Journal of Islamic Dental Association of Iran [The]-JIDA. 2006; 18 (2): 100-105
in Persian
| IMEMR
| ID: emr-77844
ABSTRACT
One of the materials used for repairing root-end fillings is mineral trioxide aggregate [MTA]. MTA has been reported to remain soft when placed in perforations with a high degree of inflammation. The purpose of this study was to evaluate the effect of environmental pH on the setting and micro structure of MTA. In this interventional study, tooth-colored MTA [Pro Root, Dentsply, USA] was mixed according to the manufactures instructions. The mixture was placed into cylindrical polycarbonate tubes. The specimens were randomly divided into four groups of 9 and were subjected to a pressure of 3.22 Mpa - 6kg applied for 1 minute in a custom-made condenser device. Each of the 9 specimens were then stored at room temperature and saturated humidity in four plastic plates containing buffer solutions of butyric and propyonic acid with a pH of 4.4, 5.4, 6.4 and 7.4, for 4 days. The Vickers hardness test was performed on each specimen. The microstructures of the specimens were analyzed using a scanning electron microscope after sectioning the specimens with a scalpel. Data were subjected to one-way ANOVA. The lowest and highest pH values were 4.4 and 7.4, respectively. A statistically significant difference was observed between all four groups [p<0.05]. Unreacted MTA particles scattered in a non uniform matrix were seen in specimens stored in pH 4.4 solutions whereas cases kept in a pH 7.4 environment had distinctive crystalline structures embedded in a more uniform matrix. The results indicate that the acidic pH of inflamed tissues can adversely affect the setting of MTA
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Index:
IMEMR (Eastern Mediterranean)
Main subject:
Oxides
/
Microscopy, Electron, Scanning
/
Silicates
/
Calcium Compounds
/
Aluminum Compounds
/
Hardness
/
Hydrogen-Ion Concentration
Language:
Persian
Journal:
J. Islam. Dent. Assoc. Iran
Year:
2006
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