Floss was once made from silk fibers twisted to form a long strand. Today, floss is usually made from nylon filaments or plastic monofilaments.1
The U.S. Food and Drug Administration classifies dental floss6
as a Class I device, which means it is deemed to be low risk and subject to the least regulatory controls. Floss may be treated with flavoring agents, such as mint, to make flossing more pleasant. There is no difference in the effectiveness of waxed or unwaxed floss,7
although rare cases of contact hypersensitivity to waxed or coated floss have been reported8
. It’s generally not what type of floss is used, but how and when it’s used. Floss-related products include floss holders, floss threaders, or floss picks.
A 2011 Cochrane systematic review evaluating the evidence for the impact of flossing on managing gingivitis9
found that by the standards of the GRADE Working Group, the evidence on this question was of very low quality, due to uncertainty about the estimate because of the small number of studies, sample sizes, and some concerns regarding interpretation of the results. With these caveats and limitations in mind, the summary of results of these short-term (i.e., up to 6 months of follow-up) investigations were that when flossing was added to toothbrushing, there was a statistically significant, albeit clinically small, reduction in the measures of gingivitis.9
An earlier meta-analysis by Berchier et al.10
explored the impact of adding flossing to brushing on indices of plaque and gingival health and failed to find statistically significant improvement. They nonetheless concluded that a first consideration ought to be whether high-quality flossing is an achievable goal.
A meta-analysis of studies examining the impact of flossing on interproximal caries11
found that regular (5 days per week) professional flossing resulted in a statistically significant reduction in interproximal caries, a result that was not seen with intermittent (every 3 months) professional flossing nor self-flossing.