It is not possible to whiten teeth by brushing alone, as the mechanical action of brushing is not enough to remove deep stains and discolorations from teeth. Regular brushing is important to keep teeth clean and healthy, but it is not enough to achieve effective teeth whitening. To whiten your teeth, you need to use specific dental whitening products that contain hydrogen peroxide or carbamide, which are the active ingredients that help remove stains and discolorations from your teeth.