Dental Amalgam
The American Dental Association Council on Scientific Affairs has concluded that both amalgam and composite materials are considered safe and effective for tooth restoration.
Dental Amalgam is a commonly used dental filling that has been used for over 150 years, and is the most thoroughly researched and tested restorative material among all those in use. Dental amalgam is a stable alloy made by combining elemental mercury, silver, tin, copper and possibly other metallic elements. Although dental amalgam continues to be a safe, commonly used restorative material, some concern has been raised because of its mercury content. However, the mercury in amalgam combines with other metals to render it stable and safe for use in filling teeth. Amalgam has many advantages over other restorative material, such as low cost, strength, durability, and bacteriostatic effects.For those reasons, it remains a valued treatment.
Amalgam is used in dentistry for a number of reasons. It is relatively easy to use and manipulate during placement; it remains soft for a short time so it can be packed to fill any irregular volume, and then forms a hard compound. Because amalgam fillings can withstand very high chewing loads, they are particularly useful for restoring molars in the back of the mouth where chewing load is greatest. They are also useful in areas where a cavity preparation is difficult to keep dry during the filling replacement, such as in deep fillings below the gum line. Amalgam possesses greater longevity than other direct restorative materials, such as composite. On average, most amalgam restorations serve for 10 to 12 years, whereas resin-based composites serve for about half that time. However, with recent improvements in composite material science and a better understanding of the technique-sensitivity of placement, it should be noted that this difference is decreasing. Amalgam fillings, like other filling materials, are considered biocompatible. They are well tolerated by patients with only rare occurrences of allergic response.
Disadvantages of amalgam include possible short-term sensitivity to hot or cold after the filling is placed. The silver-colored filling is not as natural looking as one that is tooth-colored, especially when the restoration is near the front of the mouth, and shows when the patient laughs or speaks. And to prepare the tooth, it maybe necessary to remove more tooth structure to accommodate an amalgam filling than for other types of fillings.
There are circumstances in which composite (white fillings) serves better than amalgam; when amalgam is not indicated, or when a more conservative preparation would be beneficial, composite is the recommended restorative material. These situations would include small restorations on the top, chewing portion of the tooth, in which amalgam would require the removal of a more sound tooth structure, as well as in “enamel sites beyond the height of contour.”
While questions have arisen about the safety of dental amalgam relating to its mercury content, the major U.S. and international scientific and health bodies, including the National Institutes of Health, the U.S. Public Health Service, the Centers for Disease Control and Prevention, the Food and Drug Administration and the World Health Organization, among others have been satisfied that dental amalgam is a safe, reliable and effective restorative material.