A smooth silk thread used to clean teeth is known as __________ .
Dental floss
Dental floss is a cord of thin filament used to remove food and dental plaque between the teeth in the areas a toothbrush is unable to reach. As the build-up of plaque between the teeth is the primary cause of dental diseases, such as gingivitis and dental caries, the use of floss is commonly recommended in order to prevent these diseases.