Due to my xerostomia, I have used Biotene toothpaste exclusively for the past two years, BUT with the wedding coming up, I wanted to try and get one of those glow-in-the dark smiles that you see on TV. I researched the top toothpastes for whitening and brightening, and bought Crest 3D White Deep Stain Remover figuring I'd just use it on my front teeth because every other whitening toothpaste I've tried has hurt like h---! I tried it a few days ago, and waited for the burn/sting to begin, but it didn't. The next day, I used it on all my teeth with no problem. Then, I included my tongue and the roof of my mouth... no problem. The strange thing is not only does it not hurt, but I like how my mouth feels after brushing my teeth! Go figure!