Teeth are made up of layers of mineralized material. The outer layer is called enamel and is usually translucent. This means that the enamel itself does not really affect the color of the teeth because it is see through. The inner layer of the tooth (just outside of the nerve or pulp) is made of dentin. The dentin makes up the bulk of the tooth and it is colored. The color of the dentin shows through the enamel layer which gives the teeth their color. The more darkly pigmented the dentin is, the darker the teeth appear.
Factors that can affect the color of the dentin:
- Age- As we get older, the nerve tissue or pulp of the teeth continues to make more dentin on the inside of the tooth. As the dentin thickens, the color of the tooth intensifies. This helps explain why teeth appear to darken with age.
- Medications- There are certain medications that expectant mothers can take that may affect the color of their unborn infant's teeth. Tetracycline is an example of a medication that is known to cause such discoloration.
- Genetics- There are certain specific genetic disorders that may cause individuals to have darkly colored enamel. These disorders may also have symptoms in other organ systems in the body and are somewhat rare and usually diagnosed in infancy. An example of such a disorder is Dentinogenesis Imperfecta.
- Necrosis- Sometimes when a tooth sustains trauma, the blood supply to the tooth is cut off and the nerve of the tooth dies. When this occurs the tooth may darken in color. A tooth with a dead nerve is diagnosed as being necrotic. Necrotic teeth are treated either with a root canal (endodontic procedure) or extraction to clear away the dead, infected nerve tissue.
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| tetracycline staining |
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| Necrotic upper left central incisor |
Factors that affect the color of the enamel:
- High fever in infancy- Some patients who had a high fever as an infant may have bands of discolored or and even malformed enamel on their teeth. This is because the fever disrupts the normal function of the enamel producing cells as the teeth are being formed. The location of the defects depends on how old the patient was when the fever occured.
- Fluorosis- Patients who are exposed to high levels of fluoride in their drinking water and other beverages while teeth are being formed may develop white and brown spots on the enamel of their teeth. This is because the fluoride is taken up into the structure of the teeth in place of calcium and therefore alters the structure and appearance of the tooth. Although it looks unsightly, it is not harmful to the tooth. Patients with fluorosis may opt to have cosmetic dental procedures to improve their smile as adults.
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| fluorosis |
- Cavities- It may seem obvious, but cavities also cause teeth to be discolored. Bacteria in the mouth metabolize sugar from foods and drinks and produce acid as a by product. The acid produced causes tooth enamel and dentin to erode which results in white spots, as well as brown, and black areas on the teeth.
- External Stains:
- Tobacco Stains- smoking and using smokeless tobacco products can leave stains on the enamel of the teeth.
- Beverages- Coffee, tea, dark colored sodas also can leave stains on the surface of the teeth.
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| tobacco stained teeth |
Fortunately, most external stains can be removed with a professional dental cleaning. However, repeated use of staining materials may leave behind a fine residue in the texture of the enamel that can only be removed by dental tooth whitening or other cosmetic procedures.
As you can see, there are several factors that can cause discoloration of the teeth. If you are displeased with the color of your teeth. Talk with your dentist to see what options are available to you to improve the appearance of your smile.
Happy Smiling!
