So not only do I make most of my food from scratch (or try to, at least!), I also try to make most of my toiletries from scratch as well, for generally the same reason: I'm trying to cut out the high number of preservatives and potentially harmful ingredients I'm exposed to on a daily basis.
When I ran out of toothpaste one day, I figured I'd give toothpaste making a go.
After a bit of research, it turns out that we don't necessarily need to brush our teeth with anything other than water and a toothbrush. Flossing is much more important as we really need to get the food out from in between our teeth.
As you can imagine, my breath was awful so I gave up on that after a day.
So with a bit more research, I tried making a paste with baking soda and hydrogen peroxide and brushing with that. My breath was slightly better and, WOW, my teeth were sparkling white. After 2-3 days of this mixture, my teeth became very sensitive from the whitening.
I tried just baking soda by itself, but that is nasty. Also, it doesn't really neutralize bad breath. And if I remember correctly, just baking soda still leaves grit on your teeth. Gross.
I think I experimented a bit more, but now I have this recipe that I love, adapted from Wellness Mama. My teeth feel clean, my breath smells great (generally speaking), and the calcium in this recipe potentially remineralizes teeth. (She explains how that works on her site.)
I'm not a dentist or a researcher so I'll not claim anything here, except my own experience. Between this toothpaste recipe and regular flossing, my teeth look and feel better than they ever have before.
5 parts calcium powder (dried, powdered eggshells will also work)
2 parts baking soda
3 parts xylitol
5 parts coconut oil
10-20 drops peppermint essential oil
5 drops orange essential oil
Note: I tend to use tablespoons for mine so it would 5 tbsps calcium powder, 2 tbsps, baking soda, etc.
Mix dry ingredients together.
Heat coconut oil if necessary until the oil liquefies. Add oil one part at a time until desired consistency. (I like about 5 tablespoons in mine; you may prefer more or less.)
Stir in essential oils.
Store and use!
If there are multiple people in your household, you could add an applicator or try putting it in an icing/frosting tube and squeezing it out.