Why Is Mercury Used in Dental Fillings? Learn the Answer from Our Charleston Dentist 

For over 150 years, dentists have filled cavities with a dental amalgam composed of silver, tin, copper, and mercury. If you are reading this blog, you are doubtlessly wondering why dental practitioners use mercury, a substance that is known to be toxic, in tooth restorations. Our Charleston SC dentist explains why below.  

Why Do Dentists Use Mercury in Amalgam Fillings? 

A dental amalgam filling is made of liquid mercury mixed with a powdered alloy of silver, tin, and copper. Mercury is used because it’s one of the only metals that are liquid at room temperature, making it easy to mix with the alloy powder. Mercury is the main reason why metal dental fillings are so durable, able to withstand decades of chewing and grinding.  

Why are Amalgam Fillings Considered Safe? 

Metallic mercury is essentially non-toxic if swallowed. It has been shown to pass through a healthy gastrointestinal tract without being absorbed into the body or causing harm. Even swallowing metallic mercury from a broken thermometer, a dental amalgam preparation, or pieces of an amalgam filling would not cause mercury poisoning.

In contrast, breathing in large amounts of metallic mercury vapor can cause poisoning. Once breathed into the lungs, metallic mercury vapors are quickly absorbed into the bloodstream and carried to key organs like the kidneys and brain.  Most cases of mercury poisonings occur from unprotected occupational exposure; broken medical devices; attempted folk remedies; and use of mercury during religious or magical ceremonies. 

Research and Scientific Consensus

It is true that mercury in dental fillings evaporates, is inhaled, and then absorbed into the bloodstream, causing trace amounts of mercury in the urine and bloodstream. However, the scientific community is overwhelmingly in agreement that these very small amounts are not significant enough to pose a risk to human health. Abundant research has been performed to ensure that this is the case. Most notably in the U.S., the FDA reviewed 200 studies and an additional 70 related abstracts before stating that:

Based on this evidence, FDA considers dental amalgam fillings safe for adults and children ages 6 and above. Clinical studies in adults and children ages 6 and above have found no link between dental amalgam fillings and health problems.” 

The World Health Organization also lists amalgam restorations as a safe procedure. 

Questions? Concerns? Contact our Charleston Restorative Dentists Today

If you have any questions or concerns about your fillings or your oral health in general, don’t hesitate to contact our Charleston dentist office. If you have amalgam fillings that are more than 10 years old, they may need to be replaced due to corrosion and leakage around the edges. They can also be replaced for cosmetic purposes, with a tooth-colored resin that wasn’t an option when you received your original fillings. To request an appointment with our Charleston restorative dentist, fill out our contact form here.