How good are the crest 3d whitestrips? do they really work? (home teeth withening)do they cause sensitivity?permanent or temporary results?

Effective: Tooth-whitening strips are effective when used as directed, and should not cause severe sensitivity (some sensitivity may occur briefly, occasionally it is long-lasting). It's a long-term result, but your teeth will continue to darken over time as before. If the results aren't sufficient, your dentist has even more effective methods (custom trays for bleaching, other in-office treatments.

Most bleaching : Systems have the potential to cause sensitivity. Each persons tolerence is different. The sensitivity is usually transient and dissipates in a few days. Using a toothpaste like sensodyne before and after the treatment as well as morning and night, can help lessen the sensitivity. Also avoid acidic liquids and foods during the treatment (lemonade ...). Hope this helps.

Whitening : Yes white strips work and all whitening can cause sensitivity . It is the number one side effect of whitening. It can be temporary or long lasting.

Crest 3D WhiteStrips: Can be very effective in certain circumstances-(avg. Size teeth, uniform shade, not that dark).They have limitations & are not as custom, effective or quick as professionally applied & monitored methods. All methods can cause sensitivity which is usually temporary & depends upon health of teeth & gums. They last long term but varies from individual 2 individual. Results great 4 some, so-so 4 rest.