Fill 'Er Up, Doc: Which Filling Is Right for You?
If you need a cavity filled, you can choose from several options. So what's right for you? A filling made from amalgam, which dentists have used for more than a century? Or would a composite or ionomer material work best?
The location and size of your cavity often helps you decide which material to pick. Durability, appearance, and cost are also factors.
To help you choose, here is a list of the most commonly used materials:
Dental amalgam is made by combining mercury, silver, tin, copper, and possibly other metallic elements.
Advantages: Dental amalgam is strong and easy to use. It's highly resistant to wear. And it's inexpensive compared with other materials. Amalgam fillings are good for back teeth.
Amalgam also can be used in areas where it's hard to keep the cavity and filling material dry or free of saliva. This includes deep fillings below the gum line.
Disadvantages: You may have some sensitivity to heat or cold. If the cavity is visible near the front of your mouth, the filling won't look natural.
To help prepare the tooth for amalgam, your dentist usually must remove more of the tooth around the cavity than would be necessary with a composite filling.
Composite fillings are a mixture of glass or quartz filler in a resin medium.
Advantages: Composites are durable and resistant to fracture in small- to mid-sized restorations.
Because composite materials are designed to look like tooth structure, they are often used toward the front of the mouth. The composite material bonds to your tooth. That may mean that more of your healthy tooth can be kept.
Disadvantages: Composites cost more than amalgam fillings because the material is more expensive and it takes the dentist more time to place them compared to dental amalgam. The cost is still moderate. In addition, composites can only be used in areas that can be kept clean and dry during the filling procedure. Over time, composite fillings can stain or discolor and composites can be worn down by other teeth. On average, composite fillings are replaced more frequently than dental amalgams in the same teeth.1
Glass ionomers are tooth-colored materials made of a mixture of acrylic acids and glass powders. Resin ionomers are made from glass filler with acrylic acids and acrylic resin. These less common ionomers are mainly used between the teeth or on teeth roots, not on the biting surface of permanent teeth.
Advantages: Ionomers mimic natural tooth color. They can be used in wet areas. Like composites, they require less removal of tooth around a cavity than amalgams.
Disadvantages: Ionomers cost more than amalgams. They also break more easily and suffer high wear when placed on chewing surfaces. They lack the natural look of tooth enamel.
All-porcelain fillings and gold alloys (which contain gold, copper, and other metals) are less common filling choices. Each requires more than one visit to the dentist. This makes them more expensive.
All-porcelain fillings look like natural tooth enamel, but they can break and wear down opposing teeth. Gold alloys are strong, highly resistant to corrosion and tarnishing, and gentle to opposing teeth. But they don't look like natural teeth.
Is Amalgam Safe?
Concerns have been raised about the safety of the mercury content of amalgam fillings. However, the American Dental Association states that combining mercury with the other materials--including silver, tin, and copper--stabilizes the mercury.
The safety question has been studied in-depth. The major U.S. and international scientific and health agencies--including the National Institutes of Health, the Centers for Disease Control and Prevention, the Food and Drug Administration, and the World Health Organization--have all concluded dental amalgam containing mercury is safe and reliable.
"An Evaluation of Replacement Rates for Posterior Resin-Based Composite and Amalgam Restorations in U.S. Navy and Marine Corps Recruits." Journal of the American Dental Association. February 2009, vol. 140, no. 2, pp. 200-09. http://jada.ada.org/content/140/2/200.abstract
"Dental Amalgam Use and Benefits." Centers for Disease Control and Prevention. http://www.dentalwatch.org/hg/cdcfacts.html. Accessed 2013.
"Dental Fillings." American Dental Association. http://www.ada.org/3163.aspx. Accessed 2013.
"Fillings, Silver-Colored." American Dental Association. http://www.mouthhealthy.org/en/az-topics/f/fillings-silver-colored.aspx. Accessed 2013.
"Oral Health Topics: Dental Filling Options." American Dental Association. http://www.ada.org/5866.aspx?currentTab=2. Accessed 2013.