Development of experimentally-induced periodontitis in a Sprague Dawley rat model

Abstract

Periodontitis is a common inflammatory disease that leads to the degradation of periodontium and results in alveolar bone loss. The development of a suitable animal model of periodontitis is a prerequisite to understanding better the mechanisms that underly this disease. This study evaluated periodontal disease induction via retentive ligature, intragingival injection of lipopolysaccharide (LPS), and their combination in a rat model.Seventy-two Sprague Dawley rats were divided into four groups. The first group (control) did not receive any treatment. The second group underwent the application of 4/0 nylon ligature around the second maxillary molars. The third group was treated with an intragingival injection of Porphyromonas gingivalis LPS into the palatal mucosa of the second maxilla molars, and the fourth group was treated with a combination of ligature and LPS injection (ligature-LPS). Morphological changes in the gingival tissues were evaluated after 7, 14, and 30 days of treatment.Significant degenerative changes were observed in the periodontal tissues and alveolar bone in the third and fourth groups, which were evident as early as seven days. The lesions remained until 14 days and declined with time in the third and fourth groups. The changes induced by ligature and ligature-LPS were not different. Injection with LPS alone resulted in minimal increases in the Gingival and Plaque Indices.The ligature technique induced periodontal disease successfully, more effective than the injection of LPS. The combination of ligature with LPS injection added no significant effect compared to ligature alone.

Keywords

• alveolar bone
• periodontitis
• porphyromonas gingivalis
• lipopolysaccharide