Bacterial Invasion on Spontaneous Gingivitis in SUS Rats

Abstract

The gingival tissues from SUS rats with naturally occurring gingivitis were examined histopathologically. The observations indicated that the inflammation at the early stage was severe neutrophilic infiltration with edema and that the lesion progressed to subacute-chronic inflammation rich in plasma cellular infiltration. Electron microscopic observation indicated that rod-shaped bacteria were present in the connective tissue of gingiva at both inflammation stages. RES rats (control) showed no gingival inflammation and bacterial invasion on the surface of the gingiva. These findings suggested that bacterial invasion can occur at all stages of naturally occurring gingivitis and that it directly affects the gingival tissues