Short answer: An interdental brush is a small brush with a thin wire core used to clean plaque and food debris from between the teeth. Where the spaces between teeth are open enough, it usually removes plaque more effectively than floss. The right size is the brush that goes into the space without force but does not wobble in the gap. Using it once a day with a back-and-forth motion, without twisting, is recommended.
A toothbrush is effective at cleaning the front, back and chewing surfaces of the teeth; however, it often cannot reach the surfaces where teeth face each other or the spaces between them. A large share of cavities and gum disease starts in exactly these areas. An interdental brush is a small, cylindrical or tapered brush designed to clean plaque and food debris from between the teeth. In this article we explain what an interdental brush is, how it differs from floss, how to choose the right size, how to use it step by step and who it is especially important for.
What is an interdental brush?
An interdental brush is an oral care tool made of nylon bristles arranged around a thin metal wire, which is inserted between the teeth to mechanically clean away the bacterial plaque in that area. It is also known as a between-the-teeth brush or proxy brush. It is usually sold attached to a handle, with replaceable heads, or as a single piece.
The brushes come in different shapes and thicknesses:
- Cylindrical brushes: The bristles are the same length from end to end; they clean evenly along the whole space.
- Tapered brushes: They narrow toward the tip; they can adapt to spaces of different widths, but in wide spaces they may make less contact with the surfaces.
- Angled-handle brushes: They make it easier to reach the back teeth.
- Rubber-tipped picks: They have a flexible body instead of a metal wire; they may be preferred for very narrow spaces or sensitive gums, but their plaque-removal effectiveness may differ from that of traditional brushes.
Many manufacturers distinguish brush sizes with color codes. However, because colors vary from brand to brand, the choice should be based on the diameter of the space the brush can pass through, not on its color.
How is an interdental brush different from floss?
Where the spaces between teeth are open enough, an interdental brush, thanks to its bristles, makes better contact with uneven surfaces and usually removes plaque more effectively than floss; floss, on the other hand, is more suitable for narrow spaces where the teeth are in tight contact. So the two tools are not competitors but tools for different situations.
- Surface contact: Floss works like a flat surface and has difficulty reaching the concave areas of the tooth. Brush bristles, however, can spread into these hollows.
- Ease of use: Many people find a brush easier to use than floss, especially on the back teeth. This supports the habit of regular use.
- Narrow spaces: Where the teeth are in tight contact and the brush will not go in, floss should be used. Trying to force a brush in can damage the gums.
- Around prostheses and appliances: In areas such as under bridges, around implants and under brackets, brushes are often more practical.
For many people, better results come from a combined routine using an interdental brush in open spaces and floss in narrow ones. Your dentist can show you in your mouth, space by space, which one to use where.
How do you choose the right interdental brush size?
The right interdental brush is the one that goes into the space without force but without wobbling, with its bristles touching the surfaces of both teeth. A brush that is too thin passes through without touching the surfaces and does not clean; a brush that is too thick can injure the gums or cause the wire to bend.
These points can guide you when choosing a size:
- Ask your dentist or dental hygienist to measure: The right size for each space can be determined by trying different brushes in your mouth.
- Do not stick to just one size: The spaces between the front teeth are usually narrower than those between the back teeth. Most people need two or three different sizes.
- Look for slight resistance: You should feel a very slight friction as the brush goes in. If there is no resistance at all, try one size up; if it will not go in, go one size down.
- Reassess over time: The width of the spaces can change as gum inflammation subsides or orthodontic treatment progresses.
If the wire bends as it goes between the teeth, or the bristles splay out after the first few uses, the size is most likely too large or the angle of insertion is wrong.
How do you use an interdental brush? Step by step
An interdental brush is used at least once a day by gently inserting it into the space at the gumline and moving it back and forth a few times. The steps are:
- Choose the right size and, if needed, bend the tip of the brush slightly to make it easier to reach the back teeth. Some brushes are not designed to be bent; check the instructions for use.
- Position it at the gumline: Place the brush at the lower part of the space, just above the triangle of gum tissue.
- Insert it gently: Place the brush into the space horizontally or at a slight angle, without forcing it.
- Move it back and forth: Move the brush back and forth two or three times in the space. Do not twist it; twisting can break the wire.
- Rinse: Rinse the brush with water every few spaces to remove the debris that collects.
- Work in order: To avoid skipping any space, follow a fixed order, such as right to left in the upper jaw and left to right in the lower jaw.
- After use: Wash the brush and let it air-dry; replace it with a new one when the bristles splay out or the wire bends.
Slight bleeding of the gums in the first days is usually a sign of inflammation caused by plaque that has built up in the area, and with regular use it usually decreases within one or two weeks. If the bleeding continues or is accompanied by pain, see your dentist. Using toothpaste with the brush is usually not necessary; however, if your dentist recommends it, it can also be used with a fluoride gel or toothpaste.
Who should definitely use an interdental brush?
An interdental brush is useful for anyone with open spaces between their teeth, but it is an essential part of oral care for people who have had gum disease, are undergoing orthodontic treatment or have bridges or implants.
- People with a history of gum disease: Spaces widened by gum recession or bone loss are areas where plaque builds up and a toothbrush cannot reach.
- People wearing fixed braces: The areas under the brackets and wire are much easier to clean with thin brushes.
- People with bridges: The area between the body of the bridge and the gum should be cleaned regularly with a brush and special floss.
- People with implants: Gum inflammation around implants is a significant risk to the long-term success of treatment; brushes with a coated wire may be preferred for implants.
- People with gaps between their teeth: Spaces where food gets trapped and causes odor can be cleaned effectively with a brush.
Cleaning between the teeth is also especially important for people wearing clear aligners; debris left between the teeth while the aligners are in can become trapped between the aligner and the tooth and increase the risk of decay. You can find recommendations for the daily care of both teeth and aligners in our how to clean clear aligners article.
When should you see a dentist about cleaning between your teeth?
If you are not sure which size to use, food often gets trapped between your teeth or your gums regularly bleed when you brush, we can work out an interdental cleaning routine that suits you together at a checkup appointment. At our polyclinic in Oran, Çankaya, your gum health is assessed, professional cleaning is done if needed and we show you in your mouth which tool is more suitable for each space between your teeth.
Frequently asked questions
Do interdental brushes widen the gaps between teeth?
An interdental brush used in the right size and gently does not widen the spaces between teeth. After you start using it, the spaces may look a little more noticeable as inflamed gums heal and tighten. Forcing a brush that is too thick, however, can damage the gums.
How often should an interdental brush be replaced?
The brush should be replaced when the bristles splay out or flatten, or the metal wire bends. Depending on how often it is used, this is usually anywhere from a few days to one or two weeks. Washing it and letting it dry after each use extends its life.
Is bleeding normal when using an interdental brush?
Slight bleeding in the first days is usually caused by gum inflammation and, with regular use, typically decreases within one or two weeks. If the bleeding continues or is accompanied by pain or swelling, see a dentist.
Can an interdental brush replace floss?
In open spaces between teeth, an interdental brush is often more effective than floss. However, in narrow spaces where the teeth are in tight contact, floss is needed. For many people, a routine using both tools together is the most suitable option.
