Oral hygiene is the practice of keeping the mouth and teeth clean to prevent dental problems, most commonly, dental cavities, gingivitis, periodontal (gum) diseases and bad breath.

Generally, dentists recommend that teeth be cleaned professionally at least twice per year. Professional cleaning includes tooth scaling, tooth polishing.

Tooth brushing is the act of scrubbing teeth with a toothbrush equipped with toothpaste. Since only two thirds of the outer tooth can be reached by a toothbrush, interdental cleaning (with floss or an interdental brush) can usefully accompany tooth brushing. Together, these two activities are the primary means of cleaning teeth, one of the main aspects of oral hygiene.

Brushing teeth properly helps prevent cavities, and periodontal, or gum disease, which causes at least one-third of adult tooth loss. If teeth are not brushed correctly and frequently, it could lead to the calcification of saliva minerals, forming tartar. Tartar hardens (then referred to as 'calculus') if not removed every 24 hours.

Poor dental health has been associated with heart disease and shortened life expectancy.