The Best Water Flossers

We spoke with Jessica Hilburg, associate dean for clinical affairs at NYU College of Dentistry, and Ruchi Sahota, a dentist in Fremont, California, who serves as a media spokesperson for the American Dental Association (ADA). We also spoke with Chhaju Ram Goyal, co-founder and director of All Sum Research Center (an independent research lab in Canada that tests oral-health-care products), whose name is on much of the scientific research related to water flossers (though, that research was paid for and designed by none other than Waterpik).

If you won’t or can’t use dental floss, and you don’t mind spending some cash on a device that might break or get disastrously moldy, consider a water flosser.

Water flossers are an alternative (or an addition) to string floss. They don’t require the same dexterity that string floss does (though you still need fine-motor skills). They can make it easier to clean around braces. And they are arguably more fun to use than string floss.

But they’re also pricier, bulkier, and fussier. Even using a generous 18 inches of string per floss—which allows you to use a new section of string for each tooth—you’ll go through under $10 worth of floss per year. By contrast, the least expensive water flossers cost about $40. Plus, you’ll need to clean your water flosser from time to time, but string floss is maintenance-free.

Only your own dentist can tell you whether a water flosser is the best choice for your oral hygiene, according to the dentists we spoke with. “Everyone’s teeth are different, everyone’s gums are different,” Ruchi Sahota, a dentist in Fremont, California, said. If you embark on a water-flosser experiment, get feedback from your dentist about how well it’s working.

By and large, it’s unclear how water flossers compare to regular string floss in terms of cleaning. Water flossers that bear a seal from the American Dental Association (ADA) have been evaluated by the organization and are shown to clean teeth better than a toothbrush alone. However, the ADA doesn’t compare water flossing to string flossing. (The ADA isn’t entirely independent of companies that sell dental goods: Member companies pay the organization a fee to evaluate their products. The ADA designs and controls the evaluations itself, though.)  There’s a paper arguing that water flossers are superior to string floss. But the research was funded and overseen by Waterpik. Thus, we’re skeptical of the results, even though the journal the paper appeared in is peer reviewed by an editorial board of dentists.

Actually, the evidence that even string flossing improves overall oral health isn’t of great quality. But the ADA recommends some sort of daily flossing, and the experts we spoke with likened interdental cleaning to any other routine hygiene step. “There might not be a study, but most people would agree that taking a shower is a good thing,” said Jessica Hilburg, associate dean for clinical affairs at NYU College of Dentistry. Sahota likened it to cleaning out any of the little crevices on your body, like your belly button.

There are dozens upon dozens of water flossers available. Over four years of testing these devices, we’ve considered a mix of countertop and portable, corded and cordless models in a variety of sizes, favoring those with the most favorable customer reviews and/or the ADA Seal of Acceptance.

We pinpointed the features that will have the biggest impact on what it’s like to use a particular water flosser:

• Stream style: Most flossers dispense a continuous stream of water, whereas some emit a quick, tiny burst of water (or mouthwash) whenever you press a button. It’s unclear which approach is better for your gums. We found that the continuous stream models made the spaces between our teeth feel more thoroughly rinsed. However, as they filled our mouths with water, they required us to drool as we water-flossed. Quick bursts (Philips Sonicare calls this method “air flossing,” though it still involves a tiny bit of liquid) filled our mouths more slowly, so we often had to spit just once, at the end of a cleaning. If you want to use mouthwash or other antibacterial solutions in your water flosser, the quick-burst style is better because it doesn’t require nearly as much liquid. Yet all of our picks are compatible with mouthwash, which you can dilute in the larger reservoir to avoid waste, if desired.

• Power source: Some flossers need to be plugged into the wall during use, and some are cordless. Some cordless models have a built-in rechargeable battery, and others run on replaceable batteries.
• Counter space: Philips models take up a bit more space than an electric toothbrush. Because of their larger tanks, cordless Waterpik models need as much room as a shampoo bottle. Traditional plug-in and cordless Waterpiks, with their extra-large tanks, take up as much space as a mega roll of plush toilet paper.

Other features that matter (but aren’t as important as those first three) include:

• Settings: The more you can adjust the water stream, the better you can adjust the flosser’s feel to your exact preferences. With the Waterpik and Panasonic models, this means pressure settings, which can vary from two to 10 options, depending on the model. Some Waterpik units even have a massage feature, which oscillates the pressure of the stream. This style made our teeth feel cleaner, but there was more of a learning curve as we figured out how to lean our heads above the sink in order to drool neatly. The Philips flossers let you customize between one and three “bursts” of water per button press, which some may find easier to deal with.
• Tips: All flossers shoot water out of a removable tip, allowing multiple people in a household to use the same device without sharing germs. Some models have holsters for multiple tips, while others have no storage. Some come with a range of tips that vary the stream width, though not all of these are useful—you don’t really need a tip that doubles as a toothbrush.
• Tank size: All flossers theoretically hold enough water to work through your whole mouth. But having a larger tank can be nice because it allows you to focus on any trouble spots (like a stubborn fleck of popcorn) or do a touch-up without having to refill.

No matter which model you pick, buy a water flosser only if it’s under warranty. Across the category, water flossers tend to fail easily: They can leak, wane in strength, or simply give up the ghost. We favored those that have fewer complaints. But your best option is to buy something with a long warranty (two or three years is typical), and be prepared to file a claim if needed.

We rotated through our selection of finalist flossers for several weeks (the experience of using them was so satisfying and novel that one tester water-flossed upwards of four times a day).

The Waterpik Ion is the best countertop water flosser. It cleans mouths thoroughly, and it is highly adjustable. And, thanks to its cordless charging base, the Ion can be used in all types of bathrooms—regardless of whether there’s an outlet nearby. The removable charging cord can be stored anywhere and brought out every few weeks to recharge the flosser. The Ion features a strong, steady water stream. And it has a larger-than-average, 26-ounce water tank (with a wide, easy-to-refill mouth), which holds enough water to floss between each tooth and then some.

Like many Waterpik countertop flossers, the Ion has 10 pressure settings, so you can find the perfect water-stream strength. This model also comes with six tips that offer different stream widths. But unlike other flossers, the Ion has a magnetized handle cradle, which makes it easier to store the handle and the cord that connects it to the reservoir compactly.

The Ion takes up less counter space than other countertop flossers we’ve considered, including our runner-up pick, the Waterpik Aquarius. (The Aquarius could be compared in size to a mega-roll of toilet paper, whereas the Ion is closer in size to a regular roll.) Because with the Ion you’re not tied to an outlet, you can move the device wherever on the counter you prefer.

As with most flossers that produce a constant flow of water, you’ll have to learn how to artfully drool while using the Ion.

The Ion is one of the easiest water flossers to refill after each use or so (a requirement of all flossers) and to wipe out regularly: It has a wide, dishwasher-safe reservoir that is easily removed and that doesn’t have any hard-to-reach nooks and crannies. The tank lid attaches to the unit and flips up, so there’s nothing to set aside while you fill and clean the tank. It holds around 90 seconds’ worth of water, which gives you plenty of time (and then some) to floss your entire mouth. One tester found they could do a quick floss in about 30 seconds; if they spent more than a minute, their teeth felt fantastically clean.

The Ion comes in two colors (black and white) and is warrantied for three years. If our pick is unavailable and you prefer a countertop flosser with cordless charging, consider the Waterpik Ion Professional, which is nearly the same model, but with a slightly smaller water tank.

Flaws but not dealbreakers

Although Waterpik claims the Ion can last for a month between charges, we needed to recharge the device every three weeks or so when water flossing every day. Even so, we found this model to be a worthwhile upgrade over having to keep a countertop flosser plugged in at all times in order to run it.

There’s no place to store the included extra tips, so if that is more important to you than cordless charging, consider our runner-up pick, the Aquarius.

Like most water flossers, the Ion is slightly noisy (similar to electric razors and many bathroom electronics), but not terribly so.

Because of its continuous stream, the Ion (like all of our picks) involves a learning curve. That stream means your mouth fills up with water pretty quickly. You’ll either have to pause to spit several times during a flossing session or learn to let it dribble out (even the official Waterpik literature features an image of a person straight-up drooling). And if you pull the nozzle out of your mouth too quickly, you’ll send water spraying across the bathroom.

If plugging in is not an issue, the Waterpik Aquarius is a solid water flosser that offers a similar experience to that of our pick, the Ion. The Aquarius made our mouths feel totally clean, thanks to its strong, continuous stream (which is similar to the Ion’s). This model also ties with the Ion for having the most stream pressure settings and tips of all the flossers we tested. So the Aquarius gives you the best chance of finding the pressure, pulse, and stream size that feels good to you.

With the Aquarius, there’s no charging system or batteries to contend with because it plugs into the wall via a 4-foot electrical cord. (Though, unlike the Ion, this model must remain plugged in to operate.) Although there are more reports of it breaking down or becoming caked with mold than we’d like, in three years of research and long-term testing, we’ve found the Aquarius to be a reliable device.

Though the Aquarius is not quite as easy to clean as the Ion, it does have a wide, dishwasher-safe reservoir that holds plenty of water for at least a single flossing session. This model takes up more counter space than the Ion and many other water flossers we considered. As with all of our picks, with the Aquarius you’ll be drooling a lot because of the constant water flow. Unlike our other picks, this model has two modes (for a regular “floss” stream or a “massage” mode, which shoots pulses of water), and it comes with seven different tips (one more than the Ion comes with).

The floss mode delivers a continuous stream of water, which we found to be the most effective for cleaning. On the strongest setting, it actually made one of our tester’s gums bleed, possibly because they were not used to flossing. Some water-flosser manuals acknowledge a week or two of bleeding as part of the “training period,” when your gums get used to being power-washed.

The massage mode is a pulsing stream. This mode also felt like it cleaned well, and it filled our mouths with water at a slower rate, which in turn made for less awkward drooling. The massage mode could be helpful for folks who prefer a gentler stream.

The Aquarius comes with seven basic tips offering different widths of water streams (though you probably wouldn’t use most of them on a regular basis). Unlike the Ion, this model has a spot next to the tank to store tips; this is handy if you want to share the flosser with family members or switch between a couple of tips yourself. The curly cord that connects the handle to the tank is about 33 inches long, an inch shorter than the Ion’s.

Like the Ion, the Aquarius comes with a three-year warranty. It is available in five colors: black, white, blue, gray, and orchid (a purple hue).

The Waterpik Cordless Express is a great compact option for people who desire a smaller device, for either portability or space-saving purposes. As with our other Waterpik picks, you’ll drool heavily when using this flosser. But unlike our countertop picks, this one is fully waterproof—you can use it in the shower. We found this extremely helpful both for remembering to floss and limiting cleanup (what better place to drool on oneself than in the shower?).

If you have hand-grip issues, a cordless water flosser may not be right for you. Because it’s an all-in-one device, with the water reservoir attached to the handheld sprayer, this model is much wider and heavier to hold than our other picks. When filled with water, the Cordless Express weighs more than a pound—versus our top-pick handle’s single ounce. The body of the Cordless Express features a useful grip pattern to help you avoid dropping the device, but people with smaller hands may have difficulty holding its 5-inch circumference.

With just two settings, the Cordless Express is much simpler than our other picks. It holds enough water or mouthwash (or other antibacterial solutions) for 30 seconds of spray, which is enough to complete a single floss. It’s extremely easy to fill, however, so if you feel the need to floss again, you can be back to drooling in mere seconds.

The Cordless Express uses three AA batteries, instead of plugging into the wall with a charging cord, so you’ll want to have extra batteries on hand (or use rechargeable ones). Removing and replacing the batteries is an easy process, as is cleaning the device. And, as with our other picks, this model’s water reservoir can go in the dishwasher; weekly cleaning is recommended.

This model comes with two tips—far fewer compared with our other picks. But the Cordless Express is compatible with all other Waterpik tips.

The Cordless Express has a one-year warranty (much shorter than that of our trusty corded picks), and it comes in white or black.

If you can’t find the regular Waterpik Ion in stock, consider the rechargeable Waterpik Ion Professional. This model has the same 5.5-inch footprint and 34-inch flosser cord as our pick, the Ion, but it holds 23 ounces of water (instead of 26 ounces).

If you want a cordless flosser and are willing to spend more for a stronger stream and more capacity, the Philips Sonicare Power Flosser 3000 Cordless is, as one customer reviewer called it, “a power washer for your teeth.” At $80, it’s double the price of our pick, the Waterpik Cordless Express, but it has a rechargeable battery and can hold 66% more water (8.3 ounces versus 5). It’s heavier to hold (especially when full), but it has the strongest water stream of any cordless flosser we’ve tested, and overall offers a surprisingly pleasant flossing experience. It comes with two nozzles and offers two flossing modes and three stream intensities, which our testers enjoyed tooling with. The Power Flosser 3000 Cordless has a two-year warranty (double that of Cordless Express).

If you’re looking for a traditional corded water flosser for a child, or for an adult with smaller hands or dexterity issues, Waterpik’s Water Flosser For Kids may be a worthy compact option. Its neon green coloring isn’t exactly subtle, but this flosser has the same per-minute pulses and flow rate as our picks. However, its highest pressure option is lower than that of our picks (80 psi versus 100 psi). And this model also offers only 60 seconds of flossing capacity (our picks offer 90 seconds) and a shorter warranty (two years versus three). We found this flosser’s smaller, thinner handle easy to grip, but it does not have a rotating tip option or an on/off switch. Since this one is meant to be refilled after every use, it does not come with a lid.

Countertop water flossers

In our experience, the Waterpik Ultra cleans just as well as the Ion and the Aquarius. But its lid isn’t attached to the tank (which is less preferable for regular maintenance).

We found combination water flossers and electric toothbrushes like Waterpik’s Complete Care 5.0 or Sonic Fusion SF-01 to be less appealing than using our water flosser pick and electric toothbrush pick separately.

We didn’t test the Waterpik Sidekick Water Flosser, despite its pluses. We like that this corded model is smaller than other countertop Waterpiks, can fit in a small travel case, and looks quite nice (especially the black-and-copper model). But, unfortunately, it comes with only one tip, which cannot be changed (making it a little gross for use by multiple people). Also, it has just five pressure settings, and, at the time of publication, the Sidekick was nearly double the price of the Aquarius.

The Waterpik Classic Professional Water Flosser, which we also did not test, is similar in function and size to our top pick and costs a bit less. But it has only six pressure settings and comes with just two styles of tips. There’s also no cover on the tank lid.

We chose not to test the mouthguard-style Fresh Pro Flosser. At the time of publication, it was only available for preorder. 

Cordless water flossers

The cordless Oral-B Water Flosser Advanced’s reservoir holds less water than we needed for a single test flossing session. Because this model produces a lower pressure water stream than our pick, in our experience it felt less effective when compared with the Waterpik Cordless Express.

The Panasonic EW-DJ10-W Oral Irrigator is a well-reviewed water flosser. But due to its collapsible design, it tends to stay damp for a while, which, well, dampens the overall experience. It also looks and feels a little cheaper than our cordless pick, despite being the same price. However, if the Waterpik Cordless Express is unavailable, the EW-DJ10 isn’t a completely awful substitute. It has a two-year warranty.

Philips Sonicare has discontinued its AirFloss line of water flossers, which expelled quick, tiny bursts of water or mouthwash instead of constant streams. 

We found two other cordless offerings from Waterpik, the Waterpik Cordless Freedom and the Waterpik Cordless Advanced Water Flosser, that are bulkier and less enjoyable to use than the Cordless Express.

The Burst Water Flosser has an especially strong water stream, but it holds less water and is more than double the price of our cordless pick. If you prefer a stronger stream, consider the Philips Sonicare Power Flosser 3000 Cordless.

Quip’s Rechargeable Cordless Water Flosser has the same capacity and number of settings as our cordless pick, but is more expensive.

The Aquasonic Aqua Flosser is overall more cumbersome to use when compared with the less-expensive Waterpik Cordless Express.

Shannon Palus contributed reporting in 2018.

This guide was edited by Tracy Vence and Kalee Thompson.