Hi L.,
I live in Mexico and always thought that the kids that lived in the poorer areas in the countryside had decayed teeth because of poor oral hygiene, but come to find out the well water that they drink actually contains too much natural-occurring fluoride so I did some research. This is what Mothering Magazine has to say in their feature "Ask the Experts"...
Is fluoride bad for my children? If so, where can I get toothpaste and?mouthwash without fluoride?
Like many micronutrients, fluoride exists in natural drinking water, and trace amounts are important to human health. Yes, supplemental fluoride is bad for children. Local fluoride treatment of the teeth, as with use of fluoridated toothpaste, is not harmful, as long as none is swallowed. It may even be a little helpful to the teeth. If the kids are swallowing any toothpaste, you likely want to buy a fluoride-free product. You can purchase toothpaste and mouthwash without fluoride at most healthfood stores.
Excess fluoride replaces some of the magnesium in bones, making them harder. The evidence is weak, but this might provide some advantage to teeth in small doses. This "hardness is detrimental however to the rest of the bones in the body. The important structural and limb bones become hard, as in brittle, losing their tensile or flexing strength. Bones containing extra fluoride look very dense on X-ray, but they fracture easily --- that's osteoporosis. With higher doses of fluoride, as in the child who swallows some toothpaste or receives fluoride supplements, and who drinks sodas and juices constituted from fluoridated water sources, dark staining and cavities appear in the teeth, and bones can become misshapen.
There is also evidence as to other toxic effects from fluoride, when it comes to the levels and the synthetic forms used today. No other health benefits of supplemental fluoride have been purported. Do make sure your drinking water isn't fluoridated.
I hope this was helpful. You are a great Mom to be researching something that even your Dr. recommends.
Happy New Year!