Lipid composition of human parotid and submandibular saliva from caries-resistant and caries-susceptible adults.

The lipid content and composition of parotid and submandibular saliva from caries-resistant (DMFS of 0) and caries-susceptible (DMFS greater than 15) adults was investigated. Lipids were extracted from dialysed and lyophilized saliva, collected from 10 subjects in each group, and fractionated into neutral lipids, glycolipids and phospholipids. The lipids in each fraction were separated into individual components by thin-layer chromatography and quantitated. The parotid and submandibular saliva of caries-resistant subjects contained 37 and 35 per cent fewer lipids/100 ml of saliva than that of the caries-susceptible group, and had less (p less than 0.001) neutral lipids and phospholipids. The neutral lipids of caries-resistant saliva contained (mg/100 ml of saliva) considerably (p less than 0.001) fewer free fatty acids, triglycerides and cholesterol esters. The glycolipids consisted exclusively of glyceroglucolipids and their content was similar in both groups. The content of phospholipids in the salivas of the caries-resistant was 25 and 33 per cent lower than that of the caries-susceptible. The data suggest a relationship between the level of lipids in salivary secretions and resistance to caries.