Your wedding is coming up and you want your smile to be its brightest. Or maybe you have an important speaking engagement. Whatever the reason, tooth whitening isn't just for the movie stars, and it isn't just for one day. Many people have had their teeth whitened, and probably millions more are thinking about it. The desire for a brighter smile with whiter teeth is very strong, and tooth whitening safely lightens the color of the teeth, lasting for up to five years. The most effective and safest method of tooth whitening is dentist-supervised.