Years ago, when Amalgam was removed, gold was put in the mouth. It was considered a mistake to use the white fillings in big holes.
A friend of mine who ist a dentist lived in an area, where people did not afford gold fillings. So he used the white fillings in spite of the knowledge that you should not do that.
Today he says this was the reason for his success. Most of the patients he removed the Amalgams got better. His collegues in richer areas who removed the Amalgams to put gold in the teeth found now improvement in the health of their patients. And came to the conclusion, that the reason for the bad health of their patients was not from the amalgams...