What Causes Stained Teeth?

There are two main types of yellowed or stained teeth, which are referred to as intrinsic stain or extrinsic stain. Intrinsic stain, is stain that is located deeper in the teeth or stain that occurred while the teeth were forming. Extrinsic stain occurs on the outer surface of the teeth, known as the tooth enamel.


Causes Of Intrinsic Stain

Intrinsic staining can be a result of a defect or abnormality during the tooth’s formation at the cellular level. A common cause of this is due to the use of certain antibiotics, called tetracyclines, while the mother is pregnant. Children under the ages of 8 years old who use this type of medication may also be affected. Tetracycline medication can give teeth a yellow and brown look that is permanent. Tetracycline use during pregnancy generally should be avoided.

Another cause of intrinsic stain, is due to excess fluoride during the formative years of the teeth. Too much fluoride can give teeth a brownish look and can cause spotted areas on the teeth that are permanent. This is known as dental fluorosis.


Teeth affected by dental fluorosis

Damage or injury to teeth can also cause darkening or browning of the tooth, due to abnormally high blow flow to the affected tooth.

In some cases, some people will have a condition known as dentinogenesis imperfecta. This condition causes gray or purple discolorations of the teeth.

Causes Of Extrinsic Stain

Extrinsic stain occurs on the tooth’s enamel, which is the outermost layer. This type of stain is commonly caused by diets that include tea, coffee, red wine, sodas, and other foods. A major cause of severe staining is due to smoking as well.


Effects of acid erosion on teeth.

Acid erosion can also make teeth have a brownish or darker appearance as well. Consuming acidic foods and drinks will erode the tooth’s enamel over time. Once the outer enamel layer is eroded or thinned down, the tooth’s dentin is exposed. Dentin is a naturally darker material. With less enamel covering the dentin, the dark color shows through the thin remaining enamel layer easier.

Avoiding Stained Teeth

When it comes to intrinsic stain, avoiding tetracylcine medication, especially during pregnancy is the great way to avoid this type of permanent stain. Children under 8 years of age should avoid taking tetracycline medication, unless their doctor deems it necessary.

Avoiding excess fluoride will also help to keep teeth safe from the effects of dental fluorosis. Learning about the amount of fluoride present in all dietary sources, can help you to avoid excess fluoride intake.

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Damage or trauma to teeth can be avoided by wearing a sports guard while engaging in sports or full contact activities. Once teeth are subject to excessive trauma or forces, the tooth may die and become darkened.


The cause of most stain however is extrinsic in nature. In order to avoid staining caused be foods, it is best to avoid those foods or limit their consumption if possible. If those types of foods compose a large part of your lifestyle, rinsing vigorously with water after consumption of those foods will help to wash away food residue. Rinsing with water after consuming red wine, smoking, tea, coffee, etc, will help to reduce staining and lower acid erosion as well.

Giving up smoking will help greatly, not only with reducing stain but with limiting bone loss in the mouth, that is associated with smoking.

Contact us if you have stained teeth, to learn about our teeth whitening treatment options.

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