Cultured primary osteoblast viability and apoptosis in the presence of root canal sealers

This study was designed to test the hypothesis that Roekoseal is less cytotoxic than eugenol-based Sealapex or calcium hydroxide-based Kerr's Pulp Canal Sealer. Embryonic., day-19, rat calvarial osteoblasts were cultured at 4 x 10(5) cells/well. The concentration of conditioned medium from each sealer producing 50% surviving cells (ED50) was determined and long-term viability and apoptosis of cells assessed after exposure to the ED50 of each sealer. Low concentrations of Kerr's Pulp Canal Sealer (190 mm(2)/l ml) and high concentrations of Sealapex and Roekoseal (190 mm(2)/300 mul) produced the ED50. ED50 challenged osteoblasts had fewer viable cells at 72 h than at 24 h, with significantly more viable cells; in the Roekoseal group. There was significantly less apoptotic activity in cells exposed to Roekoseal ED50 than in cells exposed to Kerr's Pulp Canal Sealer (p < 0.05) ED50. Roekoseal may be less cytotoxic than Kerr's Pulp Canal Sealer, but further studies of this new sealer are required.