Inflammatory Cytokine Variations After Non-Surgical Periodontal Therapy Across Periodontal Stages and Grades

<b>Background:</b> Periodontitis is associated with systemic inflammation; however, the relationship between disease severity and systemic inflammatory biomarkers remains unclear. This study aimed to evaluate the association between periodontitis stage and grade with systemic levels of C-reactive protein (CRP), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) and assess changes following standardized non-surgical periodontal therapy. <b>Methods:</b> Patient records from the University Dentistry Clinical Center of Kosovo were reviewed. Periodontitis was classified using the 2018 staging and grading system. Periodontal parameters (probing pocket depth, clinical attachment loss, bleeding on probing, plaque index, and gingival index) were assessed at six sites per tooth (excluding third molars). Serum levels of IL-1β, IL-6, TNF-α, and high-sensitivity CRP were measured before and after therapy using high-sensitivity ELISA. Blood samples were centrifuged, and serum was stored at -20 °C. All patients underwent standardized non-surgical periodontal therapy, including full-mouth scaling and root planning, without systemic antibiotics. Data were analyzed using SPSS v22.0. <b>Results:</b> Among the patients, 28.0% had Stage I-II, 40.0% Stage III, and 32.0% Stage IV periodontitis; 29.3% were Grade A, 45.3% Grade B, and 25.3% Grade C. At baseline, all systemic inflammatory biomarkers (CRP, IL-1β, IL-6, and TNF-α) were significantly higher in periodontitis patients compared with the control group, indicating an increased systemic inflammatory burden before therapy. After therapy, significant reductions in CRP, IL-1β, IL-6, and TNF-α were observed across all stages and grades (all <i>p</i> < 0.01), indicating a decrease in systemic inflammatory burden. <b>Conclusions:</b> Non-surgical periodontal therapy significantly lowers systemic inflammatory biomarkers regardless of periodontitis severity, supporting their role as indicators of disease activity and treatment response.