Dental amalgam: how is it recycled?

Although there are plans to phase out the use of amalgam in the UK,¹ it remains a common material in modern dentistry. Many dental patients still have amalgam fillings from past treatment. Now that more aesthetic alternatives are available, many people are opting to swap their amalgam for composite or ceramic.

Once amalgam has been collected in an amalgam separator or stored in a dental amalgam container, how is this material reprocessed and recycled?

Removing mercury

Amalgam is comprised of a mixture of metals. This includes liquid elemental mercury and a powdered alloy made from metals such as copper, tin and silver. Around 50% of the amalgam is elemental mercury.²

As you are probably aware, mercury is a toxic substance. Exposure to it in either liquid or vapour form can cause significant health problems, developmental issues in unborn children and even prove fatal.³

When amalgam is reprocessed, one of the core aims of the process is to remove the elemental mercury from the material so that it can be reused. Amalgam is heated until the mercury content transforms into mercury vapour.

Then, using vacuum distillery apparatus, this vapour is collected so that it is separate from the remaining material. If sucrose is used as a reducing agent, the silver from the alloy powder can be recovered and repurposed too.⁴

How these materials are repurposed 

Extracting mercury and silver from amalgam is, of course, just one part of the recycling process, and these metals are then reused. The mercury can be used to create more dental amalgam by once again mixing it with the powdered alloys necessary to make the material.

Alternatively, this mercury may be used in other items that utilise the unique properties of mercury, such as fluorescent lamps, thermometers, and barometers.⁵ Any silver recovered during the recycling process may also be repurposed.

Recycling dental amalgam with us – a trusted solution

In 2008, Rentokil Initial acquired Medentex – a specialist dental recycling facility to support dental practices across the globe. Dedicated to minimising the impact amalgam and mercury have on the environment, our recycling plant utilises unique mercury vapour suppressant technology to help guarantee that the whole recycling process is as safe as possible.

To find out more about our dental recycling, please visit the website HERE.

¹ Gov.uk. Dental amalgam: plan to phase down use in England. Link: https://bit.ly/3LBvoDE. [Last accessed February 23].

² FDA. Dental Amalgam Fillings. Link: https://bit.ly/3FzByAd. [Last accessed February 23].

³ World Health Organization. Mercury and Health. Link: https://www.who.int/news-room/fact-sheets/detail/mercury-and-health [Last accessed February 23].

⁴ Sadasiva, K. et al. Recovery of Mercury from Dental Amalgam Scrap-Indian Perspective. J Pharm Bioallied Sci. 2017 Nov; 9(Suppl 1): S79–S81.

⁵ UNIDO. Mercury Waste Recycling Technology: Advancements in Waste Management Technology. Link: http://www.unido.or.jp/en/technology_db/1716/#:~:text=Recovered%20materials%20are%20recycled%20into,fluorescent%20lamps%2C%20reagent%2C%20etc.&text=Secondary%20batteries%20are%20removed%20through,to%20specialized%20companies%20for%20recycling. [Last accessed February 23].