[Frontiers in Bioscience E3, 711-735, January 1, 2011]
Dentin: Structure, Composition and Mineralization
Michel Goldberg1, Askok B. Kulkarni2, Marian Young3, Adele Boskey4
1UMR-S 747, INSERM, Universite Paris Descartes, 75006 Paris, France, 2Functional Genomic Section, Laboratory of Cell and Developmental Biology, NIDCR/ NIH Department of Health and Human Services Bethesda, MD, Maryland, 3Craniofacial and Skeletal Diseases Branch, NIDCR/NIH , Bethesda, MD, Maryland, 4Starr Chair in Mineralized Tissue Research, Hospital for Special Surgery and Weill Medical College of Cornell University, USA.
TABLE OF CONTENTS
We review firstly the specificities of the different types of dentin present in mammalian teeth. The outer layers include the mantle dentin, the Tomes' granular and the hyaline Hopewell-Smith's layers. Circumpulpal dentin forming the bulk of the tooth, comprises intertubular and peritubular dentin. In addition to physiological primary and secondary dentin formation, reactionary dentin is produced in response to pathological events. Secondly, we evaluate the role of odontoblasts in dentin formation, their implication in the synthesis and secretion of type I collagen fibrils and non-collagenous molecules. Thirdly, we study the composition and functions of dentin extracellular matrix (ECM) molecules implicated in dentinogenesis. As structural proteins they are mineralization promoters or inhibitors. They are also signaling molecules. Three different forms of dentinogenesis are identified: i) matrix vesicles are implicated in early dentin formation, ii) collagen and some proteoglycans are involved in the formation of predentin, further transformed into intertubular dentin, iii) the distal secretion of some non-collagenous ECM molecules and some serum proteins contribute to the formation of peritubular