Hygiene Atlas

Atlas · Plate III · Histology and Embryology · 04

Dentin and pulp

Dentin is about 70% mineral and is made by odontoblasts, which line the pulp for life and send processes into the dentinal tubules. It keeps forming slowly as secondary dentin and faster as tertiary dentin after injury. Fluid moving in open tubules explains dentin hypersensitivity. The pulp has four zones, from the odontoblast layer inward to the pulp core.

High-yield facts · 7

  1. Dentin is about 70% inorganic, 20% organic (mostly type I collagen) and 10% water by weight.S44
  2. Odontoblasts line the pulp and send processes into dentinal tubules; they persist for life.S52
  3. Primary dentin forms before root completion; secondary dentin forms slowly for life; tertiary (reparative/reactionary) dentin forms in response to injury.S52
  4. Sclerotic dentin has tubules filled with mineral, which reduces sensitivity.S52
  5. Mantle dentin is the first-formed dentin next to the DEJ; circumpulpal dentin is the bulk.S52
  6. Pulp zones from outside in: odontoblastic layer, cell-free zone (of Weil), cell-rich zone, pulp core.S52
  7. Pulp stones (denticles) are calcified masses in the pulp, more common with age.S52

Facts are written in our own words; each tag links to its source. Values marked "sources vary" differ between references, so check the one your program uses.