Experimental contact hypersensitivity in the gingiva of dogs

Application of l-dinitro-2.4-chlorbenzene (DNCB, 0.05 % in Orabase^®) onto the gingiva in one side of the jaws was performed daily for six days in a group of sensitized dogs. Contralaterally only the vehicle was applied. Anti-thymocyte serum (ATS) was injected into the dogs after three days of application. The effects on the gingiva were studied by inflammatory cell counts in sections of gingival biopsies and by measurements of crevicular leukocytes, gingival fluid and acid phosphatase activity in crevicular samples.
The numbers of inflammatory cells in the gingival biopsies as well as the figures of the gingival crevice parameters were higher in the DNCB side as compared to the control side on day 3. Immuno-suppression with ATS affected all parameters as observed from the data of day 6 of the experiment. The results of the study indicate that gingival contact hypersensitivity to DNCB can be elicited in beagle dogs and that this reaction is reflected in crevicular parameters of gingival inflammation.