What does treatment involve?
Treatment often involves from one to three visits. During treatment, your general dentist or endodontist (a dentist who specializes in problems of the pulp) removes the diseased pulp. The pulp chamber and root canal(s) of the tooth are then cleaned and sealed.

Here's how your tooth is saved through treatment:

1.First, an opening is made through the crown of the tooth.
2.An opening is made through the crown of the tooth into the pulp
  chamber.
3.The pulp is then removed. The root canal(s) is cleaned and
  shaped to a form that can be filled.
4.The pulp is removed, and the root canals are cleaned, enlarged
  and shaped.
5.Medications may be put in the pulp chamber and root canal(s)
  to help get rid of germs and prevent infection.
6.A temporary filling will be placed in the crown opening to
  protect the tooth between dental visits. Your dentist may leave
  the tooth open for a few days to drain. You might also be given
  medicine to help control infection that may have spread beyond
  the tooth.
7.The pulp chamber and root canals are filled and sealed.
8.The temporary filling is removed and the pulp chamber and root
  canal(s) are cleaned and filled.
9.In the final step, a gold or porcelain crown is usually placed
  over the tooth. If an endodontist performs the treatment, he or
  she will recommend that you return to your family dentist for
  this final step.
10.The crown of the tooth is then restored.