Review (1/5): Wouldn't buy again!!  Warning!!
I purchased the 12-pack, and used maybe 2 or 3 over a 10-month period. First, you're "not supposed to use longer than four weeks unless recommended by the dentist" (my fault for not reading the package on TOOTHPASTE). Second, I started experiencing a burn-like feeling in my mouth, skin sloughing off, dry mouth, pain in my throat / neck glands, and lack of taste. It was TERRIBLE! Shortly before a dental appointment, I finally put two-and-two together, and realized it may be the toothpaste. Relief of all of my symptoms started within 24 hours. Read the reviews for smaller packaging, and you will see similar complaints about this product.
I thought "Oh, it's Crest, good stuff. And whitening, and gum protection, and tartar control, and plaque control, and sensitivity?!? The more the better!" Wrong!
I still have lots of this left, and I don't even feel like I can give it away at the risk of others' health. If I could give it negative stars, I would.