Floss or interdental brushes?

For tight teeth (where floss slides through with tension) I choose floss. For wider gaps (visible space under the gums) interdental brushes are more effective. Most adults have zones of both types, so I recommend using floss and brushes together, each for their areas.

Floss before or after brushing?

Before brushing. Floss loosens plaque between teeth, then fluoride toothpaste reaches the freed spaces better. This is from Journal of Periodontology 2018. The reverse order (paste then floss) is 30 percent less effective.

Can a water flosser replace floss?

No. A water flosser does not remove adhered biofilm, it only rinses food debris. A supplement, not a substitute. ADA recommends water flossers additionally for orthodontic appliances, implants, bridges. Regular healthy teeth need floss.

How often should I floss?

Every day, at least once. Best time, evening before bed. During the day plaque accumulates between teeth, at night bacteria multiply faster. If you've never flossed, start with 2-3 teeth, after 2 weeks cover all.

Is gum bleeding normal when starting?

Yes, the first 5-7 days bleeding is normal. The gums are inflamed from chronic plaque, they heal in 1-2 weeks. If bleeding continues after 2 weeks, probably gingivitis or periodontitis, see the dentist. Don't stop, the bleeding will pass.

How to choose the right floss?

Waxed: slides easily between teeth, recommended for beginners. Unwaxed: removes plaque better but tears at fillings. PTFE (Teflon): strong, doesn't tear. Tape: for wide gaps. I recommend waxed for adults with normal teeth.

How long does proper flossing take?

2-3 minutes for all teeth, at first 4-5 minutes. After 2-3 weeks it becomes automatic. Don't rush, quality matters more than speed. Better 2 minutes of quality flossing than 30 seconds careless.

Dental Floss: How to Use It Properly and Why It Matters

At a 6-month checkup I tell a 35-year-old patient with perfect brushing technique: «You have caries between three teeth. Do you floss?» Answer: «No, never.» This is the most common picture in my practice. The patient brushes twice a day, even electrically, comes for checkups every 6 months, and still gets caries. Why? Because 40 percent of tooth surface is between the teeth. The brush physically cannot reach there. Without floss, half the hygiene simply isn't done.

I tell patients: «Imagine cleaning the floor only in the centre of the room, never touching the corners. After a year there will be a layer of dirt in the corners. Same with teeth without floss.» Sounds trivial, but it's the fact that 80 percent of people in Hamburg ignore.

Dental floss, Zahnseide in German, cleans the spaces between teeth that a toothbrush cannot reach. Without it, bacterial plaque builds up on contact surfaces, leading to interproximal caries (Approximalkaries) and gum inflammation.

The German Dental Association (DGZMK) recommends flossing at least once daily, ideally in the evening before brushing.

Proper technique: step by step

1

Cut 40-50 cm of floss

Wind it around the middle fingers of both hands, leaving 3-5 cm of working length. Guide the floss with thumbs and index fingers.

2

Slide in gently, no snapping

Use a gentle sawing motion to guide the floss between teeth. Forcing it down can injure the gum papilla.

3

Curve around each tooth in a C shape

Press the floss against one tooth surface and move it up and down 5-7 times. Then repeat on the adjacent tooth in the same gap.

4

Use a clean section for each gap

Wind the floss forward to avoid transferring bacteria from one tooth to the next.

Types of dental floss

Waxed floss

Slides easily between tightly spaced teeth. Great for beginners.

Unwaxed floss

Grips plaque better due to its rough surface. May shred in very tight contacts.

Superfloss

Floss with a stiff threader end for bridges and fixed braces. Essential during orthodontic treatment.

Alternatives to floss

Interdental brushes (Interdentalbürsten): the top choice for wider gaps. Studies show they are more effective than floss for patients with gum disease.

Water flosser (Munddusche): a supplement, not a replacement. It rinses food particles but does not remove adherent biofilm as effectively.

Common mistakes

«My gums bleed when I floss, so I should stop.» The opposite is true. Bleeding signals gum inflammation (gingivitis), and flossing actually helps resolve it. After 1-2 weeks of daily use, the bleeding typically stops.

«Floss creates gaps between my teeth.» No. Floss cannot move teeth. The gaps become more visible when swollen, inflamed gums return to their healthy size, and that is a good sign.

«If my teeth are tight, I don't need floss.» Opposite, when teeth are tight floss is especially important. Plaque gets trapped in narrow gaps and is not rinsed by saliva as in wider ones.

«I floss only when something is stuck.» That's mechanical, not cleaning. Floss daily as prevention, not reactively when food gets stuck.

Why this matters so much

Between each pair of teeth there is a contact surface of about 4-5 mm². Across the whole mouth that's almost 40 percent of total tooth surface. If you don't floss, you're effectively cleaning only 60 percent of your teeth.

On contact surfaces, interproximal (Approximal) caries forms. This is the most common type of caries in adults aged 25-45. Invisible from outside, painless for years, until it reaches the nerve. Then suddenly «my tooth hurts», you go for an X-ray, and you already need a root canal plus crown, 800-1500 euros. Instead of free floss for 4 euros.

Second issue, gingivitis (gum inflammation). Untreated it becomes periodontitis, then tooth loss. It all starts with plaque in the gaps that the brush misses.

I often tell patients: «If you don't have 5 minutes a day for floss, you'll find 1500 euros for a crown in 3 years.» Sounds harsh, but it's reality.

Alternatives: who and when

Classic floss. For most adults with tight teeth. 4-8 euros per 50 m roll, lasts a month.
Floss picks. Convenient but less effective than traditional floss. For beginners and travel.
Interdental brushes. 4-12 euros per pack, sizes ISO 0-7. Dentist selects size. For wide gaps and periodontitis.
Water flosser (Munddusche). Waterpik, Oral-B Aquacare. 50-150 euros. Supplement for implants, bridges, orthodontics. Not a substitute for floss.
Air flosser. Less popular, lower efficacy than traditional floss.

At the appointment I always assess hygiene and give personalised recommendations. For one patient, floss plus interdental brushes on 6-7 molars. For another, floss plus water flosser for an implant. There is no universal answer, only personalised.

Dental Floss: how to use it and why you cannot skip it