Dowel space preparation in root canals filled with glass ionomer cement.

The aim of this study was to evaluate post space preparation difficulties in canals filled with Ketac Endo and with Grossman's sealer. Sixty-three single-rooted teeth were prepared using a step-back technique and were divided into four groups: group 1--canals were irrigated with 25% tannic acid and filled with Ketac Endo and a single-cone technique; group 2--canals were irrigated with 1% sodium hypochlorite and fillings done as in the previous group; group 3--canals were irrigated with 25% tannic acid and filled with Ketac Endo and one gutta-percha cone previously adapted with chloroform; and group 4--canals were irrigated with 1% sodium hypochlorite and filled with Grossman's sealer and a lateral condensation technique. After 72 h, canals post space were prepared using Peeso drills. The time required was measured in seconds and analyzed by Tukey multiple comparison test (level 5%). Post space preparation time for groups 1 to 3 was longer than for group 4 and longer for group 1 than for groups 2 to 4.

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.