Leakage of four root canal sealers at different thickness.

Sealers play a key role in sealing the root canal system. Fluid transport under a headspace pressure of 50 kPa (0.5 atm) through four sealers, AH26, Ketac-Endo, Sealapex and Tubli-Seal at a thickness of 0.05, 0.25 or 3 mm, was determined using 240 standard bovine root sections which were obturated with either sealer only or sealer combined with standard gutta-percha cylinders. AH26 and Sealapex sealed more tightly than Ketac-Endo or Tubli-Seal when used without gutta-percha; AH26, Ketac-Endo, and Sealapex sealed more tightly than Tubli-Seal when the sealer layer was 0.25 mm thick, while Ketac-Endo sealed more tightly than the other three sealers when the sealer layer was 0.05 mm thick. These findings indicate that the thickness of the sealer layer influences the sealing ability of a root canal filling.