TEETH-WHITENING

Teeth Stain Science

Teeth stain for many reasons, including your food and drink choices, oral hygiene, and medication use. Teeth stain occurs on the surface of the tooth (extrinsic stains) or below the tooth enamel (intrinsic stains) and some people develop both types of teeth stains. (1)

How Do You Evaluate Teeth Stain?

Tooth color is subjective, and it can be hard to tell how well teeth whitening products are working to remove or reduce teeth stains. A 2004 study in the Journal of Dentistry showed that even professionals disagree on tooth color when evaluating the same teeth, and a single professional can rate the whiteness of the same tooth differently on different occasions. (2) One method of evaluating the effectiveness of whitening products involves taking high-resolution digital images of teeth and assigning numerical values to describe the whitening effects three ways: a decrease in yellowness, decrease in redness, and an increase in lightness.(5)

What Factors Contribute to Your Teeth Stain?

Tooth color or teeth stains are a product of several biological factors, including the transparency of your tooth enamel. As the outer layer of tooth enamel thins with age, the dentin (which is more yellow in color than tooth enamel) becomes more visible, creating a type of teeth stain as the light-scattering properties of the tooth enamel change. (1), (3), (4)

Medical Conditions and Teeth Stain

Sometimes medical treatments can contribute to teeth stain, and several classes of medications including high blood pressure medications and some antipsychotic medications may cause teeth stain. (3)

Sources:

Vogel R. Intrinsic and extrinsic discolouration of the dentition: A review. Journal of Oral Medicine 1975;30:99-104
Joiner A. Tooth colour: a review of the literature. Journal of Dentistry 2004;323-12
http://www.webmd.com/oral-health/slideshow-10-secrets-to-whiter-teeth
Watts A, Addy M. Tooth discoloration and staining: a review of the literature. British Dental Journal 2001;190:309-316
Gerlach RW, Zhou X. Vital Bleaching and Whitening Strips: Summary of Clinical Research on Effectiveness and Tolerability. Journal of Contemporary Dental Practice 2001;2:1-16.