| Autor: |
Sarkar, N. K., Anand, P., Moiseyeva, R., Ritwik, R. |
| Zdroj: |
Transactions of the Indian Ceramic Society; October 2003, Vol. 62 Issue: 4 p200-204, 5p |
| Abstrakt: |
Portland cement in a modified form (MTA-Tulsa Dental/Dentsply, USA) has found its way into modern dentistry for use in root canal and pulp capping therapies. Its clinical success has been attributed to its excellent biocompatibility and sealing ability. This study was undertaken to gain an understanding of the physicochemical basis of this performance. The specific aims were to characterize the effects of interaction of MTA (75% Portland Cement + 20% Bismuth Oxide + 5% Gypsum) with (a) a synthetic tissue fluid (STF), and (b) endodontically prepared canals in extracted human teeth.All metallic constituents of MTA were found to be released in the solution in different concentrations with Ca as the dominant cation. The precipitates were of globular morphology with a composition and structure similar to that of hydroxyapatite (HA). The formation of a continuous interfacial layer between MTA and canal walls was seen. The interfacial layer resembled HA in composition in that it contained Ca, P and O.Thus, MTA has been found to be active in the oral environment. Ca ions released from MTA react with phosphates in STF leading to the oral precipitation of HA that contributes to biocompatibility. A similar reaction in the filled canal results in the formation of the interfacial layer. This layer acts as a barrier (seal) to tissue fluid preventing bacterial invasion into the canal and the associated complications. |
| Databáze: |
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