In the Sierra Club Magazine, Dr. Kravitz says:

“I am proud to share a TOOTHPASTE RECIPE that is not only environmentally safe but also a superb DIY alternative that’s effective in fighting cavities and gum disease: Mix 1/2 teaspoon of sodium bicarbonate, 10 drops of water, 1 to 2 drops of peppermint oil, and 1 to 2 drops of tea tree oil. The result: a fresh and cool peppermint flavor. Using this recipe, you can reverse the damaging effects of acids, eliminate bad breath, and strengthen teeth—all while reducing your carbon footprint.”