In the past, teeth were most commonly repaired with amalgam (silver) fillings or gold restorations. Thanks to advances in modern dental materials and techniques, teeth can be restored with a more aesthetic and natural appearance. There are different types of cosmetic fillings currently available. The type used will depend on the location of the tooth and the amount of tooth structure that needs to be repaired. The most simple form of 'white filling' is technically called a Composite. It is made up of a composite quartz resin and usually contains some sort of light sensitive agent. These light cured composites are extremely cosmetic and most often bonded into place in one appointment. For this reason, they are often referred to as "bonding". They can be used in both the front of the mouth as well as in your back teeth. These materials come in a variety of shades so that they will match the color of your own teeth. Some of these composite materials have been specifically designed to actually withstand the incredible forces you can exert when chewing on your back teeth.
Dental amalgam, in widespread use for over 150 years, is one of the oldest materials used in oral health care. Its use extends beyond that of most drugs, and is predated in dentistry only by the use of gold. Dental amalgam is the end result of mixing approximately equal parts of elemental liquid mercury (43 to 54 percent) and an alloy powder (57 to 46 percent) composed of silver, tin, copper, and sometimes smaller amounts of zinc, palladium, or indium.
Because of a general decline of dental caries among school children and young adults, the use of dental amalgam began to decrease in the 1970s. There are also changes in patterns of dental caries, largely the result of topical and systematic fluoride, sealant use, improved oral hygiene practices and products and possibly dietary modifications. In 1990, over 200 million restorative procedures were provided in the United States; of these, dental amalgam accounted for roughly 96 million, a 38 percent reduction since 1979. This trend is expected to continue.