Normal Tooth Shade and Factors Affecting Tooth Color
- Appearance of a tooth is influenced by factors such as lighting conditions, translucency, opacity, light scattering, gloss, and human perception.
- Intrinsic pigmentation, determined by genetic and natural factors, is the most influential in tooth color.
- Teeth have a thin, whiter, and semitransparent enamel layer on the outer surface.
- Underlying dentin layer is darker, yellow-brown in color, and less transparent.
- Dentin contributes most to the overall tooth color, while enamel contributes blue, pink, and green tints.
- Public opinion of normal tooth shade is often distorted due to media portrayals of cosmetically enhanced teeth.
- Tooth color varies according to race, gender, and geographic region.
- Females generally have slightly whiter teeth due to smaller tooth size and less visible dentin.
- Baby teeth are generally whiter than adult teeth due to differences in enamel to dentin ratio.
- Larger teeth, such as molars and canines, tend to be darker.

Causes of Extrinsic Tooth Discoloration
- Extrinsic discolorations can be caused by dental plaque stained by chromogenic bacteria.
- Neglected plaque can calcify and form calculus, which varies in color (grey, yellow, black, or brown).
- Tobacco products can cause a yellow-brown-black stain on teeth.
- Betel chewing and certain foods and drinks rich in carotenoids or xanthonoids can stain teeth.
- Certain topical medications and mouthwashes can cause extrinsic staining.
- Extrinsic discolorations can be caused by dental plaque, calculus, tobacco, betel chewing, certain foods and drinks, medications, and metallic compounds.
- Exposure to metallic compounds like iron, iodine, copper, nickel, and cadmium can cause staining.
- Ingesting colored liquids like sports drinks, cola, coffee, tea, and red wine can also discolor teeth.

Causes of Intrinsic Tooth Discoloration
- Intrinsic discoloration can occur during tooth development or later in life.
- Dental caries (tooth decay) can result in brown discoloration.
- Fluorosis, caused by chronic and excessive exposure to fluoride during tooth development, can lead to white flecks or severely hypoplastic patches on enamel.
- Trauma can cause red, grey, or yellow discoloration depending on the type of injury.
- Pulp necrosis, internal resorption, and root canal treatment can also cause intrinsic tooth discoloration.
- Root canal materials, such as gutta percha and root canal sealer cements, can cause discoloration.
- Lack of pulp pressure in dentinal tubules after pulp removal can lead to dietary stains in dentin.
- Amalgam fillings can darken the appearance of teeth.
- Tetracycline and its derivatives, like minocycline, can cause yellow-green or brown discoloration of dentin.
- Genetic disorders, such as enamel hypoplasia and dentinogenesis imperfecta, can affect tooth development and result in abnormal appearance.

Aging and Tooth Discoloration
- Intrinsic discoloration tends to accompany aging due to the deposition of darker secondary dentin.
- Tooth wear processes like attrition and acid erosion can thin the enamel layer and make it less porous.
- Aging can also lead to phosphate deficiency in enamel.
- Aging-related discoloration is a natural process and may or may not be of cosmetic concern.
- Management options for aging-related discoloration include tooth bleaching and dental restorations.

Management of Tooth Discoloration
- Discoloration of front teeth is a common reason for seeking dental care.
- Many individuals with teeth of normal shade still request teeth whitening.
- Management depends on the cause of discoloration and can involve cleaning, whitening toothpaste, scaling, polishing, and identification of the cause.
- Intrinsic discoloration often requires tooth bleaching or dental restorations.
- Cosmetic concern and underlying pathology should be considered in the management of tooth discoloration.

Tooth discoloration is abnormal tooth color, hue or translucency. External discoloration is accumulation of stains on the tooth surface. Internal discoloration is due to absorption of pigment particles into tooth structure. Sometimes there are several different co-existent factors responsible for discoloration.

Tooth discoloration
Other namesTooth staining
SpecialtyDentistry
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