Effect of local applications of chlorhexidine on the oral mucosa of the hamster

The effects of local applications of a 2.2 mM (0.2 per cent) chlorhexidine gluconate solution on the oral mucous membranes have been evaluated by vital microscopy and histological and enzyme histochemical methods. Chlorhexidine gluconate applied onto intact or dekeratinized hamster cheek‐pouch did not induce microvascular disturbances in the underlying connective tissue. On a defective cheek‐pouch surface, however, the test solution caused hemolysis, intravascular granulo‐cytosis and thrombus formation. These observations indicate that chlorhexidine gluconate does not penetrate the undamaged oral epithelium. Daily application of 2.2 mM chlorhexidine gluconate on the palatal or sublingual mucosa did not induce reactions in the underlying connective tissue. The application of the test solution onto the oral epithelium, however, induced an increase in non‐enzymic formazan deposition in the surface layers. These staining reactions, which developed rapidly, did not appear to increase during prolonged administration.