When the nerve inside a tooth begins to die or completely dies then it can become painful and infected.  If the infected nerve is not removed then this pain and infection can continue to cause problems.  One way to "remove" the nerve is to extract the problem tooth as the affected nerve is removed when the tooth is.  To avoid an extraction the tooth must undergo root canal or endodontic treatment.  This involves accessing the canals that run through the roots of the tooth, cleaning them out and disinfecting them.  It this is successful then the affected tooth will need to be crowned to protect what is left.  Whether a tooth requires or is suitable for a root canal treatment is dependent on the individual circumstances and will be assessed at your appointment.  Sometimes Sarah will recommend that you are referred onto a specialist endodondist to complete the treatment