Explore MySmileEd
Emergency!
Where to look first when a tooth gets hurt or something urgent happens.
Ask Cozy
What would you like to learn?
TRY ASKING
Browse by topic
Brushing cleans the outside of a tooth, but it cannot reach the spot where two teeth press together. Flossing can. Here is why it matters, when to start, which tools help, and how much of it is a grown-up job.
A toothbrush does a good job on the front, back and chewing surfaces of a tooth. What it cannot do is get in between, where two teeth touch. Those hidden surfaces still collect plaque — the sticky film of bacteria that feeds on leftover food and produces acid that harms the surface of the tooth.
The American Dental Association recommends cleaning between the teeth once a day to remove that plaque and the food caught with it. Plaque that is not cleaned away can harden into tartar, a rough deposit along the gum line that only a dentist can remove.
Your toothbrush is brilliant at the big, easy parts of a tooth. Floss is the only one thin enough to slip into the narrow gap where two teeth are touching.
The American Dental Association says to clean between your teeth once a day, and that it does not matter whether you do it before or after brushing. What matters is that it happens every day.
String floss is the classic tool, but it is not the only one — and for small hands it is often not the easiest.
There is no birthday for this one. It depends on your child’s teeth, not their age.
Flossing joins the routine as soon as your child has two teeth that touch each other, because a brush can no longer reach between them.
The American Dental Association recommends cleaning between the teeth once a day. Pick whichever time of day you can do it properly.
At first an adult does the flossing. Children usually take it over around age ten or eleven, when their hands are ready.
Flossing asks for more coordination than brushing. The American Dental Association is clear that adults handle this step at first, and that children usually take it over around age ten or eleven, when their hands are ready to hold floss or other cleaning tools. Until then, doing it for them is not babying them — it is the only way the job actually gets done.
Cleaning between the teeth should not be painful. The American Dental Association notes that flossing too hard can damage the tissue between the teeth, while being too gentle can leave food and plaque behind, and that some discomfort is normal while you are finding the right pressure. If it still hurts, talk to your dentist.
As soon as your child has two teeth that touch each other. Before that, a toothbrush can still reach every surface on its own.
The American Dental Association recommends cleaning between the teeth once a day.
As long as you floss thoroughly, it does not matter when you do it. The important part is that it becomes a daily habit — choose a time of day when you can give it proper attention.
Floss picks, pre-threaded flossers, small interdental brushes and water flossers are all recognised ways to clean between teeth, and picks are often easier for small hands to hold. Talk with your dentist about which tool suits your child, and look for the ADA Seal of Acceptance.
Children usually take over around age ten or eleven, when their hands are ready to hold floss or other cleaning tools. The AAPD advises that parents supervise and teach these home routines, so keep watching until you are confident every space is being reached.
Every clinical statement on this page comes from the American Dental Association and the American Academy of Pediatric Dentistry. Last updated 11 August 2026.
This website is for education only and does not replace care from your dentist, physician, or emergency services.