In animal tooth development, dentinogenesis is the formation of dentin, a substance that forms the majority of teeth.
Dentinogenesis is performed by odontoblasts, which are a special type of biological cell on the outer wall of dental pulps, and it begins at the late bell stage of a tooth development.
Odontoblasts increase in size, eliminating the availability of any extracellular resources to contribute to an organic matrix for mineralization.
Additionally, the larger odontoblasts cause collagen to be secreted in smaller amounts, which results in more tightly arranged, heterogeneous nucleation that is used for mineralization.
[3] Maturation of dentin or mineralization of predentin occurs soon after its apposition, which takes place two phases: primary and secondary.
Initially, the calcium hydroxyapatite crystals form as globules, or calcospherules, in the collagen fibers of the predentin, which allows for both the expansion and fusion during the primary mineralization phase.
This development continues throughout life and accounts for the smaller areas of pulp found in older individuals.