In most cases, the natural colour of teeth is within a range of light greyish-yellow shades. Teeth naturally darken with age and their appearance can be affected by the accumulation of surface stains acquired from the use of tobacco products and the consumption of certain foods or drinks. In addition, the perception of the colour of teeth is severely affected by skin tone and make-up. Independent of the real colour of their teeth, people with darker skin or who use dark makeup will look like they have brighter teeth.
Although teeth are not naturally meant to be completely white, many people want a brighter smile. Responding to this desire, a wide range of “”teeth whitening”” options have become available to consumers. These products fall into two main categories: surface whiteners and bleaches.