dental caries vs tooth decay

dental caries and tooth decay both are nouns.

Word	Noun	Adjective	Verb	Adverb
dental caries	Yes	No	No	No
tooth decay	Yes	No	No	No

As nouns, dental caries and tooth decay are synonyms defined as:

dental caries and tooth decay: soft decayed area in a tooth; progressive decay can lead to the death of a tooth

Other synonyms of dental caries include caries, cavity.

dental caries (noun)	tooth decay (noun)
soft decayed area in a tooth; progressive decay can lead to the death of a tooth	soft decayed area in a tooth; progressive decay can lead to the death of a tooth