IMPORTANCE OF ORAL HYGIENE: Plaque is the soft, grayish-white film which is formed continuously on tooth surface by the proliferation of bacteria. Within days, plaque mineralizes into calculus, or tartar, which acts as a framework for further plaque development. If not eliminated, plaque bacteria can infect the gums and structures which support the teeth. The result is gingivitis and eventually periodontal disease, which causes bad breath, pain and tooth loss. Chronic oral infection can also lead to disease in other parts of the body, including the heart, lungs and kidneys.