Amalgams improperly removed can release mercury into the system, worsen the mercury exposure and even induce autoimmune illness (such as MS). I would find another dentist who SPECIALIZES in doing this sort of thing and get him to look at what the other dentist did. This is serious. I would do this quickly. Then get properly tested for mercury levels by another licensed specialist in heavy metal detoxification work and embark on a variety of approaches to treat the issue. Some of the safer ones for mercury detoxification include cilantro, chlorella and Far Infra Red saunas. EDTA chelation should only be done by the most experienced, specialized professional.