Save your money;  THIS DOES NOT WORK
Didn't work for me. Definitely does not whiten crowns or fillings.  Hard to open without breaking the swab.  Easy to keep off your gums upper teeth,  but the lower teeth my gums were SO irritated. I'm more disappointed I waisted what I believe to be a lot of money on this product.  Try it yourself, but I regret it.  I should have recognized photo shop on the commercials;  the yellow teeth were too perfectly yellow, the white teeth were too much like movie sets use to cap the teeth temporarily.  The ONE 5 star review had to be compensated;  there is just no way this stuff works as stated.  I'm furious I succered up.
Rating: 2 stars