Caries-protective factors in saliva.

Saliva influences caries attack mainly by its rate of flow and by its content of fluoride. The salivary flow rate influences to a high degree the rate of oral and salivary clearance of bacterial substrates included in foods and snacks. This influence is site-dependent. The basal salivary fluoride concentration is low, about 1 mumol/L, independent of salivary flow rate, and not influenced by diurnal variation. After an exposure of the oral cavity to fluoride, the increased fluoride level is decreased by a process influenced mainly by the salivary flow rate and the volumes of saliva in the mouth before and after swallowing. Other less important caries-protective factors in saliva include its buffer ability, its content of calcium, inorganic phosphate, pH-increasing substances, and anti-microbial agents.