When Should Kids Start Flossing? A Parent's Guide by Age

Start flossing as soon as two of your child's teeth touch. When that happens, how to floss a toddler's teeth, and when kids can floss on their own.

By Dr. Morgan Morrow · November 10, 2026 · 3 min read

Most parents get into the habit of brushing their child's teeth early. Flossing is the step that's easy to forget. But cavities often start in exactly the places a toothbrush can't reach: between the teeth.

When to start

Start flossing as soon as two of your child's teeth touch each other. For many children this happens with the back baby molars, often somewhere between ages 2 and 3, but it varies. Some children have gaps between their baby teeth for years, and that's normal too.

Not sure whether your child's teeth touch? Gently slide a piece of floss between two teeth. If it meets resistance and "snaps" through, they're touching, and it's time to floss. We can also show you at your child's next checkup.

Why baby teeth need flossing

It's tempting to think baby teeth don't matter much since they'll fall out. But baby teeth:

  • Hold space for the permanent teeth growing underneath

  • Help your child chew, speak clearly and smile with confidence

  • Can get cavities that cause pain and infection

Cavities between the teeth can be hard to see without an x-ray, and they can grow quickly in baby teeth because the enamel is thinner.

How to floss a young child's teeth

Flossing a wriggly toddler takes practice. These tips help:

  1. Find a comfortable position. Lay your child down with their head in your lap, or stand behind them while they face a mirror.

  2. Use floss picks (floss on a small plastic handle). They're much easier than string floss in a small mouth.

  3. Slide gently between the teeth. Don't snap down hard on the gums.

  4. Curve the floss around the side of each tooth and move it up and down.

  5. Focus on the back teeth that touch, which is where cavities are most likely.

  6. Make it routine, once a day, ideally at bedtime before or after brushing.

A little bleeding in the first few days is common if the gums aren't used to it. It usually stops within a week or two of regular flossing. If it doesn't, let us know.

Making flossing fun

  • Let your child pick their own colorful floss picks.

  • Floss your teeth together.

  • Use a song or count the teeth out loud.

  • Add flossing to a sticker chart along with brushing.

  • Let your child "floss" a stuffed animal first.

When can kids floss on their own?

Flossing takes fine motor skills. Most children need a parent's help until around age 8 to 10, and often a parent should keep checking after that. A good sign your child is ready: they can tie their shoes well, and they can floss all the touching teeth without missing spots.

What about water flossers?

Water flossers can be a helpful extra, especially for kids with braces, but they're not a full replacement for floss for most children. Ask us what's best for your child.

Flossing plus a full routine

Flossing works best as part of a complete daily routine:

  • Brush twice a day with fluoride toothpaste

  • Floss once a day where teeth touch

  • Limit sugary snacks and drinks, especially between meals

  • Visit the dentist every six months

We're happy to show you

At your child's next cleaning, ask us for a quick flossing demo. We'll show you the best position and technique for your child's age. Request an appointment at our Middletown or West Dover office, or learn more about our preventive care.

This article is for general information and is not a substitute for advice from your child’s dentist. Contact our office to talk about your child’s needs.

Ready to Book Your Child’s Visit?

Call either office or request an appointment online. New patients are always welcome.