Ask The Dentist #16: Where does the waste go?

Posted Nov 9th, 2017

Ask The Dentist #16: Where does the waste go?

Ask The Dentist is a series of columns written by Dr. Mady to answer your questions about dentistry and oral health!


Dear Dr. Mady: I recently had a couple of visits to my dentist and had several teeth refilled because they had decayed again. My dentist removed the old amalgam fillings and replaced them with white tooth-colored fillings.

What happens to all the amalgam waste and its mercury content that is suctioned out of my mouth and where does it go? - Jean-Paul in Belle River

Dear Jean Paul: Many of us have concern about what mercury can do to our environment and this is an excellent question about a topic that you don’t hear too much about.

The reason this is so important is because mercury accumulation in our environment is actually bioaccumulative, meaning it builds up somewhere and eventually reaches us. An example of this is mercury build up in fish that leads to us consuming more mercury when we eat fish.

Mercury is actually a naturally formed material, but a good portion of mercury released to the environment is through people. It can ultimately accumulate in waterways, which is how it gets to us. 

Mercury is used in dental amalgam to amalgamate and harden the metal powders that are used in the mixture. Mercury in dental amalgam is stable, but should not be disposed of in the garbage or sewage systems through our drains. This is important because some municipalities burn garbage and certain types of waste, and this would release mercury vapor into the air.

Dental amalgam is still considered a durable and safe option for restoring teeth and is still widely used. It is a mixture of metals including silver, copper, zinc, tin and of course mercury. Less than one percent of the mercury released into the environment comes from amalgam and this is not in the form of methylmercury, the dangerous type.  

Today, we recycle amalgam waste and are required by law to do so.

Most, if not all, dental offices in Ontario today use a device called an amalgam separator. These are devices that are attached to the vacuum suction pump in a dental office designed to remove amalgam particles from the office wastewater instead of it going directly into sewers. It has a bottle on it and when the bottle fills up, we replace it with a new one. The waste is collected by a certified company who disposes and/or recycles it properly.

This legislation is a result of efforts to decrease the amalgam waste from dental offices into local wastewater treatment plants, and thus lessen the amount of mercury release into out environment. 

For more information or questions about this or any dental-related topics, stop by our office or contact us today!

Please contact us to book your next dental appointment.