Cell populations associated with interdental gingival bleeding. 
The purpose of this study was to characterize the cell populations of the mid-interproximal gingival tissue related to the presence or absence of bleeding.  15 bleeding and 15 non-bleeding interproximal gingival biopsies were obtained from 30 patients and processed for light microscopic evaluation.  Morphometric analysis of tissue components revealed that bleeding was associated with an inflammatory lesion located in the mid-interproximal connective tissue.  The inflammatory infiltrate was dominated by mononuclear cells of the lymphocyte/macrophage/monocyte group, and the proportions of plasma cells and polymorphonuclear leukocytes were relatively small.  The results of this study indicated that interproximal bleeding can be associated with an inflammatory infiltrate not dominated by plasma cells.  The rôle of gingival bleeding in the diagnosis of periodontal disease activity is discussed.