Discoloured teeth

Teeth that are abnormally coloured or stained. Extrinsic stains, on the tooth’s surface, are common, but are usually easily removed by polishing. They can be prevented by regular tooth cleaning. Smoking tobacco produces a brownish-black deposit. Pigment-producing bacteria can leave a visible line along the teeth, especially in children. Some dyes in foodstuffs can cause yellowing; dark brown spots may be due to areas of thinned enamel stained by foods. Some bacteria produce an orange-red stain. Stains may also follow the use of drugs containing metallic salts. Intrinsic stains, within the tooth’s substance, are permanent. Causes include death of the pulp or the removal of the pulp during root-canal treatment and the use of the antibiotic tetracycline in children. Mottling of the tooth enamel occurs if excessive amounts of fluoride are taken during development of the enamel (see fluorosis). Hepatitis during infancy may cause discoloration of the primary teeth. The teeth of children with congenital malformation of the bile ducts may be similarly affected. Many stains can be covered or diminished with cosmetic dental procedures.