Your old silver fillings, also referred to as Amalgams, are a combination or amalgamation of several different metals including silver, copper, tin and mercury. There has been a lot of research on Amalgam concerning the safety of the mercury component. Research is not conclusive - to see both viewpoints it is best to do your own research - try the American Dental Association's ADA.org for the pro-mercury view and the International Association of Oral Medicine and Toxicology's IAOMT.org for the anti-mercury stance.
We choose not to use Mercury-Silver Amalgams in our practice since we are unsure about the research and prefer to give our patients the natural look of composites. Composite fillings are a mixture of glass or quartz filler in a resin medium that produces a tooth-colored filling.
We do not 'push' our patients to remove their old Amalgams. We recommend replacing fillings when their condition deteriorates whether they are Amalgam or Composite - kind of like replacing a worn tire. And like tires it makes more sense to replace all questionable fillings in one area or quadrant of the mouth rather than just replacing one at a time.
Since views differ on mercury toxicity in the mouth (not in the environment) we offer several precautionary measures when removing amalgams. They can lower the level of mercury vapor inhaled. They include:
Isolite - provides a large suctioning surface within the mouth.
External Vacuum - placed near the mouth, this sucks away vapors as they are produced.
Rubber Dam - this blocks out the mouth and allows only the teeth being worked on to be exposed - mercury vapor can get below this though.
Oxygen - you can choose to breath pure O2 during the procedure.