Determination of systemically & locally induced periodontal defects in rats.

BACKGROUND & OBJECTIVE The role of lathyrogens on bone metabolism is unclear, therefore we undertook this study to observe periodontal and systemic alterations in experimental lathyrism in rat and compare these changes to that observed in the locally induced periodontitis group. METHODS A total of 45 male Wistar rats were equally divided in the lathyritic group (group 1), ligature-induced periodontitis group (group 2), and healthy controls (group 3). Experimental lathyrism was induced by once daily subcutaneous administration of beta-aminoproprionitrile (beta-APN), at a dose of 5 mg/0.4 ml per 100 g of body weight for 40 days. Ligature-induced periodontitis was created by tying silk ligatures on the necks of mandibular molars. After 40 days, blood samples were obtained and the animals were decapitated. Radiographic observations, extraction tests, histologic evaluations were performed, and serum ALP activity and gingival tissue IL-1beta levels were measured. RESULTS Significant alveolar bone resorption around the mandibular molar teeth (P<0.001); lower extraction force levels (P<0.001); higher numbers of lymphocytes and macrophages (P<0.01) (both in connective tissue and epithelium at the dentogingival junction); decreased ALP activity (P<0.001); and increased gingival tissue IL-1beta levels (P<0.001) were observed in groups 1 and 2, compared to those in group 3. ALP activity was higher in group 1 than in group 2 rats (P<0.05). INTERPRETATION & CONCLUSION Similar radiographical and histopathological findings and comparable increases in gingival tissue IL-1beta levels both in groups 1 and 2 showed that in addition to resorption of alveolar bone, chronic inflammation of periodontium also occurred both in the lathyritic rats as well as in ligature-induced periodontitis group rats.