Demineralizing Action of EGTA and EDTA in Endodontics

The demineralization of dentin obtained by treatment with etilendiamminotetracetic acid (EDTA) or ethylene glycol-bis(b-aminoethyl ether)-N-tetraacetic acid (EGTA), is a dynamic process involving chelation and solubilization. Objective: was to confront, first in vitro, the demineralizing action of the EDTA and the EGTA. In vivo, considering the importance of the pH in the mechanism of demineralization of EDTA, this factor has also been analyzed using EGTA, in relation to the pH values indicated in the literature for EDTA. Experimental methods: a gravimetric method was used in vitro measuring the quantity of chelated dentin power treated with both agents. In the SEM analysis we studied the variations in the pulp chamber surface of the walls after the use of both agents in vivo using the technique for impression. Results: The action of EDTA on dentin was influenced by pH. The analysis of the SEM images, obtained from the impressions of tubule pulp chamber made before and after treatment with EDTA or with EGTA, shows that there was an increase in the diameter of the tubules and a better penetration of the vinyl polysiloxane in the dentinal tubules, confirming the demineralizing action of the EDTA, and EGTA on the dentin. Conclusion: the chelating action of EGTA is a little more efficacious than the commercial EDTA. Thus, EGTA may be another chelating agent that could be used together with canal irrigants, instead of EDTA.