An abscess is usually the cause of a severe throbbing pain. It may be at an early stage or be fully developed:
The pain indicates that the pulp has been destroyed by the decay process.
A severe spell of pain can be triggered, lasting for hours.
The dead tissue forms gases, which react strongly to hot food and drinks.
An abscess will also have begun to form at the end of the root, and the gum adjacent to the tooth may be swollen.
This condition can cause a fever and a feeling of being unwell.
The treatment for this condition is to open the tooth and allow the pus to drain out. Pain relief is instant, but the tooth will still be sensitive, as the area around the end of the root is infected.
The remedy is a root canal treatment followed by a filling or replacement crown.