Everyone knows that mercury is poisonous — bite an old-school-style thermometer in half, and watch Mom come running. Indeed, mercury ingestion has been linked to serious health problems such as multiple sclerosis, cancer, and Alzheimer’s disease. But is the small amount of inorganic mercury used in silver dental fillings causing your own health to suffer? Here is why silver fillings are often the most sensible and economical choice when filling a cavity, and why the ongoing controversy over “mercury fillings” is likely nothing more than a tempest in a teapot.
Silver-colored dental fillings are comprised of a blend of silver, copper, and mercury called an amalgam. Dental professionals have successfully used this amalgam when treating cavities for over 150 years. The small amount of mercury this amalgam contains is inorganic and not easily absorbed by the human body. As a result, professional health organizations such as the American Dental Association, the World Health Organization, the European Commission, and the U.S. Public Health Service all agree there is little to no evidence that dental mercury is linked to health problems, except the rare allergic reaction.
Many patients express concern over mercury levels because of health problems caused by ingesting too much fish; however, the methyl mercury contained in fish is easily absorbed in the human gut. The inorganic mercury contained in dental amalgams is not easily absorbed, leading the majority of dental professionals to continue choosing silver-colored amalgams as the filling of choice.
A recent episode of the popular television show featuring Dr. Mehmet Oz caused a stir among viewers with a demonstration allegedly proving that the mercury in fillings is unsafe. During the demonstration, Oz brushed a tooth model fitted with an amalgam filling in a plastic box. Then, Oz and his guest measured the mercury vapor released simply by brushing; although it is true that mercury vapor is dangerous, the comparison between the experiment and what happens in an actual human mouth containing amalgam fillings doesn’t stand up to even the most cursory scrutiny.
First, and most importantly, the actual amount of mercury vapor released in human subjects is far less than what Oz measured on his program — roughly 3 micrograms in people versus 61 micrograms on Dr. Oz’s show, respectively. Because a 150-pound adult can safely withstand 136 micrograms of mercury vapor per day, according to the WHO, there is very little cause for concern — especially considering the 150 years of safe history amassed by amalgam-using dental professionals.
Many dentists avoid placing amalgam fillings because they don’t bond to the tooth. Additionally, amalgam fillings are very visible and often an eyesore. If you or your loved one needs a filling placed on a visible front tooth, a composite filling is the way to go. Composite fillings are tooth-colored so they better match the natural color of teeth — they also bond easily to the tooth. Composite fillings are preferable for a beautiful smile when the filling must be placed at or near the front of the mouth.