Yours, Etc.: Origins and Uses of 8 Sign-Offs
late 14c., from Old French restoratif from restorer (see restore).
early 15c., from restorative (adj.), or from Medieval Latin restaurativum "a restorative."
restorative re·stor·a·tive (rĭ-stôr'ə-tĭv)adj.
Of or relating to restoration.
Tending or having the power to restore.