If it wasn't a copy-only full backup (you can check this in the backup history) then it will have reset the differential bitmap. If you have all of the backup files (and if you can mix native backups with Idera backups) then theoretically you're fine, but if the user deletes that backup file or if they can't be combined in a restore, you could be in trouble. If there's any doubt, take another full backup. (Disclaimer: I am very cautious.)