Re-treatment in endodontics.

In order to achieve success in endodontics, major emphasis is placed on judicious instrumentation, microbial control, and complete obturation of the root canal system. During re-treatment of previously endodontically treated teeth, one may encounter a variety of different materials, which must be removed before these objectives can be achieved. The intent of this article is to present various methods that the practitioner may use in an attempt to safely remove these materials while adhering to sound endodontic principles. The article further emphasizes that removal of the previous filling material is only the initial step, which, when successfully accomplished, provides access to the root canal system so that therapy objectives can be carried out.