A cavity is a hole in a tooth that is the result of decay. Tooth decay occurs when plaque, the residue that builds up on teeth, combines with sugars and starches from food. This combination of plaque and food residue mixes with the bacteria in the mouth and forms an acid that erodes tooth enamel, exposing the tooth to decay. If a cavity is not treated, the decay in the tooth will spread until it affects the root of the tooth.
Cavities are treated using either a direct or an indirect filling. The most esthetically pleasing type of filling is a direct composite (or resin) filling.
Composite fillings are made of porcelain and are white in color. Composite fillings are not as strong as amalgam fillings, but they bond directly to the tooth and require less of the natural tooth to be removed. Because of this, composite fillings are used primarily on low-impact front teeth.