Processing and in vivo evaluation of multiphasic calcium phosphate cements with dual tricalcium phosphate phases

Calcium phosphate cements (CPCs) use the simultaneous presence of several calcium phosphates phases. This is done to generate specific bulk and in vivo properties. This work has processed and evaluated novel multiphasic CPCs containing dual tricalcium phosphate (TCPs) phases. Dual TCPs containing alpha- and beta-TCP phases were obtained by thermal treatment. Standard CPC (S-CPC) was composed of alpha-TCP, anhydrous dicalcium phosphate and precipitated hydroxyapatite, while modified CPC (DT-CPC) included both alpha- and beta-TCP. Physicochemical characterization of these CPCs was based on scanning electron microscopy, X-ray diffraction, specific surface area (SSA) and particle size (PS) analysis and mechanical properties. This characterization allowed the selection of one DT-CPC for setting time, cohesion and biological assessment compared with S-CPC. Biological assessment was carried out using a tibial intramedullary cavity model and subcutaneous pouches in guinea pigs. Differences in the surface morphology and crystalline phases of the treated TCPs were detected, although PS analysis of the milled CPC powders produced similar results. SSA analysis was significantly higher for DT-CPC with alpha-TCP treated at 1100 inverted perpendicular C for 5 h. Poorer mechanical properties were found for DT-CPC with alpha-TCP treated at 1000 degrees C. Setting time and cohesion, as well as the in vivo performance, were similar in the selected DT-CPC and the S-CPC. Both CPCs created the desired host reactions in vivo. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.