We aim to assess the association between periodontal disease stage and grade and systemic inflammatory biomarkers, C-reactive protein (CRP), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in patients with periodontitis and evaluate the changes in these biomarkers following standardized non-surgical periodontal therapy. This evidence concerns the gene CRP and periodontitis.