Investigation of DNA reactivity of endodontic agents by rec-assay.

Eight endodontic agents were tested for their reactivity with DNA by the rec-assay system. Employing 2 strains of Bacillus subtilis with different recombination capacities, the assay suggested that DNA damage is produced by agents for root canal cleaning containing sodium hypochloride. Other endodontic drugs, including disinfectants for caries cavities, sedatives for pulp, root canal disinfectants, and pulp devitalizing agents containing phenol, camphor, tricresol, formalin, and paraformaldehyde were also positive by rec-assay and would seem to potentially of damage cellular DNA in Bacillus subtilis. Though no clear evidence exists that drugs showing positive results by rec-assay induce malignant tumors in the oral region, these agents should be used carefully since they would seem to possibly cause genetic toxicity in mammalian cells.