How to floss: interdental brushes, water flossers and the right order

Why is it essential?

The surfaces where teeth touch and the small area just under the gum are places the bristles cannot reach. Plaque collecting there leads to interproximal decay (seen on X-ray, unnoticed from outside) and gum inflammation. Food and plaque left in these areas are also a common cause of bad breath.

Which tool?

• Floss: For places where the teeth touch tightly with no gap. Waxed floss slides more easily through tight contacts; tape (wide floss) for broad contacts.
• Interdental brush: More effective than floss for people with gaps between the teeth, gum recession, bridges, implants or braces. The size is chosen to fit the gap (the dentist measures); never forced.
• Floss pick: For limited dexterity or difficulty reaching the back teeth.
• Water flosser: Useful for clearing debris around braces, bridges and implants; it does not remove plaque as well as floss and is used alongside it, not instead.
• Toothpicks: Injure the gum and widen the gaps; not recommended.

Flossing step by step

1. Take 40–45 cm of floss; wind it round the middle fingers, leaving a taut 3–4 cm section.
2. Hold it between thumb and index finger and pass it between the teeth with a gentle sawing motion; don't snap it down — it cuts the gum.
3. Wrap the floss in a "C" around one tooth surface, take it just below the gum line and scrape upwards 3–4 times.
4. In the same gap, wrap it round the neighbouring tooth and repeat.
5. Use a clean section of floss for each gap. Don't forget the back surfaces of the last teeth.

The interdental brush

Insert the brush into the gap parallel to the gum at a slight angle; move it back and forth 2–3 times; rinse after each gap. A brush forced in injures the gum; if it won't go in, use a thinner size. With braces, pass it under the wire. Replace the brush every 1–2 weeks.

Common problems

• Bleeding: Inflamed gums bleed; as a sign of healing it decreases with regular use. If it lasts more than 2 weeks, a check-up.
• Floss catches or shreds: A sign of an overhanging filling, decay or calculus; show your dentist.
• Pain: Pressing too hard or cutting the gum; slow the technique down.
• No time: Fix a single time each day — for most people, at night just before brushing.

Before or after brushing?

By a small margin, floss first, then brush: floss opens the spaces, and then the fluoride in the brush and paste reaches those surfaces. What really matters is doing it every day.

In children

Once two teeth touch (usually 2–3 years, between the back primary teeth) the parent cleans with a floss pick. Children are not expected to floss on their own until 8–10.

Around braces, bridges and implants

With braces, a floss threader or special floss; "superfloss" under bridges; an interdental brush and water flosser for implant prostheses. The dentist and clinic staff demonstrate hands-on at the first use. More on gum treatment: Gum treatment.