if you have backup your dvd and ended up having two folders audio_ts and video_ts, you can rebuild your dvd with 2 freewares alone. afterdawn.com has this HOWTO guide which can guide you through the steps (including getting the reqd software).
quick steps:
1. grab Folder2Iso.
2. use roxio creator, nero burning rom, dvd decrypter or some software that can write the ISO file.