There are a variety of materials used to fill teeth these days, but the process of filling a tooth is similar regardless.
Types of Fillings
There are two broad categories of dental fillings: metal fillings and tooth-colored fillings. Each may offer particular advantages and disadvantages in certain situations.
Amalgam — The classic “silver” filling in use for more than a century, dental amalgam is actually an alloy made up of mercury, silver, tin, and copper. The mercury combines with the other metals in the amalgam to make it stable and safe. These fillings are strong and inexpensive, but also quite noticeable. They also require relatively more tooth preparation (drilling) than other types.
Cast Gold — Among the most expensive restorative dental materials, cast gold combines gold with other metals for a very strong, long-lasting filling. It is also highly noticeable, which can be considered a plus or minus.
Composite — A popular choice for those who don't want their fillings to show, composite is a mixture of plastic and glass, which actually bonds to the rest of the tooth. Composites are more expensive than amalgam fillings, and the newer materials can hold up almost as long. Less drilling of the tooth is necessary when placing composite as compared to amalgam.
Porcelain — These high-tech dental ceramics are strong, lifelike, and don't stain as composites can. They are sometimes more expensive than composites because they may require the use of a dental laboratory or specialized computer-generated technology. While considered the most aesthetic filling, they can also, because of their relatively high glass content, be brittle.
Glass Ionomer — Made of acrylic and glass powders, these inexpensive, translucent fillings have the advantages of blending in pretty well with natural tooth color and releasing small amounts of fluoride to help prevent decay. They generally don't last as long as other restorative materials.