Interdental brushes: how to use them and what size to choose.

1. What is an interdental brush and what is it used for?

An interdental brush is a small toothbrush designed to clean the spaces between your teeth and along the gum line, where a traditional toothbrush can't reach.
Its function is to remove plaque, food debris and bacteria that accumulate in the spaces between the teeth, helping to prevent tooth decay , gingivitis and bad breath.

Unlike dental floss, interdental brushes work in slightly larger spaces, massaging the gums and stimulating microcirculation. They are particularly suitable for those with orthodontic braces, bridges, or dental implants.

2. Interdental brush before or after brushing?

Many people wonder whether to use the interdental brush before or after brushing .
The most commonly shared answer among dental hygienists is: first .
This way, food residues that could hinder the action of the toothpaste are eliminated, allowing the fluoride to better reach the spaces between the teeth.
However, the priority remains consistency : using it once a day, preferably in the evening, guarantees maximum benefit.

3. How to use an interdental brush

Using the interdental brush correctly is simple but requires delicacy.
Here are the recommended steps:

1. Choose the right size (see below) and insert the interdental brush carefully into the interdental space, without forcing.

2. Move it horizontally, back and forth , to remove plaque and debris.

3. In the upper arch, insert it from top to bottom ; in the lower arch, from bottom to top .

4. Rinse the brush after each step and finish the routine with a toothbrush and mouthwash.

If your gums bleed in the first few days, don't stop: it's a sign of inflammation that improves with continued use.

4. Interdental brush sizes: how to choose the right one

Interdental brushes come in different sizes , usually identified by standard colors.
The correct size is the one that fits easily into the space between the teeth, filling it without forcing.
Using a brush that's too large can irritate your gums; using a brush that's too small won't remove plaque well.

When in doubt, it is always best to ask your dental hygienist for advice , who can identify the ideal measurements for each area of ​​the mouth.

5. Best interdental brush: features to consider

There is no “universal” model, but some criteria can guide the choice:

• Soft and flexible bristles to avoid gum irritation.

• Coated metal core , to protect enamel and gums.

• Ergonomic handle , useful for reaching the back teeth.

• Eco-friendly or refillable versions , to reduce plastic waste.

For those with sensitive teeth or tight spaces, ultra-thin conical nylon interdental brushes are ideal .
Those who wear implants or braces can opt for sponge-based or bendable-headed interdental brushes .

6. How long does it last and when to change it

On average, a reusable interdental brush lasts 10–15 days .
When the bristles start to open or warp, it's time to replace it.
After infections or oral procedures, it is good practice to change the interdental brush to avoid bacterial contamination.

7. Benefits of interdental brushes

Regular use of the interdental brush:

• reduces bacterial plaque by up to 40% ;

• improves the appearance and color of the gums ;

• prevents tooth decay, gingivitis and periodontitis ;

• contributes to better oral and systemic health , as it reduces the inflammatory load in the mouth.

8. Frequently asked questions

How often should you use the interdental brush?
At least once a day, preferably in the evening.

Does the interdental brush replace the toothbrush or the floss?
No: it's a complementary tool. For tight spaces, dental floss is still recommended .

What to do if the interdental brush doesn't go through?
Don't force it. In these cases, it's best to consult your dentist to determine the correct size.

Conclusion

The interdental brush is a precious ally in oral prevention: small, simple, but extremely effective.
Integrating it into your daily routine means protecting your teeth and gums, keeping your smile healthy and bright over time.

Scientific and reference sources

The information in this article has been collected and verified based on reliable scientific guidelines and publications.

• Ministry of Health (Italy) – Guidelines for the promotion of oral health and the prevention of oral diseases (2023).

• American Dental Association (ADA) – Interdental Cleaners: Floss, Picks, and Brushes (updated 2024).

• European Federation of Periodontology (EFP) – Perio & Caries Campaign: Interdental Cleaning Recommendations (2023).

• Sunstar GUM® Italia – Guide to using interdental brushes and choosing the correct size (2024).

• Curasept SpA – Daily oral hygiene: use and benefits of interdental brushes (2022 update).

• MyPersonalTrainer / Mondadori Media – Interdental brush: what it is, what it's for, and how to use it (2024 scientific review).

• Puzzilli Dental Clinics – Interdental brush: practical guide and tips for use (2025).

All sources provided are for informational purposes only and are not intended to replace the advice of a qualified healthcare professional.