dentin

/ˈdɛntən/

Dentin is a bone-like substance inside your teeth, just under the enamel.

Though it's harder than bone, dentin is more porous and flexible than enamel. The dentin in your teeth is protected by the brittle, white enamel, but in return it provides structure to the outer surface of your teeth. While dentin is vulnerable to decay and sensitive to cold, it can also sometimes repair itself. Your teeth are mostly made up of dentin, and fittingly, the word comes from the Latin dens, "tooth."

Definitions of dentin

1. noun

   a calcareous material harder and denser than bone that comprises the bulk of a tooth
   synonyms: dentine

   types:

   ivory, tusk

   a hard smooth ivory colored dentine that makes up most of the tusks of elephants and walruses

   type of:

   animal material

   material derived from animals
2. noun

   bone (calcified tissue) surrounding the pulp cavity of a tooth
   synonyms: dentine

   type of:

   bone, os

   rigid connective tissue that makes up the skeleton of vertebrates