flossing during chemotherapy safe

Is flossing during chemotherapy treatment for cancer safe?

One of our patients brought up that she learned during a chemotherapy class she shouldn’t floss during chemotherapy. It was a topic we were unfamiliar with at the office, so we did some research to answer the question:

Is flossing during chemotherapy safe?

The answer is a bit complicated and requires personalized recommendations by both your dentist and oncologist. Schedule an appointment with us to answer all of your personal questions.

Why could it not be safe?

The reason that a healthcare provider may recommend that you do not floss during chemotherapy could be because your immune system is lessened and he or she is trying to prevent bacteria from entering your bloodstream. Some oncology teams will have you discontinue brushing and flossing when peripheral blood components decrease below defined thresholds (e.g., platelets <30,000/mm3) due to the bleeding risk (1). You should speak with your oncologist about his or her personal recommendations.

Bleeding gums and gingivitis, the never ending cycle

Unfortunately gingivitis (or gum inflammation) is caused by bacteria near your gums and the increase in inflammation leads to a higher likelihood of bleeding. So, in order to reduce the risk of bleeding, the bacteria needs to be safely and effectively removed, especially during chemotherapy.

What are the recommendations?

The National Cancer Institute’s PDQ cancer information summary about oral health during chemotherapy includes:

“Discontinuing dental brushing and flossing can increase risk for gingival bleeding, oral infection, and bacteremia [bacteria entering the blood].

Dental brushing and flossing should be performed daily under the supervision of professional staff:

  • A soft nylon-bristled toothbrush should be used 2 to 3 times a day [gently using Bass method]
  • Rinsing the toothbrush in hot water every 15 to 30 seconds during brushing will soften the brush and reduce risk for trauma.
  • Oral rinsing with water or saline 3 to 4 times while brushing will further aid in removal of dental plaque dislodged by brushing.
  • Rinses containing alcohol should be avoided.
  • A toothpaste with a relatively neutral taste should be considered because the flavoring agents in toothpaste can irritate oral soft tissues.
  • Brushes should be air-dried between uses.
  • While disinfectants have been suggested, their routine use to clean brushes has not been proven of value.
  • Ultrasonic toothbrushes may be substituted for manual brushes if patients are properly trained in their use.
  • Patients skilled at flossing without traumatizing gingival tissues may continue flossing throughout chemotherapy administration. Flossing allows for interproximal removal of dental bacterial plaque and thus promotes gingival health.” (1)

How do you brush and floss without traumatizing your gums?

See this video we created with Dawn, one of our hygienists.

Don’t snap the floss downward too forcefully where your teeth touch together, you should gently get the floss below that contact point with a side-to side motion.  Then wrap the floss around the side of the tooth and use an up-and-down motion rather than back and fourth. Pay special attention to each side of the tooth, you aren’t flossing the space between your teeth, you’re flossing the side of your teeth. Be gentle on your gums.


What other resources are available to learn about oral health during cancer treatment?

The NIDCR has great recommendations and pamphlets for patients about how to manage all dental and oral health concerns during cancer.

Chemotherapy and Your Mouth Pamphlet

We also recommend that you read the recommendations to prevent cavities during your chemotherapy, especially if you have had an increase in vomiting on our post for expectant mothers here.


If you have any questions on this topic we hope you’ll leave them in the comments below. If you have any thoughts or questions that you would like us to answer with a new blog post, please leave your thoughts here.



1. PDQ Supportive and Palliative Care Editorial Board. “Oral Complications of Chemotherapy and Head/Neck Radiation (PDQ®): Health Professional Version.” In PDQ Cancer Information Summaries. Bethesda (MD): National Cancer Institute (US), 2002. http://www.ncbi.nlm.nih.gov/books/NBK65881/.

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