Waxed and unwaxed floss clean equally well. In a controlled study comparing waxed and unwaxed versions of two brands, researchers found no statistical difference in plaque removal or gingivitis. The choice comes down to fit and feel: waxed floss slides more easily and shreds less, while unwaxed floss is thinner and squeaks against clean teeth. The best floss is the one you will use every day.
Quick verdict
- Choose waxed floss if your teeth are tight, floss tends to shred or snag on you, or you have crowns, bridges or rough fillings.
- Choose unwaxed floss if you have average spacing, like a thinner strand, or prefer feeling the squeak on a clean tooth.
- Cost: both are inexpensive and priced similarly. PTFE floss usually costs a bit more per yard.
- The catch: if you find any string floss hard to use, a floss pick, interdental brush or water flosser may suit you better. Any of these beats skipping the job.
Waxed vs unwaxed floss at a glance
| Waxed floss | Unwaxed floss | PTFE (glide-style) floss | Dental tape | |
|---|---|---|---|---|
| What it is | Nylon strands with a light wax coating | Bare nylon strands twisted together | A single smooth plastic (PTFE) band | A wider, flatter ribbon, waxed or unwaxed |
| Slides between tight teeth | Well | Fair; can catch | Best | Harder in tight spots |
| Shredding | Less likely | More likely, especially on rough edges | Very unlikely | Less likely |
| Feel | Smooth, slightly thicker | Thin, squeaks on clean teeth | Very slick | Broad and flat |
| Good for | Tight contacts, dental work | Average spacing | Very tight or crowded teeth | Wider gaps |
| Plaque removal | Similar | Similar | No independent head-to-head data | No independent head-to-head data |
Does waxed or unwaxed floss clean better?
Neither. The best-known comparison, published in the Journal of Periodontology in 1982, followed 80 patients for eight weeks. Each group used one of four flosses: waxed and unwaxed versions from two manufacturers. The researchers found no statistical difference in plaque removal or in preventing gingivitis among the four types.
Older studies sometimes showed unwaxed floss slightly ahead, but the differences were small and not significant. No large modern trial has overturned that. In practice, your technique (curving the floss around each tooth and reaching just under the gum line) affects the result far more than the coating.
It is also worth knowing how strong the evidence for flossing is overall. A 2019 Cochrane review of interdental cleaning found that floss plus brushing may reduce gingivitis compared with brushing alone, though the evidence was low certainty and the effect on plaque was unclear. The same review found interdental brushes may be better than floss for gingivitis in people whose gaps are wide enough to fit them. See our guide on how often you should floss for what the evidence means in day-to-day terms.
Why waxed floss is easier for most people
The wax coating does two things. It lets the floss slide through tight contacts with less force, and it holds the nylon strands together so they are less likely to fray. That makes waxed floss a common choice for people whose floss keeps shredding or snapping, and for people with crowns, bridges or fillings that have a rough edge between teeth.
Some people find waxed floss slightly thicker, so it can feel snug in very tight spots. If that happens, a thinner waxed floss or a PTFE floss usually fits better.
Why some people prefer unwaxed floss
Unwaxed floss is thinner, so it can slip into some tight spaces even without a coating. Many users like the squeak it makes against a clean tooth surface, which gives clear feedback that the plaque is gone.
The downside is that unwaxed nylon frays more easily, especially on sharp edges or older fillings. If it shreds repeatedly in the same spot, that is worth mentioning to your dentist, since it can point to a rough filling edge or tartar build-up. Our guide to plaque vs tartar explains the difference.
PTFE floss and the PFAS question
PTFE floss is made from a single band of the same family of material used in non-stick coatings. It is very slick and almost never shreds, which is why many people with tight teeth like it. The ADA’s own description of floss notes it can be made of nylon or Teflon (PTFE).
In 2019, a study in the Journal of Exposure Science & Environmental Epidemiology measured PFAS chemicals in the blood of 178 women. Women who used Oral-B Glide floss tended to have higher levels of one PFAS called PFHxS. The researchers also tested 18 flosses for fluorine, a marker of PFAS. All three Glide products and a few similar products tested positive.
This was one observational study. It shows an association, not that floss caused the higher levels, and the researchers called for more data. If you would rather avoid PTFE, waxed nylon floss is a simple swap that still slides well.
What about dental tape and “expanding” floss?
Dental tape is wider and flatter than regular floss. It covers more of the tooth surface in each pass and can feel gentler on gums, but it is harder to slide into tight contacts. It suits people with wider gaps between teeth.
Expanding (or “gum expanding”) floss is designed to fluff up as you use it, so it fills more of the space between teeth. It may suit people with mixed gap sizes. We could not find independent trials comparing it with standard floss, so treat marketing claims about better cleaning with caution.
Floss for braces, bridges and implants
Regular floss can be threaded under a wire or a bridge with a floss threader. Some products have a stiff end built in for this. A water flosser is another option many people with braces find easier; see our comparison of Waterpik vs floss and our guide to cleaning teeth with braces.
How to choose
1. Start with waxed nylon floss if you are unsure. It is cheap, widely available and forgiving. 2. Switch to PTFE only if waxed floss still catches or shreds between very tight teeth. 3. Try unwaxed if you prefer a thinner strand and do not have trouble with fraying. 4. Look for the ADA Seal of Acceptance. The ADA says flossing products with the Seal have been shown to be safe and effective. 5. Consider alternatives like floss picks, interdental brushes or a water flosser if string floss is what stops you from cleaning between your teeth.
When to see a dentist
See a dentist if your gums bleed every time you floss for more than a week or two, if floss always shreds or catches in the same spot, if food keeps packing between two teeth, or if you notice swelling, pus, a bad taste or a loose tooth. These can be signs of gum disease, a cavity or a broken filling. Our guide to bleeding gums covers common causes.
Frequently asked questions
Is waxed or unwaxed floss better?
Neither cleans better. A controlled study of waxed and unwaxed floss from two brands found no statistical difference in plaque removal or gingivitis. Waxed floss slides more easily and shreds less, so it tends to suit tight teeth and dental work. Unwaxed floss is thinner and some people like the squeak it makes on a clean tooth.
Why does my floss keep shredding?
Floss usually shreds on a rough edge: a chipped filling, the margin of a crown, tartar or a very tight contact. Waxed or PTFE floss resists shredding better than unwaxed. If it always happens between the same two teeth, mention it at your next checkup, since a rough filling edge can trap plaque.
Is PTFE floss safe?
PTFE floss is widely sold and the ADA lists Teflon as a normal floss material. A 2019 study found women who used Oral-B Glide tended to have higher blood levels of one PFAS chemical, PFHxS. It was a single observational study and did not prove cause. If you prefer to avoid PTFE, waxed nylon floss is an easy alternative.
Is dental tape better than floss?
Dental tape is not better at cleaning, just different in shape. Its wide, flat ribbon covers more surface and can feel gentler on gums, which suits people with wider gaps. In tight contacts it is harder to slide through, and regular waxed or PTFE floss usually works better there.
How often should I floss?
The ADA recommends cleaning between your teeth once a day. Time of day does not matter much as long as you do it thoroughly. Use about 18 inches of floss, curve it into a C shape around each tooth, and slide it gently just under the gum line rather than snapping it down.
