I am thinking of having my teeth whitened at a clinic using the blue light technology, but have heard that your teeth are a bit sensitive afterwards. Anyone with experience out there..? I would be really interested to know what to expect.

My wife tried one of the home whitening kits, and it didn't seem to make any difference, so the professional route may be the way to go.

I've had mine done at a beauty salon.  It was the Beyond white spa system.  They also use a light.  I did quite a bit of research if the people used 6% hydrogen peroxide there was very little sensitivity.  My brother had his done at the Dentist and he couldnt stand the pain and had to stop.  Apparently they use much higher strength.  I was very pleased with mine I have to say.  No trays involved - thank goodness. 

Is there any research on the long-term effects of these treatments?

I've recently had mine whitened using a home treatment programme supplied by my dentist. I had to have moulds made of my teeth for the trays. A little of the bleaching paste is applied to each tooth recess and then they need to be worn for between 2 and 4 hours, or overnight. There was some sensitivity but that quickly subsided. I am very pleased with the result as I no longer have beige teeth.

Disadvantages:

Although bleaching is very effective, there can be short term disadvantages, such as sore gums or teeth from the bleach. This disappears when bleach use is discontinued. Some individuals are more chemically sensitive. If you are one of them, inform your cosmetic dentist so that you can be tested for sensitivity to the solution.

Research indicates that bleaching is completely effective in more than 78% of people. In cases of serious teeth discoloration, bleaching may not be the best choice. Veneers or crowns may be the superior choice. Bleaching is usually the first solution to try due to its lower cost.

Some people experience discomfort from wearing the mouth tray. This typically goes away in short order, but if you suspect that there is a problem with the fit of your mouth tray, call your dentist's office. They can often make small adjustments that will minimize or eliminate the problem.