endodontia vs dentistry

endodontia and dentistry both are nouns.

Word	Noun	Adjective	Verb	Adverb
endodontia	Yes	No	No	No
dentistry	Yes	No	No	No

As nouns, dentistry is a hypernym of endodontia; that is, dentistry is a word with a broader meaning than endodontia:

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

Other hypernyms of endodontia include dental medicine, odontology.

endodontia (noun)	dentistry (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