Fillings – Amalgam vs. Composite

By: Dr Larry Cook
For well over a hundred years, dentists have "filled" teeth with dental amalgam. Basically, dental amalgam consists mostly of silver with trace amounts of copper and tin mixed with virtually pure mercury to produce a putty-like mass, which hardens in about an hour. In my grandfather’s day, this mixed with a mortar and pestle, but now there is a machine specially made to mix these components together. The resulting "filling" is very hard, but is colored silver to black, which makes it cosmetically questionable in today’s esthetically-conscious market. About fifty-years ago, composite resin filling material burst upon the market. Basically a very high-grade, specialized plastic, composite was originally two pastes mixed together to then set or harden within a few minutes. This means that they set only on an exposure to a very intense blue light, giving the dentist almost unlimited time to shape or contour the filling. Today’s composites are extremely varied as to strength and polishability reflecting the requirements called for in different parts of the mouth. Teeth are etched with a mild acid, producing microscopic grooves in the enamel. Composite is then bonded into the individual teeth and, when properly done, is almost impossible to separate from the tooth without the proper dental equipment. Best of all, they are tooth-colored, with hundreds of shades available to match any particular tooth producing a very life-like result.
For many years, the dental community has been split on the appropriateness of using dental amalgam in humans. Many accusations have been leveled at amalgam, including suggestions that mercury leaking from the restorations causes everything from Multiple Sclerosis to Autism. Many studies have been done over the years and results have been produced to support every possible position. This continues to be a hot topic in dentistry. However, the American Dental Association has continued to endorse the use of dental amalgam without reservation. Composite resin is slightly more expensive than amalgam, due to the fact that it is somewhat more labor intensive and the materials are more expensive. Nevertheless, most patients today opt for composite for esthetic reasons. This certainly seems to be the direction operative dentistry is going.
Millions of dollars each year are invested in research related to making composites stronger, more beautiful, and longer lasting. Amalgam is what it always has been and probably always will be: a utility dental material with limited application.