Favorable features of a calcium phosphate cement based on a metastable α ̅-tricalcium phosphate and reinforced by hydroxyapatite whiskers

Abstract

The composition, impurities, ion substitutions, structure, peculiarities in crystallization and compressive strength were studied in the initial stage of setting (for 15 min) of a new cement based on a metastable -tricalcium phosphate and reinforced by various amounts (up to 15 wt%) of hydroxyapatite whiskers. The set cements were apatitic, highly nonstoichiometric with a Ca/P ratio below 1.5. The compressive strength increased more than twice (up to 8 MPa) at a whisker content of 4 wt% and then decreased again with increasing whisker content. The decline was associated with the growth of nanocrystals on the surface planes of whiskers and formation of micropores in the whisker vicinity caused by the consumption of the surrounding mother phase for the growth. It is expected that the micropores are favorable for the surrounding tissue to grow into enhancing the effectiveness of the set cement. The cement can primarily be used as accessible remedies for treatment of slightly-loaded bone defects.