case_images: PMC11821464_01
case_images: Preoperative findings at T=0 (initial presentation). (a) Radiograph showing a separated instrument in relation to tooth 21. (b) Clinical image displaying discoloration in relation to tooth 21.
case_images: cureus-0017-00000077393-i01.jpg
case_images: PMC11821464_01_cureus-0017-00000077393-i01.jpg
case_images: FIG1
case_images: A linear radiopacity was observed, indicating a fractured ProTaper F1 rotary instrument (Dentsply Sirona, Ballaigues, Switzerland) measuring approximately 6 mm, extending into the middle canal space (Figure 1a, b).
case_images: Operative procedures at T=1 week. (a) Try-in of the template. (b) Sagittal section of CBCT showing the virtual drill path. (c) Drill positioned adjacent to the separated instrument. (d) Retrieval of the file. (e) Retrieved file fragment. (f) Working length determination.
case_images: cureus-0017-00000077393-i02.jpg
case_images: PMC11821464_01_cureus-0017-00000077393-i02.jpg
case_images: FIG2
case_images: These files were then imported into the implant planning software Blue Sky Plan (Blue Sky Bio, LLC; Grayslake, Illinois) and merged to create a virtual drill path (Figure 2a). A trial of the virtual guide was conducted on the patient to assess fit and stability (Figure 2b). The resin guide directed the progress of the trephine within the root canal until the target point, which was radiographically confirmed (Figure 2c). The separated instrument was eventually loosened by the mechanical action of the drill (1.3 mm diameter, Neodent, Curitiba, PR, Brazil) (Figure 2d) and removed during irrigation (Figure 2e). Working length (WL) was re-established (Figure 2f), and shaping was performed using the crown-down technique up to F3 Protaper Gold (Dentsply, Ballaigues, Switzerland), combined with circumferential filing.
case_images: At T=2 weeks: Obturation and post-endodontic restorations. (a) Master cone radiograph. (b) Post-operative radiograph showing obturation in relation to tooth 21.
case_images: cureus-0017-00000077393-i03.jpg
case_images: PMC11821464_01_cureus-0017-00000077393-i03.jpg
case_images: FIG3
case_images: The middle and coronal thirds of the canal were then backfilled using the gutta-percha injection technique (Figure 3a, b).
case_images: At T=1 month: Provisional restoration with temporary crowns. (a) Labial view. (b) Occlusal view in relation to tooth 21.
case_images: cureus-0017-00000077393-i04.jpg
case_images: PMC11821464_01_cureus-0017-00000077393-i04.jpg
case_images: FIG4
case_images: At T=1 year: Follow-up. Post-operative radiograph showing evidence of periapical healing in relation to tooth 21.
case_images: cureus-0017-00000077393-i05.jpg
case_images: PMC11821464_01_cureus-0017-00000077393-i05.jpg
case_images: FIG5