Saliva-Based Digital Biomarkers for Population Oral Health Screening: Current Evidence and Future Perspectives

Abstract

Background: Oral diseases affect more than 3.5 billion people worldwide and remain a major public health concern. Conventional diagnostic methods are often invasive, expensive, and unsuitable for large-scale community screening. Saliva has emerged as an attractive diagnostic biofluid because it contains diverse molecular constituents that reflect both oral and systemic health. Recent advances in salivaomics, biosensor technologies, artificial intelligence (AI), microfluidics, and point-of-care diagnostics have transformed salivary analysis into a promising platform for digital biomarker-based disease detection. Objective: To critically review the current evidence on saliva-based digital biomarkers for population oral health screening, highlight recent technological advances, summarize their applications in major oral diseases, and discuss their potential role in precision dentistry and public health. Methods:  A narrative review was conducted using PubMed/MEDLINE, Scopus, Web of Science, Embase, Google Scholar, and the Cochrane Library. English-language studies published primarily between January 2020 and June 2026, including original research, systematic reviews, meta-analyses, consensus statements, and technological reports, were evaluated. Landmark publications published before 2020 were included where appropriate. Results:  Evidence indicates that salivary digital biomarkers can identify molecular alterations associated with dental caries, periodontal diseases, oral potentially malignant disorders, oral squamous cell carcinoma, peri-implant diseases, and salivary gland dysfunction. Emerging technologies—including electrochemical biosensors, lab-on-chip systems, microfluidic devices, wearable intraoral sensors, smartphone-assisted diagnostics, and AI-driven analytical platforms—have substantially improved diagnostic sensitivity, specificity, portability, and real-time monitoring. These innovations facilitate decentralized screening, personalized risk prediction, and continuous disease surveillance, making them particularly suitable for school-based programs, rural outreach services, tele-dentistry, and community oral health initiatives. Conclusion: Saliva-based digital biomarkers represent a paradigm shift in oral diagnostics by combining non-invasive sampling with advanced digital technologies. Although further multicenter validation, standardization, regulatory approval, and cost-effectiveness studies are required, these technologies have considerable potential to revolutionize population oral health screening and advance precision public health.