New research confirms what some scientists have suspected for a while: certain dental flosses can shed potentially harmful chemicals into your mouth. The short answer is that most people should keep flossing because the oral-health benefits are real and well-established, but it is worth knowing which products raise more questions and which simple swaps can lower your exposure.
Here are seven things the science actually shows, explained in plain English.
1. The Research Behind the Headlines Is Real
The concern stems from a peer-reviewed study published in Environmental Science & Technology and follow-up investigations reported widely in the press, including a Washington Post investigation. Researchers found measurable levels of per- and polyfluoroalkyl substances (PFAS) in the blood of people who regularly used certain Teflon-coated flosses. PFAS are sometimes called “forever chemicals” because they break down very slowly in the environment and in the human body.
This is not a fringe finding. The National Institute of Environmental Health Sciences (NIEHS) considers PFAS exposure an active area of study, and several U.S. regulatory agencies have moved toward limiting PFAS in consumer products over the past few years.
2. Not All Dental Floss Is the Same
The products that drew the most attention are those marketed as “glide-style” or “smooth-slide” flosses. The slippery coating that makes them glide easily between teeth is often made with PTFE (polytetrafluoroethylene), the same general family of chemistry as Teflon. Standard nylon or silk flosses don’t use that coating.
So the PFAS concern is specific to a product category, not flossing in general. Your basic drugstore nylon floss, unwaxed or lightly waxed, has not been implicated in the same way.
3. The Dose Question Is Still Being Studied
Here is where it is important to be careful with language: the studies show an association between use of certain flosses and higher PFAS blood levels. They do not prove that a specific harm results in a specific individual at the amounts typically encountered from flossing. PFAS exposure in the general population comes from many sources, including cookware, food packaging, water, and clothing. Floss may be a contributor, but researchers are still working to understand how much each source contributes.
Conservative takeaway: there is enough evidence to make an informed, lower-exposure choice, but there is not enough evidence to panic or to stop flossing altogether.
4. The Oral-Health Case for Flossing Remains Strong
Before anyone tosses their floss in the trash, it is worth remembering why dentists recommend flossing in the first place. Toothbrush bristles clean about 60 percent of the tooth surface. The spaces between teeth, where plaque builds up and cavities often start, are only reachable with floss, an interdental brush, or a water flosser.
The American Dental Association (ADA) continues to recommend cleaning between teeth at least once a day. Gum disease and interproximal (between-the-teeth) cavities are real and common problems. Skipping interdental cleaning because of a chemical concern you can easily manage by switching products would be trading a confirmed health risk for a speculative one.
5. Switching Products Is a Simple, Low-Effort Fix
If you currently use a glide-style or PTFE-coated floss and want to lower your exposure, the fix is straightforward:
- Plain nylon floss (waxed or unwaxed) is widely available and has not been linked to PFAS exposure in the same studies.
- Silk floss is another natural-fiber option that works well for most patients.
- Water flossers (oral irrigators) are a PFAS-free alternative that can be especially useful for people with braces, bridges, or implants. They don’t replace mechanical cleaning as effectively as string floss for everyone, but for many patients they are a practical daily option.
- Interdental brushes are small rubber-tipped or bristled picks that work well in larger gaps between teeth.
The best interdental cleaner is genuinely the one you will actually use every day. Talk with your dentist about which tool fits your anatomy and your routine.
6. This Story Fits a Bigger Pattern in Dental Product Safety
The dental floss PFAS story is part of a wider conversation about everyday products and chemical exposure. In recent years, concerns have been raised about PFAS in nonstick cookware, waterproof clothing, microwave popcorn bags, and food containers. The FDA has been phasing out some of these uses in food packaging. The Environmental Protection Agency (EPA) has moved to set enforceable limits for certain PFAS in drinking water.
Dental floss is a small piece of that puzzle, but the broader lesson is the same: when low-effort alternatives exist and the science gives you reason to consider a switch, it makes sense to do so.
7. Your Dentist Can Help You Build the Right Routine
If you are not sure which products to use, or if you have been avoiding flossing because it hurts, your gums bleed, or it just feels awkward, this is a great thing to bring up at your next cleaning and exam. Our dental team at Vaksman Dental Group in South San Francisco sees this every day. Bleeding when you first start flossing regularly usually means the gum tissue is inflamed from plaque buildup, and it often improves within a week or two of consistent cleaning. Technique matters a lot too: the curved-C motion along each tooth surface does more work than just snapping the floss up and down.
We’re happy to walk you through the mechanics, recommend products that fit your specific situation (tight contacts, bridgework, implants, or sensitivity), and make sure your home routine is actually protecting you between visits.
Frequently Asked Questions
Should I stop using Glide floss because of the PFAS research?
You don’t have to stop flossing, but switching to a plain nylon or silk floss is a reasonable, low-effort way to reduce your potential PFAS exposure. The most important thing is that you continue cleaning between your teeth every day in some form.
Are water flossers a safe alternative?
Water flossers are a PFAS-free option and can be very effective, especially for people with dental work like bridges or implants. Research suggests they reduce plaque and gingivitis, though many dentists still recommend them alongside string floss rather than as a complete replacement. Ask your dentist what makes sense for your mouth.
How do I know if my floss contains PFAS?
Products won’t always list PFAS or PTFE on the label, but “Glide” style flosses and those described as extra-smooth or Teflon-coated are more likely to use PTFE chemistry. When in doubt, plain waxed or unwaxed nylon floss is the safest default choice.
Does this mean dental products in general are unsafe?
Not at all. This research is specific to a category of coated flosses. Your toothpaste, fluoride treatments, and other standard dental products are not implicated. For any dental product you’re unsure about, a quick conversation with your dental team or a check of the ADA Seal of Acceptance program is a good starting point.
The Bottom Line
Some dental flosses, particularly smooth-glide or PTFE-coated varieties, have been linked to higher PFAS blood levels in users. The science is real, the concern is reasonable, and the fix is easy: switch to plain nylon or silk floss, or use a water flosser. What you should absolutely not do is stop cleaning between your teeth. Gum disease and cavities from skipped interdental cleaning are guaranteed problems. A small switch in product is a much smarter trade-off than abandoning one of the most effective habits in oral health.
If you have questions about your flossing routine or want a product recommendation tailored to your teeth, bring it up at your next visit. Our team at Vaksman Dental Group is always happy to geek out about this kind of thing with you.
We offer professional dental cleaning and dental hygiene care in South San Francisco to help keep your whole mouth healthy between cleanings. And if it has been a while since your last dental exam, now is a good time to get back on track.
Written by the Vaksman Dental Group team and medically reviewed by Dr. Irena Vaksman, DDS — South San Francisco. Last reviewed October 2026.