Apical leakage in canals filled with glass ionomer sealer and gutta-percha after dentin conditioning

This study assessed in vitro apical leakage in root canals filled with gutta-percha and Ketac-Endo using different dentin conditioning and filling techniques. The root canals of 63 single-rooted teeth were instrumented and randomly divided into the following four groups: group A--canals were irrigated with 25% tannic acid and filled with Ketac-Endo and a standardized gutta-percha cone; group B--canals were irrigated with 1% NaOCl and filled as in group A; group C--canals were irrigated with 25% tannic acid and filled with Ketac-Endo and a chloroform-softened gutta-percha cone adapted to the canal walls; group D--canals were irrigated with 1% NaOCl and filled with Grossman's sealer and laterally condensed gutta-percha. After storage for 72 hours at 37 degrees C and 100% humidity, the gutta-percha was removed to a level 4 mm short of the working length, using a Peeso reamer. Teeth were immersed in India ink for 48 hours and cleared, and the coronal extent of dye penetration examined under a binocular dissecting microscope at x 15 magnification. The mean value of leakage for group A was 0.86 mm, for group B 2.23 mm, for group C 2.34 mm, and for group D 0.56 mm. Tukey's multiple comparison test disclosed significant differences (P < 0.05) between group A and groups B and C, and between group D and groups B and C. Differences between groups A and D, as well as between groups B and C, were not significant.