(HealthDay News) -- Fluoride is a natural substance found in water, and is added to many municipal water supplies to help prevent cavities.

The Nemours Foundation offers these guidelines about the use of fluoride in children::

• Children should only use fluoride supplements if they live in areas with non-fluoridated water, or if they drink only non-fluoridated bottled water.
• Children under age 6 should never use a fluoride mouth rinse.
• Children under 6 months don't need fluoride supplements and shouldn't been given them.
• Fluoride toothpaste should not be used on children younger than 2 unless recommended by a doctor or dentist.
• Children should use only a pea-sized amount of toothpaste.
• Watch children up to age 6 when they brush their teeth to make sure that they spit out the toothpaste, and that not too much is swallowed.