Well, I'm certainly happy to hear that! Chelation is a very difficult process and there are many variables that can throw things off, diet, as you now know, is one of those things. I wish I could be of more help but I don't have any experience in dealing with your problem other than what I have read from my studies.
I suggest to continue to ask this question on several different forums and also check out Dr. Mercola's website...he may have some info on this, or you could contact him and ask his opinion. Also, you may want to call some local holistic dentists in your area for advice.