Nader Nezafati; Fathollah Moztarzadeh; Saeed Hesaraki; Nasim Nosoudi
Volume 2, Issue 4 , June 2008, , Pages 277-283
Abstract
Calcium phosphate cements are among the formable calcium phosphate cements which are widely used for reconstruction of hard tissue injuries. Unfortunately, due to low mechanical strength, the application of such materials is only limited to non-load bearing like skull. We have investigated some mechanical ...
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Calcium phosphate cements are among the formable calcium phosphate cements which are widely used for reconstruction of hard tissue injuries. Unfortunately, due to low mechanical strength, the application of such materials is only limited to non-load bearing like skull. We have investigated some mechanical and characteristics of a calcium phosphate cement which was reinforced with glass fiber. Compressed strength, setting time, phase composition and microstructure of the composite cement were among the cases which were investigated using appropriate techniques. The results indicated that adding only 15 weight percent of glass fiber (with about 100µm diameter) which was prepared using sol-gel method, does not show any meaningful change in the setting time of calcium phosphate cement This period of time was estimated about 20 minutes. Compressed strength of the cements without any fibers was 0.635MPa which was increased by adding fiber to 3.69MPa.The toughness of the cement was changed from 0.098KJ/m2 for cement without any fibers to 0.545KJ/m2 cement containing fibers. The XRD pattern of the composite samples which were maintained in the Ringer's solution showed that the reactant materials of the cement have almost thoroughly converted to hydroxyapatite which in this case does not show much difference with the non-fiber samples. As a whole, it seems that using glass fiber prepared by sol-gel method can considerably increase mechanical strength and toughness of calcium phosphate. This occurs without any effect on the quality of the cement.
Tissue Engineering
Abdorreza Sheikh Mehdi Mesgar; Zahra Mohammadi
Volume -1, Issue 1 , June 2004, , Pages 47-55
Abstract
The conditions for synthesis of amorphous calcium phosphates (ACPs) according to the crystallization principles were described. By selecting reaction parameters correctly (low temperature, high pH, immediate removing of water and using solutions containing calcium cations and phosphate anions at low ...
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The conditions for synthesis of amorphous calcium phosphates (ACPs) according to the crystallization principles were described. By selecting reaction parameters correctly (low temperature, high pH, immediate removing of water and using solutions containing calcium cations and phosphate anions at low concentrations), full ACPs can be reproducibly synthesized. The X-ray diffraction patterns of synthesized amorphous specimens were showed a characteristic broad peak. The Ca/P ratio of the resulting precipitates was weakly dependent on the initial Ca/P ratio. Solubility of synthesized specimens in simulated osteoclastic activity conditions was showed that the rate of dissolution would be decreased with increasing crystallinity level. The synthesized amorphous calcium phosphates showed the highest dissolution rate in the simulated solution, and can be a suitable candidate for using in the field of hard tissue engineering applications.
