Do you have sensitive teeth? I occasionally have sensitive teeth when I eat cold foods, and I know there are toothpastes on the market for sensitive teeth, and I just learned of one made by Arm & Hammer. I just sent for my free sample of Arm & Hammer Sensitive Toothpaste, and it was painless to do so. I didn't even have to give them my phone number, just an email address (one I use for these kinds of things), and my mailing address.
It claims to provide "Maximum relief without a prescription", and the tube also says it is a whitening toothpaste that contains baking soda. I find these sample sizes great for travel, so if I like it I may stick it in my travel bag. Nothing worse than having tooth pain when you are away from home, right?
To get yours, (I'm assuming while supplies last, but not sure how it works), click this link: freeahsensitive.com/