Toothpastes contain abrasives: silica, diamond dust and baking soda to polish the surface of the teeth and remove surface sediments. If you use them a few times it may give you a satisfactory result. However, it is not recommended to use this type of toothpaste on a regular basis, as this may cause abrasion the surface of the teeth. In particular, those who have the neck of their teeth exposed (these are those places that are no longer protected by the hard enamel) must avoid abrasive pastes sold as a whitening toothpaste.
In Surgery Teeth Whitening involves trade-controlled liberation of simple chemical processes within the stains which have penetrated the tooth structure. Our teeth, as a result of aging and "ill-treatment", gather in their micropores organic compounds from coffee, tea, wine, cola and orange juice etc. Using these preparatory methods we can invoke the breakdown of complex organic compounds to CO2 and H2O. So, chemically speaking, the process is safe and predictable and as a result the tooth colour becomes white.