Also called: Dental Filling Allergy, Metal Filling Allergy
Amalgam allergy is a very rare condition in which a patient reacts to the small amounts of mercury contained in amalgam dental fillings. Fewer than 100 cases of such a reaction have ever been reported, according to the American Dental Association.
Amalgam fillings are more commonly known as “silver” fillings. These fillings are made of a mixture that is equal parts:
- Liquid mercury. A substance that causes the rare allergic reaction in some people.
- Alloy powder. Usually contains silver, tin and copper. Sometimes, lesser amounts of zinc, palladium or indium also are used.
In most cases, no medical attention is required to treat an amalgam reaction. Symptoms usually resolve within a few days. In rare instances, amalgam fillings may need to be replaced with another substance, such as tooth-colored resin, porcelain or gold.
Questions about the safety of amalgam are not limited to allergies. For years, a debate has raged in the dental community over whether or not the mercury used in amalgam can have toxic effects on the body. Most experts and public health agencies – including the American Dental Association, U.S. Centers for Disease Control and Prevention, and U.S. Food and Drug Administration – maintain that amalgam is safe and point to the substance’s 150-year track record as the primary material used in tooth repair.
About amalgam allergy
Amalgam allergies are extremely rare reactions to the mercury used in the most popular form of dental filling. The condition is so unusual that fewer than 100 cases have ever been reported, according to the American Dental Association.
Amalgam has been used for more than 150 years to repair teeth damaged by decay. The amalgam itself is a mixture of equal parts liquid mercury and alloy powder containing silver, tin, and copper. Sometimes, lesser amounts of zinc, palladium or indium also are used. Mercury is the only element known to bind together these metals in a way that can be used to fill a cavity (a small hole in a tooth caused by tooth decay).
Dentists long have preferred working with amalgam because of its relatively low sensitivity to moisture, such as saliva. This means dentists do not have to be quite as precise when placing amalgam, as it is more durable and “forgiving” than other substances used in tooth repair.
An amalgam allergy occurs when the immune system becomes sensitized to a component in amalgam and then mistakes the substance as a foreign invader. The immune system then attacks the substance, producing symptoms of an allergic reaction (e.g., skin rash, itching). The substance in amalgam that is a potential trigger for this allergic reaction (allergen) is liquid mercury. Individuals with this condition must have other restorative materials (e.g., resin, porcelain, gold) used on them during dental procedures.
Patients who suffer amalgam allergies typically have a personal history or family history of allergies to metals.