If a tooth breaks or has decay, bacteria from your mouth can infect the hollow chamber in the middle of the tooth where the blood vessels and nerves are and may cause an abscess. Unfortunately the only way to treat infection of the tooth is to have root canal treatment or have the tooth removed.
If you are in pain due to infection, antibiotics can be taken to help with the pain. Antibiotics will not get rid of the infection though and the tooth will still need treating so it does not cause problems again in the future.
Root canal treatment (endodontics) involves making a hole in the tooth to gain access, cleaning the inside, removing the nerve and then filling the space with a special material. A filling or crown is then put on top to seal the tooth.
For more information on root canal treatment, click here to visit the British Dental Health Foundation website.