Experimental gingivitis in ODU plaque-susceptible rats. VI. Histopathological studies

The purpose of this study was to document the histological development of gingivitis in the plaque-susceptible ODU rat. Specimens were taken every 3 months over a 12 month period. In the 1st month a mile lymphocytic infiltrate was seen near the junctional epithelium. This infiltrate spread to the deeper connective tissue by the 3rd month. In the 6 to 9 month animals the cells of the junctional epithelium were partially destroyed resulting in beginning of sulcus ulceration. At this time osteoclasts were noted. By 12 months the cellular infiltrate was diffuse and large macrophages were evident. There were numerous enlarged capillaries.