Dental researchers are continuing their often decades-long work developing materials, such as ceramics and polymer compounds that look more like natural teeth. As a result, dentists and patients today have several choices when it comes to selecting materials to repair missing, worn, damaged or decayed teeth.
These new materials have not eliminated the usefulness of more traditional dental materials, such as gold, base metal alloys and dental amalgam (silver fillings). That’s because the strength and durability of traditional dental materials continue to make them useful for situations, such as fillings in the back teeth where chewing forces are greatest.
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.
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.
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 fillings, like other filling materials, are considered biocompatible—they are well tolerated by patients with only rare occurrences of allergic response.