There are two ways in which fluoride impacts a tooth - before it erupts, and after. During tooth development, rather than a calcium ion being incorporated into the mineralization of dental structures, a fluoride ion replaces it instead. Fluorine is a very greedy element and it is taken up more readily than the calcium. Therefore, the fluoride becomes part of the actual tooth structure and is intrinsic to the tooth. This is where fluorosis takes place and it is permanent.

The formation of dental structures takes place inside the actual jaw bone and the fluoride gets there systemically. The whole process actually starts before birth - so what a mother takes in also has an impact on this process for a developing baby. Tooth development continues after birth till around the average age of 12. After the tooth structure is complete and a tooth erupts, the only impact fluoride can have on a tooth is topically in the mouth as the enamel is exposed to the oral environment. The fluoride is only able to interact with the enamel surface and not internally within the tooth. Whatever mineralization a tooth possesses before it erupts, is the maximum mineralization the tooth with have. This is why most of the damage that people deal with on their teeth was a process that started in childhood when they could care less about taking care of them. It is basically a downhill process.

Fluoride also is taken up into the bones as well - but no one wants to talk about that. I heard from some older orthopedic surgeons that had been around long enough to notice the changes in their patients that may or may not have been exposed to all the water fluoridation when younger. They told me that they did notice the difference in bone structure and that it was more brittle. They said they had to adjust their techniques to account for these changes when doing procedures like hip and knee replacements. This is an area that some of the younger surgeons may not be as acutely aware of since the bulk of their patients now have all been exposed to fluoridated water. In addition, fluoride does some really nasty things to thyroid function and is not good for gut or brain health. Overall, fluoride is a poison and should not be taken internally.