Effect of EDTA with and without surfactants or ultrasonics on removal of smear layer.

This study compared the in vitro efficacy of Smear Clear (Sybron Endo, CA), a 17% ethylenediaminetetraacetic acid (EDTA) solution with surfactants, to 17% EDTA, with and without the use of ultrasonics, in removal of the smear layer. Seventy-five extracted teeth, randomly distributed into 5 test groups, were prepared by using ProFile rotary instruments (Dentsply Maillefer, Ballaigues, Switzerland) and subjected to different final irrigating regimes; group A, 1% sodium hypochlorite; group B, 17% EDTA; group C, 17% EDTA with ultrasonics; group D, Smear Clear; and group E, Smear Clear with ultrasonics. Samples were examined under the scanning electron microscope and scored for debris and smear layer removal. Statistical analysis showed that groups D and E did not perform significantly better than groups B and C. Group C performed significantly better than group B. Addition of surfactants to EDTA in Smear Clear did not result in better smear layer removal. The use of ultrasonics with 17% EDTA improved smear layer removal.