Periodontal disease (aka gum disease) is a condition where the tissues surrounding the teeth (periodontium) have become inflamed due to bacteria. The primary cause of gum disease is plaque. Plaque is a film that surrounds the tooth and it is composed mainly of various types of bacteria, which stick to your teeth and roots over and below the gum line. Plaque begins to form within minutes after brushing and flossing and if it is not removed daily with good oral hygiene plaque hardens into calculus (or tartar). Calculus can only be removed with a professional cleaning or periodontal treatment.