my daughter had aprcedure done on her canine ( she had a chain attached to her tooth) and now there telling us that the root is dead and to pull it

If your daughter is a minor, you may have a claim against the individual who attached the chain to her tooth.  If it was a licensed professional, then there may be a professional malpractice claim.  However, if your daughter was eighteen or older at the time of the attachment of the chain, then there is likely no legal option for her to seek compensation for the dead tooth.