Saliva – a charismatic fluid

Oral fluid is often called the ‘mirror of the body’. The noninvasive nature of salivary testing has made it an attractive and effective alternative to blood and urine. Use of saliva has become more extensive in recent years, particularly in relation to estimation of systemic levels of lipid-soluble drugs and hormones. 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. Saliva as a whole, however, is most frequently used for diagnosis of systemic diseases, since it is readily collected and contains serum constituents. As a diagnostic fluid, saliva offers distinctive advantages over serum because individuals with modest training can collect it non-invasively. This review presents the translational value of saliva as a credible clinical diagnostic fluid and the scientific rationale for such use.