The chemical reactions of irrigants used for root canal debridement

This study determined the amount of chlorine gas that was evolved when a sodium hypochlorite solution was mixed with other root canal irrigating solutions (hydrogen peroxide, citric acid, or EDTA). Significantly more chlorine gas was evolved when the sodium hypochlorite solution was mixed with the citric acid solution than with the EDTA solution. Mixing the sodium hypochlorite solution with a hydrogen peroxide solution did not evolve any detectable concentration of chlorine gas. From the observations made, the stoichiometry of the chemical reactions was developed.