Is it normal for floss to smell after flossing?

Flossing is an important part of maintaining good oral hygiene and health. It helps remove plaque and food debris between teeth and below the gumline that brushing alone cannot reach. However, some people notice an unpleasant smell when they remove floss from between their teeth after flossing. So, is it normal for floss to smell after you use it?

Why Does Floss Smell After Flossing?

There are a few reasons why you may notice a smell from the floss after flossing:

  • Food debris – Flossing helps remove excess food particles and debris from between teeth that brushing misses. These food particles often cause bad breath and can make the floss smell unpleasant after use.
  • Plaque – Plaque buildup between teeth and under the gumline causes bad odors. The floss removes some of this smelly plaque when you floss, making the used floss take on an unpleasant odor.
  • Bacteria – There are billions of bacteria in your mouth. Most are harmless, but some contribute to bad breath and smells. Flossing scrapes away some of these smelly bacteria, transferring the odor to the floss.
  • Gingivitis – This mild form of gum disease causes inflammation, bleeding gums, and bad breath. The bacteria and toxins related to gingivitis can make floss smell after using it between inflamed gums.
  • Periodontal disease – More advanced gum disease involves deep bacterial infection. As floss scrapes along the gums and gets between teeth, it picks up foul-smelling bacteria and pus associated with periodontal disease.

So in most cases, the unpleasant floss smell can be attributed to some type of debris, bacteria, or infection it collected from your mouth. The floss is simply transferring the smells from your oral cavity to the floss itself.

Is Floss Smell Normal?

A mild smell on used floss is very common and generally nothing to be concerned about. But an extremely foul, putrid odor may indicate an underlying problem needing attention from your dentist.

Here are some guidelines on when post-flossing odors could be normal vs abnormal:

  • Normal floss smell:
    • Slightly unpleasant odor
    • Smells like food or something recently eaten
    • Odors are relatively mild and dissipate quickly
  • Abnormal floss smell:
    • Very foul, putrid odor
    • Smells like rotten eggs or feces
    • Odor is intensely bad and lingers on the floss
    • Notice the same bad smells repeatedly

So while a slight musty smell from floss is perfectly normal, an intensely foul odor likely indicates a dental health problem needing attention. Contact your dentist if you notice strong rotten or feces-like smells repeatedly after flossing.

When To See a Dentist About Floss Smells

Make an appointment with your dentist or periodontist if you notice any of the following:

  • Intensely foul, lingering odors on floss
  • Bad smells every time you floss
  • Visible blood on the floss after flossing
  • Swollen, tender, or bleeding gums
  • Pain or sensitivity when flossing
  • Loose teeth
  • Receding gums
  • Increased tooth decay or cavities
  • Ongoing bad breath

These can all be signs of periodontal disease, infection, or other dental issues that require professional attention and treatment. The dentist can examine your mouth, diagnose any problem, and provide the proper care to manage floss odors and improve your oral health.

Tips to Reduce Floss Smells

You can take steps to cut down on foul floss odors between cleanings and dental visits:

  • Floss thoroughly each day – This removes more bacteria, plaque, and debris and prevents buildup.
  • Use antiseptic mouthwash – This kills odor-causing bacteria.
  • Brush your tongue – This scrapes away smelly bacteria.
  • Get regular dental cleanings – Professional cleanings remove hardened plaque you can’t reach with floss.
  • Avoid strong-smelling foods – Onions, garlic, spices, etc can transfer smells to floss.
  • Quit smoking – Smoking causes bad breath.
  • Drink more water – This helps flush your mouth and prevents a dry mouth.
  • Chew gum with xylitol – This sweetener inhibits odor-causing bacteria.

Practicing thorough oral hygiene and avoiding odorous foods can help minimize smells on used floss. But some odor is still normal. Just be watchful for intensely foul, persistent odors that warrant seeing a dentist.

Flossing Technique and Proper Use

To get the most from flossing and minimize odor, use proper flossing technique:

  • Use 18-24 inches of floss wound around middle fingers of each hand.
  • Hold floss taut between thumbs and index fingers.
  • Gently guide floss between teeth using a zig-zag motion.
  • Avoid snapping floss down, which can damage gums.
  • Curve floss into a C-shape against each tooth.
  • Rub floss up and down along the sides of each tooth.
  • Floss behind your back teeth and all surfaces between teeth.
  • Floss beneath the gumline, not just between teeth crowns.
  • Use a clean section of floss as you move from tooth to tooth.
  • Throw away used floss after flossing your entire mouth.

Proper flossing technique helps dislodge debris and bacteria buildup from areas where your toothbrush can’t reach. This minimizes odors and supports complete oral hygiene.


It’s very common to notice some unpleasant smells on used floss after flossing your teeth. Odors typically come from food debris, plaque bacteria, and gingivitis germs dislodged from areas between your teeth. But extremely foul, rotten smells may indicate an underlying dental health problem needing professional attention. See your dentist if foul odors persist despite good oral hygiene. With proper daily flossing technique and oral care, mild floss odors are normal and not a major concern.

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