HISTOPATHOGENESIS OF SPONTANEOUS PERIODONTAL-DISEASE IN CONVENTIONAL RATS .1. HISTOMETRIC AND HISTOLOGIC-STUDY

The development of gingivitis and periodontitis lesions in rats fed a normal laboratory chow diet was compared to that which occurred in rats fed a high sucrose diet (Keyes'diet 2000). Histometric analysis of mesio‐distal sections through the 1st maxillary interdetal area revealed that the area of inflamed connectve tissue(ICT) increased more rapidly in the diet 2000 group. A greater incidence of periodontitis lesions with active bone resorption was noted in the diet 2000 group. Analysis of cell types in the ICT revealed no statistically significant differences between the two diet groups. However when the percent age of various cell types present in the periodontitis lesions of both dietary groups were compared to the percentage of the cell typed present in the periodontitis lesions of both dietary groups were compared to the percentage of the cell typed persent in gingivitis lesions a statistically significant increase in both large mononuclear cells was found to exist in the ICT of the Periodontitis lisions. A statistically significant decrease in the number of endothelial cells was also observed in periodontitis lesions. At the ultrastructural level cytopathologic alterations of fibroblasts and decreased collagen fibers were noted beneath the gingival epithelium. Denudation of the cemental surface beneath the epithelial attachment became progressively more severe and preceded the migration of the epithelium along the cemental surface. Copyright © 1979, Wiley Blackwell. All rights reserved