What should I know about fluoride before using it?

Fluoride is a naturally-occurring element which can help to prevent cavities by strengthening tooth structure. It can be ingested through water (fluoride is present in some amounts in almost all natural water sources), prescription supplements, fluoridated toothpaste, or applied at the dentist's office. 

While fluoride in the proper amounts is safe and effective in preventing cavities, too much fluoride given to very young children can lead to a slight mottling or discoloration of the teeth, so it is important to prevent young children from swallowing too much fluoridated toothpaste, or to prepare powdered infant formula with fluoridated water if that is the only source of nutrition for your baby. 

The U.S. Public Health Service, through its Centers for Disease Control and Prevention, called community water fluoridation one of 10 great public health measures of the 20th Century.

You should not use fluoride if you are allergic to fluoride or tartrazine. Tell your doctor about any other drug or food allergies you might have. You should not use fluoride if the percentage of fluoride in your drinking water is greater than 0.6 parts per million (ppm). You should not take fluoride with milk or other dairy products, or with a calcium supplement, as doing so could make it difficult for your body to absorb the fluoride. Wait one hour after consuming a dairy product before taking fluoride. Wait one hour after taking fluoride before consuming a dairy product.
You may need to avoid using antacids while taking fluoride, since these often contain calcium. Tell your doctor about any medications, vitamins, or supplements you are taking before you use fluoride. You may not be able to take calcium, iron, or magnesium supplements with fluoride. If you are on a low-sodium or sodium-free diet, talk to your doctor before using fluoride. Fluoride may not be appropriate for you.
If you are pregnant, trying to become pregnant, or breastfeeding, talk to your doctor before taking fluoride. Do not give fluoride to a child under age 3 or to any child if the percentage of fluoride in his drinking water is higher than 0.3 ppm. Talk to your doctor about the appropriate use of fluoride in children.

Fluoride is a natural mineral that helps keep your bones and teeth strong. Fluoride can be taken in different ways: as an oral medication or supplement, by drinking tap water, in a mouthwash or toothpaste, and in special fluoride treatments given by a dentist.

Studies show that getting adequate fluoride may help prevent tooth decay. When children take fluoride treatments, the mineral enters the bloodstream and becomes part of the process of forming permanent teeth. If fluoride is swallowed with tap water or a fluorinated mouthwash, it becomes part of the saliva and strengthens the enamel of the teeth. When the enamel is strong, acidic drinks and foods are less likely to harm the tooth.