Even after simply brushing, the color is not possible to be restored. These particles get deposited over the enamel so closely that washing the mouth or brushing it with toothpaste doesn't allow the coloration to fade. In such a case the teeth whitening products are required, which provide a white look to the tooth. There can be hundreds of reason for the whiteness to be discoloured. Sometimes the consumption of tobacco in different forms can be harmful along with causing the discoloration. When people are embarrassed by their smiles, they can take the recourse to different agents that will help in making the white color come back. It is not an easy task because the solution is sometimes not found with the doctors.
But over the years, and with experience, one can see that the teeth whitening gel is sometimes effective in getting a better smile which is now bright white. This is possible by the regular application of the gel that will erode away the superficially deposited materials and return the glaze of the tooth. In some cases where the discoloration is due to an inherent compound or lack of calcium, the gel will take a lot of time. Some of the teeth whitening products are also devised in such a way that they will leave a coating of the artificial synthetic material over the tooth so that it hides the discoloured tooth. For more info, visit this link.