Murine Models of Experimental Periodontal Disease

Periodontal disease (PD) is a chronic inflammatory process of infectious etiology that affects the periodontal tissues. PD is caused by the subgingival biofilm, which, in dysbiosis, leads to an uncontrolled response of the immunological system in the periodontal tissues. To further understand the mechanisms involved in PD and how it is linked to other diseases, several animal models have been developed. These models allow researchers to study the different aspects of PD in a controlled setting, such as its pathogenesis and treatment options. Oral inoculation of periodontal bacteria, such as Aggregatibacter actinomycetemcomitans or Porphyromonas gingivalis, is one of the most commonly used models for studying PD. In these methods, the bacteria are inoculated directly into the oral cavity, allowing for rapid colonization and development of the disease. Another widely used mouse model for PD involves the application of a silk ligature around the second molar, the ligature triggers oral micro-organisms accumulation inducing an inflammatory response in the surrounding tissues, leading to gingival inflammation and pocket formation. The application of mouse models of PD has several advantages, such as relatively low cost, fast results, and the possibility of performing more accurate studies. In this chapter, we will describe bacteria- and ligature-induced periodontal disease models in detailed steps.