This will depend entirely on the type of staining your teeth are left with after the braces are removed. If the staining is superficial, or a result of leftover cement residue, the stains may be able to be polished off. However, the staining may actually be the result of decay or erosion in the enamel. If this is the case, teeth whitening may not be the ideal solution, as damaged teeth are more vulnerable to the whitening solution than healthy teeth. Consult with your dentist to determine the reason for the stained appearance, and to find out if your teeth are healthy enough for teeth whitening.