Numerous and varied chemical agents are used as topically applied drugs in dental practice. As they are administered directly to the oral cavity, it is important to study the safety of these agents. In the present study, to assess safety regarding mutagenicity, we investigated the abilities of six antiseptics to induce chromosome aberrations in human dental pulp cells. The antiseptics tested were benzalkonium chloride, benzethonium chloride, iodine glycerin, iodine tincture, oxydol, and povidone-iodine. In addition, we tested two agents used for root canal enlargement and cleaning, ethylenediaminetetraacetic acid and sodium hypochlorite. Chromosome aberrations were induced only in cells treated with the highest concentration of iodine tincture for 30h. The other chemical agents failed to induce chromosome aberrations in the presence or absence of exogenous metabolic activation. The concentration of iodine tincture to which patients are exposed in dental practice is 1000-fold the concentration that induced chromosome aberrations in the present study. Our findings suggest that iodine tincture is mutagenic to human cells.