Lipid Components of Sound and Carious Dentin

Abstract

That lipids constitute an integral part of both sound and decayed dentin has been known for a number of years. Leopold, Hess, and Carter ' have previously reviewed the literature and further determined that root dentin from third molars contains up to 0.024 per cent cholesterol. In a more recent study, Hess, Lee, and Peckham2 have reported 0.36 per cent total lipids in dentin, of which 0.014 per cent was phospholipids; however, the nature of the phospholipids and those lipids in excess of cholesterol had not been investigated. Other studies3 ' 4 concerning carious lesions have demonstrated the presence of lipid materials in the decalcified areas; the non-specific histochemical procedures, unfortunately, did not give insight into the different lipids present. Thus the nature of the lipid material present in both sound and carious dentin bears further investigation. Marinetti and his associates5-10 have recently introduced silicic acid paper chroma-tography for the separation of different phospholipids and non-phospholipids. This paper presents the application of these techniques for the qualitative analysis of the lipid materials in sound and decayed dentin.