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.
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.
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