Experimental gingivitis in humans. A clinical and histologic investigation

AN EXPERIMENTAL GINGIVITIS STUDY was carried out to relate the clinical parameters (plaque and gingival index) to the histologic appearance of the associated gingival lesions. Fifteen third-year dental students took part in the study. Following the withdrawal of oral hygiene, biopsies were taken on days 0, 4, 8 and 21 of the experimental period. A statistically significant association was found between the plaque and gingival indices and the various time intervals throughout the experimental period (P less than 0.001). At day 0, although all sites had a GI of 0, all but 2 of the 15 specimens showed some degree of inflammation. Histologically, these lesions consisted of over 60% lymphocytes, while plasma cells comprised less than 5% of the infiltrating population. Although the degree of inflammation increased both clinically and histologically throughout the experimental period, the nature of the infiltrate did not change significantly. Lymphocytes remained as the dominant cell type. In fact, no association was seen between the degree of inflammation and the nature of the infiltrating cells.