Australian Dental Council (ADC) Practice Test

The ideal length of root canal treatment (RCT) is recommended to be 0.5 - 1.5 mm before the apex. This approach is based on the understanding of the anatomy of root canals and the complexities involved in their treatment.

Maintaining the instrumented length a little short of the apex helps to reduce the risk of inadvertently damaging the apical structures, which can occur if the instruments or filling materials extend beyond the apical foramen. This space serves as a barrier to infections and is critical in maintaining periapical health. Additionally, arriving at the apex can lead to the extrusion of debris or filling material into the periapical tissues, potentially causing inflammation or other complications.

Choosing this length also facilitates proper cleaning, shaping, and filling of the canal while still providing adequate sealing and preventing reinfection. It strikes a balance between ensuring that the canal is fully treated and avoiding risks that could compromise the success of the treatment.

Understanding the significance of keeping the treatment slightly shy of the apex underscores the essential principles of conserving tooth structure and leveraging the body's natural defenses in the area, adhering to best practices in endodontics.