If you do what your dentist tells you, you’ll brush your teeth at least twice a day. I do, and – like most people - I use toothpaste. The other day I found myself reading the ingredients and it was quite a list. That got me thinking about the very nature of toothpaste, a substance that – to do its job – must exhibit a wide range of characteristics. So I’ve compiled a list of common toothpaste ingredients and what they do. I also stumbled upon an explanation for why the orange juice you drink after brushing your teeth tastes so foul.  More . . .