Necrotizing ulcerative gingivitis in beagle dogs. II. Histologic characteristics of NUG in relation to interproximal contacts

Clinical studies in beagle dogs have indicated that NUG occurs at sites of predilection. The purpose of the present investigation was to compare the histologic characteristics of interdental sites exhibiting clinical NUG with those without clinical NUG in relation to the presence or absence of interproximal contacts. In six beagle dogs, aged three years, NUG was experimentally induced. At the end of a longitudinal clinical study the dogs were sacrified and prepared for histological evaluation. The occurrence of ulcerations in the col epithelium and the adjacent epithelium is related to the clinical NUG scores as well as to the presence of interproximal contact. The same holds true for the presence of an inflammatory infiltrate in the subjacent connective tissue. Ulcerations of the col epithelium as well as the infiltrate subjacent to this area appears to be related to the clinical NUG scores, but the ulcerations in the sulcular and junctional epithelium are not, nor is the infiltrate subjacent to these epithelial areas. The results suggest two possibilities. The first is that the clinical NUG score is insufficient to trace the sulcular expression of the disease, and the second possibility is the existence of two different periodontal diseases in these beagle dogs.