Negative Positive
Title: This stuff works great!
Review: My teeth are hard to whiten. I really like Opalescence because it does a good job in a relatively short time. I was using the 5% before, and for me the 10% is even better because I only need about 2 nights, 3 maximum, for a really good whitening job, then can go months with just a one-night tune-up now and then. So it's lasting me even longer. Good product!
Is the review positive or negative? 