Practical Aspects Of Salivary Analyses

The use of different stimulants of saliva secretion produces samples where the secretions from the major salivary glands occur in different proportions. The concentrations of most salivary constituents depend on the flow rate of saliva. Standardization of saliva collections is especially important, since saliva varies greatly both inter- and intraindividually. The presence of bacteria, epithelial cells, and leukocytes further complicates the analyses of whole saliva. The bacterial action can also be stopped by centrifugation of the saliva. Centrifugation removes both the cells and the turbidity, which can interfere with many analytical techniques. Most salivary electrolytes can be determined from stored samples. Electrolytes, which are labile or which participate in precipitate formation in saliva, have to be determined immediately after collection. Special collection conditions and equipment may be used to avoid these effects.