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5088208 
Journal Article 
Hydration characteristics of alpha-tricalcium phosphates: Comparison of preparation routes 
Camire', CL; Jegou Saint-Jean, S; Hansen, S; Mccarthy, I; Lidgren, L 
2005 
Yes 
Journal of Applied Biomaterials and Biomechanics
ISSN: 1722-6899
EISSN: 1724-6024 
3 
2 
106-111 
English 
20799230 
Alpha tricalcium phosphate ( á -TCP) cement powders were obtained by solid state reaction and milling (M1) and by precipitation from aqueous solution followed by heating (M2). The materials were hydrated to form calcium-deficient hydroxyapatite (CDHA) with a 2.5 wt% solution of Na2 HPO4 (liquid to powder ratio = 0.34 ml/g, temperature = 37.5 degrees C) and subjected to isothermal calorimetry, mechanical compression tests, X-ray powder diffraction, at various times during hydration, as well as scanning electron microscopy (SEM), laser diffraction and gas adsorption. The particle characteristics of the two powders were similar, but M2 exhibited two reaction events in the thermal power curve, while M1 showed a single event. Both reaction events were attributed to á -TCP dissolution and CDHA recipitation. The minimum in the reaction rate response of M2 was probably due to the formation of a passivating product layer. No such layer was formed on the milled M1 due to its rougher surfaces. Both preparations reached a compressive strength of 30-40 MPa after 24 hr.