What does Boxing Day have to do with boxing?
late 14c., "a means of healing or restoring health; renewing of something lost," from Old French restoration (Modern French restauration) and directly from Late Latin restorationem (nominative restoratio), noun of action from past participle stem of Latin restaurare (see restore).
Mid-15c. as "the repairing of a building;" c.1500 as "a restoring to a former state." With a capital R-, in reference to the reestablishment of the English monarchy under Charles II in 1660, from 1718. As a period in English theater, attested from 1898. In French history, it refers to 1814. An earlier word in this sense was restauration (late 14c.), from French.
restoration res·to·ra·tion (rěs'tə-rā'shən)
Any of various dental fittings, such as an inlay, crown, bridge, or denture, that restore or replace lost tooth structure, teeth, or oral tissues.
A substance used to restore the missing portion of a tooth.