The restoration is the metodological act in wich an aftwork is recognized and given back to its original nature, both in its physical peculiar features and its historical and aesthetical meanings, in consideration of its transmission to the future.
It must point to achieve the potential unity of an artwork, while avoiding the possibility of historical or artistical forgery, and without deleting the results of artwork's own transit through time.
The goal of a Restoration is to give back to the "product" its full, original funcionality as well, and it can be:
Conservative: ment to re-establish the funcionality, respecting stratificacion in time of the instrument
Filologic: ment to rebuild all the missing or strongly altered parts with methods and techniques as near to the original as possible.