Home / Personal care

Dental floss guide: how to floss, types and what the evidence says

By the Life in Good Form editors. Updated 2026-10-15.

We research products from makers' specs and health sources; we do not run hands-on tests. Links to Amazon may earn us a commission at no cost to you. How this works.

Why floss at all

The ADA's MouthHealthy site says even the best toothbrush cannot fully cleanse the spaces between your teeth, and that plaque left behind by brushing or flossing can harden into a rough substance called tartar or calculus. It recommends flossing once a day to remove food particles and plaque. For your brush, see our electric toothbrush guide.

The Cochrane review explains why this matters: dental plaque is the primary cause of tooth decay and gum disease, which can cause pain, eating and speaking difficulties, and even tooth loss. A toothbrush cleans the front and back surfaces, while floss, brushes, sticks and irrigators are often recommended to reach the spaces between teeth.

What the evidence shows

A 2019 Cochrane review of 35 randomized trials with 3929 adult participants compared home interdental cleaning plus toothbrushing with toothbrushing alone. Floss was studied in 15 trials. The review found low-certainty evidence that flossing plus toothbrushing may reduce gingivitis at one month, three months or six months, while results for bleeding sites and plaque were inconsistent.

Interdental brushes, studied in 2 trials against brushing alone, may reduce plaque more than toothbrushing alone, with low-certainty evidence. No trials assessed decay between teeth, and many participants had low levels of gum inflammation at the start, so the evidence has limits. The review also compared other tools head to head with floss, including interdental brushes in 9 trials and rubber cleaning sticks in 9 trials.

How to floss

The ADA's steps are:

• Break off about 18 inches of floss and wrap most of it around one of your middle fingers.
• Hold the floss tightly between your thumbs and forefingers.
• Guide it between your teeth with a gentle, rubbing motion.
• At the gum line, curve it into a C shape against one tooth.
• Hold it tightly against the tooth, slightly away from the gums.

Choose a time of day when you can give your teeth a little extra attention, as the ADA suggests.

Types of floss compared

Details are from Cocofloss and Oral-B product pages. The ADA describes traditional floss as a smooth strand of nylon or teflon made to slide easily between teeth. Cocofloss says its floss is non-PTFE with no added PFAS, if that matters to you.

Cocofloss also describes its floss as BPA-free, vegan and refillable in its dispensers, and says its original floss is made with 85% recycled materials. Refills cut down on plastic if you floss every day.

Other ways to clean between teeth

• Picks and tiny brushes. The ADA says dental picks and tiny brushes can be good for reaching out-of-the-way spots.
• Interdental brushes. In the Cochrane review, interdental brushes had low-certainty evidence of reducing plaque more than brushing alone.
• Water flossers. The ADA describes these as using a gentle stream of water to rinse away food and plaque. In the Cochrane review, very low-certainty evidence suggested they may reduce gingivitis at one month.
• The ADA Seal. The ADA says flossing products with its Seal of Acceptance have been proven safe and effective.

Comfort and when to see a dentist

The ADA says cleaning between your teeth should not cause pain. Use the gentle, rubbing motion it describes. If you have braces or a bridge, threader-style floss such as Super Floss is made for those spaces.

See a dentist if flossing hurts, if your gums keep bleeding, or if you notice swelling or a loose tooth. Pair flossing with regular brushing; for fluoride-free toothpaste questions, see our hydroxyapatite toothpaste guide.

What to look for when you buy

Questions people ask

How often should you floss?

The ADA recommends flossing once a day.

Should I floss before or after brushing?

The ADA says it does not matter when you floss, as long as you do it thoroughly.

Does flossing actually work?

A Cochrane review found low-certainty evidence that flossing plus brushing may reduce gingivitis compared with brushing alone.

How much floss should I use?

The ADA suggests breaking off about 18 inches and wrapping most of it around a middle finger.

Is it normal for flossing to hurt?

No. The ADA says cleaning between your teeth should not cause pain; see a dentist if it does.

Sources

• Flossing (mouthhealthy.org), American Dental Association MouthHealthy
• Home use of interdental cleaning devices, in addition to toothbrushing, for preventing and controlling periodontal diseases and dental caries (pmc.ncbi.nlm.nih.gov), Cochrane Database of Systematic Reviews (PMC6953268)
• Frosty Peppermint Dental Floss (cocofloss.com), Cocofloss
• Cocofloss Thin Dental Floss (cocofloss.com), Cocofloss
• Super Floss for Braces, Bridges and Wide Gaps (oralb.com), Oral-B

Sources checked 2026-10-15.