<p>Periodontitis disease (PD) is a serious gum infection that progresses from gingivitis. PD is defined by gingival recession and bone loss and can lead to tooth loss. Bacterial infections are the main cause, as they induce inflammation and the development of periodontal pockets. Traditional therapies such as scaling and root planning aim to remove the subgingival biofilm via mechanical debridement but fail to address the fundamental inflammatory imbalance within the periodontium. The immune homeostasis linked to periodontal health necessitates a regulated immuno-inflammatory response, within which the presence of regulatory cells is critical to guarantee a managed response that reduces unintended tissue damage. Given that regulatory cells influence both innate and adaptive immunity, pathological conditions that might be alleviated through the establishment of immuno-tolerance, such as PD, could potentially gain from the application of regulatory cell immunotherapy. This review will reveal regulatory cell types, how they change phenotypes, and how they can be targets for new immunotherapies. As our understanding of regulatory cell biology advances, we can create novel therapeutics to improve their stability and function in PD.</p>