bp's science: do whitening toothpastes really work? (v.1)

My last year of undergraduate, I took a technical writing class that required a research paper. Whitening toothpastes was the subject. So here's 20 pages of research in a nutshell.

Whitening toothpastes don't change the natural color of your teeth in any way. These toothpastes do not whiten by changing the shade of your teeth, so in that respect they do not whiten teeth. However, toothpastes can claim that they whiten because they contain abrasive ingredients like silica or baking soda. These ingredients act like mini bits of sandpaper, grinding particles off your teeth that have gathered over time from food. So yes, if you've got some stains accumulated on your teeth from different foods, they will be removed by your "whitening" toothpaste. But if you'd like to improve the color of your teeth by a couple of shades, you're going to need something else.