%0 Journal Article
%T Properties of Calcium Phosphate Cements With Different Tetracalcium Phosphate and Dicalcium Phosphate Anhydrous Molar Ratios
%A Hirayama
%A Satoshi
%A Takagi
%A Shozo
%A Markovic
%A Milenko
%A Chow
%A Laurence C.
%J Journal of Research of the National Institute of Standards and Technology
%D 2008
%I The National Institute of Standards and Technology
%X Calcium phosphate cements (CPCs) were prepared using mixtures of tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA), with TTCP/ DCPA molar ratios of 1/1, 1/2, or 1/3,with the powder and water as the liquid. Diametral tensile strength (DTS), porosity, and phase composition (powder x-raydiffraction) were determined after the set specimens have been immersed in a physiological-like solution (PLS) for 1 d, 5 d, and 10 d. Cement dissolution rates in an acidified PLS were measured using a dual constant composition method. Setting times ((30 ¡À 1) min) were the same for all cements. DTS decreased with decreasing TTCP/DCPA ratio and, in some cases, also decreased with PLS immersion time. Porosity and hydroxyapatite (HA) formation increased with PLS immersion time. Cements with TTCP/DCPA ratios of 1/2 and 1/3, which formed calciumdeficient HA, dissolved more rapidly than the cement with a ratio of 1/1. In conclusion, cements may be prepared with a range of TTCP/DCPA ratios, and those with lower ratio had lower strengths but dissolved more rapidly in acidified PLS.
%K absorption
%K calcium phosphate
%K calcium phosphate cements
%K hydroxyapatite
%K mechanical properties
%K porosity
%U http://nvl.nist.gov/pub/nistpubs/jres/113/6/V113.N06.A02.pdf