The crown and root parts of mammal’s teeth associate different types of
dentin: peripheral dentin (mantle dentin, hyaline’s Hopewell-Smith layer and Tome’s
granular layer) and circumpulpal dentin, which include intertubular and peritubular
dentin. Firstly, we describe the structural characteristics and specific composition of the
different sorts of dentin. Secondly, as odontoblasts sustain dentin formation, we analyze
the role of these cells in the synthesis and secretion of dentin extracellular matrix
(ECM) components. Morphological changes occur during the successive stages leading
the pre-odontoblasts to become post-mitotic polarized secretory odontoblasts, and
ultimately senescent cells. In the third part, we report the immunohistochemical and
radioautographic investigations that shed lights on the intracellular uptake and secretion
of dentin components, and the self- associative properties coordinating post-secretory
interactions between ECM molecules. Dentin extracellular matrix proteins include type
I collagen, phosphorylated proteins, glycoproteins, proteoglycans and proteolipids. In
addition, forming a minor part of ECM, a few molecules originate from intercellular
diffusion of blood serum molecules. Interactions between ECM molecules, the tissue
non-specific alkaline phosphatase (TNAP) and calcium-binding proteins are key factors
in promoting dentin mineralization.
Keywords: Mantle dentin, circumpulpal dentin, odontoblast, dentin extracellular
matrix proteins, type I collagen, SIBLINGs, proteoglycans, proteolipids, tissue
non-specific alkaline phosphatase, calcium-binding proeteins, dentin
mineralization.
