dental caries

decay and crumbling of the substance of a tooth. Dental caries is caused by the metabolism of the bacteria in plaque attached to the surface of the tooth. Acid formed by bacterial breakdown of sugar in the diet causes demineralization of the enamel of the tooth. If no preventive measure or treatment is carried out it spreads into the dentine and progressively destroys the tooth. It is the most common cause of toothache, and once infection has spread to the pulp it may extend through the root canal into the periapical tissues to cause an apical abscess.

Frequent intake of sugar is a major cause, and the disease is more common in young people and has a predilection for specific sites. Dental caries can be most effectively prevented by restricting the frequency of sugar intake and avoiding sweet food and drinks at bedtime. The resistance of enamel to dental caries can be increased by the application of fluoride salts to the tooth surface from toothpastes or mouth rinses. fluoridation of water also makes teeth resistant to caries during the period of tooth development. Once caries has spread into the dentine, treatment usually consists of removing the decayed part of the tooth using a drill and replacing it with a filling.

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localized destruction of calcified tissue initiated on the tooth surface by decalcification of the enamel of the teeth, followed by enzymatic lysis of organic structures, leading to cavity formation that, if left unchecked, penetrates the enamel and dentin and may reach the pulp. There are several theories on etiology: see acidogenic theory, proteolytic theory, and proteolysis-chelation theory, under theory. Classified by Black into five groups on the basis of similarity of treatment required; a sixth group is sometimes added. (See table.) See also cavity. Called also tooth decay.