By-pass with style

Fig. 1

Figure 1 shows initial x-ray with a fractured NiTi file, 5-6mm in length, lodged at the mid-apical part of the mesiobuccal canal. The tooth had a big carious cavity in the mesial half and a periapical lesion in the palatal root. 

After anaesthesia and proper isolation, caries were removed and the cavity was sealed peripherally with RubberDam liquid. The pulp chamber was adequately enlarged preserving at the same time precious pericervical dentine.

Four canals were identified (MB1, MB2, DP and P). MB1 and MB2 orifices were very close, so after orifice opening, they became one canal.

With the aid of Gates Glidden burs, the MB canal was enlarged up to the fractured file, providing a straight access.

Although in the initial x-ray, the mesiobuccal root seems to be fairly straight, in reality the root had a mesiopalatal inclination. The coronal part was visible under magnification, so it was decided to be removed. With the use of dedicated ultrasonic tips (E9, Fanta), 1-2 mm of the coronal part of the file was revealed and an attempt to dislodge the file was made. The file could be seen that can be moved and a BTR pen was used to grasp the file. The loop was secured and small movements were made in order to free the separated file. Unfortunately, the file was overused, distorted and possibly lodged further apically. That led to separation of the coronal part and the remaining file was beyond the curve, so it was decided to change the approach and try to bypass it.,

Fig. 2

Whenever we try to bypass a fractured file, especially a NiTi file, we need to remember two things. Fractured NiTi files tend to straighten inside the canal, touching always the outer wall of the canal, and that the majority of the NiTi files have a triangular design. That means that we can only bypass the file  by staying on the inner curve of the canal. By soaking the canal with EDTA 17% and with the use of a no10 C-pilot or D-finder file, a path was created. After several attempts, the apex was reached, indicated by the apex locator and verified with an interim x-ray (Figure 2).

Fig. 3

The pathway was further enlarged with the use of no15 D-finder and no20 K-file. Figure 3 shows files in all the canals to the apex. For the instrumentation of the MB canal AF F One rotary instruments were used. This line with R-wire technology and the flat design on one side, is easier to bypass the fractured instrument. The canal was instrumented up to 25.04 . Palatal canal was instrumented up to 60.02 (Hyflex EDM) and Distal canal up to 50.03( Hyflex EDM). The chemomechanical disinfection was completed with copious irrigation of EDTA 17% (3 mins) and NaOCl 5,25% (10ml per canal, 10 mins) with the aid of ultrasonic activation (Ultra-X). The canals were dried with intracanal suction and paper points. Intracanal medicament was placed for 10 days (Calcipast).

Fig. 4

At the second visit, patient was symptom free and confirmed an uneventful period. The intracanal medicament was removed with irrigation and ultrasonic activation. Instrumentation to the established working length with the master file for each canal was executed. Canals were dried and a cone fit x-ray was done (figure 4).

Fig. 5

Obturation was done with cold compaction of single cone with bioceramic sealer (NeoSealer, Avalon). Figures 5 and 6 show the final x-rays after obturation. The patient was sent back to the referral dentist for permanent restoration.