Accumulation of bacteria, food particles and plaque between the teeth and gums, causing cavities (pockets) with chronic inflammation and suppuration. Symptoms are redness, swelling and pain; in the long term the tooth may became loose because the surrounding bone tissue is affected. The cause is not always clear. It is often poor oral hygiene, but the condition also occurs when oral hygiene is good. A general disease such as diabetes mellitus can be a factor.