Salivary Matrix Metalloproteinase-7, Human Beta-Defensin 1, and Mucin-4 as Potential Diagnostic Biomarkers in Periodontal Disease: A Review

Periodontal diseases are a group of chronic, immune-mediated inflammatory conditions affecting the periodontium, the supportive structures of the teeth. With severe forms affecting nearly 20% of the worldwide adult population, these diseases represent a significant global health challenge. Their impact extends beyond the oral cavity, as periodontitis is a recognized risk factor for systemic conditions like cardiovascular disease and diabetes mellitus. Characterized by the progressive destruction of tooth-supporting tissues, early diagnosis is crucial to prevent tooth loss. However, conventional diagnostic methods primarily quantify historical tissue damage rather than indicating current disease activity or predicting future progression. To overcome these limitations, research has focused on biomarkers, objectively measured characteristics that can indicate normal biological processes or pathogenic states. Saliva has emerged as a promising diagnostic biofluid for such analysis, due to its non-invasive collection and rich composition of biomolecules. This review evaluates the potential of three functionally distinct salivary biomarkers. Evidence suggests that levels of matrix metalloproteinase-7, an epithelial-derived enzyme involved in tissue remodeling, are elevated in periodontitis, indicating active tissue degradation. Conversely, mucin-4, a transmembrane protein that forms a protective barrier, is consistently found at lower concentrations in saliva, suggesting a compromised or degraded mucosal shield. The role of human beta-defensin 1, a constitutively expressed antimicrobial peptide involved in innate immunity, remains ambiguous due to inconsistent findings across studies. While these salivary biomarkers show considerable promise, large-scale validation studies are essential to confirm their clinical utility for early diagnosis, risk assessment, and monitoring of periodontal diseases.