Sealapex is the original non-eugenol, calcium hydroxide polymeric root canal sealant. This formulation produces rapid healing and hard tissue formation.Root canal sealers are used in root canal with combination of core filling materials, such as guttapercha or silver points. At one time it was thought that sealer played a secondary role by simply cementing the core filling material into the canal .However, it is now appreciated that the sealer has a primary role in sealing the canal by obliterating the irregularities between the canal wall and the core materials.
All modern obturating techniques make use of sealer to enhance a fluid tight seal of the pulp space .Calcium hydroxide is the most commonly used intracanal medicament and also available as a therapeutic sealer in different compositions. These sealers show varied antimicrobial action to various microorganisms detected in the root canal flora and this action is attributed to their calcium ion release and change in pH. Hence, this study was done to compare the efficacy of four commonly available calcium hydroxide sealers.