Question:
I've heard mixed opinions on the various over the counter teeth-bleaching
products, do they work, and are they harmful to the tooth enamel?
Answer:
I don't think it's legal to sell over the counter a product that can damage
the enamel, so they're at least safe. My mother wasted her money on one
of those products (for me), and it didn't work. Since dentists use some
treatments that can even damage the *roots* of teeth, I doubt any over-the-
counter gimmick will work consistently (though they may work, at least
temporarily, for some people).