Will tooth whitening be too harsh for sensitive gums and teeth?

Some products are less "sensitivity inducing" than others, but it IS common Pre dosing with ibuprofen helps, as does wearing the trays with dentist distributed Fluoride prior to the bleaching gel.
Most of the time the pain is from dehydration of the teeth while bleaching. The water is "wicked" out of the teeth, but then returns shortly.
It is commonly stated that "beauty is pain" and it may apply here. There may be some discomfort during the process, but when all is complete the pain will go away. There is no permanent damage done with this process.

Some teeth whitening systems will cause more pain and sensitivity than others. We use Kor Whitening and Whiter Image.  We have no problems with pain and sensitivity with our patients. We try to use ones that have a built in protection from  dehydration. This is what causes pain. While bleaching teeth, there is a point where all of the water is removed from the tooth and then returns. This is the painful part and Kor Whitening has a built in process that counteracts the dehydration and hence, no pain.  Also we have our patients use MI paste to help remineralize the tooth structure to reduce sensitivity. Wearing trays with flouride before bleaching helps as well as brushing with a soft brush and using a good desensitizing toothpaste.  Try to follow some of the above suggestions and we hope you have  beautiful pain free white teeth and a smile you are happy with!

In my personal experience, the Deep Bleaching system I use in my office with AcquaBrite bleach in the office and then having the patient do at home bleaching with Nite White, using the same custom trays, works incredibly well. Patients get at least 10 shades lighter in 2 weeks with no sensitivity in general. Even patients who have been told they can't whiten have had tremendous results with our protocol. One in office bleaching session just does not work to get long lasting, predictable results, as much as we all wish it would! And the light and the laser bleaching can often dry out the teeth which is the number one reason for sensitivity both during and after the visit. Yes, the teeth will look whiter at the end, but the color tends to rebound (darken) within a few days as the teeth rehydrate.  Patients of mine who have had sensitive teeth for years have been able to finally get the smile of their dreams with our system.  I've tried all the other ones out there as I've been bleaching teeth since 1998 and this is by far the most predictable and comfortable system I've ever used.