Types of Tooth Discoloration By Thomas G. Zarger Jr., D.D.S. on December 11, 2013

Knoxville Tooth DiscolorationIf you suffer from tooth discoloration, it’s important to understand the cause so you know how to tackle it.  

There are two main types of discoloration:

  • Outer or “extrinsic” discoloration, which affects the tooth’s enamel exterior.
  • Inner or “intrinsic” discoloration, which is caused by changes to the tooth’s interior, the “dentin.”

If your teeth discolor without a logical explanation, consult a dentist, who can determine the cause and recommend an effective treatment. Dr. Thomas G. Zarger, Jr., serves Knoxville and is skilled in cosmetic dentistry. He can assess tooth discoloration and recommend the appropriate treatment, such as teeth whitening.

Outer Discoloration

Outer, extrinsic stains are often caused by poor oral care or certain foods or products. Poor oral hygiene causes discoloration when inadequate brushing and flossing leaves plaque behind, which causes stains and eventually discoloring decay.

Foods or products that stain include:

  • Coffee
  • Tea
  • Red wine
  • Dark fruit juices, such as cranberry or grape
  • Tobacco, either smoked or chewed
  • Iron supplements and some medications
  • Chlorhexidine mouthwash sometimes causes stains, particularly if there is residue plaque

Inner Discoloration

As the name implies, inner discoloration occurs when the tooth’s interior discolors. The stain becomes part of the internal mineral or chemical structure of the tooth, which makes it harder to remove.

Intrinsic discoloring can occur before the tooth even appears. This may happen if you were given tetracycline as a child or if your mother was prescribed tetracycline when she was pregnant with you.

Sometimes trauma or nerve damage inside a tooth can discolor the tooth. Other causes of intrinsic discoloration include:

  • Exposure to excessive fluoride in early childhood.
  • Genetics. Some people have naturally brighter or thicker enamel, which is better at hiding the yellow dentin below.  

Age Related Discoloration

Age related discoloration is a combination of both intrinsic and extrinsic problems. Dentin yellows as we age and enamel thins allowing the darkening dentin to show through. Food and smoking stains can accumulate and damage to tooth roots is more likely. Even aging dental materials, such as amalgam fillings, cast a gray-black color over time.


Understanding the source of discoloration is key to treatment. Outer, surface stains are easier to treat. Since they are often caused by lifestyle choices, they can be managed through good oral hygiene and by avoiding products that stain. If whitening toothpastes don’t remove surface stains, consult a dentist about teeth whitening products or a professional cleaning.

Intrinsic discoloration is harder to overcome. Since the color is bound to the structure of the tooth, you will probably need professional help and the solution will depend on how the tooth was discolored. If your tooth darkened due to damage in the root, a dentist may be able to bleach the interior of the tooth. However, bleaching will not lighten some intrinsic stains, such as tetracycline. When bleaching is not an answer, dental bonding, crowns, or veneers may be the solution.

Next Steps

Not sure what caused your tooth discoloration? Please call us for a consultation. We can diagnose the cause by looking at your teeth, and then recommend appropriate treatment.

Related to This

Dr. Thomas G. Zarger, Jr., DDS Family Dentistry in Knoxville

Our practice has provided skilled and compassionate dentistry for patients in the Knoxville, TN, community for over 30 years. Dr. Zarger is a member of:

  • American Dental Association
  • Second District Dental Society
  • Tennessee Dental Association
  • American Academy of Cosmetic Dentistry

We strive to make care convenient and affordable to all patients and accept CareCredit financing to help reduce the cost of treatment. Schedule your consultation today online, or by calling (865) 693-7631.

Contact Us Today

Rate, Review & Explore

Social Accounts Sprite
Google map image of our location in 240 S Peters Rd Ste 103 Knoxville, TN

Knoxville Office

240 S Peters Rd
Ste 103
Knoxville, TN 37923

Open Today 7:00am - 2:30pm

What is the best time for you?

Add additional time

Tell us a bit about yourself...

(865) 693-7631 Send a message