Water Flosser vs Floss: Which Actually Cleans Better?

The Waterpik Aquarius WP-660 is the water flosser worth buying if you want the biggest measured gap against string floss: a University of Nebraska Medical Center trial found it cut gum bleeding up to 93% more and gingivitis up to 52% more than a manual toothbrush-and-floss routine over four weeks. Oral-B’s Glide Floss Healthy Gums, at $4.17 a spool, is the pick if you just want an ADA-accepted way to clear food and plaque from between your teeth without a countertop appliance or a recurring tip bill.

Both products carry the ADA Seal of Acceptance, and both show up in this comparison because their claims are backed by published data rather than marketing copy alone. The picks below come from brand spec sheets, the ADA’s public Seal of Acceptance database, and named published clinical trials, not from testing in a lab of our own. See how we score for the full method.

Water flosser vs floss: full spec comparison

Where the Waterpik Aquarius WP-660 wins

The Aquarius WP-660 wins on measured cleaning performance and on adaptability. Its case rests on two named, published studies: Barnes et al., published in the Journal of Clinical Dentistry in 2005, put a Waterpik water flosser and a manual toothbrush against a toothbrush-and-floss control group for four weeks with 105 subjects, and found the water flosser group had up to 93% less bleeding and up to 52% less gingivitis. Separately, Gorur et al., published in Compendium of Continuing Education in Dentistry in 2009, used scanning electron microscopy to show the flosser’s Classic Jet Tip removed 99.9% of plaque biofilm from extracted tooth slices after a single 3-second treatment. That is an in vitro lab result, not a mouth, so treat it as a plaque-removal ceiling rather than a real-world guarantee.

The WP-660 also ships with 7 interchangeable tips, including an Orthodontic tip for braces and a Plaque Seeker tip that Waterpik’s own citations link to better results around implants and crowns. A reviewer on Waterpik’s own product page, posting as “MarshaJen,” wrote that a dentist recommended the unit to address receding gums and that a later cleaning check came back clean. Set against that, another reviewer on the same page, “Summrbrz,” said the unit works well but that “the motor is quite loud,” and a separate question in Waterpik’s own Q&A section asked whether a squeaking sound at high pressure settings was normal, which Waterpik’s support team confirmed is expected motor noise.

Where Oral-B Glide Floss Healthy Gums wins

Glide wins on upfront cost, on portability, and on ADA-backed reassurance without any moving parts. A single 50 m spool runs $4.17 at Walmart, works out to 7.6 cents per yard, needs no counter space, no outlet, and nothing to charge before a trip. The ADA’s Council on Scientific Affairs accepted it after review of clinical evidence, with a seal statement that reads: the product “is safe and has shown efficacy in removing plaque between teeth and helping to prevent or reduce gingivitis, when used as directed.”

The catch is consistency. Oral-B has reformulated this line: several 2025 Walmart reviewers who bought the same “Glide” name describe a flatter tape that behaves differently from the older round Glide Original floss. One verified Walmart purchaser, reviewing on May 19, 2025, wrote that “the Healthy Gums version I received is a flat tape that shreds in your teeth like crazy,” while adding that the round “Original” version “works really well.” Walmart still shows a 4.3-of-5 average across 2,142 ratings for the current formulation, so the complaint is not universal, but it is repeated enough across recent reviews to flag before you buy a multi-pack.

Choose the Waterpik Aquarius WP-660 if

• You have braces, implants, crowns, or bridges and want a tip built for that situation.
• You or a family member struggles with the hand dexterity that string floss requires.
• You want the larger measured gap in bleeding and gingivitis reduction documented in the Barnes 2005 trial.
• You have counter space and do not mind an appliance that needs occasional tip replacement.

Choose Oral-B Glide Floss Healthy Gums if

• You want the lowest possible cost per use and no appliance to maintain.
• You travel often and need something that fits in a toiletry bag.
• You already have good flossing technique and do not need a pressure-assisted tool.
• You would rather buy a single $4.17 item than commit to a $99.99 unit plus tip refills.

FAQ

Is a water flosser actually better than string floss?

On the single published trial cited here, yes, by a measurable margin: Barnes et al. (2005) found a Waterpik water flosser paired with a toothbrush reduced bleeding up to 93% more and gingivitis up to 52% more than a toothbrush-and-floss routine over four weeks in 105 subjects. That is one study of one water flosser brand against one string floss, not a blanket claim about every product in either category, and neither device treats or cures existing gum disease.

Does Oral-B Glide Floss Healthy Gums carry the ADA Seal?

Yes. It is listed in the ADA’s public Seal of Acceptance product database under the name “Oral-B Glide Floss Healthy Gums,” credited to Procter & Gamble Co., with a seal statement covering plaque removal between teeth and help preventing or reducing gingivitis when used as directed.

How often do you need to replace Waterpik tips?

Waterpik’s own product pages say to replace plastic tips like the JT-100E Precision Tip about every 6 months, and tips with bristles, such as the Plaque Seeker or Orthodontic tip, about every 3 months. A 2-pack of Precision tips lists for $14.99, which is the basis for the 3-year cost estimate in the table above.

Can you use a water flosser and floss together?

Nothing in the clinical trials cited here tested combining both in the same routine, so no percentage exists to cite for that specific combination; the closest published comparisons pit a water flosser against string floss as alternatives, each paired with brushing, rather than testing them stacked together.