RESUMO
OBJECTIVE: The histologic and TNF-alpha changes of the experimental periodontitis were studied in diabetic rat model in different periods. The mechanism of the occurring and developing of periodontitis was probed on the aspect of cytology. METHODS: The diabetic rat models were established by injecting streptozotocin into its abdomen. The local stimulation was caused by tiring silk thread to teeth. The histologic changes of periodontium were observed at 6,9,and 12 weeks. The level of TNF-alpha was testified using immunohistochemistry method at 12 weeks. RESULTS: Periodontitis occurred in diabetic rats earlier than in non-diabetic ones. The destructions were more severe and more widely in diabetic rats than in non-diabetic ones. The level of TNF-alpha was higher in the experimental periodontium of diabetic rats than those non-diabetics. CONCLUSIONS: Diabetes mellitus has an accelerating effect on occurring and developing of periodontitis. When with diabetes, more cytokines were released, and cause the unbalance of ruin and repair and result in the enhancing of periodontitis.