The removal of the smear layer using EGTA: a scanning electron microscopic study

The smear layer associated with endodontic instrumentation is currently thought to be a thin layer that

occludes the orifices of the dentinal tubules and covers the intertubular dentin of the prepared canal

wall. The purpose of this study was to compare the effect of ethylene glycol bis ( – amino ethyl ether)

– N, N, N’, N’ – tetra acetic acid (EGTA) and ethylene diamine tetra acetic acid (EDTA) on removal

of the smear layer through the scanning electron microscopy. Twenty four single rooted teeth were

selected, instrumented and irrigated with various solutions and the specimens were processed for

scanning electron microscopy. It was found that though both EGTA and EDTA completely removed

the smear layer, EDTA caused erosion and conjugation of the tubules, whereas, EGTA effectively

removed the smear layer without inducing any erosion. It was thus concluded that EGTA can be

effectively used as an alternative chelator for the removal of the smear layer.

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