I began searching for the alternative when I realized that fluoride is actually quite dangerous. It is true that a certain amount of fluoride makes teeth somewhat resistant to acid (thus preventing many cavities). It is also true that fluoride is not biodegradable and accumulates in your body, eventually poisoning it. According to my online research, fluoride causes demineralization of bone and teeth (fluorosis). Osteosclerosis, exostoses of the spine, genu valgum (whatever it is), and some other conditions are also (at least partially) caused by accumulated fluoride in a person's body.
I'm not up for hospital adventures like that, so I really began searching for something safe. And I think I found it :) Many people (I even know some of them personally) claim that baking soda cleans even better than any toothpaste. I've tried it for a while and I must admit, it really does work better than toothpaste. Only about 2-3 brushes and my teeth were as white as if I just got back from a dentist. And so far I have not heard of any health defects in the short or long run that are caused by brushing your teeth with baking soda.
I've found two ways to do this:
1. Place baking soda directly on your toothbrush and begin brushing right away.
2. Put baking soda in a glass and add just enough water to make a paste-like substance. Then use it like you would use a toothpaste.
I must warn you of one downside though. Baking soda cleans teeth pretty well, but unlike toothpaste it does not give you that minty fresh breath. So you might want to rinse with a mouthwash, or add a mint extract to your baking soda paste. :) Thanks for reading!