To avoid fluoride I have been brushing my teeth with a combination of baking soda and borax for about five months. Initially I used half baking soda and half borax, then I used one third borax, and now I use about a fifth borax and four fifths baking soda. I try to rinse most of it out of my mouth after I'm done brushing. I wet my brush and then set it on the powder, however much sticks to the brush is how much I use. It seems to have a smoother feel and better taste than brushing with just baking soda. I have bleached my teeth a little fairly recently and they look quite clean after I brush.