The short answer: Neither is a clear winner. A water flosser may calm gum inflammation at least as well as string floss in the short term, but the evidence is low certainty and it hasn’t been shown to remove more plaque. Use whichever tool you’ll stick with every day; a water flosser is especially handy if you have braces, implants, a bridge or trouble handling floss.
Brushing cleans the front, back and chewing surfaces of your teeth, but toothbrush bristles alone can’t clean effectively between them. That’s why the American Dental Association (ADA) recommends cleaning between your teeth once a day with floss or another interdental cleaner, such as a small interdental brush or a water flosser (American Dental Association, 2026).
So which tool does the better job? Here’s how each one works, what the research shows and who benefits most from a water flosser. If you’re new to cleaning between your teeth, the complete guide to flossing covers the basics, and the daily dental hygiene routine shows where it fits in your day.
Why does cleaning between your teeth matter?
Plaque, the sticky film of bacteria on teeth, forms along the gumline, including between teeth where bristles can’t reach. If it isn’t removed, it can harden into tartar. Your gums may then swell and bleed when you brush or clean between your teeth, a condition called gingivitis, the early stage of gum disease (American Dental Association, 2026).
Gum disease is common. A national survey estimated that 42% of US adults aged 30 and older who still had teeth had periodontitis, the more advanced form of gum disease, and 7.8% had severe periodontitis (Eke et al., 2018). Cleaning between your teeth reaches surfaces your brush misses and reduces the likelihood of gum disease and tooth decay (American Dental Association, 2026). The guide to gum disease and bleeding gums explains the warning signs.
How do floss, water flossers and interdental brushes work?
- String floss is a thin strand of nylon or plastic that you slide between two teeth and curve against each tooth to wipe plaque off its sides. Waxed and unwaxed floss work equally well (American Dental Association, 2026).
- A water flosser, also called an oral irrigator, is a device that sprays a stream of water in steady pulses. Like floss, the water removes food from between teeth (American Dental Association, n.d.). They come as countertop units with a water tank or as cordless handheld models.
- Interdental brushes are tiny brushes that come in a range of sizes to match the spaces between your teeth, in cone or cylinder shapes. Versions made for implants have a coated wire so they don’t scratch the implant (American Dental Association, 2026).
All three work alongside brushing, not instead of it.
Is a water flosser better than string floss?
The most thorough summary is a 2019 Cochrane review of 35 randomized trials involving 3,929 adults. It compared each device, used alongside brushing, with brushing alone and with the other devices (Worthington et al., 2019). Its main findings:
- String floss: adding floss to brushing may reduce gum inflammation at one, three and six months (low-certainty evidence). Results for bleeding and plaque were inconsistent.
- Water flossers: adding a water flosser may reduce gum inflammation at one month, but not at three or six months (very low-certainty evidence). It did not reduce bleeding sites or plaque more than brushing alone (low-certainty evidence).
- Water flosser vs. floss: a water flosser may reduce gum inflammation more than floss at one month (low- to very low-certainty evidence), with no clear difference in plaque.
- Interdental brushes vs. floss: interdental brushes may reduce gum inflammation more than floss at one and three months (low-certainty evidence).
The authors rated the overall evidence as low to very low certainty. Most studies were short, many participants had only mild gum inflammation to begin with, the effects may be too small to matter clinically, and no trial measured cavities between the teeth. No device caused serious side effects (Worthington et al., 2019).
A 2024 scoping review of 275 sources on water flossers paints a similar picture: they reduced gum inflammation consistently, but results for plaque removal were mixed. The devices were safe and well accepted when used appropriately (Sarkisova et al., 2024). In short, water flossers seem good at calming gums, but neither they nor floss has been shown to clean clearly better.
Who benefits most from a water flosser?
According to the ADA, water flossers can be an option for people who have trouble flossing by hand and for people whose dental work makes flossing difficult, such as braces or fixed bridges (American Dental Association, n.d.). A periodontist quoted by Cleveland Clinic adds that people with dental implants, bridges or a lot of gaps between their teeth benefit most (Cleveland Clinic, 2023).
Braces
With braces, floss has to be threaded under the wire for every gap, which is slow. Whether a water flosser improves gum health during treatment is less clear.
A 2024 review of seven trials found that adding a water flosser to brushing did not significantly improve gum, plaque or bleeding scores in people with braces, based on low- to very low-quality evidence (Zarei et al., 2024). A 2025 review of 18 trials concluded that a water flosser may slightly reduce gum bleeding compared with floss or brushing alone, and gum inflammation compared with brushing alone, especially in people with braces (Badahdah et al., 2025).
Dental implants
A 2025 review of seven small studies (360 people) found that adding a water flosser to brushing reduced plaque, gum inflammation and bleeding around implants more than brushing alone. In the comparison with floss, bleeding fell by 81.8% at implant sites cleaned with a water flosser versus about 33% with floss, but the authors rated the certainty of the evidence as very low (Gandhi et al., 2025).
Another 2025 review, which pooled two studies, found no statistically significant difference in bleeding or plaque between brushing alone and brushing plus a water flosser, and it called the evidence limited (Bishti et al., 2025). Ask your dentist which tools suit your implant; our guide to dental implants covers aftercare.
Bridges and limited dexterity
A fixed bridge makes flossing difficult (American Dental Association, n.d.), and so can arthritis, a disability or an injury that limits how well you use your hands. A water flosser asks much less of your fingers. Research in people with special needs is limited but promising (Sarkisova et al., 2024).
How do you use each one correctly?
Whichever tool you choose, use it once a day. It doesn’t matter whether you clean between your teeth before or after brushing, as long as you’re thorough (American Dental Association, 2026).
String floss
- Wrap the ends of a length of floss around your fingers so you can hold a short, taut section.
- Ease it between two teeth with a gentle back-and-forth motion. Don’t snap it down onto your gums.
- Curve the floss into a C-shape against one tooth and gently slide it up and down the side of the tooth (NHS, 2025).
- Repeat on the neighboring tooth, then move to a clean section of floss for the next gap.
Water flosser
- Fill the reservoir with warm water and choose a tip that suits you, such as an orthodontic tip if you wear braces (Cleveland Clinic, 2023).
- Start on a low pressure setting and turn it up only as far as feels comfortable. Used incorrectly, a water flosser can irritate your gums (Cleveland Clinic, 2023).
- Lean over the sink, place the tip in your mouth and turn it on. Aim the stream along the gumline and into the spaces between your teeth, making sure to reach every tooth (Cleveland Clinic, 2023).
- Keep your mouth slightly open so the water falls into the sink instead of splashing.
- Clean the device as the manufacturer recommends.
Interdental brushes
Pick a size that fits snugly between your teeth without forcing it (NHS, 2025). You may need several sizes; a dentist or hygienist can help you choose. Slide the brush gently in and out of each space a few times.
Which is cheaper and easier to use?
String floss is the cheapest and most portable option and needs no power, but it takes practice, especially at the back of the mouth. A water flosser costs far more up front, needs water and electricity or charging, and can be messy while you learn; cordless models are easier to store and travel with. Interdental brushes are inexpensive and quick once you know your sizes, but they won’t fit very tight gaps.
| Feature | String floss | Water flosser | Interdental brush |
|---|---|---|---|
| How it cleans | Wipes plaque off the sides of each tooth | Pulsing water flushes food from between teeth | Small bristles scrub the gap between teeth |
| Evidence when added to brushing | May reduce gum inflammation for up to six months (low certainty) | May reduce gum inflammation at one month (very low certainty) | May reduce gum inflammation and plaque, and may beat floss (low to very low certainty) |
| Up-front cost | Lowest | Highest | Low |
| Needs power and water | No | Yes | No |
| Often a good fit for | Tight spaces between teeth | Braces, implants, bridges, trouble using floss | Gaps where a brush fits snugly |
What does the ADA Seal of Acceptance tell you?
A company earns the ADA Seal of Acceptance by submitting scientific evidence that the ADA’s Council on Scientific Affairs evaluates. For floss and other interdental cleaners, the company must show that using the product with brushing reduces plaque and gingivitis more than brushing alone, that its components are safe in the mouth, and that everyday unsupervised use won’t harm your teeth, gums or dental work (American Dental Association, 2026).
Water flossers that carry the Seal have been tested to be safe and effective at removing plaque and reducing gingivitis (American Dental Association, n.d.). But the Seal compares a product with brushing alone, not with other cleaners, so it can’t tell you whether a water flosser beats floss.
What it means for you
If you find flossing a chore
You don’t have to use string floss. The ADA lists interdental brushes and water flossers as alternatives to floss, and interdental brushes may even reduce gum inflammation more than floss (American Dental Association, 2026; Worthington et al., 2019). The best tool is the one you’ll use every day.
If you wear braces
A water flosser with an orthodontic tip can make cleaning around brackets quicker (Cleveland Clinic, 2023), although trials disagree on how much it improves gum health (Zarei et al., 2024; Badahdah et al., 2025). Our guide to braces covers care during treatment.
If you have implants or a bridge
A water flosser is a reasonable option, and interdental brushes for implants have a coated wire that won’t scratch them (American Dental Association, n.d.; American Dental Association, 2026). Ask your dentist which tools suit your dental work.
If your gums bleed when you clean
Bleeding gums are a sign of gingivitis (American Dental Association, 2026). Keep cleaning gently every day, and book a dental visit if the bleeding doesn’t stop (National Institute of Dental and Craniofacial Research, 2026). Our gum disease guide explains what to expect.
Questions to ask your dentist
- Which tool would work best for the spaces between my teeth?
- What size interdental brushes should I use?
- Would a water flosser help with my braces, implants or bridge?
- Can you check my flossing or water flosser technique?
- Are my gums healthy, or do I have signs of gum disease?
When to see a dentist
Book a dental visit if you notice any of these possible signs of gum disease (National Institute of Dental and Craniofacial Research, 2026):
- Gums that bleed easily, or bleeding that keeps happening even though you clean gently every day
- Red, swollen or tender gums
- Gums pulling away from your teeth, making them look longer
- Loose or sensitive teeth, or pain when you chew
- Bad breath that doesn’t go away
Also check with your dentist before using a water flosser after gum surgery or around new implants, and ask your hygienist to check your technique. For a broken braces wire, a knocked-out tooth or other urgent problems, see what to do in a dental emergency.
The bottom line
Floss, water flossers and interdental brushes all help when added to brushing, and the research doesn’t crown a clear winner. A water flosser may calm gums slightly better than floss in the short term and suits many people with braces, implants, bridges or stiff fingers, while interdental brushes may beat floss where they fit. Choose the tool you’ll use once a day.
References
American Dental Association. (2026). Dental floss/interdental cleaners. https://www.ada.org/resources/ada-library/oral-health-topics/floss
American Dental Association. (n.d.). Water flossers and water flossing. https://www.mouthhealthy.org/all-topics-a-z/water-flossers
Badahdah A, Hariri MA, Aljohani MS, Alshehri LS, Natto ZS. (2025). Alleviation of plaque and gingivitis with dental water jet in regular and orthodontic patients: A systematic review and meta-analysis. Healthcare, 13(4), 396. https://doi.org/10.3390/healthcare13040396
Bishti S, Wolfart S, Tuna T. (2025). Optimizing implant hygiene: the added value of interproximal cleaning devices around implant-supported restorations—a systematic review and meta-analysis. International Journal of Implant Dentistry, 11(1), 64. https://doi.org/10.1186/s40729-025-00652-4
Cleveland Clinic. (2023). Why you should add a water flosser to your oral health routine. https://health.clevelandclinic.org/do-water-flossers-work
Eke PI, Thornton-Evans GO, Wei L, Borgnakke WS, Dye BA, Genco RJ. (2018). Periodontitis in US adults: National Health and Nutrition Examination Survey 2009–2014. Journal of the American Dental Association, 149(7), 576–588.e6. https://doi.org/10.1016/j.adaj.2018.04.023
Gandhi G, Masanam BSL, Nair AS, Semani N, Chopra A, Ramanarayanan V. (2025). Efficacy of oral irrigators compared to other interdental aids for managing peri-implant diseases: a systematic review. BDJ Open, 11(1), 7. https://doi.org/10.1038/s41405-025-00301-3
National Institute of Dental and Craniofacial Research. (2026). Periodontal (gum) disease. https://www.nidcr.nih.gov/health-info/gum-disease
NHS. (2025). How to keep your teeth clean. https://www.nhs.uk/live-well/healthy-teeth-and-gums/how-to-keep-your-teeth-clean/
Sarkisova F, Morse Z, Lee K, Bostanci N. (2024). Oral irrigation devices: A scoping review. Clinical and Experimental Dental Research, 10(3), e912. https://doi.org/10.1002/cre2.912
Worthington HV, MacDonald L, Poklepovic Pericic T, Sambunjak D, Johnson TM, Imai P, et al. (2019). Home use of interdental cleaning devices, in addition to toothbrushing, for preventing and controlling periodontal diseases and dental caries. Cochrane Database of Systematic Reviews, 4(4), CD012018. https://doi.org/10.1002/14651858.CD012018.pub2
Zarei Z, Yazdi M, Sadeghalbanaei L, Tahamtan S. (2024). The effectiveness of oral irrigators on periodontal health status and oral hygiene of orthodontic patients: a systematic review and meta-analysis. BMC Oral Health, 24(1), 1469. https://doi.org/10.1186/s12903-024-05255-w
References checked October 2026 · Editorial policy · Report a correction
Discover more from HappyTeeth.Care
One email a month with new guides and one study, explained. Join and get a free printable dental emergency card. No spam, unsubscribe any time.
