Almost all the whitening methods are similar in concept but some are much more effective because of the way the whitening material is delivered to the teeth. The other factor in effectiveness of the method is the concentration of material, which is the reason why over the counter whitening systems usually don t give patients the result they are hoping for.
The two main methods of professional whitening are tray whitening and in office whitening. Tray whitening is when a custom tray is made for the patient after an impression is taken, then a supply of whitening gel is given to the patient and he/she will wear the tray for a few hours a day (techniques differ) for a period of time until an acceptable result is achieved. Sensitivity of the teeth is a normal complication of this method of whitening and is almost always transitional.
In office whitening on the other hand is the most effective method of whitening. There are a few different ways that are available for example, Britesmile, Zoom, Laser whitening....But in all these methods the process is similar and you can have your teeth whitened in one session with great results. Your dentist can give you more detailed information and tell you which method is more suitable in your case and which one is indicated for your teeth.