Why do Teeth Discolor?

We all tend to think of teeth as hard, but this is basically the outer coating called the enamel. It is one of four major tissues that teeth are comprised of.

• Enamel
• Dentin
• Cementum
• Pulp

Enamel is also the hardest and most highly mineralized substance of the human body. Under the enamel is the dentin. This substance is porous and softer than the enamel, and can be subject to decay and severe cavities. Despite this, it still acts as a protective layer. The Cementum is a specialized substance covering the root of a tooth that is softer than both the enamel and the dentin. Its principal role is to serve as a medium by which ligaments can attach to the tooth and stabilize it. The Central part of the tooth is the Pulp, also referred to as the “nerve” of the tooth. The pulp contains blood vessels and nerves that enter the tooth from a hole at the apex of the root

So why do teeth discolor?

First of all, teeth are not really white to start with. The enamel is naturally a light yellow to grayish white . Further yellowing of the enamel, which is the symptom most people are aware of, is a natural aging process that occurs due to the enamel becoming less porous and changing in it's mineral structure. The surface enamel is also prone to cracks and erosions, which exposes the dentin. The dentin being a more porous substance absorbs food colors and pigmentation.

There are other discolorations associated with teeth. Certain antibiotic medications such as tetracycline can lead to grayish discolorations. Grayish-blue discolorations can also be caused by hereditary factors or damage to the root of the tooth. In these cases, the discoloration may be located in the dentin. This discoloration is noticeable as enamel is semi-translucent.

Lifestyle choices can also lead to discoloration and staining. Dark pigments in foods and beverages particularly tannin (found in coffee, tea and red wine) can contribute to staining by binding to the enamel, staining the surface of the tooth. Tobacco in both smoking and chewing form can contribute markedly to a brownish to yellow appearance in teeth.

To lessen the effects of staining due to foodstuffs and tobacco, try to brush or at least rinse after exposure to these. Milk and saliva can help to break down tannin, so adding milk to coffee, and chewing gum to promote saliva production can also help lesson the staining.