The Complete Guide to Flossing

Despite decades of public health messaging, only about four in ten Americans floss their teeth at least once daily. That gap between recommendation and reality has real consequences — tooth decay and gum disease both develop primarily in the spaces between teeth that a toothbrush never reaches. Understanding what flossing actually does, which tools work best for different situations, and how to build the habit makes it easier to close that gap and protect your oral health for the long term.

What Flossing Does for Your Teeth and Body

Reaching Where Brushing Can’t

A toothbrush cleans the front, back, and chewing surfaces of the teeth effectively, but it cannot reach the tight contact points between adjacent teeth or the area just below the gumline where the tooth meets the gum. These interdental spaces harbor bacteria that feed on food debris, produce acids that erode enamel, and release compounds that irritate and inflame gum tissue.

Flossing disrupts this bacterial activity by physically removing plaque from these unreachable zones. The U.S. Department of Health and Human Services identifies flossing — along with brushing and professional cleanings — as a core component of preventing plaque buildup, tooth decay, and gum disease. Without interdental cleaning, about one-third of each tooth’s surface remains untouched by any oral hygiene tool.

The Connection Between Flossing and Cardiovascular Health

The benefits of flossing extend beyond the mouth. Research has found a link between gum disease and cardiovascular disease — specifically, the chronic inflammation that gum disease creates throughout the body contributes to arterial inflammation, which plays a central role in heart disease. Studies suggest that consistent interdental cleaning helps keep arteries “younger” and more flexible by reducing the bacterial load that drives this systemic inflammatory response. While more research continues to refine our understanding of the oral-systemic connection, the evidence consistently supports treating gum health as a whole-body health issue rather than purely a dental one.

How to Floss With Traditional String Floss

Technique

The American Dental Association recommends the following approach for traditional string floss, and mastering it makes the process both more effective and more comfortable.

Break off 18 to 20 inches of floss — more than you think you need. Wind most of it around the middle finger of one hand, and the remainder around the middle finger of the other. This leaves the index fingers and thumbs free to guide the floss. Hold the working section taut between the index fingers and thumbs with about one to two inches of floss exposed.

Guide the floss gently between the teeth using a zigzag motion rather than snapping it straight down, which can cut into the gum tissue. Once the floss reaches the gumline, curve it into a C-shape against one tooth and slide it carefully below the gumline. Glide the floss up and down against the tooth surface to remove plaque, then curve it against the adjacent tooth and repeat. Use a clean section of floss as you move from tooth to tooth to avoid redistributing bacteria around the mouth.

When to Floss

The ADA recommends flossing at least once per day, and the timing matters less than the consistency. Denis F. Kinane, a professor at Penn Dental Medicine, recommends flossing at night because it clears the day’s accumulated debris before the eight-hour period during which saliva production slows and the mouth is most vulnerable to bacterial activity. That said, morning flossing provides genuine benefit, and some people floss twice daily — once in the morning and once before bed. Choose the timing that you can maintain reliably; a consistent habit at any time outperforms an inconsistent one at the “ideal” time.

Tips for Getting Children to Floss

Listen to Their Specific Challenges

Children often resist flossing for legitimate physical reasons, not simply stubbornness. Reaching the back molars requires fine motor control and spatial awareness that many young children haven’t yet fully developed. Fitting floss into tight interdental spaces can feel unfamiliar and uncomfortable. And the sensation of floss catching or temporarily wedging between teeth can startle or frighten young children who don’t understand what’s happening.

Take their concerns seriously and respond practically. If back teeth are the challenge, consider switching to a floss pick or child-sized interdental tool that’s easier to maneuver in tight spaces. If the floss keeps catching, try a waxed variety that slides between the teeth more smoothly. Addressing the specific friction point removes the barrier more effectively than generic encouragement.

Give Children Ownership of the Process

Research consistently shows that children retain and internalize skills better when they actively participate in learning them rather than passively observing. Apply this to flossing by letting your child choose their own floss from a selection of appropriate options — flavored floss, a favorite character on the package, or a type they find easier to use. Let them try the technique themselves, even when the execution is imperfect. The sense of ownership and autonomy makes them more likely to continue the behavior independently.

As children gain confidence, gradually reduce hands-on parental involvement while staying present for guidance. The transition from parent-assisted flossing to independent flossing typically occurs somewhere between ages six and eight, depending on the child’s dexterity.

Model the Behavior

Young children learn primarily through imitation. When they see parents and caregivers floss regularly as part of a normal routine, flossing becomes a normal thing that people do — not an adult-imposed task applied only to them. Invite your child to join you when you floss, narrate what you’re doing and why in simple terms, and celebrate their participation without making the process feel performative or high-stakes.

The message to convey is simple: flossing is something our family does to keep our teeth healthy, the same way we wash our hands and eat vegetables.

Interdental Brushes: The Better Tool for Some Situations

How They Work and When to Use Them

An interdental brush — also called an interproximal brush — consists of a small bristled head on a handle, designed to slide between the teeth and clean the interdental space with a back-and-forth scrubbing motion rather than a sliding motion. They come in two configurations: I-shaped brushes for front teeth (which can be bent at the tip for angled access) and L-shaped brushes designed for the rear teeth.

Interdental brushes work particularly well for people with braces, as they can navigate around wires and brackets that make traditional flossing difficult or impractical. They also suit people with larger spaces between their teeth, where string floss might not make adequate contact with the tooth surfaces.

To use an interdental brush effectively, lubricate the tip with water or a small amount of toothpaste, then hold the handle the way you’d hold a pencil. Insert the brush gently into the interdental triangle — the space where the gum, tooth, and adjacent tooth meet — and move it back and forth two to three times. Work systematically from the back of one side to the back of the other, rinsing the brush with warm water between teeth. Rinse your mouth when finished and clean the brush thoroughly before storing it.

Considerations

Interdental brushes offer excellent maneuverability and work well for people who find string floss difficult to handle. On the downside, they cost more than basic string floss and don’t maintain sterility the same way a fresh strand of disposable floss does. For very tight contact points, string floss often outperforms interdental brushes, which require a bit of space to insert comfortably.

Oral Irrigators: The High-Tech Option

How Oral Irrigators Work

An oral irrigator — commonly known by the brand name Waterpik — uses a pulsating stream of pressurized water to dislodge plaque and food particles from between the teeth and along the gumline. The pulsating action provides a massaging effect on the gum tissue that may improve gingival health beyond what mechanical flossing achieves.

To use an oral irrigator, fill the reservoir with warm or room-temperature water. Attach the appropriate tip for your needs — standard, orthodontic, or periodontal tips serve different purposes. Lean over the sink, place the tip in your mouth before turning the device on, and direct the stream at a 90-degree angle to the gumline. Work from the back teeth forward along both the upper and lower arch, pausing briefly at each tooth. When finished, turn the device off before removing it from your mouth, expel remaining water, and rinse the tip with warm water before storing it.

Who Benefits Most From Oral Irrigators

Dental professionals particularly recommend oral irrigators for patients in orthodontic treatment, those with dental implants or bridges, people managing chronic gum disease, and anyone with a history of sensitive or inflamed gum tissue. Research has found that oral irrigators reduce gingival bleeding at roughly twice the rate of traditional string floss, making them especially valuable for people whose gums bleed regularly during flossing.

The tradeoffs include cost — oral irrigators represent a meaningful upfront investment compared to string floss — and the need to replace tips every three to six months. They also require a learning period; using too much pressure or the wrong angle can drive debris further into gum pockets rather than removing it. Starting at the lowest pressure setting and working up gradually solves this problem for most users.

Choosing the Right Tool: A Practical Comparison

Each flossing method carries its own strengths, and the right choice depends on your individual dental situation, dexterity, and preferences.

Traditional string floss fits in spaces of any width, cleans tightly packed teeth effectively, stays sterile because each section is used once, and costs very little. Its downsides are the dexterity requirements and the time needed to use it properly — factors that contribute to its relatively low adoption rate.

Interdental brushes suit people with wider gaps between teeth, brace-wearers, and those who find string floss mechanically difficult. They’re more expensive than string floss and require careful cleaning between uses.

Oral irrigators provide the most thorough cleaning along the gumline and suit people managing active gum disease or orthodontic hardware. They deliver excellent results but come with a higher cost and a learning curve.

Additional options serve specific needs. Floss picks hold a pre-stretched section of floss on a plastic handle, making flossing more manageable for people who struggle to manipulate the string directly. Electric flossers use a vibrating tip to dislodge particles. The Sonicare AirFloss uses compressed air to force water and air between the teeth, claiming to remove significantly more bacteria than manual brushing alone — a useful tool for anyone who wants the effectiveness of a water flosser in a more compact format.

No single option works best for everyone. Many dental professionals suggest choosing the tool you’ll actually use consistently, because the best flossing method is the one you do every day.

A Brief History of Dental Floss

The concept of cleaning between the teeth dates to 1819, when New Orleans dentist Levi Spear Parmly recommended using silk thread to remove debris from between the teeth — a practice he considered as important as brushing. The first commercially available dental floss appeared in 1882, when Massachusetts-based Codman and Shurtleff began marketing unwaxed silk floss. By 1898, Johnson & Johnson produced floss from the same silk material used in surgical stitches and secured a patent on the product.

Nylon replaced silk in the 1940s. Nylon offered greater durability, a more consistent texture, and significantly better resistance to shredding — all meaningful improvements for a product designed to slide repeatedly through tight interdental spaces. Waxed floss emerged during the same decade, making the product easier to use in tight contacts. Dental tape, a broader and flatter version suited to wider gaps and sensitive gums, appeared in the 1950s.

Today’s market offers dozens of floss varieties — flavored, unflavored, waxed, unwaxed, textured, biodegradable, and more — along with the array of alternative interdental cleaning tools that have expanded the category considerably since Parmly’s original silk thread.

National Flossing Day

The National Flossing Council established National Flossing Day in 2000 with the goal of promoting awareness of interdental cleaning and better dental health broadly. The holiday falls on the day after Thanksgiving — appropriately enough, given that the holiday meal gives dental hygiene concerns a certain topical relevance.

National Flossing Day offers a useful annual reminder, but the goal it represents is daily rather than annual. Treating it as a prompt to re-examine and reinforce your interdental cleaning habits — or to introduce flossing to a child who hasn’t started yet — captures its spirit better than treating it as a once-a-year observance.