Performs Endodontic Surgery.  Sometimes nonsurgical endodontic therapy is ineffective. The endodontist may then use an in-office surgical procedure called root end resection and root end filling to remove the root tip and seal the root canals with a filling in the end of the root.

           :What is an Endodontist and what do they do

Endodontists are dentists who specialize in maintaining teeth through endodontic therapy -- procedures, involving the soft inner tissue of the teeth, called the pulp.  The word "endodontic" comes from "endo" meaning inside and "odont" meaning tooth.  Like many medical terms, it's Greek.  All dentists are trained in diagnosis and endodontic therapy, however, some teeth can be especially difficult to diagnose and treat.  That’s why you may have been referred to an endodontic specialist.  In addition to dental school, endodontists receive two or more years of advanced education in this kind of treatment. They study root canal techniques and procedures in greater depth, for diagnosis and treatment of more difficult cases. For this reason, many  dentists choose to refer their patients to endodontists

Root canal, or Nonsurgical Endodontic Therapy. This procedure is performed to save a tooth when the inner tissue, called the pulp, becomes damaged. Therapy consists of opening the tooth, removing the pulp, cleaning, shaping, and filling to seal the root canals. Endodontic therapy is usually highly successful (up to 90% of the time)!

Retreatment. Occasionally a tooth that has undergone endodontic, treatment fails to heal or pain continues despite therapy. Although rare, sometimes a tooth initially responds to root canal therapy but becomes painful or diseased months or years later. When either of these situations occur, the tooth often can be maintained with a second endodontic treatment.