Leukoplakia induced by repeated deposition of formalin in rabbit oral mucosa. Long-term experiments with a new "oral tank".

Rabbits were exposed repeatedly to formalin irritation using a new oral tank which allows a chronical contact with the oral mucosa. In long-term experiments (11 months) a preneoplastic unrest of the epithelium with dyskeratosis could be produced. This new model of "oral tank" can be used for soluble and insoluble test substances for analyzing pathogenetic processes in the oral cavity.