The Role of Saliva and Mouthwashes in the Detection and Reduction of Oral Viral Load: A Scoping Review

Background: The oral cavity is an entry site and a reservoir for viruses. Viral particles accumulate in saliva, which serves as a diagnostic fluid and vehicle for transmission (droplets and aerosols). Antiseptic mouthwashes were proposed as adjunctive measures to temporarily reduce oral viral load. Objectives: This scoping review aims to investigate the role of the oral cavity in viral infections, focusing on saliva and the use of antiseptic mouthwashes to reduce salivary viral load. Methods: Following the PRISMA-ScR guidelines, PubMed, EMBASE, and Web of Science were searched for human studies (2015–2025) investigating oral viral infections, saliva, or mouthwashes. Eligible studies were classified and analyzed for population, intervention, and outcomes. Results: Twenty-three studies met inclusion criteria (sixteen randomized controlled trials and seven systematic reviews). All included studies focused exclusively on SARS-CoV-2, as no clinical evidence on other oral viruses met the eligibility criteria. Saliva was consistently identified as a reliable, non-invasive specimen reflecting disease dynamics and transmission potential. Mouthwashes containing povidone-iodine, cetylpyridinium chloride, chlorhexidine, hydrogen peroxide or β-cyclodextrin–citrox produced measurable but short-lived reductions in salivary viral load. Heterogeneity and lack of standardized outcomes limited comparability. Conclusions: Antiseptic mouthwashes can provide a transient and complementary reduction in salivary viral load, particularly before aerosol-generating procedures; however, they should be regarded only as adjunctive measures and not as substitutes for standard infection-control protocols.