A tooth infection is characterized by a collection of pus that develops as a result of a bacterial infection at the center of a tooth or the area between the gums and tooth. This is a common dental condition that is extremely painful. The collection of pus is made up of dead tissue, live bacteria and white blood cells.
If it accumulates in a small area (and there is no place for the pus to drain), an abscess in formed. The more pus that accumulates, the more pressure is put on tissue and as a result the tooth abscess is excruciatingly painful. If the infection spreads it is likely to cause swelling in the face and lower jaw.
The abscess may then rupture and cause the pus to drain out of the mouth. Although this rupture may ease the pain (as the pressure is lessened), the infected area should still be treated. Many of these tooth infections may not cause any pain at first and for years one may not experience any symptoms.