An amalgam filling is made by mixing metals such as silver, tin, copper and zinc with roughly half liquid mercury. The WHO and FDA state it does not cause significant poisoning in the general population, but it is not recommended for pregnant or breastfeeding women, people with kidney or neurological disease, young children or those with metal allergies.
- The main concern is mercury vapor released at a microscopic level over time.
- Removing a sound amalgam filling simply because it is amalgam is not recommended.
- More mercury vapor is released during removal.
- If there is a fracture, leakage or secondary decay, the filling should be replaced.
- Alternatives are composite fillings and porcelain/ceramic inlays and onlays.
Are Amalgam Fillings Harmful? Mercury Risk, Symptoms and Current Dental Approaches
As one of the most widely used materials for treating tooth decay for decades, amalgam fillings have in recent years become one of the most researched topics because of their effects on health. In this guide you will find everything you may want to know about the content, potential risks and removal of this type of filling, also commonly known as a “gray filling” or “black filling”.
What Is an Amalgam Filling and What Is It Made Of?
An amalgam filling is a durable filling material made by mixing metals such as silver, tin, copper and zinc with approximately 50% liquid mercury.
Combining the metals with mercury allows the filling to harden and withstand chewing pressure for years. However, this high mercury content raises questions about the material’s safety.
Are Amalgam Fillings Harmful?
The main concern about amalgam fillings is the mercury vapor released over time.
During daily activities such as chewing, drinking hot beverages or brushing, mercury vapor is released from amalgam fillings at a microscopic level. This vapor can enter the bloodstream through the lungs.
Potential Risks and Groups Who Should Be Cautious
Health organizations such as the World Health Organization (WHO) and the U.S. Food and Drug Administration (FDA) state that amalgam fillings do not cause significant poisoning in the general population, but they do not recommend amalgam for certain sensitive groups:
-
Pregnant and Breastfeeding Women: There is a risk of mercury passing to the baby through the placenta and breast milk.
-
Kidney Patients: Since heavy metals are eliminated from the body through the kidneys, it may place an additional burden on them.
-
People with Neurological Diseases: In individuals with neurological conditions such as Alzheimer’s or Parkinson’s, heavy metal load is considered a risk factor.
-
Children Under 6: The nervous system of developing children is more sensitive to heavy metals.
-
People with Metal Allergies: Those who react allergically to mercury or other metals may experience tissue sensitivity and lesions in the mouth.
Should Amalgam Fillings Be Removed?
If you have an amalgam filling that is intact, unbroken and has no new decay underneath, removing it simply because it is amalgam is not recommended.
The main reason is that the mercury vapor released during removal is much higher than the vapor the filling releases while it remains in the tooth.
However, the filling may need to be replaced in the following situations:
-
Fractures, wear or leakage at the edges of the filling,
-
Secondary decay developing under the filling,
-
Aesthetic expectations and a preference for composite (white) fillings,
-
A metal allergy or medical necessity identified by the dentist.
What Should Be Used Instead of Amalgam?
In modern dentistry, amalgam fillings have been replaced by alternatives that are more aesthetic and more biologically compatible:
-
Composite (Aesthetic/White) Fillings: Tooth-colored fillings that bond chemically to the tooth. They are used safely in both front and back teeth.
-
Porcelain / Ceramic Inlays and Onlays: Highly durable restorations prepared in a laboratory, especially for cases of significant tooth structure loss.
When should a black filling be replaced?
It should be replaced under a dentist’s supervision when the marginal fit of the filling deteriorates, a gap forms between the tooth and the filling, or decay is detected.
For questions and detailed information, we recommend that you contact your dentist.
