Amalgam Fillings vs. Composite Fillings
Used by dentists for more than a century, dental amalgam is the most thoroughly
researched and tested restorative material among all those in use. It is durable, easy to
use, highly resistant to wear and relatively inexpensive in comparison to other materials.
For those reasons, it remains a valued treatment option for dentists and their patients.
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.
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, the dentist may need to
remove more tooth structure to accommodate an amalgam filling than for other types of
Composite fillings are a mixture of glass or quartz filler in a resin medium that produces
a tooth-colored filling. They are sometimes referred to as composites or filled resins.
Composite fillings provide good durability and resistance to fracture in small-to- mid
size restorations that need to withstand moderate chewing pressure. Less tooth
structure is removed when the dentist prepares the tooth, and this may result in a
smaller filling than that of an amalgam. Composites can also be "bonded" or adhesively held in a cavity, often allowing the dentist to make a more conservative repair to the
The cost is moderate and depends on the size of the filling and the technique used by the
dentist to place it in the prepared tooth. It generally takes longer to place a composite
filling than what is required for an amalgam filling. Composite fillings require a cavity
that can be kept clean and dry during filling and they are subject to stain and
discoloration over time.
As published by the American Dental Association