Cytotoxic effects of activated bromine on human fetal osteoblasts in vitro

Although sodium hypochlorite is routinely used as an irrigant, the scope and limitation of another hypohalide sodium hypobromite has not been adequately studied. The objective of this study was to compare the cytotoxic effects of sodium hypobromite and sodium hypochlorite on human osteoblasts by evaluating cell proliferation. One day after plating and every other day after that, cells were treated with a combination of sodium hypochlorite and sodium bromide, resulting into three molar ratios of activated sodium hypobromite. Positive control cells were not treated with hypohalides, while negative controls were separately treated with hypochlorite or bromide alone. Photomicrographic analysis of the cultures was done on days 1 and 6 of treatment. Trypsinized cells were counted to determine cell proliferation. Our results show that sodium bromide is more cytotoxic compared to sodium hypochlorite or activated sodium hypobromite. In activated sodium hypobromite, 4:1 molar ratio was less cytotoxic compared to other molar ratios.