In 1986, the ADA changed its code of ethics to make it a violation of that code for any dentist to recommend the removal of amalgam because of the mercury. Dr. Joel Berger, a dentist who was removing amalgams, was charged with fraud by the new York State dental authorities. The ADA provided an expert witness to testify against him. His license was revoked. Dr. Berger never told a patient that they would get healthier or better from a disease if he removed mercury amalgams. He just told them that he could remove a known risk, a poison, toxin, and carcinogen from their bodies. Dr. Murray Vimy of the World Health Organization testified as a scientific expert in Berger's defense. Dr. Vimy said that the United States has taken away the constitutional rights of dentist and the right of patient who no longer have freedom of choice of expression. "A dentist can no longer say he is against dental amalgam, so it's a fear tactic. It's a witch hunt," said Dr. Vimy.

The ADA representative, Dr. Heber Simmons, denied that it was a witch hunt and said that evidence that removing amalgams helps diseases is just anecdotal. The word anecdotal doesn't mean a report is not true. It means that a doctor has observed a change in a patient, or a few patients, but a large-scale scientific study has not yet been done. For example, Dr. Alfred Zamm, an allergist and dermatologist in Kingston, New York, reported that hundreds of his patients recovered from a variety of disease including arthritis and allergies after having fillings removed. While Dr. Simmons didn't totally dismiss the anecdotal evidence he felt that the facts were "clinically insignificant," and said that there were only 50 cases of amalgam allergy reported in the previous 85 years. The point that he missed, however, is that we are not talking about allergies. Says Dr. Zamm, "It's not allergy. It's poisoning of the critical immune processes." Even if the problem is allergy to mercury, why aren't patients tested for mercury allergy before fillings are put into their teeth? Morley Safer then asked, "If the mercury in amalgam fillings is as poisoneous as you say it is, why hasn't the medical comunity jumped on it and banned it?" Dr. Zamm said that diagnosing mercury poisoning is difficult because each affected person may have different symptoms: tiredness in one person, headaches in another, joint pain in someone else. Also, doctors are unfamiliar with the disease and its symptoms.