Principles of Access Opening

Once the diagnosis and treatment plan has been established, the first part of the endodontic treatment directly applied to the tooth is the access cavity preparation. You must understand that adequate access is essential for successful endodontic treatment. Knowledge of the pulp chamber morphology, along with an examination of pre-operative radiographs, should be integrated when designing the access cavity to a tooth for non-surgical root canal treatment.

Preparation may be divided into two phases: Coronal phase and the Intra-radicular (within the root) phase. The coronal phase, which is the access cavity, must give direct access to the root canals and the apical foramina so that these areas may be properly cleaned and shaped by the intra-radicular phase. Hence, success of the treatment that follows rests on a carefully prepared access cavity. As you are aware, there is great variance in overall tooth size, morphology, and arch position. This therefore, means that no two access openings are identical, although common access guidelines have been established depending on the location of the tooth. There is an old cliché that “Access is Success”. Unlike other aspects of dentistry, root canal treatment is carried out with little visual guidance; therefore, the difficulties that you are likely to encounter while preparing an access cavity need to be considered.

The access cavity must provide clear and unobstructed access to each and every orifice and must be designed in such a way so as not to interfere with the often difficult intracanal procedures to follow.

In this unit you will learn the rationale for a carefully prepared access opening and the principles that you should keep in mind while preparing the access opening. The armamentarium required and the basic procedure to be followed while preparing an access will be also dealt with, in the later part.