When added, fluoride is generally adjusted to 0.5-1.5ppm, a bit less than ocean water. Depending where you live, your water supply probably has plenty of fluori

When added, fluoride is generally adjusted to 0.5-1.5ppm, a bit less than ocean water. Depending where you live, your water supply probably has plenty of fluoride. (Perhaps you can consider it "pre-medicated"). Natural water sources vary widely. Above 2ppm it starts to become a problem. In Africa and China 60% of the population have these levels or higher in their drinking water. Some of the initial studies in the early 1900s which identified fluoride as a factor in dental health were of children in Colorado with discolored, but very strong, teeth. Their water sources were up to 13ppm fluoride.