[Clinical and biochemical analysis of ligature-induced periodontitis in rats]

The most common experimental model of periodontitis is a "ligature" model. However due to the complexity connected with performing on rats, modification of existing model is proposed, which differs by fixture of cotton ligature around the central incisor and not around the second molar. The purpose of research - a comparative evaluation of "peroxide" and modified by us, "ligature" models of periodontitis in rats. 2 series of experiments on 36 white Wistar rats were conducted. The animals were divided into two groups: intact rats (control) and rats with a "peroxide" model of periodontitis, which was reproduced by the addition to the diet of rats overoxidized sunflower oil (5% by weight of the feed), daily, for 45 days. "Ligature" model in rats was reproduced by applying a cotton ligature on the central incisor of the upper jaw for 14 days. Elastase activity, malondialdehyde content and catalase activity in the gums and in the blood serum was measured by biochemical methods. The degree of atrophy of the alveolar bone of the mandible was determined by morphometric method. It is found that in both models of periodontitis in rats, changes in the periodontal tissues and in the organism as a whole, is common for periodontal disease in humans. Clinically apparent inflammation of the periodontal tissues is observed, metabolic disorders in the gums, change of biochemical parameters in serum and progressive decline in the alveolar bone are determined. A comparative analysis of the two models showed that the modified "ligature" model of periodontitis in rats has several advantages over the "peroxide" model: shorter term of modeling, more pronounced clinical inflammation of periodontal tissues and faster resorption of alveolar bone.