Over the past several years, concerns have been raised about silver-colored fillings, otherwise called amalgams. Because amalgams contain the toxic substance mercury, some people think that they are responsible for causing a number of diseases, including autism, Alzheimer's disease, and multiple sclerosis.
The Dental Council of New Zealand (DCNZ) and The New Zealand Dental Association (NZDA), the FDA, and numerous public health agencies say amalgams are safe, and that any link between mercury-based fillings and disease is unfounded. The cause of autism, Alzheimer's disease, and multiple sclerosis remains unknown. Additionally, there is no solid, scientific evidence to back up the claim that if a person has amalgam fillings removed, he or she will be cured of these or any other diseases.
In February of 2009, the FDA reconfirmed the safety of amalgams. Although amalgams do contain mercury, when they are mixed with other metals, such as silver, copper, tin, and zinc, they form a stable alloy that dentists have used for more than 100 years to fill and preserve hundreds of millions of decayed teeth. The National Institutes of Health conducted several large-scale studies that concluded in 2006 that amalgam fillings were safe.
In addition, there has been concern over the release of a small amount of mercury vapor from these fillings, but according to the DCNZ, there is no scientific evidence that this small amount results in adverse health effects.