Review (2/5): Didn't like it-
I bought these a while back ago, I didn't like the results. I don't think they really work, they have a satisfactory guarantee, or your money back. I wasn't motivated to get my money back, only once I felt a stinging sensation, that was after I brushed my teeth "not recommended" yeah it says not to brush your teeth before you use this product. I did anyways and that's the only time I ever felt any stinging sensation. The product didn't do it's job, I don't think I'll buy anything from crest again related to whiting. I should have saved up my money and got my moneys worth, I'd advise you do the same. Just save a bit, to get better results else where.