When a tooth becomes infected is is called an abscessed tooth. Pus collects in a pocket that forms in the bone at the end of the root. An abscess almost always begins in the central or pulp area of the tooth and spreads into the surrounding bone.

What is going on in the body?

When the nerve and blood vessels inside the tooth pulp begin to decay, it causes the cells to die. The area then becomes infected with bacteria that break down the healthy tissue forming pus. An abscessed tooth usually starts with a deep cavity or caries. Left untreated the cavity can extend into the tooth pulp. The pus that collects in the center of the tooth eventually spreads to the bone tissue at the end of the root. Most of the time, this causes a toothache and soreness in that part of the mouth. Even though the toothache may come and go,the abscess will remain until it is treated.

Second to tooth decay, trauma is the most common cause of tooth abscess. This can consist of a hard blow to the tooth or a fracture from biting on a hard object. Tooth trauma is a much less common cause of tooth abscess than tooth decay.

What are the causes and risks of the infection?

Tooth abscess occurs when decay attacks the central area of the tooth pulp. This can be avoided by treating cavities when they are small. Once a tooth abscess forms, treatment is always necessary to stop the process. Root canal therapy can sometimes save the tooth.