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Interdental cleaning

Water Flosser vs String Floss: What the Evidence Shows

Water flossers vs string floss and interdental brushes: what Cochrane research found, who each suits, pressure settings, tips and running costs.

Quick answer

The ADA recommends cleaning between your teeth daily with floss, interdental brushes, water flossers or similar tools. A 2019 Cochrane review found that adding floss or interdental brushes to brushing may reduce gum inflammation, with interdental brushes looking most effective, and that evidence for water flossers is limited but suggests a benefit for gingivitis. The best tool is the one you will use every day.

Cleaning between teeth reaches the areas a toothbrush misses. Which tool you use matters less than using it daily.

Options

Tool Strengths Watch for
String floss Cheap, portable, tight contacts Technique; harder with braces
Floss picks Easy one-handed Can be less thorough
Interdental brushes Effective where gaps allow Need the right sizes
Water flosser Easy with braces, bridges, implants Cost, counter space, mess at first

What research says

A 2019 Cochrane review of interdental cleaning found:

  • Floss plus brushing may reduce gingivitis compared with brushing alone.
  • Interdental brushes plus brushing may reduce gingivitis more than floss.
  • Oral irrigators (water flossers) may reduce gingivitis, with low-certainty evidence.

Evidence for preventing cavities between teeth was limited for all tools.

Choosing a water flosser

Spec Why
Pressure range Adjustable, starting low
Reservoir Bigger means fewer refills; cordless models hold less
Tips Orthodontic, implant and periodontal tips
Countertop or cordless Power vs portability
ADA Seal Independent review of claims

Replace tips per the maker, often every three to six months.

Pair it with the right brush; see oscillating vs sonic. Ask your dental team about bleeding gums. Browse flossing and interdental.

Common questions

Is a water flosser as good as flossing?

Evidence is limited, but water flossers may help reduce gingivitis. Many people use them more consistently, which matters.

Do water flossers help with braces?

They are popular with braces and bridges because they clean around brackets and wires easily. Ask your orthodontist.

Are interdental brushes better than floss?

Research suggests interdental brushes may reduce gum inflammation more than floss where they fit between teeth.

What pressure should I use on a water flosser?

Start low and increase gradually to a comfortable setting.