This review examines the diagnostic application of saliva for systemic diseases. As a diagnostic fluid, saliva offers distinctive advantages over serum because it can be collected non-invasively by individuals with modest training. Furthermore, saliva may provide a cost-effective approach for the screening of large populations. Gland-specific saliva can be used for diagnosis of pathology specific to one of the major salivary glands. Whole saliva, however, is most frequently used for diagnosis of systemic diseases, since it is readily collected and contains serum constituents. These constituents are derived from the local vasculature of the salivary glands and also reach the oral cavity via the flow of gingival fluid. Analysis of saliva may be useful for the diagnosis of hereditary disorders, autoimmune diseases, malignant and infectious diseases, and endocrine disorders, as well as in the assessment of therapeutic levels of drugs and the monitoring of illicit drug use.

A number of markers show promise as sensitive measures of disease and the effectiveness of therapy. At this time, host-derived enzymes and other inflammatory mediators orginating from the gingival crevice appear to hold the greatest promise as salivary diagnostic tests for periodontal disease. Longer-term longitudinal studies, however, are required to establish the relationship between specific markers and progression of periodontal disease. Furthermore, analysis of saliva may offer a cost-effective approach to assessment of periodontal disease in large populations.

Black cohosh was not significantly more efficacious than placebo against most menopausal symptoms, including number and intensity of hot flashes. Our study illustrates the feasibility and value of standard clinical trial methodology in assessing the efficacy and safety of herbal agents.