dentalamalgamguide.com

Little do many know that the silver fillings they have in their teeth may contain significant amounts of mercury which has been proven to result in health risks. That is why the EPA has released information on how dentists should store and dispose of removed fillings as much of them, though put in a long time ago still have active mercury within them making them unsafe for dumping into the waste disposal system.
Considered to be toxic, it has been identified as a source of mercury in the body after some fillings break leading to ingestion. Most dentists today prefer to remove the mercury filled fillings replacing them with composite materials that are inert and safer for the human body without the risk of leeching into the bloodstream.