Evaluation of the effect of EDTAC, CDTA, and EGTA on radicular dentin microhardness

The effect of EDTAC (ethylenediamine tetra-acetic acid plus Cetavion, an ammonium surfactant), CDTA (cyclohexane-1,2-diaminetetra-acetic acid), and EGTA (ethylene glycol-bis-(beta-amino-ethyl ether) N,N,N',N'-tetra-acetic acid) on the microhardness of radicular dentin of the cervical third of human teeth was studied. Five newly extracted maxillary incisors were sectioned transversely at the cementoenamel junction, and the crowns were discarded. The roots were embedded in blocks of high-speed polymerized acrylic resin and cut transversely into 1-mm sections. The second slice of the cervical third of the root of each tooth was sectioned and divided into four parts. Each part was placed on an acrylic disc that was used as a base for microhardness measurement. Fifty microliters of 15% EDTAC, 1% CDTA, or 1% EGTA were applied to the dentin surface. Deionized and distilled water was used as control. Dentin microhardness was then measured with a Vicker's microhardness apparatus with a load of 50 g for 15 s. Statistical analysis showed that the three chelating solutions significantly reduced dentin microhardness when compared with water; however, there was no statistically significant difference among the three solutions.