Calcium Phosphate Phase Transformation Produced by the Interaction of the Portland Cement Component of White Mineral Trioxide Aggregate with a Phosphate-containing Fluid
| Autor: | Frederick A. Rueggeberg, Franklin R. Tay, R. Norman Weller, Robert J. Loushine, David H. Pashley |
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| Rok vydání: | 2007 |
| Předmět: |
Calcium Phosphates
Mineral trioxide aggregate Materials science Dental Cements Mineralogy chemistry.chemical_element Buffers Calcium Crystallography X-Ray Phase Transition Apatite Phosphates law.invention Root Canal Filling Materials chemistry.chemical_compound Nephelometry and Turbidimetry law Apatites Spectroscopy Fourier Transform Infrared Hydroxyapatites Amorphous calcium phosphate Aluminum Compounds General Dentistry Silicates Oxides Calcium Compounds Hydrogen-Ion Concentration Phosphate Drug Combinations Portland cement chemistry Chemical engineering visual_art visual_art.visual_art_medium White Portland cement |
| Zdroj: | Journal of Endodontics. 33:1347-1351 |
| ISSN: | 0099-2399 |
| DOI: | 10.1016/j.joen.2007.07.008 |
| Popis: | The bioactivity of mineral trioxide aggregate (MTA) has been attributed to its ability to produce hydroxyapatite in the presence of phosphate-containing fluids. It is known that stoichiometric hydroxyapatites do not exist in biological systems and do not contribute to the osteogenic potential of calcium phosphate-based biomaterials. Because Portland cement is the active ingredient in white MTA, we have characterized the calcium phosphate phases produced when set white Portland cement was immersed in phosphate-buffered saline using pH and turbidity measurements, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, electron diffraction, x-ray diffraction, and Fourier transform-infrared spectroscopy. An amorphous calcium phosphate phase was initially formed that transformed to an apatite phase, with the latter consisting of calcium-deficient, poorly crystalline, B-type carbonated apatite crystallites. Amorphous calcium phosphate is a key intermediate that precedes biological apatite formation in skeletal calcification. Thus, the clinical manifestations of bioactivity with the use of MTA may at least be partially attributed to the mineralization induction capacity of its Portland cement component. |
| Databáze: | OpenAIRE |
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