Root Canal Filling with Paste

Errors in using devitalizing pastes

At the initial stages of endodontic treatment, when preliminary pulp preparation is necessary, specialists may resort to devitalizing agents. Iatrogenic errors at this stage are associated with gross violations of the instructions for use of the materials.

The key issues here are:

• Overdose of the applied devitalizing agents when placing them into the tooth cavity.
• Exceeding the allowable time for the devitalizing paste to remain inside the tooth, which can entail unpredictable consequences for the surrounding tissues.

Complications during endodontic access preparation

Creating proper access to the root canal system is the foundation for successful obturation and instrumentation. Incorrect actions by the clinician at this stage lead to a number of critical errors.

The main shortcoming is incomplete unroofing of the pulp chamber. If the clinician fails to completely remove the roof of the pulp chamber, overhanging edges of coronal dentin are formed. The presence of such edges is a gross error, as they act as a physical barrier to creating adequate straight-line access to the canal orifices and the root canal lumen itself. As a result, the endodontic instrument begins to enter the root canal incorrectly: it is forced to bend already in the coronal part of the pulp chamber, which completely violates the concept of straight-line access.

Furthermore, during the access preparation stage, the clinician risks making the following iatrogenic errors:

• Perforation of the tooth wall directly during access opening.
• Perforation of the pulp chamber floor.

Issues with mechanical instrumentation

Access preparation is followed by mechanical instrumentation of the root canal, which also carries a high risk of operator errors. Inadequate instrumentation fails to properly prepare the root canal system for subsequent obturation.

Among the most frequent complications are:

1. Thinning of the coronal tooth wall, as well as excessive thinning of the root canal wall itself.
2. Perforation of the root canal wall, which occurs particularly often in its apical third.
3. Fracture (breakage) of the endodontic instrument directly within the root canal lumen.

Special attention should be paid to instrument handling technique. Inconsistent use of endodontic instruments, manifested as violations of generally accepted working protocols (such as step-back, crown-down, and other techniques), dramatically increases the likelihood of developing the aforementioned complications.

Errors in irrigation and drying

The final stages before obturating the root canals with paste or other materials include irrigation and drying. Errors here can nullify all previous work.

First, the clinician may encounter the consequences of inadequate use of medications (irrigants) used during canal treatment. Second, a serious error is the use of an air syringe. Supplying a stream of pressurized air from an air syringe during root canal drying is strictly not recommended and is regarded as an iatrogenic error.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Topography of the pulp chamber floor and prevention of perforations.
• Principles and differences of step-back and crown-down instrumentation protocols.
• Errors in selecting and using irrigants during chemical preparation.
• Causes of root canal wall perforation in the apical third.
• Clinician tactics in case of an endodontic instrument fracture within the canal lumen.

Other topics in "Chapter 7. Endodontics"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.