Why Are Mercury Fillings Considered Unsafe?

Amalgam fillings have been in use in dentistry for over 150 years, and their use continues today. Yet these shiny, metallic fillings contain about 50% mercury by weight, a substance known to be harmful to humans. Are things containing mercury considered unsafe? 

It’s a complex question with a complex answer. At RR Dentistry in Georgetown, Texas, we can help you find the answers about fillings and providing alternatives to amalgam — including composite resin fillings that mimic the appearance of your natural tooth enamel. Here’s what you need to know and understand about the safety of mercury fillings.

What is dental amalgam? 

Dental amalgam is a mix of liquid mercury and an alloy powder that includes copper, silver, and tin. The mercury binds with the other metals to form a substance that’s economical, strong, and long-lasting. 

When first mixed, dental amalgam has a consistency like putty, so it’s ideal for placement in a tooth cavity that’s been cleaned and prepared to receive a filling. The amalgam hardens quickly once it’s in place. 

Why are mercury fillings considered unsafe?

Exposure to high levels of mercury over a long period of time affects the human nervous system. It can cause neurological symptoms like tingling and numbness in fingers and toes as well as motor nerve problems affecting coordination and muscle strength. 

Everyone has some level of mercury in their bodies because it’s found virtually everywhere in the natural environment. The mercury in dental amalgam doesn’t cause high levels of mercury in the human body, but it can cause slight increases in the amount of mercury detectable in blood and urine samples. 

You’re most exposed to mercury when a filling gets placed or removed. Even during these situations, though, that exposure isn’t significant in clinical or practical terms for most patients. 

Toxicity is a matter of both substance and dosage. Any substance can be toxic, depending on the dose. There may be individual factors at play, too.

When the US Food and Drug Administration declares a substance safe, it’s based on statistical analysis covering as wide a field of data as is practical. There are always individuals who fall outside the central data that helps to declare a substance as safe. 

Who should avoid dental amalgam? 

While dental amalgam fillings can be safe for many people, some patients should discuss their condition with our dentists, including: 

• Pregnant women or women planning to have a baby: While there’s little evidence that spikes in mercury can affect an unborn child, it’s a matter of playing it safe
• Breastfeeding mothers: Similarly, mercury levels are typically low in breast milk and there are no studies that point to elevated risk, but you may decide that you want another filling material if needed during this time of your life
• People with allergies: It’s possible to have a sensitivity to mercury or other components of an amalgam filling
• People with impaired kidney function: Mercury collects in the body in several places, including the kidneys
• Neurologically impaired patients: Mercury is also found in the brain in higher concentrations

Because composite resin fillings provide many very similar benefits to amalgam fillings, you may simply feel better about avoiding mercury altogether. 

The best way to make an informed decision is in consultation with our dentists at RR Dentistry. Call our office directly or request an appointment online today.