Amalgam fillings are the dental term for metal fillings. These were once the standard for filling a cavity. They were often called silver fillings, but they’re not made of pure silver. Amalgam is a mixture of mercury and other metals like copper, tin and silver. Both the American Dental Association and the FDA say that the mercury in these fillings poses no threat to health, even though mercury vapor can be released from them. Several countries have banned amalgam fillings outright. Tooth-colored composite fillings, which are composed of a type of resin that is hardened with a special light, are the more common filling material used today.

The Problem with Mercury

Even if the mercury isn’t a health threat, there is still another problem with the mercury in them. This element is very sensitive to changes in temperature. Mercury can expand and contract in response to the hot and cold liquids and foods you consume. That’s why mercury was once used in oral thermometers. Placed in the mouth, the mercury in the thermometer’s glass tube reacted to the temperature there and gave a reading in a marked vertical column. An amalgam filling in a tooth, especially if it’s large, can expand enough over time to actually crack a tooth. If this happens, a crown may be required to repair the damage. Over time, the amalgam filling can also pull away from the edges of the cavity hole and allow food and bacteria to enter, causing a cavity to begin again in the existing tooth structure.

Replace Old Fillings

Amalgam fillings can be removed and replaced with composite ones at any time. This can be done as a preventative measure. There is no need to wait until the amalgam fillings cause a problem. If you have these kinds of fillings and begin to feel pain in the filled tooth, see your dentist immediately. This is also true if the tooth is sensitive to pressure, heat or cold. Some people think a filled tooth can’t be decayed, but it can.

If you’re concerned about your amalgam fillings, especially if you’re an older person with amalgams placed in childhood, speak to your dentist about replacing them with composite fillings before there’s a problem.