Influence of Si substitution on the reactivity of alpha-tricalcium phosphate

Author(s)

Motisuke, Mariana ; Mestres, Gemma ; Reno, Caroline O. ; Carrodeguas, Raul G. ; Zavaglia, Cecilia A. C. ; Ginebra, Maria-Pau

• Document type: Journal article
• Source: Materials Science & Engineering C-Materials for Biological Applications; v. 75, p. 816-821, JUN 1 2017.
• Web of Science Citations: 5

Abstract

Silicon substituted calcium phosphates have been widely studied over the last ten years due to their enhanced osteogenic properties. Notwithstanding, the role of silicon on alpha-TCP reactivity is not clear yet. Therefore, the aim of this work was to evaluate the reactivity and the properties of Si-alpha-TCP in comparison to alpha-TCP. Precursor powders have similar properties regarding purity, particle size distribution and specific surface area, which allowed a better comparison of the Si effects on their reactivity and cements properties. Both Si-alpha-TCP and alpha-TCP hydrolyzed to a calcium-deficient hydroxyapatite when mixed with water but their conversion rates were different. Si-alpha-TCP exhibited a slower setting rate than alpha-TCP, i.e. k(SSA) for Si-TCP (0.021 g.m(-2).h(-1)) was almost four times lower than for alpha-TCP (0.072 g.m(-2).h(-1)). On the other hand, the compressive strength of the CPC resulting from fully reacted Si-alpha-TCP was significantly higher (12.80 +/- 0.38 MPa) than that of alpha-TCP (11.44 +/- 0.54 MPa), due to the smaller size of the entangled precipitated apatite crystals. (C) 2017 Published by Elsevier B.V. (AU)