There is a widespread perception, which is confirmed by many but not all rabbis, that it is forbidden to brush your teeth on Shabbat. Understandably, the companies that make toothbrushes must not like this state of affairs.
So I should not have been too surprised to walk into a beit midrash today and see a pile of pamphlets, published by Oral-B, entitled "Mouth health: halachot of tooth brushing on Shabbat". After a substantial discussion of the sources, the pamphlet concludes of course that it is perfectly acceptable to brush teeth on Shabbat! And then it has a couple pages of ads for their specific toothbrushes. But even these are religiously oriented; the catch-phrase at the top of one of them comes from probably the only Biblical verse to mention white teeth.
Here is a partial scan of the pamphlet. My roommate and I think it's hilarious.
P.S. There seems to be a discrepancy between how some of the sources are quoted in the pamphlet versus in the article I linked to above. As you might expect, the pamphlet understands them to be much more lenient. Having not seen the sources myself I can't tell you for sure which interpretation is more accurate. But it's clear who has the bigger ulterior motive. :)