Molecular Biomarkers of Periodontal Health: Biological Significance of Salivary and Gingival Crevicular Fluid Markers in Periodontal Homeostasis: A Cross-Sectional Study

Abstract

Background: Periodontal diseases are chronic inflammatory conditions characterized by alterations in host immune responses and progressive destruction of tooth-supporting tissues. Salivary and gingival crevicular fluid biomarkers, particularly interleukin-1β (IL-1β), interleukin-6 (IL-6), and matrix metalloproteinase-8 (MMP-8), have emerged as promising indicators of periodontal inflammation and tissue degradation.

Objective: To evaluate the relationship between salivary and gingival crevicular fluid concentrations of IL-1β, IL-6, and MMP-8 and clinical periodontal parameters among individuals with periodontal health, gingivitis, and periodontitis.

Methods: An analytical cross-sectional study was designed for Peshawar Dental College and Khyber Medical University, Peshawar, from March 2025 to April 2026. The proposed sample comprised 87 adults, equally distributed among periodontally healthy participants (n=29), patients with gingivitis (n=29), and patients with periodontitis (n=29). Clinical parameters included plaque index, gingival index, probing pocket depth, clinical attachment loss, and bleeding on probing. Salivary and gingival crevicular fluid concentrations of IL-1β, IL-6, and MMP-8 were to be determined using enzyme-linked immunosorbent assay. Group comparisons and correlations were planned using appropriate statistical tests, with p<0.05 considered significant.

Results: In the analysis of 87 participants, 29 (33.3%) were classified as periodontally healthy, 29 (33.3%) had gingivitis, and 29 (33.3%) had periodontitis. The mean age was 34.64 ± 8.09 years. Clinical periodontal parameters, including plaque index, gingival index, probing pocket depth, clinical attachment loss, and bleeding on probing, differed significantly among the groups (p<0.001). Median salivary IL-1β concentrations increased from 57.5 pg/mL in healthy participants to 145.8 pg/mL in gingivitis and 226.1 pg/mL in periodontitis (p<0.001). Corresponding IL-6 concentrations were 14.3, 40.2, and 48.5 pg/mL, while MMP-8 concentrations were 14.5, 34.0, and 42.2 ng/mL, respectively (both p<0.001). Gingival crevicular fluid biomarkers also differed significantly among the groups (p<0.001). Salivary IL-1β demonstrated strong positive correlations with probing pocket depth (r=0.78) and bleeding on probing (r=0.77), while IL-6 and MMP-8 were positively associated with clinical periodontal parameters.

Conclusion: IL-1β, IL-6, and MMP-8 are biologically relevant candidates for evaluating periodontal inflammation and tissue degradation. Their clinical diagnostic utility requires confirmation through validated biomarker measurements and analysis alongside established periodontal examination parameters.