BURST Expanding Floss Review: Is It Better Than Regular Floss?

BURST Expanding Floss is a black, woven floss with a wax and xylitol coating that spreads out between teeth. It costs about $6.99 for 40 yards. The company says it removes twice as much plaque as unwaxed floss, but that claim comes from its own lab tests, not a published trial. It’s a good floss if you like it; it isn’t proven better.

Quick verdict

• Worth trying if you find thin floss cuts into your gums, you have small gaps or slightly open contacts, you want a PTFE-free floss, or the black color and flavor actually get you to floss every day.
• Skip it if your teeth are very tight and floss already snags, you’re on a tight budget, or you’re buying it because of the “2x plaque” claim alone.
• Budget alternative: an ordinary waxed nylon floss does the same basic job for less money. See our waxed vs unwaxed floss guide.
• The bottom line: a pleasant, well-made floss with marketing that runs ahead of the evidence.

What BURST Expanding Floss is

According to BURST’s product page, BURST Expanding Floss is:

• Woven from 300+ fibers that spread out as you use it, so the strand covers more of the tooth surface than a single tight strand.
• Black, so you can see the plaque and food you pull out.
• Coated with microcrystalline wax, xylitol and a mint eucalyptus flavor.
• Free of parabens, phthalates, BPA, Teflon (PTFE) and PFAS, according to the company. It’s also described as vegan.
• Sold as 40 yards in a refillable case made largely from recycled plastic.

Expanding floss isn’t a new idea. Several brands make woven or “puffy” floss designed to fluff out in wider gaps. BURST’s version stands out mainly for its color, coating and branding. We didn’t find BURST floss among ADA Seal of Acceptance products in our searches. The Seal requires a company to submit safety and effectiveness evidence for ADA review, and the program is voluntary, so a missing Seal doesn’t by itself mean a floss is unsafe.

Does BURST floss remove more plaque?

BURST says its floss removes 2x more plaque than regular unwaxed dental floss, removes up to 85% of plaque between teeth, and gives up to 58% plaque reduction on root surfaces just below the gumline. Each claim carries a footnote: “in laboratory tests; data on file.”

What that means for you:

• “Laboratory tests” usually means plaque-like material on model teeth, not people’s mouths over weeks. Lab results don’t always carry over to real-world gum health.
• “Data on file” means the study hasn’t been published where outside researchers can check it. We couldn’t find a peer-reviewed trial of BURST floss in PubMed or other searches.
• The comparison is with unwaxed floss, not with the waxed or PTFE floss most people buy.

That doesn’t mean the floss doesn’t work. It’s floss, and floss cleans between teeth. It means the “twice as effective” framing isn’t independently confirmed.

What the research says about floss in general

The ADA calls cleaning between your teeth an essential part of caring for your teeth and gums, because a toothbrush can’t reach the tight spaces between teeth. It also notes that waxed and unwaxed floss work about the same.

A 2019 Cochrane review of 35 trials found low-certainty evidence that flossing plus brushing may reduce gum inflammation (gingivitis) more than brushing alone. In the same review, interdental brushes (tiny brushes that fit between teeth) may have done better than floss for gingivitis, and water flossers may have helped gingivitis but not plaque in the short term. Most of the evidence was low quality.

In other words, the gap between one floss and another is probably small compared with the gap between flossing and not flossing. Our guide on how often you should floss covers how much is enough.

Xylitol coating and the PTFE-free angle

Xylitol. BURST says the xylitol coating helps fight cavities. Xylitol is a sugar alcohol that cavity-causing bacteria can’t use well, which is why it shows up in gum and some toothpastes. But we found no studies on xylitol-coated floss specifically. The small amount on a strand of floss is unlikely to make a measurable difference on its own. Fluoride toothpaste remains the main cavity-prevention tool the ADA recommends.

PTFE-free. Very slick “glide-style” floss is made from PTFE, part of the PFAS chemical family. One 2019 observational study linked one PTFE floss brand to higher blood levels of one PFAS. It showed an association, not proof that the floss caused it. If that concerns you, a floss that says it’s PTFE-free, including BURST or any waxed nylon floss, avoids the issue. Our waxed vs unwaxed floss post covers that study in more detail.

BURST floss vs regular floss

BURST prices are from the company’s own store at the time of writing and may change; retailers may charge differently.

Some customer reviews on BURST’s own site mention the floss fraying or feeling too thick in tight spaces, while many others praise how clean it feels. These reviews aren’t independent, so treat them as a rough guide to fit, not cleaning power.

Who BURST floss suits, and who it doesn’t

It may be a good fit if you:

• Have small natural gaps, slightly open contacts, or gums that have pulled back a little, where a fuller strand can contact more surface.
• Find thin floss cuts into your gums or feels harsh.
• Want a PTFE-free floss with a pleasant flavor and like seeing what you’ve removed.
• Will actually floss more often because you like using it. That’s the biggest benefit any floss can offer.

It may not be the best fit if you:

• Have very tight teeth where floss already snags or shreds. A thinner waxed floss or PTFE floss is usually easier.
• Have wider gaps, bridges, implants or braces. Interdental brushes, floss threaders or a water flosser often work better. See floss picks vs floss and Waterpik vs floss.
• Are flossing on a budget. Basic waxed floss does the job for less.

When to see a dentist

See a dentist if your gums bleed every time you floss for more than a week or two, if your gums are swollen, tender, pulling back from your teeth, or if you notice bad breath that won’t go away. These can be signs of gum disease, which our bleeding gums guide explains. Also mention it if floss keeps shredding or catching in the same spot, since that can point to a rough filling edge, tartar or a cavity between teeth. Get prompt care for a loose tooth, pus around the gums, or facial swelling.

Frequently asked questions