Dental floss is a strand of fiber that is used to clean between the teeth, particularly where toothbrushes may not be able to reach. Daily use of dental floss is a recommended preventative measure to guard against gingivitis and plaque buildup; the American Dental Association (ADA) estimates that flossing can remove up to 80% of dental plaque.


It is widely believed that dental floss was invented in 1819 by a New Orleans dentist named Levi Spear Parmly. He recommended the use of waxed silk thread to remove debris that was trapped between the teeth, which he identified as the source of dental disease. Floss became widely available in 1882 and was patented in 1898 by the Johnson & Johnson Corporation, using the same silk thread that was used in medical sutures. During World War II, manufacturers began using nylon instead of silk to make dental floss, and by the 1970s, dental floss was widely accepted throughout the United States as an integral part of daily oral hygiene practices.


Dental health professionals recommend flossing once daily, either before or after brushing with fluoride toothpaste and a soft-bristled brush, to clean between the teeth and to introduce fluoride to the spaces between the teeth. Dental floss may be held in the fingers or on a floss threader and is guided between the teeth and gently under the gumline. This can effectively remove both residual food particles and dental plaque from between the teeth and below the gumline.


Dental floss is available in a nearly infinite number of forms and flavors. Floss may be made of a collection of filaments that are waxed together, or it may be made of a single filament that is either waxed or unwaxed. The wax used in waxed floss may contain fluoride or antibacterial agents. Dental floss is also available in multiple different thicknesses, the widest and flattest being known as dental tape. None of these factors is necessarily better than any other, and the choice of dental floss is largely based on the preference of the user. The amount of space between the teeth may help determine what type of floss you will prefer, as will the shape of the gum tissue and your own comfort with the act of flossing. For people who lack the manual dexterity to hold floss comfortably, floss picks may be helpful. These are plastic wands that hold floss, and they may ameliorate discomfort in the hands, but they may also be difficult to wield effectively at all the angles necessary for thorough flossing. Some people also prefer to use a floss threader, which is a nylon loop that holds floss and can be threaded through the teeth. Innovations in dental technology have also led to the power flosser, a self-powered flosser that may be preferable for people with physical or developmental challenges that cause traditional flossing to be challenging.


While it is widely believed that flossing, when combined with brushing the teeth, can help prevent gum disease and improve bad breath, benefits vary depending on individual flossing technique. Dentists can train patients on proper flossing techniques and specific techniques that may be recommended for them. For example, orthodontic appliances, like braces, may create a more significant need for flossing and may also necessitate specific types of floss and flossing instruments.