- Tooth Colour
- Tooth Discolouration
- Extrinsic Causes
- Intrinsic Causes
Tooth color is determined by a combination of phenomena associated with optical properties and light. Essentially, tooth color is determined by the color of dentin and by intrinsic and extrinsic colorations. Intrinsic color is determined by the optical properties of enamel and dentin and their interaction with light. Extrinsic color depends on material absorption on the enamel surface. Any change in enamel, dentin, or coronal pulp structure can cause a change of the light-transmitting properties of the tooth – teeth discolouration.
Tooth discoloration varies in etiology, appearance, location, severity, and affinity to tooth structure. It can be classified as:
- or a combination of both
according to its location and etiology.
The principal causes are chromogens (colour agent) derived from habitual intake of dietary sources, such as wine, coffee, tea, carrots, oranges, licorice, chocolate, or from tobacco, mouth rinses, or plaque on the tooth surface.
The most commonly used procedure to remove discoloration from a tooth surface is by using abrasives (such as prophylactic pastes) or a combination of abrasive and surface active agents such as toothpastes. These methods prevent stain accumulation and to a certain extent remove extrinsic stains; however, satisfactory stain removal depends on the type of discoloration. Unfortunately, the chemical interactions that determine the affinity of different types of materials that cause extrinsic dental stains are not well-understood.
Unlike extrinsic discolorations that occur on the surface, intrinsic discoloration is due to the presence of chromogenic (coloured) material within enamel or dentin, incorporated either during tooth developing (odontogenesis) or after eruption. This type of stain can be divided into 2 groups, preeruptive and posteruptive. The most common type of pre-eruptive staining is endemic fluorosis caused by excessive fluoride ingestion during tooth development. Post-eruptive stain usually associated with pulp problems such as pulp necrosis, or root canal material. Generally, intrinsic stain can be divided into:
Systemic causes are
- drug-related (tetracycline), excessive fluoride ingestion;
- metabolic: dystrophic calcification, fluorosis;
- genetic: congenital erythropoietic porphyria, cystic fibrosis of the pancreas, hyperbilirubinemia, amelogenesis imperfecta, and dentinogenesis imperfecta
Local causes are
- pulp necrosis,
- intrapulpal hemorrhage,
- pulp tissue remnants after endodontic therapy (RCT),
- endodontic/RCT materials,
- coronal filling materials (eg. Crown, filling material),
- root resorption,