Depending on where you live, mercury is a lifetime problem. Dentally most dentist don't remove it all, they take the large parts and cover the tooth with plastics that may be almost as bad as metals. Either way there is glue and chemicals as well as the poisons they use to numb with.
If your taking a kidney cleanse type herb, it helps allot. The best of all herbs is the simple cheap cilranto plant people cook with. I do not suggest chelation with solvents, etc.