Papers by Keyword: Silicon Substitution

Abstract: Dense and porous HA and Si-HA discs and granules with varying percentages of silicon substitution have been produced and physically and chemically characterised using scanning electron microscopy, surface area analysis, porosimetry, density measurement, image analysis, Xray diffraction, X-ray fluorescence, FT-infrared spectroscopy and in-vitro and in-vivo testing. Results have shown that cell adhesion in-vitro and bone apposition in-vivo are enhanced by the presence of silicon substitution in the hydroxyapatite structure. The biological response to the materials appears to indicate an optimum outcome for levels of silicon substitution of 0.8wt%.

Abstract: A simplified preparation method of silicon-substituted calcium phosphates with a very high yield (close to 100%) has been elaborated, according to the principles of Green Chemistry. The technique consists of mixing of crystals of calcium nitrate and ammonium dihydrogen phosphate in the desired proportions, following by addition of the necessary amount of a silicon-containing compound. The homogenous mixture is sintered between 900 and 1200°C. Either a siliconcontaining hydroxyapatite (Si-HA) or a silicon-stabilized tricalcium phosphate (Si-αTCP) can be synthesized, depending on the Ca/P, Ca/(P+Si) and Si/P molar ratios.