What's in toothpaste? National Geographic's chemist George Zaidan tries to create his own homemade toothpaste. Ancient toothpaste used stuff like rocks and bones -- and modern toothpaste isn’t all that different.
What's in toothpaste? National Geographic's chemist George Zaidan tries to create his own homemade toothpaste. Ancient toothpaste used stuff like rocks and bones -- and modern toothpaste isn’t all that different.