Effects of proprietary oral rinses containing chlorhexidine, hexetidine and benzydamine on the proliferation of human buccal epithelial cells in culture.

Cell cultures were established from small samples of buccal tissue, using a 3T3 fibroblast feeder-layer technique. After exposure to increasing dilutions of three proprietary oral rinses for 22 h or 2 h, the effects upon cell proliferation were studied by measurement of [3H]-thymidine incorporation into cellular DNA. Cell membrane damage was assessed by measurement of lactate dehydrogenase content. Cultures exposed to hexetidine-containing or chlorhexidine-containing rinses for 22 h at dilutions of 250-fold or lower showed almost complete inhibition of [3H]-thymidine incorporation. Cultures treated with benzydamine-containing rinse at the same dilutions showed no significant inhibition of incorporation. Exposure to the same dilutions of hexetidine- and chlorhexidine-containing rinses for 2 h resulted in 65% and 20% inhibition of incorporation, respectively. Lactate dehydrogenase content decreased to negligible levels after exposure to the rinse containing hexetidine at a 250-fold dilution, but was unaffected by the other two rinses. Thus dividing buccal epithelial cells in vitro may be adversely affected by exposure to certain commercial oral rinses.