Is the amount of fluoride in our water supply dangerous? can it affect tooth decay?

No and Yes: The amount of Fluoride in the water supply is perfectly safe and it's been proven to aide in the prevention of tooth decay.

No/Yes: Fluoride if added to a water supply is not considered dangerous. Depending on where you live, some water supplies (mostly in the west) have naturally occurring Fluoride far in excess of recommended limits. Have your water checked to be sure. In children's developing teeth the f ion replaces the ca ion to make the dental hard structures less soluble in acid which makes for less decay.

Check with dentist: Community water suppliers will monitor the level of fluoride. The only way to know the current level is to check with them for information or have it tested yourself. Fluoride will help reduce cavities but it is not the cure all. Brushing, flossing, good dietary choices are still necessary. You can also check with your local dentist regarding Fluoride status.