Manitoba researchers investigate possible allergies to dental floss

Mystery prompts dentist to advise no flossing Josh Crabb on a dental mystery that prompted Manitoba researchers to investigate possible allergies to dental floss.

Dentists have long taught people the benefits of flossing as part of good oral health.

A new made in Manitoba study put the practice under the microscope and the results are surprising.

Dentists actually asked some of their patients to stop flossing and now their work is changing the way some people clean between their teeth.

Dental hygienist, Miriam Neuman, makes it a priority to take care of her teeth.

For years she flossed at least once a day but the results were disappointing.

"I just noticed that my gums weren't pink and tight to my teeth,” said Neuman. “They were ever so slightly inflamed in the front and I couldn't figure out why because my oral hygiene is impeccable."

Frustrated and worried, Neuman sought help from specialists and started flossing twice a day but there was no improvement.

Southwest Specialty Group periodontist Anastasia Kelekis-Cholakis tried treating Neuman for five years with no success.

After seeing other patients at her practice with similar symptoms, Kelekis-Cholakis suggested Neuman do something you'd never expect to hear from a dentist.

"Very flippantly we said ‘stop flossing’,” said Kelekis-Cholakis. “A lot of our patients were dental health care professionals so that did go against the grain a little bit.”

“They were reluctant or skeptical but most of them had tried so many different venues of treatment that had been unsuccessful, so they took a leap of faith and went along with it.”

Within three months the condition of Neuman’s gums dramatically improved.

"I was very surprised because I’ve always taught to floss,” said Neuman. “I've always taught my patients to floss and I still teach that."

Kelekis-Cholakis has documented four similar cases where redness and bleeding disappeared when a patient stopped flossing.

Her work, now published in the Journal of the American Dental Association concluded the four patients each with known allergies may also be allergic to some of the ingredients in certain kinds of dental floss.

"We found it's mostly on coated and waxed floss,” said Kelekis-Cholakis. “But again we don't have the ingredient list so we're only surmising that there may be a component that may be responsible, one or more multiple components, it's hard to tell."

Researchers said it would be beneficial if companies listed the ingredients in floss. They said the public has a right to know and it could help them narrow down what could be causing an allergic reaction in some people."

"When you think of the thousands of patients that are seen and use dental floss on a regular basis for huge benefit, this would be a select group of individuals,” said oral pathologist John Perry.

Perry said the study is something “we would want patients and dentists and specialists to bear in mind."

Neuman tossed her floss.

She still cleans between her teeth but now she uses special interdental brushes.

"I won't use waxed floss just like someone with an allergy to a certain substance won't eat that substance,” said Neuman. “I won't use anything with a coating on it."

Health Canada said manufacturers aren’t required to post the ingredients in floss on the packaging because it’s considered a low-risk a medical device.

The federal agency said manufacturers are required to possess objective evidence their device is safe and effective.

A spokesperson tells CTV News, consumers who have questions or concerns about the ingredients in dental floss can contact the manufacturer.