Long-term sealing ability of a calcium hydroxide sealer.

A calcium hydroxide sealer (Sealapex) was compared with a zinc oxide and eugenol sealer (Tubli-Seal) over a 32-wk interval to examine solubility in an in vitro simulation. After obturation with gutta-percha and the appropriate sealer, specimens were immediately immersed in a saline solution to challenge the sealers' solubility. The solutions were changed weekly to allow for a continued dissolution of the sealers and to prevent establishment of an equilibrium between the solution and the sealers. The 2- and 32-wk specimens were removed from the solutions, immersed in India ink for 3 days, and then made transparent by a clearing process. Microscopic examination was used to determine the linear penetration of the ink for each tooth. Results revealed that Sealapex statistically had no greater dissolution (based upon linear penetration) than Tubli-Seal at both 2 and 32 wk. It is suggested that Sealapex has a sealing ability comparable to Tubli-Seal and can withstand long-term exposure to tissue fluids without significant leakage. This may allow time for the biochemical action of the calcium hydroxide to stimulate physiological calcification of the apical foramen.