restoration vs regaining

restoration and regaining both are nouns.

Word	Noun	Adjective	Verb	Adverb
restoration	Yes	No	No	No
regaining	Yes	No	No	No

As nouns, restoration and regaining are synonyms defined as:

Other synonyms of restoration include restitution, return.

restoration (noun)	regaining (noun)
the act of restoring something or someone to a satisfactory state	getting something back again
getting something back again
some artifact that has been restored or reconstructed
a model that represents the landscape of a former geological age or that represents and extinct animal etc.
the state of being restored to its former good condition