Twice a day we carry out the same old minty ritual—several up-and-down strokes, rinse and spit. If the experience is a bore, most of us shrug it off as the price for shiny whites. But now, a new crop ...

Now we're all checking our toothpaste tubes. As if conspiracy theories could get any more wild, now there's one involving the different kinds of toothpaste that we use. The theory, which was discussed ...