A few years ago, the Associated Press published a story calling into question whether flossing actually works — and the internet erupted. “We don’t have to floss anymore!” The celebration was premature. As a dentist who looks inside mouths all day, let me tell you clearly and without hesitation: yes, you should floss. Here is why, and — more importantly — here is how to actually do it in a way that makes a difference.
What the “Study” Actually Said
The 2016 AP investigation found that many of the studies on flossing were small, short-term, and inconsistently designed. What it did not find is that flossing does nothing. In fact, the studies that were methodologically sound consistently showed that flossing reduces gingival inflammation (gum disease) and removes plaque from between teeth — areas your toothbrush simply cannot reach.
Here is the number I want you to hold onto: approximately 40% of the surface area of your teeth is in the space between them. A toothbrush — no matter how sophisticated — does not clean that space. Floss does.
What Happens When You Don’t Floss
When plaque sits undisturbed between teeth, it hardens into tartar (calculus) within as little as 24 to 72 hours. Once it hardens, a toothbrush cannot remove it — only a professional cleaning can. Over time, this buildup irritates the gums, leading to gingivitis (early gum disease) and, if left untreated, periodontitis, which involves irreversible bone loss around the teeth.
I have honestly never looked at a patient’s mouth and thought “this person flosses too much.” But the reverse? Daily.
“You don’t have to floss all your teeth — just the ones you want to keep.”
How to Floss Correctly
Most people who floss are not getting the full benefit because they are doing it in a way that misses the most important part. Here is the technique that actually works:
- Use about 18 inches of floss, wound around your middle fingers, leaving an inch or two to work with
- Slide gently between teeth — never snap the floss down into your gums
- Curve the floss into a “C” shape around each tooth and slide up and down against the tooth surface, going slightly below the gumline
- Use a fresh section of floss for each tooth — you are cleaning, not redistributing
- Floss before brushing so the fluoride in your toothpaste can reach the freshly cleaned spaces
What If Traditional Floss Just Doesn’t Work for You?
Good news: floss picks, water flossers (like the Waterpik), and interdental brushes are all effective alternatives for patients who struggle with traditional string floss. If you have braces, bridges, or tight contacts, a water flosser may actually be your best option. The best flossing tool is the one you will actually use consistently.
So: once a day. Any time of day, though before bed is ideal. And if your gums bleed when you start flossing after a break, don’t stop — that is inflammation, and it almost always resolves within two weeks of consistent flossing. Push through it. Your gums will thank you.
With warmth,
Dr. Sharifa Walker, DMD