• Hard portion of the tooth surrounding the pulp, covered by enamel on the crown and cementum on the root, which is harder and denser than bone but softer than enamel, and is thus readily abraded when left unprotected.
  CRISP Thesaurus
  National Institutes of Health, 2006
• The hard portion of the tooth surrounding the pulp, covered by enamel on the crown and cementum on the root, which is harder and denser than bone but softer than enamel, and is thus readily abraded when left unprotected. (From Jablonski, Dictionary of Dentistry, 1992)
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• The layer of hardened tooth tissue under the enamel and around the pulp.
  Harvard Dictionary of Health Terms
  Harvard Medical Publishing, 2011
• (dentin of tooth) Substance of tooth produced by odontoblasts; surrounds the pulp of the tooth and is subjacent to enamel and cement.
  Foundational Model of Anatomy
  University of Washington, 2017
• Dentin, in anatomy, the yellowish tissue that makes up the bulk of all teeth. It is harder than bone but softer than enamel and consists mainly of apatite crystals of calcium and phosphate. In humans, other mammals, and the elasmobranch fishes (e.g., sharks, rays), a layer of dentin-producing...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2025