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General product and standards information for lab, clinic and supply staff. It is not medical advice; patients should ask their dentist or hygienist which cleaning aids suit them.
Short answer
Interdental brushes are small-headed brushes made to clean between the teeth, sold in several sizes to match the gap. The American Dental Association (ADA) lists them among the cleaners that can be used in place of floss. Evidence is more modest than product marketing suggests: a 2019 Cochrane review found they may be more effective than floss, but graded the overall certainty low to very low.
Definition and scope
The ADA describes interdental brushes as “small-headed toothbrushes that are available in a range of different sizes to match the space between teeth”, and says they can be cone shaped or cylindrical. Brushes designed for cleaning around implants have coated wire, so the wire does not scratch the implant.
They sit within a wider group the ADA calls interdental cleaners: floss, wooden or plastic sticks, tiny brushes, powered air or water flossers, and wooden plaque removers. For the first two, see dental floss types; for the powered water category, see oral irrigators.
How interdental brushes are used in practice
The ADA places interdental brushes among the interdental cleaners that can stand in for floss, and says it does not recommend using devices that clean between the teeth more than once, because a worn device can be less effective. Patient handouts and clinic stock labels should keep that wording consistent with the ADA page. Choice of product for an individual is a matter for a dentist or hygienist.
Interdental brushes compared with other interdental cleaners
The table below uses only the ADA’s own summary of the 2019 Cochrane review (Worthington et al.) on home-use interdental cleaning devices added to toothbrushing.
| Cleaner | What the ADA reports from the review |
|---|---|
| Interdental brushes | Together with floss, may reduce gingivitis or plaque more than toothbrushing alone; may be more effective than floss |
| Floss | May reduce gingivitis or plaque more than toothbrushing alone. A separate 2011 Cochrane review rated the flossing evidence for gingivitis as very low quality |
| Tooth-cleaning sticks and oral irrigators | Available evidence limited and inconsistent |
The ADA adds that the review found no randomized controlled trials assessing the effect on interproximal caries and very few studies on periodontitis. Outcomes were mostly measured over 1 to 3 months, and the effect sizes observed may not be clinically important.
Where it matters for labs, clinics and supply decisions
Three separate documents describe what an interdental brush is, and they do not cover the same products. A short checklist for supply staff:
- FDA classification. FDA’s record for 510(k) K870906 (CareRite interdental brushes, models 3500 and 4500, decided 30 March 1987) lists product code EFW under regulation 21 CFR 872.6855, the manual toothbrush regulation. That regulation defines a manual toothbrush as a shaft with natural or synthetic bristles at one end intended to remove adherent plaque and food debris from the teeth. It classifies the device as Class I (general controls) and exempt from premarket notification (510(k)), subject to the limitations in 21 CFR 872.9. A given product’s own FDA record and labeling still decide how it is regulated.
- Quality system. Under the same regulation, a device not labeled or represented as sterile is exempt from the quality management system requirements in 21 CFR part 820 except records and complaint files (820.35).
- ISO 16409:2016. The standard “Dentistry – Oral care products – Manual interdental brushes” (published 12 October 2016) sets requirements and test methods for performance criteria. Its scope covers round-headed brushes with a wired stem and inserted filaments, including usage instructions and package labelling. It excludes plastic-core brushes, powered brushes, manual toothbrushes, floss, tapes, strings and interdental cleaners without filaments.
- Single use. The ADA does not recommend reusing interdental devices; check that handout language does not imply otherwise.
The practical consequence: a claim of conformity to ISO 16409 can apply only to the wired-stem, round-headed type the standard describes, not to every product sold as an interdental cleaner. For general background on how FDA defines devices, see what is a medical device, and for how consensus standards are used in FDA review, FDA recognized consensus standards. Sizes vary between manufacturers, so a size number on one brand’s pack should not be assumed to match another’s.
Common misunderstandings
“Interdental brushes are proven to be the most effective option”
The ADA’s wording is that they “may be more effective than floss”, from low to very low certainty evidence. Neither “proven” nor “most effective” is supported by that summary.
“All interdental cleaners meet the same standard”
ISO 16409:2016 is limited to manual wired-stem interdental brushes. Floss, sticks and powered devices fall outside it.
“A brush can be rinsed and reused indefinitely”
The ADA does not recommend using devices to clean between the teeth more than once.
FAQ
What are interdental brushes?
Small-headed brushes, cone shaped or cylindrical, available in a range of sizes to match the space between teeth (ADA).
Are interdental brushes better than floss?
The 2019 Cochrane review, as summarized by the ADA, found they may be more effective than floss, with overall low to very low certainty evidence.
Can an interdental brush be reused?
The ADA does not recommend using devices to clean between the teeth more than once.
Is there a standard for interdental brushes?
Yes. ISO 16409:2016 covers manual interdental brushes of the round-headed, wired-stem type.
How does FDA regulate them?
FDA’s record for K870906 lists an interdental brush under 21 CFR 872.6855, the manual toothbrush regulation, a Class I device exempt from 510(k) subject to 21 CFR 872.9.
Sources
- American Dental Association, Dental Floss/Interdental Cleaners, checked 30 October 2026.
- eCFR, 21 CFR 872.6855 Manual toothbrush, checked 30 October 2026.
- FDA, 510(k) K870906, checked 30 October 2026.
- Standards Council of Canada, ISO 16409:2016 catalogue record, checked 30 October 2026.
- Worthington HV, et al. Home use of interdental cleaning devices, in addition to toothbrushing, for preventing and controlling periodontal diseases and dental caries. Cochrane Database Syst Rev 2019 (as summarized by the ADA), https://www.ada.org/resources/ada-library/oral-health-topics/floss, checked 30 October 2026.
