Lipids of supragingival calculus

The matrix of supragingival calculus constitutes 15.7% of the calculus dry weight and contains 54.9% protein and 10.2% lipids. Of the total lipids, 61.8% are represented by neutral lipids, 28% by glycolipids, and 10.2% by phospholipids. The neutral lipids exhibit a high content of free fatty acids (63.9%) and triglycerides (15.8%). The glycolipids are comprised of simple glycosphingolipids (17.2%), mainly lactosyl- and glucosylceramides, and of neutral and sulfated glyceroglucolipids (82.8%). The phospholipids contain large quantities of phosphatidylethanolamine (34.2%) and diphosphatidylglycerol (25.5%). Comparison with salivary and submandibular stone lipids indicates that both saliva and bacteria contribute to the lipid content of supragingival calculus.