The facts on fillings

Silver fillings -- the most common type of dental filling -- are not actually pure silver, but a combination of silver, mercury, tin and copper. They are also referred to as "amalgam" fillings, which is simply the term for the metals bonded permanently together. Mercury is necessary because it triggers the chemical reaction that hardens the filling once it is set in the tooth. More than 100 million of these fillings are placed each year in the United States.

A hundred year history

Since 1895, scientists have been studying mercury as a safe and effective material for use in dental fillings. Scientists have proven that mercury, in small, specified amounts, does not pose a health threat to patients. The mercury released from your fillings is actually less than the amount naturally occurring in food, air and water. Mercury specifications were standardized by the American Dental Association (ADA) in 1932 to ensure the proper universal use of mercury in fillings. Today, more than 100 brands of dental amalgam have been accepted for use by dentists.

The allergic few

In extremely rare cases, some patients may experience a hypersensitivity or allergy to mercury. These reactions are usually seen as a rash on the mouth and face, similar to other types of allergies. Once the filling has been removed and replaced with gold, porcelain or a compound substance, the symptoms disappear within a few days. Sometimes a filling will cause a reaction that lasts a few days and never reoccurs. In that case, removing the amalgam may not be advisable because it could cause a second reaction. According to the ADA Journal, a study conducted by French researchers from 1905 to 1986 found only 41 published cases of allergic reactions to mercury in fillings. That's a very small amount when you consider the more than 100 million amalgam fillings placed every year.

Just the facts

In the late 1970s, a number of articles were published questioning the safety of dental amalgam fillings. These reports, while unsupported by any scientific or medical evidence, caused public concern over potential side effects of amalgam fillings. A few dentists, seizing the opportunity to generate new business, began to advocate replacement of all amalgam fillings with plastic or gold. While scientific research continues to prove the safety of amalgam fillings, some dentists may still try to scare patients into replacing fillings unnecessarily. Know the facts, and be sure to confirm any diagnosis of mercury allergy with a medical specialist, such as an allergist or dermatologist, before agreeing to any tests or amalgam filling removals. Fillings should be replaced only if the restoration is defective or worn. Practicing good oral hygiene and visiting your dentist regularly will ensure a long life for all your dental restorations.