Long term effect of systemic tetracycline administration on the severity of induced periodontitis in the rat.

The present investigation was undertaken to determine the influence of systemically administered tetracycline on periodontitis in the rat. Thirty Sprague-Dawley rats were arranged into two groups, one group received 21 mg of tetracycline hydrochloride each day for 10 weeks in the drinking water. Periodontitis was induced in the maxillary left segment with a 0.008 inch stainless steel ligature wire and by modifying the normal diet with sucrose. The direct microscopic and histometric measurements obtained were analyzed for statistical significance, which revealed the following: 1. Tetracycline-treated animals demonstrated significantly less resorption of the buccal alveolar bone. There were no statistical differences however, in the amount of alveolar bone resorption palatally or interdentally. 2. Tetracycline-treated animals demonstrated significantly less apical migration of the junctional epithelium on the distal root of the maxillary first molar tooth. 3. Tetracycline-treated animals demonstrated significantly fewer inflammatory cells. In conclusion, long term systemic administration of tetracycline in the rat may be of value in reducing the amount of tissue destruction in experimentally induced periodontitis.

Vitamin E and periodontitis in the rat.

This investigation was designed to study the effect of vitamin E on the course of periodontitis in thirty-six adult male albino rats. The rats were divided into three groups of twelve and placed on test diets which consisted of pelleted feed that either was deficient in, or contained adequate and high amounts of, vitamin E. After the animals had been on their respective diets for 8 weeks, a local irritant in the form of a stainless steel wire was placed around the maxillary left second molar of each animal. The wire served both as a mechanical irritant and as a collector of plaque and debris. Six weeks after the wire was placed, the animals were killed and the periodontium was examined histologically. Migration of the epithelial attachment, alveolar bone level, and numbers of inflammatory round cells were then evaluated on both sides of the maxilla. Multivariate analysis of variance was used to determine significant difference in the parameters. The results of this experiment indicate that a deficiency of vitamin E does not cause increased destruction of the periodontium in the presence of periodontitis. Moreover, no beneficial effects from the therapeutic use of vitamin E to combat periodontitis were found.