Comparative Testing of Two Ligature-Induced Periodontitis Models in Rats: A Clinical, Histological and Biochemical Study

Simple Summary This study is the first study comparing the same parameters of inflammation in two periodontal disease experimental models proposed by the literature and used in the research. The importance of the method used to induce periodontitis in animals resides in the efficacy of proposed technologies and treatments used in preclinical trials. The inflammatory markers Interleukin-1 alpha(IL-1 alpha), Tumor Necrosis Factor-alpha (TNF-alpha), and high sensitive C reactive protein (hsCRP), the hematological analyses, and the histological probes showed a similar and reproducible periodontal inflammation for the molar induced periodontitis model. Ligation-induced periodontitis in rats has limitations and will never reproduce all aspects of periodontal disease in humans. The findings of this study with the complex association between clinical, biochemical, and histological aspects of the two experimental models of periodontal pathology induction in rats suggest that a similar periodontal pathology to the one we find in humans is best replicated in rats with the molar induced periodontitis model. Experimental animal models for studying the mechanisms of periodontitis and its links are a better alternative to in vitro studies. The aim of this study is to compare two ligature induced periodontitis models and validate the best one for further use in research. An experimental study was performed on male Wistar rats that were divided into three groups: Test 1 (n = 10), incisor ligated, Test 2 (n = 10), molar ligated, and Control (n = 10). The animals were clinically evaluated at the beginning and at the end of the experiment by recording body weight, gingival bleeding index, tooth mobility score, changes in color, and consistency of gingival tissue. Two blood samples were obtained for each animal at baseline and at the end of the experiment. The hematological parameters Interleukin-1 alpha (IL-1 alpha), high sensitive C Reactive Protein (hsCRP), and Tumor Necrosis Factor-alpha (TNF-alpha) were measured. Seven days after the induction of periodontitis, the animals were sacrificed, and samples were prepared for histological evaluation. The results of this research demonstrated that the association between clinical, histological, and biochemical parameters initiate a periodontal pathology in the molar induced model in rats while the incisor experimental model initiates only a moderate and incomplete periodontal inflammation, mainly due to mechanical irritation.