Fluoride is the safest and best way to prevent tooth decay. It's added to most toothpaste brands and can be professionally applied using varnish or gel.

This Brush Up on Oral Health tip sheet describes how fluoride works to prevent and repair tooth decay. It offers tips Head Start staff can use to help parents understand the benefits of fluoride.

Understanding Tooth Decay

To understand how fluoride works, it is important to know how tooth decay occurs. Tooth decay can be explained using two simple, related equations.

 

How Fluoride Prevents Tooth Decay

Fluoride protects teeth from developing tooth decay in three ways:

• It makes teeth strong and more resistant to acid.
• It can stop early tooth decay by putting minerals back into teeth.
• It interferes with bacteria's ability to make acid.

Tips to Help Parents Prevent Tooth Decay with Fluoride

• Encourage parents to brush their child's teeth with fluoride toothpaste twice a day. The best times to brush are in the morning and at bedtime. Parents should put a rice-size amount on the toothbrushes of children under age 3 and a pea-size amount on the brushes of children ages 3 and older. Children can spit out any remaining toothpaste but should not rinse after brushing. Healthy Habits for Happy Smiles: Brushing Your Child's Teeth provides additional tips and photos of toothpaste amounts that can be shared with parents.
• Remind parents to ask their child's dentist or doctor about fluoride varnish. Fluoride varnish can be painted onto a child's teeth in their dental or medical office. Varnish can be applied up to four times a year. It strengthens enamel, making teeth less likely to develop tooth decay. Fluoride varnish should be used in addition to fluoride toothpaste.

Last Updated: July 16, 2025