Effect of smear layer on coronal microleakage.

The purpose of this study was to examine the effect of smear layer on coronal microleakage. Fifty-two single-rooted extracted human teeth with a straight root canal were chemomechanically prepared and equally divided into experimental groups A and B. The teeth in group B were treated with ethylenediamine tetraacetic acid and sodium hypochlorite to remove the smear layer. All teeth in the experimental groups were next obturated with gutta-percha and sealer. Finally they were tested for dye leakage with methylene blue. Linear and volumetric measurement of dye penetration was used to assess leakage. The results of this study suggest that the removal of smear layer significantly improves the tightness of the sealing in the coronal area.