- Differentiation of odontoblast cells
- Secretion of dentine matrix
The odontoblast cells begin to secrete an unmineralised dentine matrix. As more dentine matrix is deposited, the odontoblast cells retreat in the direction of the pulp leaving an elongated process known as the odontoblast process. The dentine matrix formed prior to mineralization is termed predentine. A narrow layer of predentine is always present on the surface of the pulp.
- Mineralisation of dentine
Mineralisation of dentine begins when the predentine is approximately 5 ìm thick. Spherical zones of hydroxyapatite called calcospherites are formed within the dentine matrix. Mineralisation of the dentine matrix starts at random points and eventually these calcospherites fuse together to form mineralised dentine.
Dentinal tubules form around each odontoblast process. The odontoblasts retreat in S-shaped curves towards the dental papilla. The first layer of mineralised dentine is called mantle dentine and the remaining bulk of the mineralised dentine is known as circumpulpal dentine.