The ligature-induced periodontitis model: Literature overview and description of the technique

Abstract

The model of periodontal disease (PD) induction in rodents is a useful tool for studying this pathology, since it is possible to control various factors involved in its development and progression. There areseveral models to induce periodontitis in experimental animals, and placement of a ligature around a molar tooth is widely used. The aim of this chapter was to review the literature about periodontitis induction by ligature and describe the technique in rats and mice, based on the experience of the authors’ research group, to assist the researchers who wish to develop this model. For this purpose, the authors conducted a search in PubMed from January 2009 to April 2014, using the terms “periodontitis ligature rats” and “periodontitis ligature mice.” One hundred sixty five articles using rats and 11 articles using mice were selected. The following variables were analyzed: breed, type of thread (thickness and material), periodontitis induction time, teeth used, negative control and the method of analyzing alveolar bone loss. The most widely used rat breed was the Wistar (69.67% of the studies) and the most common ligature was made with a cotton thread (42.42%), 3-0 thickness (30.30%), in the mandibular first molars (47.27%) for the period of 1-14 days (58.19%), and using a different group of animals as negative controls (72.73%). Histometric evaluation was the most common method of analyzing bone loss (44.24%). In mice, the most widely used breed was the C57BL/6 (63.63%). Silk ligature thread (63.64%), 9-0 thickness (27.27%) in the maxillary second molars (54.54%) for the period of 1-14 days (54.54%) were the data most commonly found, in addition to macroscopic morphometry (63.64%) for alveolar bone loss analysis. The authors concluded that the PD induction model by ligation is effective in rodents. The breed, material and thread thickness, chosen tooth, negative control and PD induction time varied widely, and must be chosen for convenience or possibility of being compared with the literature.