Plaque is a sticky, colourless film that builds on your teeth over time. Bacteria in plaque produce acids that irritate gum tissue and cause tooth decay. This irritation triggers an inflammatory response in your body, which can lead to gingivitis and periodontitis. Plaque hardens into calculus if it is not removed on a regular basis with dental cleaning and flossing. Calculus is impossible to remove with a toothbrush; it can only be eliminated by a dental professional during an oral cleaning. Brushing your teeth twice a day, flossing at least once a day, and visiting your dentist for regular cleanings are all necessary to keep plaque and calculus under control. Calculus is also known as tartar.