Earlier quoted context omitted.
It removes flouride as well, for better or worse -- one of very few available filters which do. (Some think flouride is good and some think it's bad.) I have it, and purely ergonomically, it's the best filter I've ever used. It's also quite expensive with expensive filters that need replacing frequently.
If you brush your teeth with toothpaste, it shouldn't matter.
It keeps fluoride in your saliva. Which toothpaste cannot do.