X-rays during Root Canal Treatment

Dr. Bettina Basrani
Authored By:
Dr. Bettina Basrani

A patient undergoing endodontic treatment should expect to have radiographs taken at several stages during treatment. Radiographs are important for the dentist to identify structures harbouring disease, as well as during the progression of the treatment, as these are not visible to the naked eye.

Pre-operative radiograph:

Pre-operatively, the process of taking the radiograph is similar to that of standard dental radiography. The patient will be seated in an upright position in the dental chair, and instructed to remove any metallic objects that may be in the path of the x-ray beam. These objects will create radiopaque shadows or superimpositions on the image which may obscure important structures. The patient will then be covered with a lead apron and collar.

The film or digital sensor will be placed in a receptor holder, which is a device that is placed in the mouth to support the film or sensor, while maintaining the proper position. The dentist will then position the patient and then the x-ray head according to the view necessary. The patient is instructed to maintain their position and avoid any movement as the operator leaves the room to expose the radiograph.

This pre-operative radiograph is necessary in order to identify the presence and nature of pathosis. It may be necessary to take more than one radiograph, with the x-ray beam moved in a slightly different position, in order to obtain maximum diagnostic information.


Before the endodontic treatment begins, the dentist will place a rubber dam in the patients’ mouth to protect them from accidental inhalation of materials used during treatment. The rubber dam must stay in place during any radiographic exposures, which presents a bit of a challenge in order to acquire the desired image. To assist in this, specially designed holders are available, and at times other instruments can be used to properly position the receptor.

Radiographs are taking at several stages during treatment. The first will be taken to establish the working length of the canal and to verify tooth anatomy. This radiograph is taken with a small file placed inside the canal of the tooth.

A radiograph may be taken during the cleaning and shaping portion depending on how the treatment is progressing. Once this stage is complete, another radiograph will be taken with the master file in place which confirms that the file is equivalent to the working length and that the shapes of the canals are adequately tapered after the preparation.

The final radiograph taken during treatment will be with the master cone placed in the prepared canal. An accurate cone fit assures that the tooth is properly prepared with an ideal tapered preparation.

Postoperative Radiograph:

The postoperative radiograph will be taken with the same technique as the preoperative radiograph for proper comparison. For this radiograph, the dentist will remove the rubber dam. It is this radiograph that the dentist will use to assess healing during follow-up appointments.

Recall Radiographs:

In order to determine the success of the endodontic treatment, the dentist will examine the patients’ teeth and take radiographs at recall appointments. This will help the dentist determine whether the tooth has healed or is still in the healing process, and to determine if there are any signs of persistent infection.

Radiography is an indispensable and necessary tool in any endodontic treatment. Without it, the dentist will not be able to see pathologies hidden deep inside the canals of the roots. Taking radiographs at several stages before, during and after treatment ensure success of the endodontic therapy.

Special thanks to Dr. Calvin Torneck and Dr. Ross Barlow for helping to provide some of the radiographic examples shown.