dentin vs ivory

dentin and ivory both are nouns.

Word	Noun	Adjective	Verb	Adverb
dentin	Yes	No	No	No
ivory	Yes	No	No	No

As nouns, ivory is a hyponym of dentin; that is, ivory is a word with a more specific, narrower meaning than dentin:

dentin: a calcareous material harder and denser than bone that comprises the bulk of a tooth
ivory: a hard smooth ivory colored dentine that makes up most of the tusks of elephants and walruses

Other hyponyms of dentin include tusk.

dentin (noun)	ivory (noun)
bone (calcified tissue) surrounding the pulp cavity of a tooth	a shade of white the color of bleached bones
a calcareous material harder and denser than bone that comprises the bulk of a tooth	a hard smooth ivory colored dentine that makes up most of the tusks of elephants and walruses