osteodentine

from The Century Dictionary.

• noun One of the varieties of dentine, resembling bone; that modification of dentine observed in the teeth of the cachalot and some other cetaceans, also in those of many existing and extinct fishes, in which the tissue is traversed by irregularly ramified vascular or medullary canals.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Anat.) A hard substance, somewhat like bone, which is sometimes deposited within the pulp cavity of teeth.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun anatomy A hard bony substance that is sometimes deposited within the pulp cavity of teeth.