Removal of separated files; More than one way to achieve.

Fig. 1

Figure 1

37 year-old female patient with non-contributory medical history was referred for root canal retreatment of tooth 46.

Dental records report acute pain and swelling on right lower jaw 3 months ago, for which Amoxicillin (1gr per 12 hours for 1 week) was prescribed by her dentist. Since then no other major pain incident reported aside for slight sensitivity on percussion. Initial radiograph (Figure 1) suggests a large periradicular lesion related to the distal root apex. Two fragments of endodontic files are evident in the mesiobuccal root canal, and one small fragment in the distal root possibly located into an apical split.

After inferior alveolar nerve block with mepivacaine, the tooth was isolated and careful removal of the occlusal composite filling was performed until gutta-percha was revealed in the three root canal orifices (mesiobuccal, mesiolingual, distal).

Mesiobuccal root canal was already enlarged, possibly in an attempt to remove the fragments. Ultrasonic tip ET20 (Satelec, Acteon Group, France) was used to remove lingual dentine overhangs, so as to obtain an improved visualization of the coronal stainless steel fragment. The fragment was then gradually released and removed, using the ultrasonics in a counterclockwise motion.

The same tip was used to release the coronal 2mm of the apically broken Niti file. Because those files are prone to fracture at the point of contact with the ultrasonic vibration, it is vital to avoid constant touch of the coronal part of the fragment and use a lower power mode during dentine removal at the circumference. In addition, it is preferable to use a grasping tool when the right time comes. In this case, EndoCowboy  (Köhrer Medical Engineering GmbH, Germany) was used with a 0.12 lasso tip to grab and retrieve this fragment.

Fig. 2

Figure 2 shows the cone fitting after removal of instruments in the mesiobuccal root canal. A fragment of small size probably 8 or 10 is evident in the mesiolingual canal at the apical third, which has been by-passed by the cone. 

Cone fitting is still not ideal and in the distal root canal the guttaperhca cone is short of the apex, despite the fact that the apex locator (ipex II, NSK, NAKANISHI INC, Japan) gave signal at this point, possibly due to the apically located small metallic fragment distal to the main canal.

Fig. 3

Figure 3

At this point, final obturation of the mesial root canals with warm vertical compaction technique and AH plus sealer was performed, while in the distal root canal the apical fragment is clearly depicted.

With an ultrasonic tip enlargement of the distal root canal to a lingual direction was carefully done and the coronal tip of the instrument became evident. To avoid further enlargement of the distal canal an XP-endo Finisher (FKG Dentaire, Switzerland) at 1000 rpm speed was used at working length with small coronally directed strokes.

Fig. 4

Figure 4

The fragment was finally dislodged and removed. At this point, obturation of the mesiolingual canal was revisited due to some voids and cone fitting for the distal canal was checked. 

In an attempt to compensate for the pre-existing loss of dentin, the middle and coronal part of the mesiobuccal canal were filled with Biodentine (Septodont, France), which has mechanical properties close to human dentin.

Cones in the distal root canal slightly extruded working length and were adapted accordingly.

Fig. 5

Figure 5 

Final obturation of the distal canal and deep split was performed with Ah plus sealer and WVC technique. 

A small piece of Teflon tape was placed just over the floor and the orifices and temporary restoration with Cavit G was done.