Yes, I'll add my thoughts to this, too. I got out my mercury fillings -- by a biological dentist up here in Canada -- he really knows his stuff and I was also very well protected.
I had pursued this action because my blood pressure had gone from being in the lower range to being dangerously high. Although I was in a high-stress (crazy!) job, I looked for other causes and the mercury was one of them. I had also found that my memory was definitely not so good as it had been and it really concerned me.
I did a couple of heavy metal detoxes after the removal of the metal -- it takes quite a while to get rid of it from the tissues and my memory improved a great deal.
It is about three years since I had this work done and I am extremely happy that I did. I don't know if the teeth will crack or not. Being able to eat and my vanity seem to be the driving forces for me to keep my teeth. However, I don't know how successful I will be in keeping them because they are shifting.
The health benefits of getting the metal out would far outweigh concerns about the breaking of the teeth. But, do take the time and find a biological dentist. You want this job to be done well.