Dental caries, also called tooth decay or cavities, is a condition in which the tooth structure is progressively destroyed by bacteria on the tooth surface. It can affect both children and adults and if left untreated may eventually lead to pain, infection and tooth loss. Dental caries is primarily treated by drilling out the carious tooth structure and restoring it with an appropriate filling material such as composite resin or porcelain. If there is excessive destruction of tooth structure, a cap or crown may be constructed. If caries has spread to the dental pulp, a root canal procedure is indicated. Removal of the tooth is sometimes necessary for cases of severe caries.