Almost all whitening methods are similar in concept, but some are much more effective because of the way the whitening material is delivered to the teeth. Another contributing factor is the concentration of the material, which is why less potent over-the-counter whitening systems usually don’t give patients the results they are hoping for.
The two main methods of professional whitening are tray whitening and in-office whitening. In tray whitening, an impression is taken and a custom tray is made for the patient. Then, a supply of whitening gel is given to the patient and he/she wears the tray for a few hours each day (techniques differ) for a period of time until an acceptable result is achieved. Sensitivity of the teeth is a normal side-effect of this whitening method and is almost always transitional.
On the other hand, in-office whitening is the most efficient means of whitening. There are a number of different types used, but the process is very similar for these methods; you can have your teeth whitened in one session and achieve significant results. Your dentist can give you more detailed information and help you decide which method is more suitable for you and your teeth.