67. Lattice parameters increased due to substitutions of ions. In SEM analysis, smaller grains were observed for HT doped with ions. In FTIR analysis, the characteristic bands of HA and -TCP were exhibited. Increased Sr2+ ion contents resulted in increased microhardness values. The highest microhardness value was obtained for the HT doped with 5%Sr2+ and 1%F−. In order to evaluate the cytocompatibility of doped HT, in vitro cytotoxicity tests were performed using Saos-2 cells. Higher initial cell attachment was observed on Sr2+and F− doped HT discs than observed on pure HT.SEM analysis was conducted to examine the morphology of the cells on the surface of the samples. And it was observed that the surface of all discs was covered with cell layers showing perfect cell-material interaction. HT doped with 5%Sr2+ and 1%F− had the optimum structural, mechanical and biocompatibility properties and can be suggested as a good biomaterial for biomedical applications. 

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Citation Formats
E. Pourreza, “Microstructural, biological and mechanical investigations of hydroxyapatite-β-tricalcium phosphate composites doped with strontium and fluoride,” M.S. - Master of Science, Middle East Technical University, 2016.