Dental floss is an interdental cleaning aid (i.e. cleaning between teeth). It is a cord of thin filaments used to remove food and dental plaque from teeth. The floss is gently inserted between the teeth and wiped along the teeth sides, especially close to the gums or underneath them. Dental floss may be made of either plastic (nylon, PTFE or polyethylene) or silk, and can be flavored or unflavored, and waxed or unwaxed. An alternative tool to achieve the same effect is the interdental brush, which is better suited where the gap between 2 teeth is wider.
Toothbrushes do not clean between teeth or below the gumline. Flossing in addition to toothbrushing can reduce gingivitis and halitosis compared to toothbrushing alone. There is weak evidence that flossing plus toothbrushing may help to reduce plaque buildup relative to toothbrushing alone.