Problem #10: Capturing the Apex during an Endodontic Procedure

Discussion and Solution: Completing images when the tooth is under rubber dam and has files or gutta percha points in place is challenging. Using rod and ring aiming instruments specific for endodontics places the apices of the tooth within the aiming ring. Proper placement of the sensor holder is critical. The operator can also use a simple sticky tab and hemostat to secure the sensor. The variables (horizontal and vertical angulation, head position, and sensor position) must be controlled and correct. The patient’s head position is often forgotten, and when left positioned towards the ceiling, a maxillary tooth may be cut off, and a mandibular tooth will be foreshortened. Images of working length files in a maxillary first molar, where the patient’s head position was the problem (looking up towards the ceiling shown in Figure 37B). The occlusal plane was repositioned towards the floor, and the apices were captured (Figure 37 A). When the occlusal plane cannot be level with the floor, the vertical angulation must be adjusted to ensure coverage of the apices with radiation. The PID will move with the occlusal plane, typically the patient is looking towards the ceiling, and the vertical angulation will be increased past the suggested values.

Figure 37 - Endodontic procedure #14 working length files.
(A) Occlusal plane was positioned parallel to the floor of the room. The 3 canals are imaged without distortion (green circle). (B) Occlusal plane was up towards the ceiling. The working length files were not captured.

Figure 37 - Endodontic procedure #14 working length files.
(A) Occlusal plane was positioned parallel to the floor of the room. The 3 canals are imaged without distortion (green circle). (B) Occlusal plane was up towards the ceiling. The working length files were not captured.