Bacteria in your mouth feeds off of food and drink you ingest, collecting around your teeth and forming a thin colorless film called plaque. Regular brushing and flossing removes this film, but if left untreated, plaque hardens into tartar. Tartar, also known as calculus, forms at and underneath the gum line as a rough porous mineral buildup that is yellow or brown. Tartar is usually visible to the naked eye and is a common cause of discoloration of the teeth. The bacteria inside of the tartar excrete toxins that create a very acidic environment against your teeth, damaging the tooth enamel, creating cavities, and causing gum inflammation that results in periodontal pockets developing that contain even more bacteria and toxins. If left untreated, this condition can continue deeper into your jaw, loosening teeth or causing them to fall out, and even destroying the bone of your jaw that holds teeth in place.