Demineralization of root canal dentine with EDTA and citric acid in different concentrations, pH and application times.

The aims of the study are: 1. Determination of the amount of extracted Ca ions from den-tine using 17% and 20% EDTA, at pH 7 and pH 9. 2. Determination of the amount of extracted Ca ions front den-tine using citric acid 5% and 1%, at pH 7 and pH 9. Methodology 30 extracted, single rooted, human teeth were tested. Their crowns were sectioned at CEJ using diamond disks. The root canals were manually prepared with K-files #50-60. After each instrument 2.5 ml of 5.25% NaOC1 was used and 0.9 NaC1 as final irrigation. All teeth were longitudinally sectioned and 8 samples of den tine taken front each. sample. EDTA 10% and 17% and citric acid 1% and 5% in neutral and alkaline pH were used. Each sample was immersed in acid and then exposure time was evaluated after 1, 5, 10, 15 and 25 min. The release rate of calcium ions front root dentine was evaluated by atontic absorption spectrometer. Results There were significant differences in the amount of extracted Ca by citric acid 1% and5% or EDTA 10% and 17% in human teeth. Conclusions It may be concluded that EDTA is a better chelating agent than citric acid, The decalcifying activity of these solutions is related to the duration of exposure, pH and their concentrations. [ABSTRACT FROM AUTHOR]