Dentin

**Definition:** 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)

**Tree numbers:** - A14.549.167.900.280

**Synonyms:** - Dentine