IL6 and periodontitis: Research shows that patients with periodontitis have a significantly higher level of serum markers of oxidative stress as well as inflammation markers (such as C-reactive protein (CRP), IL-1, IL-6, and fibrinogen) compared to healthy individuals, and that periodontal therapy, in addition to reducing the clinical signs of periodontal inflammation, also leads to their reduction in serum [102,103,104,105,106,107,108].