Quick Facts
Predentin is the soft fibrillar substance composing the primitive dentin and forming the inner layer of the circumpulpar dentin (Dorland, 2011).
Structure and/or Key Feature(s)
Predentin is progressively produced by odontoblasts at the surface of the pulp cavity, which reduces the size of the cavity throughout life (Standring, 2016).
Predentin consists of randomly scattered type 1 collagen fibers embedded in an extracellular matrix of phosphoprotein and glycosaminoglycans (Lowe, Anderson and Anderson, 2018).
Anatomical Relations
Adjacent to the odontoblast layer at the periphery of the pulp, there is a thin zone of immature uncalcified dentin, called predentin. The predentin layer is surrounded by the outer dentin layer, which typically stains darker than its unmineralized predentin counterpart (Lowe, Anderson and Anderson, 2018).
Function
Predentin is a precursor to the mature, calcified dentin, which makes up the bulk of the tooth and ensures its structural integrity. Following its synthesis and formation by odontoblasts, predentin becomes mineralized at the border with previously mineralized dentin. As the predentin layer nears the predentin-dentin border, its collagen fibers become more numerous and tightly packed which facilitates dentin rigidity (Standring, 2016).
References
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
Lowe, J. S., Anderson, P. G. and Anderson, S. I. (2018) Stevens & Lowe's Human Histology- E-Book. 5 edn.: Elsevier Health Sciences.
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41 edn.: Elsevier Limited.
