An Abscess

One of the most painful dental conditions is an abcess. The pain is caused by the pressure build up of pus at the base of the tooth. This pushes the tooth up from the socket and may make the tooth feel high when biting.

How an abcess forms

Our body fights disease with our immune system. The cells which fight bacteria travel around in the blood and use the blood vessels as a type of highway. The problem arises when a tooth becomes infected as the only large blood vessels enter through a small hole at the tip of the root.

When the pulp has died no blood can enter the inside of the tooth, therefore the bodies cells can't enter the tooth and kill any bacteria. The tooth acts as a reservoir of bacteria which breed and leak out of the end of the tooth to produce toothache.

For this reason the dentist must open the tooth and clean the inside with instruments and disinfectants.
When the nerve in a tooth becomes infected and dies your dentist must clean the inside of the tooth to prevent an abcess forming.

The dentist needs to drill a hole in the top of the tooth which will allow him access to the nerve chamber. In many cases this has to be large and may cause the tooth to be weakening, for this reason many dentists suggest that a metal crown be placed on the tooth once the root treatment is complete.
A healthy tooth contains a living nerve which is supplied by blood vessels which enter via the apex of the root.
The space between the bone and the tooth is roughly the same along the whole length of the root. The periodontal ligament is found here.
Once the bacteria have started to kill the nerve the body reacts with a inflammatory reaction which may extend to the tip of the root.
The body attempts to wall off the bacteria by forming inflammatory tissue at the tip of the root.
Once the bacteria take hold the body continues to wall them in by forming a capsule around them. This can be extremely painful as then capsule contains pus which is under pressure. This forces the tooth up in the socket and the tooth feels high and pain occurs when the patient bites on it.