SALIVARY ALPHA-AMYLASE - ROLE IN DENTAL PLAQUE AND CARIES FORMATION

Salivary alpha-amylase, one of the most plentiful components in human saliva, has at least three distinct biological functions. The enzymati c activity of alpha-amylase undoubtedly plays a role in carbohydrate d igestion. Amylase in solution binds with high affinity to a selected g roup of oral streptococci, a function that may contribute to bacterial clearance and nutrition. The fact that alpha-amylase is also found in acquired enamel pellicle suggests a role in the adhesion of alpha-amy lase-binding bacteria. All of these biological activities seem to depe nd on an intact enzyme conformation. Binding of alpha-amylase to bacte ria and teeth may have important implications for dental plaque and ca ries formation. Alpha-Amylase bound to bacteria in plaque may facilita te dietary starch hydrolysis to provide additional glucose for metabol ism by plaque microorganisms in close proximity to the tooth surface. The resulting lactic acid produced may be added to the pool of acid in plaque to contribute to tooth demineralization.