abstract
The influence of magnesium- and strontium-substitutions on injectability and mechanical performance of brushite-forming alpha-TCP cements has been evaluated in the present work. The effects of Mg- and Sr-substitutions on crystalline phase composition and lattice parameters were determined through quantitative X-ray phase analysis and structural Rietveld refinement of the starting calcium phosphate powders and of the hardened cements. A noticeable dependence of injectability on the liquid-to-powder ratio (LPR), smooth plots of extrusion force versus syringe plunger displacement and the absence of filter pressing effects were observed. For LPR values up to 0.36 ml g(-1), the percentage of injectability was always higher and lower for Mg-containing cements and for Sr-containing cements, respectively, while all the pastes could be fully injected for LPR > 0.36 ml g(-1). The hardened cements exhibited relatively high wet compressive strength values (similar to 17-25 MPa) being the Sr- and Mg-containing cements the strongest and the weakest, respectively, holding an interesting promise for uses in trauma surgery such as for filling bone defects and in minimally invasive techniques such as percutaneous vertebroplasty to fill lesions and strengthen the osteoporotic bone.
keywords
CALCIUM-PHOSPHATE CEMENT; BETA-TRICALCIUM PHOSPHATE; TO-POWDER RATIO; CRYSTAL-STRUCTURE; RHEOLOGICAL PROPERTIES; STRENGTH IMPROVEMENT; HYPODERMIC INJECTION; IONIC MODIFICATION; DEFICIENT APATITE; MAGNESIUM
subject category
Engineering; Materials Science
authors
Pina, S; Torres, PMC; Ferreira, JMF
our authors
José Maria da Fonte Ferreira
Retired Professor
Paula Maria da Costa Torres
Assistant Researcher
Sandra Cristina de Almeida Pina
Post-doc Fellowshipacknowledgements
Thanks are due to CICECO for the support and to the Portuguese Foundation for Science and Technology for the fellowship grant of S. Pina (SFRH/BD/21761/2005). The first author is grateful to C. Stabler, from Institute of Mineralogie, University of Erlangen-Nuremberg, Germany, for his valuable help.