tophus vs incrustation

tophus and incrustation both are nouns.

Word	Noun	Adjective	Verb	Adverb
tophus	Yes	No	No	No
incrustation	Yes	No	No	No

As nouns, incrustation is a hypernym of tophus; that is, incrustation is a word with a broader meaning than tophus:

Other hypernyms of tophus include crust, encrustation.

tophus (noun)	incrustation (noun)
an incrustation that forms on the teeth and gums	a decorative coating of contrasting material that is applied to a surface as an inlay or overlay
a deposit of urates around a joint or in the external ear; diagnostic of advanced or chronic gout	a hard outer layer that covers something
	the formation of a crust