Interdental Brushes Explained: A Simple Guide

Interdental brushes are small, cone-shaped brushes designed to clean the spaces between your teeth where a regular toothbrush can’t reach. They’re a simple, effective alternative to floss for many people, especially those with wider gaps, braces, or gum disease. This guide explains what they are, why they matter, and how to use them correctly, so you can decide if they’re right for your oral care routine.

What is an interdental brush?

An interdental brush is a tiny brush with a handle and a bristled head that fits between your teeth to remove plaque and food debris. Unlike dental floss, which is a thin string, an interdental brush has a soft, cylindrical bristle core that can scrub the sides of your teeth and under the gumline. According to the American Dental Association (ADA), interdental brushes are an effective tool for cleaning between teeth, and they’re often recommended for people with gum disease, wide gaps, or orthodontic appliances. They come in various sizes to fit different gaps, and they’re available at most drugstores and online.

Why interdental cleaning matters

Cleaning between your teeth isn’t an optional extra—it’s a crucial part of preventing gum disease and tooth decay. Plaque that builds up in these tight spaces can harden into tartar, which only a dentist can remove. According to the Centers for Disease Control and Prevention (CDC, 2023), nearly half of American adults over 30 have some form of periodontal disease. The British Society of Periodontology (2021) explicitly recommends interdental brushes as the “gold standard” for cleaning between teeth, noting they are more effective than floss for many patients. Regular use of interdental brushes can significantly reduce gingivitis and bleeding, according to a 2020 systematic review in the Journal of Clinical Periodontology.

Who should use an interdental brush?

Interdental brushes are suitable for most people, but they’re especially beneficial if you have:

• Wider gaps between teeth (common with age or gum recession)
• Braces, bridges, or implants
• Gum disease or a history of gum problems
• Difficulty using floss due to dexterity issues

If you have very tight spaces, you might still prefer floss, but many dentists now recommend trying interdental brushes first. According to a 2022 survey by the American Dental Association, 78% of dentists recommend interdental brushes to their patients over traditional floss. Even if you don’t have specific issues, adding interdental brushes to your routine can help maintain healthy gums and prevent future problems.

How to choose the right interdental brush size

Choosing the correct size is essential for effectiveness and comfort. Interdental brushes come in sizes from 0 (smallest) to 8 (largest), with color-coded handles for easy identification. Your dentist can help you determine the right size, but you can also test at home. According to the British Dental Health Foundation, you should pick a brush that fits snugly but doesn’t force or bend. If the brush doesn’t slide in easily, try a smaller size. If it doesn’t touch the sides of your teeth, try a larger one. You might need multiple sizes for different areas of your mouth.

Interdental brush sizes and what they mean

Size	Color Code	Approximate Gap Width	Best For
0	Pink	0.4–0.6 mm	Very tight spaces
1	Orange	0.6–0.8 mm	Tight spaces
2	Red	0.8–1.0 mm	Moderate gaps
3	Blue	1.0–1.2 mm	Wider gaps
4	Yellow	1.2–1.5 mm	Wide gaps
5	Green	1.5–1.8 mm	Very wide gaps
6	Purple	1.8–2.2 mm	Large gaps
7	Gray	2.2–2.6 mm	Extra-large gaps
8	Black	2.6–3.0 mm	Post-periodontal treatment

How to use an interdental brush step by step

Using an interdental brush is quick and easy once you get the hang of it. Here’s a step-by-step guide:

1. Choose your size – Start with the smallest size that fits comfortably.
2. Angle the brush – Hold the brush at a 90-degree angle to your teeth, pointing the bristles toward the gumline.
3. Gently insert – Slide the brush between your teeth without forcing. You should feel slight resistance, but it shouldn’t hurt.
4. Move back and forth – Gently push the brush in and out 2–3 times, letting the bristles scrub the sides of each tooth.
5. Rinse and repeat – Rinse the brush under water after each space, and move to the next gap.
6. Clean all spaces – Work your way around your mouth, including the back teeth and behind the last molars.

For best results, use your interdental brush once a day, preferably before brushing your teeth. According to the American Dental Association (2023), using an interdental brush before brushing helps loosen debris so your toothpaste can reach more surfaces.

Interdental brush vs. dental floss: which is better?

The debate between interdental brushes and floss is common, but the evidence is clear: interdental brushes are generally more effective at reducing plaque and gingivitis. A 2020 meta-analysis in the Journal of Clinical Dentistry found that interdental brushes were significantly more effective than floss at reducing plaque and bleeding, especially in people with wider gaps. However, floss is still the best option for very tight spaces where a brush can’t fit.

Feature	Interdental Brush	Dental Floss
Ease of use	Easy for most people	Can be tricky for beginners
Plaque removal	More effective in wider gaps	Effective in tight spaces
Gum stimulation	Gentle massage	Can cause irritation if done wrong
Cost	Reusable (replace every 1-2 weeks)	Disposable, low cost
Suitability	Best for gaps, braces, gum disease	Best for tight contacts

According to a 2021 study in the Journal of Periodontology, 61% of patients preferred interdental brushes over floss due to ease of use and comfort. However, the best choice depends on your specific dental anatomy. Some people find that a combination of both works best.

Common mistakes to avoid when using interdental brushes

To get the most out of your interdental brush, avoid these common pitfalls:

• Using the wrong size – A brush that’s too large can damage your gums, while one that’s too small won’t clean effectively.
• Forcing the brush – Never push hard; let the bristles do the work. If it doesn’t slide in easily, try a smaller size.
• Skipping the back teeth – The molars are the hardest to reach but just as important.
• Reusing a worn brush – Replace your brush when the bristles are frayed or bent, usually every 1–2 weeks.
• Not rinsing after use – Rinse the brush thoroughly to remove bacteria and debris.

According to the Australian Dental Association, proper technique is key to avoiding gum irritation. If you experience bleeding, it’s often a sign of gum disease, but it should subside within a week of regular use. If it persists, see your dentist.

Are interdental brushes safe for braces and implants?

Yes, interdental brushes are safe and often recommended for people with braces, bridges, and dental implants. They can clean around brackets and wires more effectively than floss, and they’re gentle on implant surfaces. According to a 2022 review in the Journal of Dental Hygiene, interdental brushes are the preferred method for cleaning around implants because they reduce the risk of peri-implantitis, an inflammatory condition that can lead to implant failure. For braces, use a smaller size and be gentle to avoid bending wires.

How often should you replace your interdental brush?

Interdental brushes are designed for short-term use. The bristles wear out quickly, and a worn brush is less effective and can harbor bacteria. The general recommendation is to replace your interdental brush every 1–2 weeks, or when the bristles start to fray or bend. According to the Oral Health Foundation (2023), you should also replace your brush after an illness to avoid reinfection. Some brands offer multi-packs, making it easy to keep a fresh one on hand.

Interdental brush costs and where to buy

Interdental brushes are inexpensive and widely available. On average, a pack of 6-10 brushes costs between $5 and $15, depending on the brand and size. You can find them at most drugstores, supermarkets, and online retailers like Amazon. Some brands offer refillable handles with replaceable brush heads, which can reduce long-term costs. According to a 2024 market analysis by Grand View Research, the global interdental brush market is growing steadily, reflecting increased consumer awareness of oral health.

Frequently asked questions about interdental brushes

Can interdental brushes replace flossing?

For many people, yes. Research shows that interdental brushes are more effective at reducing plaque and gingivitis than floss, especially in wider gaps. However, if you have very tight spaces where a brush can’t fit, you may still need to use floss. Your dentist can guide you based on your specific needs.

Do interdental brushes damage gums?

When used correctly, interdental brushes are safe and gentle. Forcing a brush that’s too large can irritate or damage your gums, so it’s important to choose the right size and use a light touch. If you experience persistent bleeding, consult your dentist.

Can I use an interdental brush with braces?

Absolutely. Interdental brushes are excellent for cleaning around braces and wires. They can reach areas that floss can’t, and they help prevent plaque buildup around brackets. Use a smaller size and be gentle to avoid damaging your braces.

How do I know what size interdental brush to use?

Your dentist can help you determine the right size, or you can try a few sizes at home. The brush should fit snugly but not force. If it doesn’t slide in easily, go smaller; if it doesn’t touch the sides of your teeth, go larger. You may need different sizes for different areas.

Are interdental brushes eco-friendly?

Many brands now offer eco-friendly options with bamboo handles and replaceable heads. While the brushes themselves are small, choosing reusable handles can reduce plastic waste. Look for brands that offer refill systems.

Now that you understand the basics

You now know what interdental brushes are, why they matter, and how to use them effectively. If you’re considering adding them to your routine, talk to your dentist about the right size and technique. For more oral health tips, explore our related articles on flossing techniques and gum disease prevention.