In 2016, the Associated Press ran a story titled "Medical benefits of dental floss unproven." The article went viral. Floss sales dropped. People everywhere rejoiced: "Finally, I don't have to floss!"
Except the story was more complicated than the headline suggested. Let me walk you through the actual truth.
What the 2016 story actually said
The AP investigation looked at the scientific evidence for flossing and found that most existing studies were:
- Small sample sizes
- Short durations
- Poorly designed (not blinded, not controlled)
- Industry-funded (some by floss manufacturers)
Conclusion: the evidence base for flossing is weaker than you'd expect for something recommended so universally.
But weak evidence for something is NOT the same as evidence against it. Flossing wasn't proven ineffective. It was just under-studied.
What we actually know about flossing
Since 2016, better research has continued. Here's the current state:
The current evidence on flossing
• Reduces interproximal bacteria (between teeth) — mechanistically obvious
• Reduces gingivitis — multiple trials show modest but real reduction
• Cavity reduction — mixed evidence, hard to study
• Works best combined with brushing, not as a replacement
The consensus from the ADA and most periodontists: floss daily. The mechanism is clear (physical removal of debris + biofilm from between teeth, where brushes can't reach) even if the clinical trials are imperfect.
Why most people floss wrong
This is the real scandal. Most people who floss do it incorrectly in one of several ways:
Mistake 1: Sawing back and forth
The floss should form a C-shape around each tooth, hugging the tooth surface as you move up and down. Sawing back and forth just irritates your gums without removing much plaque.
Mistake 2: Only flossing between the easy teeth
The front teeth are easiest to floss. The back molars are harder. Most people skip or rush the back molars. But the back molars are where most cavities form and where bad breath bacteria concentrate.
Mistake 3: Using the same section of floss for every tooth
You should unwind fresh floss for each tooth (or pair of teeth). Otherwise you're just moving bacteria from tooth to tooth.
Mistake 4: Flossing after brushing
Actually, evidence favors flossing BEFORE brushing. This way, flossing loosens debris between teeth, and brushing clears it out. Plus, the fluoride from toothpaste can penetrate between teeth after flossing has opened up the spaces.
Floss vs. interdental brushes vs. water flossers
| Tool | Pros | Cons |
|---|---|---|
| Regular floss | Cheap, effective, portable | Technique-dependent |
| Interdental brushes | Easier for wide gaps, implants, braces | Don't fit in tight spaces |
| Water flosser (Waterpik) | Great for braces, orthodontia, arthritis, gums | Less effective than floss for plaque per studies; expensive |
| Floss picks | Convenient, portable | Can't get proper C-shape around teeth; floss is short |
Best choice for most people: regular floss, used properly. Water flossers are great additions but not replacements.
Premium floss vs. basic
You don't need fancy floss. But texture matters:
- Waxed — slides easier between tight teeth, doesn't shred
- Unwaxed — "squeaks" cleaner by some reports, can shred
- Tape floss — wider, good for wider gaps
- Premium textured floss — can grab more debris
Cocofloss
Textured floss with woven fibers that physically grab more debris than standard floss. Coconut oil infusion for smooth gliding. Not necessary, but measurably more effective per use — and if premium gets you to actually floss daily, worth it.
Try Cocofloss →If you're not going to floss, at least do this
If flossing is never going to become a habit for you (and for a lot of people, it won't — I'm bacteria, not a therapist), at minimum:
- Tongue scrape (addresses 80% of bad breath)
- Chlorine dioxide mouthwash (addresses plaque + VSCs)
- Get professional cleanings every 6 months (catches what you miss)
- Use a water flosser as a low-effort alternative
Is it as good as flossing daily? No. Is it better than nothing? Dramatically.
The ROI math on flossing
One box of floss: $3-5. Lasts a month.
One cavity filling: $150-300.
One root canal: $1,000-2,000.
Full mouth deep cleaning for periodontitis: $1,000-4,000.
Skipping flossing to save 2 minutes a day is the worst ROI trade in the history of hygiene. Even with the imperfect evidence base, the downside risk is too high.
— Gus