It's not a true tooth "whitening" process, but rather a lightening, as it doesn't alter the tooth's natural color. A tooth's color is determined by the shade of the tooth's core (dentin) and by the enamel's transparency and ability to refract light.
The color of the core is not altered; however, over time the enamel becomes stained by tobacco, lipstick, coffee, tea, tomatoes, chemical pigments, cola drinks, the use of certain medications, etc.
Teeth whitening involves using chemicals to remove anything from the enamel that alters its original color. The most suitable procedures for each patient should be chosen based on their diagnosis; therefore, our dentist will advise you.