Salivary biomarkers and their diagnostic importance in oral diseases.

OBJECTIVE: This review critically evaluates the diagnostic potential of salivary biomarkers in oral diseases, highlighting their role as non-invasive tools for early detection, disease monitoring, and precision oral healthcare. DESIGN: A narrative review was conducted using PubMed, Scopus, Web of Science, and Google Scholar for studies published between 2005 and 2026. Keywords included salivary biomarkers, salivaomics, oral diseases and diagnosis. Only English peer-reviewed articles focusing on salivary biomarkers and analytical methods in oral diseases were included, while studies lacking clinical relevance were excluded. RESULTS: Saliva harbors a variety of molecular biomarkers, such as proteins or nucleic acids, that mirror local and systemic pathological phenomena8. In oral squamous cell carcinoma, salivary biomarkers like Interleukin-6 (IL-6) and Interleukin-8 (IL-8) have a sensitivity of 70-90% and a specificity of 75-95%; however, salivary microRNAs display strong discriminatory power with AUC values ≥ 0.85. For periodontal diseases, MMP-8, among others, found in the biomarkers, shows high accuracy (AUC > 0.80). Recent progress in salivaomics, including proteomics, genomics, metabolomics, and microbiomics, has notably increased detection sensitivity, specificity, and clinical applicability. However, heterogeneity of biomarker expression, lack of a clinically validated standardized protocol for the collection and processing of saliva, and insufficient large-scale clinical validation are still significant limitations to everyday clinical utilization. CONCLUSIONS: Salivary biomarkers are non-invasive and offer an opportunity to complement traditional diagnostic sources in oral health. Further standardization, clinical validation and adaptation of multi-omics and artificial intelligence-based technologies are necessary to facilitate their positive translation into precision oral medicine.