In vitro evaluation of the sealing ability of a calcium phosphate cement when used as a root canal sealer-filler.

A calcium phosphate cement (CPC) was examined for its ability to seal the root canal when used as a sealer-filler. Extracted human teeth were divided into three groups. Root canals were filled with either CPC paste containing dicalcium phosphate anhydrous (group 1), CPC containing dicalcium phosphate dihydrate (group 2), or gutta-percha points sealed with Grossman's cement (group 3). After filling, all specimens were kept in 100% humidity for 1 day, immersed in a CaPO4 solution or distilled water at 37 degrees C for 1 wk, and then immersed in 1% Poly-R dye solution at 37 degrees C for 1 wk, after which they were rinsed and sectioned longitudinally for microscopic examination. Specimens in groups 1 and 2, especially those aged in the CaPO4 solution showed considerably less dye penetration than those in group 3. The good sealing ability of the CPC against dye penetration in vitro suggests that it may provide an adequate seal of the canal without a separate sealer.