Cell-mediated immune response to dog pulp tissue altered by eugenol within the root canal

After pulpal extirpation of twenty teeth in each of four dogs, these animals were primarily immunized intramuscularly with the dog's own pulp (three dogs) and saline solution with pulp (one dog). A fifth dog was used as a control for skin tests. Secondary immunizations were accomplished via the root canal every 7 days over a 28-day period. Cell-mediated skin-test reactions demonstrated less of a response to the eugenol alone than when the dog's pulp was incubated with this material. In vitro analysis of cell-mediated immune response (lymphocyte proliferation) showed a marked response to the pulp altered by eugenol as compared to the saline-treated pulp (p less than 0.004). Therefore, dog's pulp tissue became antigenically altered by eugenol material, recognized by the host, and a specific cell-mediated lymphocyte proliferation resulted.