Interdental Brushes: What They Are and How to Use Them

Editorially reviewed by the Dental.me Editorial Team · Updated July 2026

A regular toothbrush does a good job on the broad front and back surfaces of your teeth, but it cannot reach the narrow spaces where two teeth meet. That is exactly where interdental brushes come in. These tiny brushes are made to slip into the gaps between teeth and clean the surfaces a toothbrush always misses. For many people they are easier to use and more effective than string floss, especially around braces, bridges, implants, and gums that have pulled back. This guide explains what they are, why they matter, how to choose the right size, and how to use them properly every day.

What Are Interdental Brushes?

An interdental brush is a small cone- or cylinder-shaped brush mounted on a short handle, a little like a miniature bottle brush. Fine bristles spiral out from a thin central wire, and the whole head is small enough to pass through the space between two teeth. They are designed to clean between the teeth and around gaps, braces wires, bridges, and dental implants, reaching places a normal toothbrush simply cannot get to.

They come in a wide range of sizes, from very fine heads for tight spaces to thicker heads for larger gaps. Most brands color-code their sizes so you can quickly grab the right one each time. Some have a straight handle, others are angled or have a long handle to make the back teeth easier to reach.

Why Cleaning Between Your Teeth Matters

Brushing alone leaves roughly a third of each tooth’s surface untouched, because the sides where neighboring teeth touch are hidden from the bristles. Plaque, the sticky film of bacteria that constantly forms on teeth, builds up in exactly those hidden gaps. Left there, it causes cavities between the teeth and irritates the gums, which is how gum disease starts. That is why cleaning between your teeth every day is not optional extra credit, it is a core part of keeping your mouth healthy, and it is a big part of why cleaning between teeth genuinely matters.

Interdental brushes are one of the most effective ways to do this. For many people, particularly those with slightly larger gaps, some gum recession, open spaces called black triangles, or dental work like braces and bridges, research suggests interdental brushes can remove as much plaque as floss, and sometimes more, while being noticeably easier to handle. They are not a replacement for brushing twice a day, but they finish the job your toothbrush starts.

Interdental Brushes vs. Floss: Which Is Better?

Interdental brushes and floss both clean between the teeth, but they suit different mouths. Where there is enough space for a brush to fit, an interdental brush usually cleans more thoroughly because its bristles wrap around the curved sides of the teeth, and most people find it quicker and less fiddly than winding string around their fingers. That advantage grows if you have gum recession, wider gaps, or appliances in the way.

Floss still has its place. For very tight contacts where no brush will fit without forcing, string floss is the better tool because it can be eased into a gap far too narrow for even the finest brush. Many people end up using both: brushes for the spaces that accept them and floss for the tight ones. If floss is your main tool, our step-by-step guide to flossing covers the correct technique, and if you are weighing a powered option you can compare a water flosser against string floss too. The best tool is the one that reaches your gaps and that you will actually use every day.

Choosing the Right Size

Getting the size right is the single most important part of using interdental brushes well. Because gaps vary around your mouth, one size rarely fits every space, and many people need two or three different sizes to cover the whole mouth.

• The right size fits snugly without forcing. You should feel a light resistance as the brush passes through, and the bristles should touch both teeth, but it should never hurt.
• Too big is a problem. Jamming an oversized brush into a gap can hurt, scratch the gum, and over time damage the soft tissue.
• Too small does not clean. A brush that slides through with no contact is not wiping away plaque.

A dentist or dental hygienist can measure your spaces and tell you which sizes to buy, which takes all the guesswork out of it. This is well worth asking about at your next check-up, especially if you are just starting out.

How to Use Interdental Brushes Step by Step

The technique is simple once you have the right sizes. Aim to work around your whole mouth once a day. Many people prefer to do it before brushing, so fluoride toothpaste can then reach the freshly cleaned gaps.

• Pick the right size for each space. As gaps change around your mouth, switch brushes rather than forcing one size everywhere.
• Insert gently and straight. Guide the brush through the gap at the gumline without forcing it or angling it sharply. Let the space guide the brush.
• Move it in and out a few times to sweep plaque from the sides of both teeth.
• Rinse the brush under the tap and move on to the next space.
• Work methodically around the whole mouth so you do not miss any gaps.

Never snap or jam the brush into a space. If a brush will not go in, it is too big for that gap, so switch to a smaller one or use floss there instead. If you wear braces, use the brush to clean under the wire and around each bracket, where food and plaque love to collect; our guide to cleaning between teeth with braces has more on working around the hardware.

Caring for Your Brushes and Avoiding Common Mistakes

Interdental brushes are reusable, but not forever. Rinse the head under running water after each use and let it air dry. Replace a brush once the bristles start to look worn, splayed, or bent, or if the wire kinks, which for most people is after about one to two weeks of daily use. A worn brush cleans less and is more likely to bend awkwardly in a gap.

A few mistakes come up again and again:

• Forcing a brush that is too big. This hurts and can damage the gum. Size down or use floss.
• Skipping the tight spots. If a brush will not fit a gap, that gap still needs cleaning, so reach for floss there.
• Stopping because the gums bleed. A little bleeding in the first few days of cleaning between your teeth is common and usually means the gums are inflamed from plaque that has been building up, a mild form of gum disease called gingivitis. Bleeding typically settles within a week or two of regular cleaning, so it is a reason to keep going, not to stop. If bleeding is heavy or continues beyond a couple of weeks, see your dentist.

Who Benefits Most, and When to Ask Your Dentist

Almost anyone can use interdental brushes, but some people benefit especially:

• Anyone with gum disease or larger gaps between the teeth, where brushes clean more thoroughly than floss.
• People with braces, bridges, or dental implants, which create nooks a toothbrush cannot reach.
• Anyone with receding gums that have opened up the spaces near the roots.
• People who find string floss fiddly, including those with limited dexterity, who often find a small handled brush far easier to control.

The takeaway is straightforward. Interdental brushes are an easy, effective way to clean between your teeth, and for larger gaps and most dental work they often outperform floss while being simpler to use. Get the right sizes, use them gently once a day, and keep the very tightest gaps handled with floss. If you are unsure which sizes fit your mouth or your gums keep bleeding, ask your dentist or hygienist. A few minutes at your next visit can set up a routine that protects your teeth and gums for years.

Find care near you: compare dentists in your area, or browse dental specialties.