Evaluation Of Salivary Biomarkers In Patients With Periodontal Disease: A Case–Control Study

Abstract

Periodontal disease is a chronic inflammatory condition characterized by progressive destruction of the tooth-supporting tissues, ultimately leading to attachment loss, alveolar bone resorption, and tooth loss if left untreated. Early detection and accurate assessment of disease activity are essential for effective periodontal management; however, conventional diagnostic methods primarily evaluate historical tissue destruction rather than ongoing disease processes. In recent years, salivary biomarkers have emerged as promising non-invasive tools for the detection, monitoring, and risk assessment of periodontal disease because saliva can be collected easily, safely, and cost-effectively without the need for invasive procedures. Among the numerous biomarkers investigated, matrix metalloproteinase-8 (MMP-8) and interleukin-1β (IL-1β) have attracted considerable attention due to their close association with periodontal tissue destruction and inflammatory activity. MMP-8, a collagen-degrading enzyme released predominantly by neutrophils, plays a central role in the breakdown of periodontal connective tissue, while IL-1β is a potent pro-inflammatory cytokine that promotes inflammatory responses, osteoclast activation, and alveolar bone resorption. The present case–control study was conducted to evaluate salivary levels of MMP-8 and IL-1β in patients with periodontitis compared with periodontally healthy individuals and to assess their diagnostic performance as potential biomarkers of periodontal disease. A total of 150 participants were enrolled, comprising 75 patients diagnosed with periodontitis and 75 periodontally healthy controls. Unstimulated whole saliva samples were collected from all participants and analyzed for MMP-8 and IL-1β concentrations using enzyme-linked immunosorbent assay (ELISA) techniques. Biomarker levels were compared between groups, and their relationships with clinical periodontal parameters, including clinical attachment loss, were evaluated. Receiver operating characteristic (ROC) curve analysis was performed to determine diagnostic performance, including sensitivity, specificity, optimal cutoff values, and area under the curve (AUC). The results demonstrated significantly elevated salivary concentrations of both MMP-8 and IL-1β in individuals with periodontitis compared with healthy controls (p < 0.001). Furthermore, both biomarkers showed positive correlations with clinical attachment loss, indicating a close relationship between biomarker expression and disease severity. ROC analysis revealed that salivary MMP-8 exhibited excellent discriminative ability for identifying periodontitis, achieving an AUC of approximately 0.88. When MMP-8 and IL-1β were combined in a diagnostic model, the discriminative performance improved further, reaching an AUC of approximately 0.91, indicating high diagnostic accuracy. These findings suggest that salivary MMP-8 and IL-1β are reliable indicators of periodontal inflammation and tissue destruction and may serve as valuable adjunctive tools for periodontal screening and assessment. In conclusion, elevated salivary levels of MMP-8 and IL-1β were strongly associated with periodontitis and demonstrated good diagnostic performance, supporting their potential use as non-invasive biomarkers for the early detection, monitoring, and clinical evaluation of periodontal disease....