prosthodontics vs odontology

prosthodontics and odontology both are nouns.

Word	Noun	Adjective	Verb	Adverb
prosthodontics	Yes	No	No	No
odontology	Yes	No	No	No

As nouns, odontology is a hypernym of prosthodontics; that is, odontology is a word with a broader meaning than prosthodontics:

prosthodontics: the branch of dentistry dealing with the replacement of teeth and related mouth or jaw structures by artificial devices
odontology: the branch of medicine dealing with the anatomy and development and diseases of the teeth

Other hypernyms of prosthodontics include dental medicine, dentistry.

prosthodontics (noun)	odontology (noun)
the branch of dentistry dealing with the replacement of teeth and related mouth or jaw structures by artificial devices	the branch of medicine dealing with the anatomy and development and diseases of the teeth