Do crest white strips work?

yes. But, if you have sensitive teeth, they can HUUUURT. (like mine)

Here are some good earlier answers

They do, but only on the exact place you use them. A friend of mine had long teeth, so after a few weeks: Sure, it worked. Upon closer inspection, you can see he had two-tone colored teeth.

The best, but most expensive, is to have plastic molds made and then use the gel provided by dentist. Molds can be reused in a year or so and you can purchase more gel, again from dentist.

I can’t speak to the strips per se. I use trays like gailcalled mentions. It is a custom molded tray and it does work. The results are fantastic. My teeth are a bit sensitive to cold for about a day after each bleaching (I sleep w/ one tray at a time)......so I wouldn’t recommend using on concesecutive days.
Once you get to the brightness you want, it is just a matter of maintaining.
Also, the bleach stuff doesn’t taste so great…....

@Snoopy; I wore my trays for an hour a day; it took several weeks to use up the gel. And it’s hard to talk with them on. It is easy to mumble and drool, however.

@gailcalled I wear mine at night….and only on nights when I am really tired so I will sleep w/ them on….My dentist told me to wear them at least 8 hours per session…..doesn’t seem like you would get too far w/ the whitening at an hour/day…..?

It worked very nicely and w/o any sensitivity. Maybe I wore them 30 minutes/ twice a day. Teeth still look good after several years, but I don’t drink coffee.