Editing Dentin (section)

==Development==
Prior to [[Tooth enamel|enamel]] formation, dentin formation begins through a process known as [[dentinogenesis]], and this process continues throughout a person's life even after the tooth has fully developed. Events such as [[tooth decay]] and [[tooth wear]] can also initiate dentin formation.<ref name=":3">{{cite journal | vauthors = Barron MJ, McDonnell ST, Mackie I, Dixon MJ | title = Hereditary dentin disorders: dentinogenesis imperfecta and dentin dysplasia | journal = Orphanet Journal of Rare Diseases | volume = 3 | issue = 1 | pages = 31 | date = November 2008 | pmid = 19021896 | pmc = 2600777 | doi = 10.1186/1750-1172-3-31 | doi-access = free }}</ref><ref name=":4">{{cite journal | vauthors = de La Dure-Molla M, Philippe Fournier B, Berdal A | title = Isolated dentinogenesis imperfecta and dentin dysplasia: revision of the classification | journal = European Journal of Human Genetics | volume = 23 | issue = 4 | pages = 445–451 | date = April 2015 | pmid = 25118030 | pmc = 4666581 | doi = 10.1038/ejhg.2014.159 }}</ref>

[[Dentinogenesis]] is initiated by the [[odontoblast]]s of the pulp. Odontoblasts are specialised cells that lay down an organic matrix known as pre-dentin. This predentin is subsequently mineralized into dentin. Mineralization of predentin begins at the [[dentinoenamel junction|dentinoenamel junction]] during [[Human tooth development|tooth development]] and progresses towards the [[Pulp (tooth)|pulp]] of the tooth.<ref name=":3" /><ref name=":4"/> After growth of predentin and maturation into dentin, the cell bodies of the odontoblasts remain in the pulp, along its outer wall, and project into tiny tubules in the dentin.

Predentin is composed of 90% type I [[collagen]] and 10% non-collagenous proteins (including [[phosphoprotein]]s, [[proteoglycan]]s, growth factors, phosphatases such as [[alkaline phosphatase]], and [[Matrix metalloproteinase|matrix metalloproteinases (MMPs)]]), and this composition is significantly altered when it is mineralized into dentin.<ref name=":4" /> See the Structure section for information about the composition of dentin.