If your Integration for eCopy ShareScan solution is licensed for an Enterprise Integration for eCopy ShareScan license, then no MFP registrations need to be restored. A proper restoration of your OnBase database from a valid backup will properly restore all registration information.
If your Integration for eCopy ShareScan solution is licensed per device, using Integration for eCopy ShareScan licensing, then each MFP device is re-registered the next time it accesses OnBase.