How to floss properly (and whether to floss first)

The short answer

Floss once a day, using about 18 inches of floss and a gentle up-and-down motion that hugs each tooth in a C shape. The American Dental Association (ADA) says the time of day does not matter, as long as you do it well.

As for floss first or brush first: both are fine. Pick the order you will stick with. What counts is that plaque gets cleaned from between your teeth every single day.

Why flossing matters

Your toothbrush cleans the front, back and top of each tooth. It cannot reach the tight spaces where teeth touch. Those spaces are where plaque (a sticky film of bacteria) hides, and where many cavities and gum problems begin.

The ADA lists cleaning between your teeth every day as one of the main ways to prevent cavities, along with brushing twice a day with fluoride toothpaste. Plaque left alone for a day or two can harden into tartar, and only a dental hygienist can remove that.

Flossing also helps your gums. When plaque sits along the gum line, the gums can turn red, puffy and bleed. That early stage is called gingivitis, and it can be reversed with good daily cleaning. Left alone, it can move deeper into gum disease.

A good test is to smell and look. If your floss comes out with a bad odor or bits of food after you thought your teeth were clean, you just found out what brushing alone leaves behind. That small proof is what pushes many people to keep the habit.

The step-by-step method

This is the method the ADA teaches. It takes about two minutes once you get the hang of it.

Take your time the first week. Flossing every tooth the right way can feel clumsy at first. Most people get faster within a few days, and the whole mouth takes about two minutes once the motion feels natural.

• Break off about 18 inches of floss. Wind most of it around one middle finger. Wind the rest around the same finger on your other hand. That second finger takes up the floss as you use it.
• Hold the floss tight between your thumbs and pointer fingers, with about an inch of floss to work with.
• Slide the floss between two teeth with a gentle rubbing motion. Never snap or force it down onto your gums.
• When it reaches the gum line, curve it into a C shape against one tooth. Slide it gently into the space between the gum and the tooth.
• Hold the floss against the tooth and rub up and down along the side, away from the gum. Then switch and do the neighboring tooth.
• Use a fresh section of floss as you move along. Do not forget the back side of your very last tooth on each side.

Floss first or brush first?

People argue about this one, but the ADA does not say one order is better. It says to pick a time you can stick with.

There are fair reasons for each choice. If you floss first, you loosen food and plaque from between the teeth, and the toothbrush and fluoride toothpaste can then reach those spaces. If you brush first, you get fluoride on your teeth, and flossing afterward spreads some of it between them.

Our suggestion: choose the one that makes you do it. Flossing at night, right before brushing, works well for many people. Others like to floss while watching TV, then brush at the sink. A habit you keep beats a perfect order you skip.

Does flossing hurt? What about bleeding?

Flossing should not hurt. The ADA says flossing too hard can damage gum tissue, and flossing too gently can miss plaque. You want firm but kind.

If your gums bleed when you first start, do not quit. It often means your gums are irritated from plaque that has been sitting there. For many people, bleeding gets better within a week or two of daily flossing. If it keeps happening, or if your gums hurt, swell or pull away from your teeth, see your dentist. It could be a sign of gum disease that needs a cleaning or treatment.

A few other signs to mention to your dentist: floss that shreds or gets stuck in the same spot every time (it can mean a rough edge or a loose filling), and a bad taste or smell that comes from between two particular teeth.

One more tip: never ignore a spot that always bleeds. A single area that bleeds every time, while the rest of your gums are fine, can mean a cavity between the teeth, a rough filling edge or a pocket where tartar is hiding. Your hygienist can find the cause quickly.

If string floss is hard for you

Not everyone can use string floss easily. The ADA says floss is not the only choice. Other tools clean between teeth just as well for many people:

• Floss picks or pre-threaded flossers, for people who struggle to hold string floss. They are handy for back teeth.
• Small interdental brushes (tiny brushes that fit between teeth). They work well for wider gaps, braces and around bridges.
• Water flossers, which use a gentle stream of water to rinse away food and plaque. The ADA says they can help if other tools are hard to use, and people with braces or bridges may find they reach every area.
• Wooden or plastic picks, for quick cleaning in a pinch.

Tips for special situations

Braces and permanent retainers. Regular floss gets caught on wires. A floss threader, which looks like a tiny plastic needle, guides the floss under the wire. Interdental brushes and water flossers also help a lot.

Bridges and implants. Plaque builds up around them like it does on natural teeth. Your dentist can show you a floss threader, a special floss or a small brush that fits your work. Our team can walk you through it.

Kids. Start flossing as soon as two teeth touch each other. Most children need help for years. Floss picks make it easier.

Tight teeth. If the floss snaps or shreds, try a waxed or thin tape-style floss. If it still will not slide, a dentist should take a look.

Build the habit. The hardest part of flossing is remembering. Put the floss where you will see it, like next to your toothbrush or on your nightstand, and pair it with something you already do, like brushing at night. Start with the teeth that bother you most and add more each week.

Do not worry about being perfect. Even a quick round beats skipping it. The goal is to disturb the plaque every day before it hardens into tartar. Many people find that after two weeks of daily flossing, their gums look pinker and bleed less, and the habit starts to feel automatic.

Flossing help at KDA

At Kendall Dental Associates, our hygienists take a full hour for routine cleanings, so there is time to show you how to floss for your own mouth and to answer your questions. We have been in the Kendall Mall since 1973, and our hygienists have decades of experience. Cristina Dominguez has 33 years as a hygienist.

Visit us at 8833 SW 107th Ave, Miami, FL 33176, Monday to Friday, 8:00 AM to 5:00 PM. Emergency care is available 24/7. We accept most dental insurances and most Medicare supplemental plans, and financing is available. Call 305-271-1421 to book a cleaning and exam.

Common questions

This article is general information, not medical advice. Your dentist will confirm what is right for you at your exam. General information checked against: mouthhealthy.org, mouthhealthy.org.