Dental amalgam has been used to restore teeth for nearly two hundred years, and doubts about the apparent contradiction of providing a health care service with a material that contains mercury have persisted the whole time. There has always been an undercurrent within the dental profession of anti-amalgam sentiment, a “mercury-free” movement. While expressions of that sentiment have grown in recent years as it becomes easier to accomplish good restorative dentistry with composites, the general attitude of dentists toward amalgam may be summarized as “there’s nothing wrong with it scientifically, we just aren’t using it so much anymore.”

To ask whether anything is or is not scientifically wrong with amalgam, one must look to the vast literature on exposure, toxicology and risk assessment of mercury. Most of it lies outside the sources of information dentists are commonly exposed to. Even much of the literature on mercury exposure from amalgam exists outside of dental journals. An examination of this extended literature can shed some light on the assumptions that dentistry has made about amalgam safety, and can help explain why some dentists have persistently objected to the use of amalgam in restorative dentistry.

No one now disputes that dental amalgam releases metallic mercury into its environment at some rate, and it will be interesting to briefly summarize some of the evidence for that exposure. The toxicology of mercury is too broad a subject for a short article, and is thoroughly reviewed elsewhere. The subject of risk assessment, however, goes straight to the heart of the debate over whether amalgam is safe, or not, for unrestricted use in the population at large.

Dental amalgam has been used to restore teeth for nearly two hundred years, and doubts about the apparent contradiction of providing a health care service with a material that contains mercury have persisted the whole time. There has always been an undercurrent within the dental profession of anti-amalgam sentiment, a “mercury-free” movement. While expressions of that sentiment have grown in recent years as it becomes easier to accomplish good restorative dentistry with composites, the general attitude of dentists toward amalgam may be summarized as “there’s nothing wrong with it scientifically, we just aren’t using it so much anymore.”

To ask whether anything is or is not scientifically wrong with amalgam, one must look to the vast literature on exposure, toxicology and risk assessment of mercury. Most of it lies outside the sources of information dentists are commonly exposed to. Even much of the literature on mercury exposure from amalgam exists outside of dental journals. An examination of this extended literature can shed some light on the assumptions that dentistry has made about amalgam safety, and can help explain why some dentists have persistently objected to the use of amalgam in restorative dentistry.

No one now disputes that dental amalgam releases metallic mercury into its environment at some rate, and it will be interesting to briefly summarize some of the evidence for that exposure. The toxicology of mercury is too broad a subject for a short article, and is thoroughly reviewed elsewhere. The subject of risk assessment, however, goes straight to the heart of the debate over whether amalgam is safe, or not, for unrestricted use in the population at large.