Methods: 90 extracted teeth with single canals were randomly divided into 3 sealer groups (Roth's, Sealapex, AH-26). Each tooth was accessed, cleaned and shaped. The canal walls were coated with one of the sealers followed by lateral condensation of gutta-percha. The teeth were placed into 100% humidity at 37°C. After 4 months the roots were notched and fractured longitudinally and the dentin lifted to expose the gutta-percha/sealer/dentin walls. Qualitative assessment was made in the apical and coronal half as to the amount of sealer coverage at the gutta-percha/canal wall interface with a light microscope at 10X. Sealer coverage was categorized by the amount and location: 1) no sealer 2) slight-partial coverage 3) moderate-partial coverage 4) complete coverage.
Results: Sealer was often absent between gutta-percha and the canal wall. There was a general pattern of moderate-partial canal coverage in each of the three groups. No sealer group demonstrated complete gutta-percha canal wall coverage; however AH-26 did show more consistent moderate-partial canal coverage. Each sealer type showed better coverage in the coronal than the apical half.
Conclusions: Sealer distribution did not result in a continuous layer between the gutta-percha obturant and the canal wall.