Sealing properties of Ketac-Endo glass ionomer cement and AH26 root canal sealers.

Sealing capacity, setting shrinkage and setting time of a recently introduced glass ionomer cement Ketac-Endo were compared with that of a conventional sealer AH26. Sixty half-cylinders, 8 mm long, 4 mm in diameter, made from fresh bovine root dentine, had their smear layer removed before being cemented together while separated by 1-mm spacers. This resulted in a group of 15 cylinders cemented with Ketac-Endo and a similar group with AH26. After coating the lateral surface with nail varnish, one end of each cylinder was connected with a tube filled with water under 120 kPa (1.2 atm) pressure. At the other end the fluid leaking through the cemented interface of the cylinders was measured by displacement of an air bubble in an attached standard glass capillary. In this particular set-up where the sealers were used in bulk between two opposing dentine surfaces, Ketac-Endo leaked significantly more than AH26. After shear loading the cemented specimens, it was found that the area of adhesive failure was 88% for Ketac-Endo, and 15% for AH26. The leakage pathways were most probably at the dentine-sealer interface for Ketac-Endo and through cohesive fractures in the sealer for AH26.