Salivary Secretion Rate, Buffer Capacity, and pH

Saliva has an important role in maintaining oral health. The mucous membranes are lubricated and protected by the salivary glycoproteins and mucoids. Saliva accomplishes its mechanical cleansing and protective functions through various physical and biochemical mechanisms. Low salivary secretion rate increases the risk for various diseases in the mouth, especially dental caries. Saliva can be collected under both resting and stimulated conditions. Flow rate is usually calculated by dividing the volume of saliva per minute. The duration of the collection period is important, since the flow rate can vary with time. Measurement of whole saliva may be superior and more relevant than measurement of individual gland secretion. The reliability, validity, and correlation between different methods for measuring the flow rate of whole saliva have been studied. The salivary output of parotid glands is usually collected in a two-chambered type of suction and collection cup according to Lashley.