Periodontitis is a chronic inflammatory disease influenced by microbial challenges and host immune responses, with Th17 cells playing a central role in both protection and tissue destruction. These cells contribute to immune defense by producing cytokines such as IL-17, IL-22, and IL-23, which stimulate neutrophil recruitment, antimicrobial peptide secretion, and epithelial barrier integrity. This early response is crucial for controlling bacterial biofilms and maintaining periodontal health. However, when dysregulated, Th17 responses promote excessive inflammation, oxidative stress, and osteoclast activation, leading to alveolar bone resorption and tissue destruction.