There is constant debate on whether or not this is safe and whether or not it is actually beneficial to our teeth. Most sources of information contradict themselves at best. It is also a by-product of the aluminum industry. Its greatest concentrations in the body are in the teeth, bones, and vital organs. I have yet to find studies or tests that prove conclusively that it is beneficial to our health when supplemented.
Most sources state that it is readily available in our food.
Good sources being organ meats, gelatin, saltwater fish, and tea. Fluorides are absorbed into the body very easily and can be toxic. The teeth can become mottled from too much fluoride and death can occur with large doses of it. Furcelleran - This additive is also known as Danish agar. It comes from a cold-water red alga.