case_images: PMC10516697_01
case_images: (a) Perioperative clinical examination showing a fractured tooth #9. (b) Perioperative periapical radiograph showing inadequate endodontic treatment with a fractured fiber post in the root canal. (c) Perioperative CBCT assessment. The sagittal slice of tooth #9 confirms a radiolucent area with an intact buccal and palatal plate.
case_images: CRID2023-7982368.001.jpg
case_images: PMC10516697_01_CRID2023-7982368.001.jpg
case_images: fig1
case_images: Tooth #9 showed normal mobility upon clinical examination, and its periodontal probing depths were found within normal limits (Figure 1(a)). A periapical radiograph revealed a fractured fiber post and poor endodontic treatment, causing a periapical lesion around the apex of the root (Figure 1(b)). The imaging showed a radiolucent area with intact buccal and palatal plate (Figure 1(c)).
case_images: (a) Optical impression of the maxillary arch using STL format. (b) The STL file and the DICOM file obtained by CBCT are virtually merged. (c) Virtual planning of fiber post removal in the coronal plane and (d) sagittal plane. The drill was positioned along the long axis of the fiber post set up to its apical tip.
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case_images: PMC10516697_01_CRID2023-7982368.002.jpg
case_images: fig2
case_images: An intraoral scan was taken from the upper arch using the CS 3600 scanner (Carestream Health, Atlanta, Georgia, USA) (Figure 2(a)). Tessellation Language (STL) file obtained by optical impression and the DICOM file obtained by CBCT were merged using Blue Sky Plan software (Blue Sky Bio ). The software automatically superimposed the two mentioned files (Figure 2(b)). The virtual path was positioned three-dimensionally along the axis of the fiber post (Figures 2(c) and 2(d)).
case_images: (a) Munce bur and static endodontic guide with metallic sleeve. (b) The guide was positioned on the teeth to check the correct fitting. (c) A microscopic view showing a check on the drilling axis towards the gutta-percha. (d) Periapical radiograph indicates some deviation from the intended pathway. (e) Working length determination radiograph. (f) Final radiograph with temporary filling.
case_images: CRID2023-7982368.003.jpg
case_images: PMC10516697_01_CRID2023-7982368.003.jpg
case_images: fig3
case_images: Munce bur (Meisinger, Germany) size #1 was used which had a length of 16 mm and a diameter of 1 mm in performing this process (Figure 3(a)). The correct fitting of the guide was verified again (Figure 3(b)). The entire process of drilling was completed in three stages until exposing the gutta-percha (Figure 3(c)). After the completion of drilling, the periapical radiograph showed some deviation from the intended path (Figure 3(d)). A size 20 K-file was placed in the canal for length determination using an electronic apex locator (Root ZX; J Morita, Tokyo, Japan), and this length was confirmed by a radiograph (Figure 3(e)). Finally, the tooth was temporarily restored with light-cure glass ionomer cement (GC Fuji II LC, Tokyo, Japan) and referred for a permanent restoration (Figure 3(f)).
case_images: (a) Postoperative clinical view of a permanent restoration. (b) Clinical view of 6 months postoperatively. (c) Radiograph view of 6 months postoperatively showing periapical healing. (d, e) Coronal and sagittal view of postoperative CBCT showing the dimensional reduction of the periapical lesion. The superimposed preplanned pathway is located in the center of the canal.
case_images: CRID2023-7982368.004.jpg
case_images: PMC10516697_01_CRID2023-7982368.004.jpg
case_images: fig4
case_images: Finally, due to the aesthetic zone, the tooth was restored with a full ceramic zirconia crown (Figure 4(a)). The tooth was asymptomatic (Figure 4(b)), and the radiograph revealed successful healing of the apical area (Figure 4(c)). Due to the placement of the metallic post inside the root canal and the CBCT artifact, it was not possible to calculate the deviation from the intended path (Figures 4(d) and 4(e)).