Are you in the habit of backing up the iPad? If you have important files on the iPad shouldn't you be taking steps to insure that if something goes wrong, you can recover your files?
Well of course you are backing up. Why wouldn't you be doing so.
Backup your iPad and the files will be in the backup and then you can restore from the backup in order to restore the files.
How to backup and restore from a backup
And yet another proactive step to secure your important files would be to use iOS file sharing in order to transfer those important files into your computer's iTunes and then to the hard drive and from the hard drive you could back them up to a another external drive and you would have copies of the important files in a number of different places.iOS: About File Sharing
- Contacts* and Contact Favorites (regularly sync contacts to a computer or cloud service such as iCloud to back them up).
- App Store Application data including in-app purchases (except the Application itself, its tmp and Caches folder).
- Application settings, preferences, and data, including documents.