endodontics vs dental medicine

endodontics and dental medicine both are nouns.

Word	Noun	Adjective	Verb	Adverb
endodontics	Yes	No	No	No
dental medicine	Yes	No	No	No

As nouns, dental medicine is a hypernym of endodontics; that is, dental medicine is a word with a broader meaning than endodontics:

endodontics: the branch of dentistry dealing with diseases of the dental pulp
dental medicine: the branch of medicine dealing with the anatomy and development and diseases of the teeth

Other hypernyms of endodontics include dentistry, odontology.

endodontics (noun)	dental medicine (noun)
the branch of dentistry dealing with diseases of the dental pulp	the branch of medicine dealing with the anatomy and development and diseases of the teeth