This has plagued me for quite some time....
I have a mouthful of silver fillings(mercury amalgams), I will call the dentist and see how many I actually have. I have heard that you release the toxins worse by trying to remove them...
Here is a very in depth article on mercury, what it does to your body and how to get rid of it.
http://www.spiritofhealing.com/articles/html/mercury_detox_amalgam_fillings.htm