What are interdental brushes used for?

1. What is an interdental brush?

An interdental brush is a miniature cylindrical toothbrush designed specifically for cleaning the interdental surfaces (interdental spaces). Resembling a miniature bottle brush, it consists of a soft, flexible plastic frame with a dense array of bristles. The bristles are typically conical or cylindrical, with diameters ranging from 0.4 mm to 1.5 mm, adapting to various interdental spaces. Some interdental brushes also feature flexible handles to accommodate the molar areas deep within the mouth. Unlike dental floss, which uses friction to clean between teeth, interdental brushes penetrate directly into the interdental spaces, using a physical brushing action similar to a toothbrush to remove plaque and food debris. This makes them an advanced tool for interdental cleaning.

The core function of interdental brushes is to fill the gaps left by traditional cleaning tools. Toothbrush bristles struggle to reach interdental spaces wider than 0.5 mm, while dental floss is less effective in wider spaces. When interdental spaces are wider than 1 mm, flossing fails to fully contact the tooth surface, creating blind spots. Interdental brushes, with a diameter designed to match the width of interdental spaces, fit snugly against adjacent tooth surfaces. The lateral and vertical movement of the bristles mechanically removes soft plaque and bacteria adhering to the tooth surfaces. They are particularly effective in areas with atrophied interdental papillae (enlarged interdental spaces), areas around braces and brackets during orthodontic treatment, areas around implants, and adjacent bridges. Studies have shown that using interdental brushes can increase plaque removal rates in interdental spaces by over 30%, significantly exceeding the effectiveness of dental floss in wide interdental spaces. They also effectively prevent gingivitis and interproximal caries caused by food impaction.

Compared to dental floss, interdental brushes offer three advantages: They offer improved cleaning efficiency, with the three-dimensional structure of the bristles allowing simultaneous cleaning of both sides of the tooth gap, reducing handling time. They are also easier to use, requiring no C-wrapping or angle control techniques like with dental floss. Simply insert the brush head of the appropriate diameter vertically or slightly angled between teeth and gently push and pull. This makes them easy for the elderly, children, and those with limited manual dexterity. They are also more widely applicable, particularly for those with wide gaps (over 0.8 mm) or uneven teeth, which are often weak points in flossing. Furthermore, some interdental brushes feature replaceable heads and reusable handles, balancing environmental performance with cost-effectiveness.

The characteristics of interdental brushes can be summarized as "precise fit" and "efficiency and safety." Interdental brushes are available in diameters down to 0.1 mm. Users should choose the right size based on their individual interdental width. If slight resistance is felt during insertion but no pain, the brush is the right size. If it is too loose, it will not clean properly. If forcing the brush causes bleeding gums, a smaller size should be used. The bristles are mostly made of nylon or polyester, which is softer than regular toothbrush bristles, minimizing mechanical irritation to the gums while remaining flexible enough to reach deep between teeth. The handles are ergonomically designed, with some featuring anti-slip grooves or extended handles for easier cleaning of the molar area at the back of the mouth. While less portable than dental floss, interdental brushes offer a more durable cleaning effect, making them particularly suitable for those with chronically wide interdental spaces.

It's important to note that interdental brushes aren't a universal tool: for tight interdental spaces smaller than 0.5 mm, dental floss or waxed floss picks are still necessary. Avoid forceful horizontal insertion to avoid damaging the gingival papillae. The width of interdental spaces within a mouth can vary significantly, so it's important to have a variety of sizes available. Generally speaking, interdental brushes are precision cleaning tools tailored to specific oral conditions. Together with dental floss and a toothbrush, they form a complete oral care system: interdental brushes provide deep cleaning between wide spaces, dental floss cleans the fibers between tight spaces, and the toothbrush covers the main surface of the teeth. Together, these three tools provide comprehensive oral hygiene. Choosing an interdental brush requires considering your individual interdental width, oral health status, and your doctor's recommendations to fully realize its core value in interdental care.

2.How to use interdental brushes correctly

(1). Choose the right size

Determine the width of the gaps between teeth. Use your fingers to touch the gaps between teeth or observe: If you can clearly see the gaps (more than 0.5mm), there is often food stuck after brushing, or the doctor indicates "interdental papilla atrophy" during the examination, then it is suitable to use an interdental brush.
Test size The diameter of the interdental brush ranges from 0.4mm (minimum) to 1.5mm (maximum), with each 0.1mm as a step.
Selection principle:
Slight resistance but no pain when inserting: the brush head can fill the gaps between teeth, and the bristles are slightly bent, indicating that the size is appropriate.
Too loose (the brush head shakes): it cannot clean the tooth surface, and you need to change to a larger size;
Too tight (pain when inserting/gum bleeding): it is easy to damage the gums, and you need to change to a smaller size. It is recommended to choose 3 adjacent sizes for trial (such as 0.6mm, 0.7mm, 0.8mm) when purchasing for the first time.

(2). Operation steps: 3 steps to achieve deep cleaning

Grip and angle:
Grip: Hold the handle lightly like holding a pencil, keeping your wrist flexible. Angle: Hold the brush head perpendicular to the teeth (90°), or slightly tilt it 15° (to avoid irritating the gums when inserting the brush vertically).

Insertion and Cleaning:
Gentle Insertion: Aim the brush head at the gap between teeth and slowly insert it vertically or slightly tilted until the brush head is fully inserted (the bristles cover the entire depth of the gap), but do not force it into the gum sulcus (clean only the sides of the teeth).
Back and Forth Brushing: Gently push and pull the brush head in small movements (3-5mm), or rotate the brush head clockwise or counterclockwise, ensuring the bristles contact the tooth surface on both sides of the gap. Clean each gap 5-8 times to avoid excessive abrasion of the gums.

Cleaning the Back Teeth and Special Areas:
Back Molar Area: If the handle is short, bend the brush head partially (some interdental brushes support bending), or use a long-handled interdental brush to ensure the brush head reaches the innermost gaps. Orthodontics/Dental Implants: When wearing braces, insert the brush head between teeth from under the brackets. Softer bristles should be used around dental implants to avoid scratching the implant surface.

(3).Frequency of Use and Precautions

Frequency: At least once daily, preferably after brushing at night to prevent food debris from accumulating overnight and breeding bacteria.
Cleaning and Replacement: Rinse the brush head with clean water after each use, shake off excess moisture, and store in a dry place (to prevent moisture from breeding mold).
Replace bristles if they are deformed, unraveling, or if they have been used for more than one month (for models with replaceable heads, only the head needs to be replaced).
Contraindications: In case of acute gingivitis (severe bleeding), discontinue use until the inflammation subsides. For tight spaces (less than 0.4mm), use dental floss first. Forcibly using small interdental brushes may cause gum recession.

(4).Common misunderstandings about interdental brushes

Mistake 1: Choosing Size Based on Gut Feeling
Mistake: Buying a random interdental brush size and using the same model regardless of the width of the gaps.
Harmful Effects:
Too small: The brush head will move around in the gaps between teeth, failing to make contact with the tooth surface, making the cleaning process a mere formality.
Too large: Forcing the brush in can squeeze and scratch the gums, causing bleeding, pain, and even worsening gum recession.
Correct:
Use trial and error to choose the right size: Start with 0.6mm (a common basic size). If there is slight resistance but no pain when inserting the brush, and the bristles fit snugly against the tooth surface, then the size is appropriate.
Choose Size by Region: The gaps between front teeth are generally narrower (0.4-0.8mm), while the gaps between back teeth and areas of gum recession are wider (1.0-1.5mm). It is recommended to have two or three sizes.

Mistake 2: Forcing the brush in between teeth for a "deep clean"
Mistake: Pushing the interdental brush into the gaps like a toothpick, even trying to "push it deep into the gums." Harm: Directly bruising the gingival papilla (the flesh between teeth) can cause redness, swelling, and bleeding. This can lead to gum recession and widening of the gaps in the long term.
Correct Method:
"Glide in gently": Aim the brush vertically or at a slight angle (15°) between the teeth. Use your thumb and index finger to gently push the brush head until you feel slight resistance. There's no need to dig into the gingival sulcus.
Cleaning Focus: The bristles should cover the tooth surfaces on both sides of the gap, not "poke all the way to the bottom."

Mistake 3: Cleaning horizontally; the wider the stroke, the better
Mistake: After inserting the brush, forcefully pull it back and forth like sawing wood, or rotate the brush head vigorously.
Harm: Excessive friction can damage the enamel at the neck of the tooth (close to the gums) and may cause the bristles to deform and spread, reducing cleaning efficiency. Correct Method:
Small Push and Pull: After the brush head enters the gap between teeth, push and pull the brush head 5-8 times in short intervals of 1-2 cm to ensure full contact between the bristles and the tooth surface.
Avoid Over-Turning: Use only slight rotation (within 90 degrees), focusing on the lateral friction of the bristles to remove plaque.

Mistake 4: Using the Same Interdental Brush for the Whole Mouth Without Changing Brush Heads or Rinsing
Mistake: Using the same interdental brush from front teeth to back teeth, rinsing it briefly after use, and then putting it away.
Harmful Effects:
Cross-contamination: Bacteria from the front teeth gaps can be carried to the back teeth gaps, increasing the risk of oral infection.
Brush Head Harm: In a humid environment, food debris can harbor bacteria, making the brush head a breeding ground for bacteria, making it a "contaminated" area the next time it is used. Correct Method:
Cleaning Areas: If the gaps between teeth vary in width, it is recommended to use different sized interdental brushes for the front and back teeth.
Rinse Thoroughly After Use: Rinse the brush head under running water, shake off any excess moisture, and store it in a dry interdental brush container (avoid the humid environment of the bathroom).

Mistake 5: Stop using interdental brushes if they bleed
Misconception: The first time you use an interdental brush, or if it bleeds occasionally, you assume it's damaging your gums and immediately give up.
Cause Analysis: Initial bleeding is often due to gum inflammation (plaque irritation) or temporary discomfort with the foreign object. If bleeding persists (over 3 days), it may be due to the brush being too large or being used roughly. Corrective Action:
Continue using interdental brushes for minor bleeding: Choose a smaller interdental brush and use it gently. After 2-3 days, the inflammation will subside and the bleeding will stop naturally.
Continuous bleeding requires medical attention: If bleeding persists after adjustment, it may indicate cavities, periodontal pockets, or gingival aneurysms between teeth, and oral health issues should be investigated.

Mistake 6: Use only when you have food stuck in your teeth, not on a regular basis
Misconception: Use interdental brushes only after meals when you feel food stuck in your teeth, but don't actively clean them regularly.
Damage: Plaque builds up every day, and food stuck in your teeth is only an extreme case. Long-term neglect can lead to tartar accumulation between teeth, contributing to periodontal disease. Correct Use:
Regular Use: At least once daily, preferably after brushing at night, to thoroughly remove plaque accumulated throughout the day.
Use with dental floss: Use floss for narrow spaces between teeth and an interdental brush for wider spaces, ensuring full coverage.

Mistake 7: Not Replacing After Use
Mistake: Using an interdental brush for 1-2 months, only replacing it when the bristles become severely deformed and unravel.
Harm: Deformed bristles cannot effectively clean, may fall off, and may remain between teeth, even scratching the gums.
Correct Use:
Regular Replacement: It is recommended to replace a standard interdental brush every 1-2 weeks (or replace the brush head immediately if it becomes deformed).
Replaceable Brush Heads: The handle is reusable, requiring only regular replacement of the brush head (more environmentally friendly and economical).

3.Maintenance Guide for Interdental Brushes

(1) After use: Clean promptly

Rinse the brush head thoroughly: Rinse the brush head with running water immediately after use, and gently rub the bristles with your fingers to ensure that any remaining food residue and toothpaste (if used with toothpaste) are washed away.
Tip: If cleaning between orthodontic teeth or around dental implants, you can gently shake the brush head to use centrifugal force to remove deep residue.
Dry out moisture and avoid moisture: After rinsing, turn the brush head downward and shake it vigorously 2-3 times to remove excess water, or use a clean paper towel to dry the surface moisture of the bristles.
Contraindications: Place the damp interdental brush directly into a sealed container. A humid environment is prone to mold growth (especially in the bathroom).

(2) Daily storage: dry + ventilated, away from pollution sources

Choose a dedicated storage box: use an interdental brush box with air holes (such as the independent partition storage box on the market) to avoid contact between the brush head and other items.
Recommendation: a storage box with a compartment design can store interdental brushes of different sizes at the same time to prevent confusion.
Store in a dry area on the sink, away from shower steam or faucet splashes; avoid direct sunlight, as long-term exposure may cause the plastic handle to age and the bristles to harden.
Clean the storage container regularly: wipe the inner wall of the storage box with neutral soapy water or diluted alcohol every week, let it dry before placing the interdental brush in it to prevent bacteria in the box from contaminating the brush head.

(3) Regular replacement

Ordinary interdental brushes: It is recommended to replace them once every 1-2 weeks (even if the bristles are not obviously deformed), because bacteria are easily accumulated at the base of the bristles after long-term use;
Replaceable brush head: The brush head should be replaced at the above frequency, and the handle can be disinfected once a month with an alcohol pad. If used continuously for more than 1 year, it should be checked for aging.

(4) Special situation handling: accidental damage or contamination

Brush head falls to the ground: rinse immediately with soapy water, then wipe the brush head with a 75% alcohol cotton pad. If it cannot be thoroughly cleaned, it is recommended to discard it directly (to avoid cross infection).
Broken handle: If the broken part is sharp, do not continue to use it (to prevent scratching the mouth), and directly replace the interdental brush; for replaceable brush heads, only the brush head part needs to be replaced.
Long-term unused (more than 1 month): Before using again, soak the brush head in boiling water for 30 seconds (for disinfection). After drying, check whether the bristles have become soft. If they have lost their elasticity, it is recommended to replace them.

(5) Misconception reminder: These practices are "destroying" interdental brushes

Boiled water for disinfection: High temperature will cause the bristle material to age and deform, reducing the cleaning power (it is recommended to rinse with clean water at room temperature).
Sharing interdental brushes with others: Even family members may cross-transmit oral bacteria (such as caries bacteria and periodontal disease bacteria). Do not discard used interdental brushes at will: The plastic handles belong to dry garbage, so it is recommended to cut them into pieces before disposal to reduce environmental pollution (the handles of replaceable brush heads are recycled first).

(6)Replacement standards for interdental brushes

1) Core Replacement Indicator: Bristle Condition

Bristle Deformation/Unraveling (The Most Visual Sign): Bristles become bent or curled from their original upright position, or their tips become forked or flared (similar to "frizzed hair").
Cause: Repeated friction with the tooth surface causes the bristles to lose their elasticity, or excessive force during cleaning can damage the structure.
Danger: Deformed bristles lose contact with the tooth surface, reducing cleaning efficiency by over 50%, and may even cause bristles to fall off and lodge between teeth.
Treatment: Replace immediately; further use is not recommended.

2) Bristle Hardening/Loss of Elasticity

Symptoms: Bristles feel stiff to the touch, and a "jabbing" sensation instead of a "gentle resistance" when inserted between teeth.
Cause: Long-term exposure to moisture or material degradation after use for more than two weeks.
Danger: Hard bristles can scratch the gums, causing bleeding or inflammation.
Treatment: Even if there is no noticeable deformation, bristles that become stiff should be replaced.

3) Regular interdental brushes (not individually packaged)

Replacement cycle: Replace every 1-2 weeks (based on daily use).
Reason: The brush head is exposed to oral saliva and food debris for extended periods. Even after rinsing, bacteria can grow at the base of the bristles (especially when stored in a damp environment). Bacterial counts can increase significantly after two weeks, posing a risk of cross-infection.

4) Individually packaged/replaceable brush heads

Individually packaged brushes: Use within one week after opening (exposure to air can easily contaminate).
Replaceable brush heads: Use the same as regular interdental brushes every 1-2 weeks. The handle can be used for extended periods (assuming it is not cracked or worn).

5) Persistent bleeding after use (excluding operational issues)

If frequent bleeding persists with a particular interdental brush after changing the size and adjusting the pressure, the bristles may be too hard or have burrs. Replace the brush head with a new one.

6) Replacement Tips: Extend Lifespan + Avoid Waste

Adjust the cycle based on "frequency of use": For interdental brushes used twice daily (morning and evening), it's recommended to replace them once a week; if used once a day, this can be extended to two weeks.
Store by Size: Store interdental brushes of different sizes separately to avoid mixing and wear (e.g., large brush heads squeezing smaller ones).
Choose "Eco-Friendly": Prefer interdental brushes with replaceable heads to reduce plastic handle waste (handles can be used for 6-12 months without deterioration).

4.Benefits of using interdental brushes

The benefits of using interdental brushes primarily lie in their effective cleaning between teeth, prevention of oral diseases, wide applicability, and ease of use. They are essential tools for maintaining interproximal oral health.

Interdental brushes, with cylindrical brush heads designed to fit the width of interdental spaces, can penetrate wide spaces (typically larger than 0.5 mm) difficult for traditional toothbrushes and floss. The physical scrubbing action of the fine bristles thoroughly removes plaque and food debris. Compared to floss, their three-dimensional bristle structure allows for simultaneous cleaning of both sides of the interdental space, improving cleaning efficiency by over 30%. They are particularly suitable for those experiencing gum recession (enlarged interdental spaces), those undergoing orthodontic treatment (around braces), and those undergoing dental implants or bridge restorations. Studies have shown that consistent interdental brush use can significantly reduce the incidence of interproximal caries and gingivitis, as well as alleviate bad breath caused by food impaction.

Interdental brushes are also easy to use and require no complex techniques. Simply insert the brush head of the appropriate size vertically into the interdental space and gently push and pull. They are also easily mastered by the elderly, children, and those with limited manual dexterity. Their refined diameters (ranging from 0.4 mm to 1.5 mm) precisely fit between teeth of varying widths, eliminating the problem of inadequate flossing in wide spaces. For those with misaligned teeth or atrophied interdental papillae, interdental brushes are a more effective and safe option for interdental cleaning. Long-term use helps maintain periodontal health, reduce the risk of periodontal disease, and indirectly protect overall health.

The core function of an interdental brush is to remove plaque and food debris from between teeth with its fine bristles. During use, the bristles become contaminated with oral bacteria, plaque, and desquamated epithelial cells. Even after rinsing with clean water, microorganisms can remain trapped within the bristle fibers. Repeated use can reintroduce these bacteria into the interdental spaces, leading to cross-infection between teeth and increasing the risk of gingivitis and tooth decay. Furthermore, the bristles of interdental brushes are made of a soft, flexible material and may slightly fall or deform after a single use. Repeated use reduces cleaning efficiency and prevents them from effectively contacting the tooth surface to remove plaque.

While the handle can be cleaned, the brush head is a key part that comes into direct contact with the oral cavity and was originally designed for single-use. Reusing an interdental brush to save costs can lead to wear and tear of the bristles and bacterial growth, which can negatively impact oral health and ultimately be counterproductive. Therefore, to ensure effective cleaning and hygienic safety, interdental brushes should be discarded immediately after each use and replaced with a new brush head. For interdental brushes with replaceable heads, the brush head should be replaced regularly. The handle can be reused, but it must be kept clean and dry. This is the most fundamental principle for maintaining oral health and is key to avoiding infection from tool reuse.

5.When to use interdental brushes?

Interdental brushes are suitable for cleaning the interdental spaces (interdental spaces). The following are specific usage scenarios and precautions:

(1) Identify applicable scenarios

When the interdental spaces are large or there is gum recession: When the interdental space is wide enough to accommodate an interdental brush (usually ≥1mm) and dental floss is easily loose or cannot be effectively cleaned, interdental brushes are preferred.
For example: patients with periodontal disease, elderly people with gum recession, and people with increased interdental spaces after orthodontic treatment.
Frequent food impaction between teeth: After meals, fibrous food (such as meat and vegetables) is often stuck in the interdental spaces. Interdental brushes can deeply clean residual food debris and are more efficient than dental floss.
After crowns, dental implants or fillings: The interdental brush can accurately clean the gaps between restorations (such as porcelain crowns, implants and adjacent surfaces) and natural teeth to prevent secondary caries.
Advanced needs for daily oral care: Use with a toothbrush to fill in the adjacent areas that are difficult for the bristles to reach, reducing plaque accumulation and the risk of periodontal disease.

（2）. Situations Where Use Is Not Recommended

Narrow interdental spaces: If you experience noticeable pain or bleeding when inserting an interdental brush, it may be too large. Forcing the brush in may damage the gums. We recommend trying fine dental floss first.
Acute gingival inflammation: If your gums are red, swollen, or bleeding, discontinue use of the interdental brush. Wait until the inflammation subsides, then select an appropriate size under the guidance of a doctor.

（3）. Frequency and Method of Use

Frequency: Once daily, recommended for use after brushing at night or after meals to remove impacted food.
Method:Select an interdental brush that matches the size of your interdental spaces (try from fine to coarse, aiming for pain-free, light friction between teeth).
Insert the brush vertically or at a 45-degree angle between the teeth, gently moving it back and forth 2-3 times to avoid excessive pressure and damage to the gums.
Rinse with clean water after each use and replace the brush every 3 months (or if the bristles become deformed).

6.Frequently Asked Questions (FAQs) and Answers about Interdental Brushes

(1) Size selection related

How to judge whether the interdental brush size is appropriate?
Standard: No obvious pain when inserted between teeth, can slightly rub the adjacent surfaces between teeth, and the bristles are not seriously deformed when removed.
Trial and error method: Start with the smallest size (such as 0.4mm). If it is loose after insertion, change to a larger size. If it is painful, change to a smaller size.

Does the same mouth need multiple sizes?
Yes: The interdental spaces between front teeth are usually smaller (choose 0.5-0.7mm), and the back teeth or gum recession may require 0.8-1.2mm. It is recommended to prepare 2-3 sizes.

(2) Usage and frequency

How many times a day should it be used? When is the best time to use it?
Frequency: Once a day, it is recommended to use it after brushing your teeth at night (saliva secretion is reduced at night, and dental plaque is easy to accumulate).
Special circumstances: It can be used temporarily when food is stuck between teeth after a meal to avoid long-term retention of residues.
Is it normal to have bleeding gums when using it?
First time use: Slight bleeding 1-2 times is normal (gum adaptation period). If it lasts for more than 3 days or the amount of bleeding is large, you need to stop and check whether the size is too large or the gums are inflamed.
How to insert the brush correctly? 
Angle: Vertical or tilted at 45°, aim at the tooth gap and push gently, avoiding lateral force; Movement: Move back and forth slightly (2-3 times is enough), do not go deep into the bottom of the gingival sulcus (it may damage the periodontal tissue). 

(3) Applicable and contraindications

Who must use interdental brushes?
Periodontal disease patients: After gum atrophy, the tooth gap increases, and interdental brushes are more efficient than dental floss; Restoration users: The gaps around dental implants and porcelain crowns need to be cleaned accurately to prevent secondary caries; After correction/extraction: Changes in tooth arrangement cause the tooth gaps to widen, and targeted cleaning is required. 

In what situations should interdental brushes not be used? Too small gaps between teeth: It is painful to insert the brush, and forcing it can damage the gums. It is recommended to use dental floss instead;
Acute inflammation period: When the gums are red, swollen, or ulcerated, it is necessary to stop using it. Wait until the inflammation subsides before using it under the guidance of a doctor.

(4) Cleaning and maintenance

Can interdental brushes be reused? How often should they be replaced?
Single use: They can be reused on the same day. Rinse with clean water after each use to remove food residues;
Replacement cycle: Replace every 3 months. If the bristles are deformed or split, they need to be replaced immediately (to avoid bacterial growth).

Can it be used together with dental floss?
Recommended combination: Use dental floss first in areas with small gaps, and then use a fine interdental brush to strengthen them; use an interdental brush directly in areas with large gaps. The two complement each other and can fully cover the blind spots of cleaning.

(5) Common misunderstandings

Will using an interdental brush make the gaps between teeth wider?
No: The size of the gaps between teeth is determined by the gums and alveolar bone. Proper use of interdental brushes will not widen the gaps between teeth. Instead, it can prevent gum atrophy caused by worsening periodontal disease. Can it be used by children?

A doctor's evaluation is required: Children under 12 years old have narrow spaces between their teeth and may have food impaction. We recommend choosing an ultra-fine model (under 0.4mm) under the guidance of a dentist, with parental assistance.