Evaluation of Mechanical Properties of Natural Hydroxyapatites Fabricated by Cold Isostatic Pressing Method for Bone Substitute Applications

Objectives: Hydroxyapatite (HA) has been broadly employed for bone treatment applications. The purpose of this research was to investigate the mechanical characteristics of natural hydroxyapatite fabricated by cold isostatic pressing methods for bone substitute applications.

Methods: In the present research, HA was extracted from hen, goat and cattle bone. Samples were prepared by cold isostatic pressing method (CIP) and sintered at 1100, 1200 and 1300 °C. In order to evaluate the characteristics of the produced HA, X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier Transform spectroscopy (FTIR), scanning electron microcopy (SEM) and energy dispersive spectroscopy (EDS) analyses were performed. Hardness and compression tests were examined before and after sintering. Lastly, the morphology of the samples at different sintering temperatures was studied using SEM imaging.

Results: The obtained experimental results demonstrated that increasing the sintering temperature up to 1300 °C increased the relative density and hardness of the samples. In addition, producing HA extracted from cattle was more efficient than from either hen or goat. The relative density and hardness increased with increasing the sintering temperature, and also, compressive strength was highest for the sample sintered at 1200 °C.

Conclusions: The developed biocomposites have high potential to be used for bone substitute applications.