Flossing Study Raises Concerns Over Materials

A recent article in the Journal of Exposure Science & Environmental Epidemiology raises concerns about the use of dental floss containing polytetrafluoroethylene (PTFE) — perhaps best known by the trade name Teflon. The cross-sectional study drew its participants from individuals who had participated in a multigenerational cohort study in California. This group of second-generation daughters had blood samples collected and evaluated for the presence of environmental chemicals. The blood draws were done between 2010 and 2013 on 300 women, and the samples were analyzed in 2014. Eventually, 211 participants were interviewed about behaviors hypothesized to influence exposure to various environmental chemicals; of these, 178 were placed in the final study. The self-reported use of various entities included nonstick cookware, microwave popcorn, dental floss reportedly containing PTFE, coated cardboard containers, seafood, and stain-resistant carpet and furniture.

One conclusion was that use of dental floss containing PTFE increased the concentration of perfluoroalky and polyfluoroalky substances (PFASs) found in study subjects — chemicals that have been linked to systemic disease. As might be expected, this conclusion generated a great deal of consternation. What’s more, the study provided fodder to individuals who shied away from flossing altogether, based on the exclusion of this oral hygiene practice from “The Dietary Guidelines for Americans, 2015–2020,” a report recently published by the U.S. Department of Health and Human Services.

Should patients stop flossing? After all, few long-term studies have been published on the efficacy of flossing. This lack of studies is easily explained by the fact an overwhelming volume of clinical and anecdotal data suggest flossing improves oral health. In addition, long-term studies would mean absence of interdental hygiene over a long period, which would lead to increased dental disease and periodontal issues.

 Regarding the study’s assertion about toxicity induced by floss containing PTFE, consider the following. First, there was no mention of any connection between the chemicals found and their toxic effect on individuals in the study. Second, the range of detection of these materials varied widely: While the average flossing subject had higher levels of PFASs than controls, others had significantly lower levels than nonflossers in the study.

THE STUDY PROVIDED FODDER TO INDIVIDUALS WHO SHIED AWAY FROM FLOSSING ALL TOGETHER

What can we glean from this? It is certainly my clinical experience that individuals with good oral self-care, including flossing, tend to keep their teeth longer, have lower rates of caries, and have a better chance of controlling inflammatory periodontal disease. Indeed, if patients are concerned about the possible negative effects of PTFE and PFASs from any source — including floss — there are alternatives that do not contain these materials. Oral health professionals should stand ready to offer appropriate suggestions.

Ultimately, these concerns also emphasize the fact that we, as oral health professionals, need to read the studies that fuel mainstream news media headlines designed to grab our attention.

Thomas G. Wilson Jr., DDS

Editor in Chief

twilson@belmontpublications.com

From Decisions in Dentistry. May 2019;5(5):6.