Dental amalgam is a mixture of metals including mercury, copper, silver and tin. Amalgam fillings have been used for over 150 years to fill cavities in dental patients caused by tooth decay. They are sometimes referred to as “silver filling” because of the color.
To place amalgam fillings, the dentist drills to remove the decayed area of the tooth and properly shape the cavity for filling. If the filling is going to be an “unbonded” type, ledges and other structures may need to be created in the tooth to hold the filling in place. The alloy powder part of the amalgam, which contains the copper, silver and tin, is mixed with the liquid mercury portion of the filling to make a putty. The putty is then placed into the cavity where it hardens to a solid.
Benefits of amalgam fillings:
- the least expensive filling material available
- durable and long-lasting
- able to withstand the forces of chewing
- less likely to break than other materials
- only require one visit to the dentist to fill
Drawbacks of amalgam:
- contains mercury, which is associated with damage to the brain and kidneys in high amounts
- some patients have sensitivity to the materials in the amalgam which might cause irritation or oral lesions
- fillings can contract and expand, which can lead to gaps and cracks, providing places for bacteria to develop
- over time, amalgam fillings can corrode or tarnish
- some patients prefer the appearance of composite, or tooth-colored, fillings
The FDA has studied dental amalgams extensively and has proven them safe, but the mercury content is still concerning to some patients. If you are concerned about your amalgam fillings, it is important to contact your dentist to discuss your options. If your fillings are in good shape, there is usually no reason to replace them, since the procedure would require additional drilling into healthy tooth structure and you could be exposed to additional mercury vapor during the process. However, if your fillings have become loose over time or gaps have developed that are allowing bacteria to develop and possibly lead to decay, it might be time to consider having them replaced.