The bringing back of a thing to a former condition. Restoration returns the form; the interval is never returned.
Latin restauratio, from restaurare (to restore, to rebuild), from instaurare (to renew, to set up again): in- (upon) + a root related to Greek histanai (to stand); restoration brings back a form, and the root makes no claim about the time that passed while the form was gone.
The bringing back of a thing to a former condition. Restoration returns the form, and the root is silent on the interval — that is never returned along with it.