Dentin (dentinum, LNH; Lat. Dens, dentis - tooth) is the hard tissue of the tooth that makes up its main part. The crown part is covered with enamel, the root part of the dentin is covered with cement. It consists mainly of hydroxyapatite (70% by weight), organic material (20%) and water (10%) [1] penetrated by dentinal tubules and collagen fibers.
It serves as the basis of the tooth and supports tooth enamel . The thickness of the dentin layer ranges from 2 to 6 mm. Dentin hardness reaches 58.9 kgf / mm².
Distinguish near-pulp (internal) and cloak (external) dentin. In the near-pulpal dentin, collagen fibers are located mainly tangentially and are called Ebner fibers. In raincoat dentin, collagen fibers are located radially and are called Korf fibers.
Dentin is divided into primary, secondary (replacement) and tertiary (irregular). Primary dentin is formed in the process of tooth development, until it erupts. Secondary (replacement) dentin is formed throughout a person’s life. It differs from the primary one at a slower pace of development, a less systemic arrangement of dentinal tubules, a large number of erythroglobular spaces, a large number of organic substances, higher permeability and less mineralization. Tertiary dentin (irregular) is formed during tooth injuries, tooth preparation, during carious and other pathological processes, as a response to external irritation.
Notes
- ↑ Cate, AR Ten. Oral Histology: development, structure, and function. 5th ed. 1998. Page 150. ISBN 0-8151-2952-1 .
Literature
- Bykov V. L. Histology and embryology of the organs of the human oral cavity. - St. Petersburg, 1998.
- Gemonov V.V., Lavrova E.N., Falin L.I. Atlas on histology and embryology of the organs of the oral cavity and teeth. - Moscow, 2003.
- Kuznetsov S. L., Torbek V. E., Derevyanko V. G. Histology of the organs of the oral cavity. - Moscow, 2012.