A Diagnostic Fluid: A Review

Saliva as a diagnostic specimen can give not only the same information as serum testing, but also additional or new information that cannot be obtained from serum. 1 Saliva in humans is a mouth fluid possessing several functions involved in oral health and homeostasis, with an active protective role in maintaining oral healthiness. Saliva helps bolus formation by moistening food, protects the oral mucosa against mechanical damage and plays a role in the preliminary digestion of food through the presence of α-amylase and other enzymes. It also facilitates taste perception, allowing soluble food-derived molecules to reach the gustative papillae and buffer the acid components of food with the bicarbonates (originating from salivary gland carbonic anhydrase). 2 The idea of using saliva in diagnostics was made in the second half of the 20th century. Its main advantage is easy and non invasive sample taking compared to peripheral blood. As with the latter, salivary analysis has two main objectives: early detection of certain diseases and monitoring the disease course in conjunction with treatment. A third use is in the detection of addictive drugs. 3