PMC9868984_01
A) Initial periapical radiography; B) Radiography of fistulous path, revealing the origin of chronic apical periodontitis; C) Axial plane of initial CBCT, where presence of two canals (MB1 and MB2) in mesio-buccal root is observed; D) Sagittal plane of initial CBCT scan performed at level of canal MB1, highlighting severe calcification presented and drawing attention to probable difficulty in locating it; E) Sagittal plane of initial CBCT scan performed at level of canal MB2, highlighting its permeability and continuation with pulp chamber, which facilitated its localization; F) Gutta-percha radiopaque point applied at MB end of pulp chamber floor; G) Coronal plane of intraoperative CBCT with radiopaque gutta-percha point showing palatal location of canal in relation to radiopaque marker; H) Intraoperative CBCT axial plane showing no deviation in various planes; I) Intraoperative CBCT sagittal plane with radiopaque gutta-percha marker showing no excessive wear mesially or distally and apical location to radiopaque marker. J) Selective grinding in region marked by intraoperative CBCT, with ultrasonic insert Finder (Helse, Brazil). K) Final radiograph, highlighting obturation of Vertucci type IV canals MB1 and MB2
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F1
The initial periapical radiograph revealed three independent roots, with alterations at the level of the periapical bone trabeculae and apparent reduction in volume of the pulp chamber, especially in the area of the mesial pulp horn (Figure 1A and 1B). For this reason, a preoperative CBCT scan was performed (Veraview 800; J Morita MFG, Kyoto, Japan), with 90 kV, 2mA, 4040 mm field of view (FOV) and 0.2 mm voxel (Figures 1C-1E), as a complementary tool for use in diagnosis and planning. A small portion of injectable gutta-percha was used as a radiopaque marker, which was applied with Obtura II Gutta-percha gun (Obtura Spartan, Fenton, MO, USA) at the furthest MB end of the floor of the access cavity (Figure 1F). Observation of these CBCT images enabled visualization of the MB1 canal orifice and the radiopaque gutta-percha points, and allowed three-dimensional correlation, making it possible to conclude that the MB1 canal entrance was in a more apical and more palatal location to the point indicated by the radiopaque gutta-percha point (Figure 1G-1I). This detailed information made it possible to locate the MB1 canal quickly and without procedural error, with the aid of Finder ultrasonic insert (Helse, Santa Rosa de Viterbo, SP, Brazil) (Figure 1J) and ISO #10 C-Pilot hand file (VDW, Munich, Germany), under microscopic magnification. After cleaning the pulp chamber with alcohol, intra-coronal sealing was performed with glass ionomer (Ionoseal, Voco GmbH, Cuxhaven, Germany) cement, and provisional restoration (Cavit, 3M, Seefeld, Germany), followed by occlusal adjustment (Figure 1K).
PMC9868984_02
A) Initial periapical radiograph demonstrating severe internal calcification of root canal; B, C) Sagittal and axial planes, respectively, of initial CBCT, where presence of resorption and its exact three-dimensional location can be observed, with no associated root perforation; D) Photograph taken after access surgery, showing presence of granulation tissue in area of resorption; E) Intraoperative periapical radiograph, where slight deviation in distal direction was detected; F) Picture after placing gutta-percha radiopaque point, in deepest area of abrasion performed with ultrasound; G, H and I) Axial, sagittal and coronal planes, respectively, of intraoperative CBCT, in which radiopaque gutta-percha marker can be seen and correlated with center of root, where canal is located; J) Final radiograph, with three-dimensional obturation of root canal and internal resorption
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F2
The initial periapical radiograph revealed severe root canal calcification, presence of internal resorption located in the region of the coronal third of the root and thickening of the periodontal ligament (Figure 2A). This examination confirmed severe calcification of the root canal and the presence of internal resorption, with irregular peripheral expansion in the region of the coronal third of the root, without root perforation (Figures 2B and 2C). Inibsa, Spain) and absolute isolation , access to the resorption site was obtained with a spherical diamond bur rotating at high-speed, under microscopic magnification (Flexion Advanced, CJ-Optik, Germany), enabling the presence of granulation tissue to be observed (Figure 2D). Irrigation with 5.25% sodium hypochlorite (Denta Flux, J. This radiograph revealed a slight distal deviation in the mesial-distal direction that made it impossible to evaluate any possible deviation in the vestibular-lingual direction (Figure 2E). The radiopaque marker chosen was a small portion of injectable gutta-percha, applied with Obtura II gutta-percha gun (Obtura Spartan, USA) at the deepest site of wear (Figure 2F). Therefore, these CBCT images made it possible to conclude that there was an effective deviation in the distal and buccal direction (Figures 2G-2I). After cleaning the pulp chamber with alcohol, glass ionomer (Ionoseal; Voco GmbH, Cuxhaven, Germany) was used for intracoronal sealing, and provisional restoration was performed (Cavit, 3M, Seefeld, Germany) (Figure 2J).
PMC9868984_03
A) Initial photograph showing difference in coloration due to dentin deposition; B) Initial periapical radiograph demonstrating severe calcification of root canal; C and D) Coronal and sagittal planes, respectively, of initial CBCT; E) Photograph after placement of radiopaque gutta-percha point in deepest zone of ultrasound-guided abrasion; F and G) Coronal and sagittal planes, respectively, of intraoperative CBCT, in which radiopaque gutta-percha marker is observed and correlated with root center; H) Intraoperative periapical radiograph, after canal location; I) Intraoperative periapical radiograph, after main cone positioning; J) Final radiograph, with three-dimensional root canal obturation
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F3
Patient complained of sporadic discomfort with precise location in tooth 11, with a history of trauma; however, the patient did not know the specific date of occurrence, as he only remembered the fact because the tooth color changed (Figure 3A). The initial periapical radiograph revealed reduction in the volume of pulp chamber and root canal up to the middle third (Figure 3B). For this reason, a preoperative CBCT scan (Veraview R100, Morita, Japan), with settings of 80 kV, 3 mA, FOV 40 mm40 mm and voxel 0.2 mm was performed as a complementary tool for use in diagnosis and planning (Figures 3C and 3D). For this purpose, a small portion of injectable gutta-percha was applied with gutta-percha gun EQ-V (Metabiomed, Cheongju, South Korea) (Figure 3E) to act as a three-dimensional guide. FOV 40 mm40 mm and voxel 0.2 mm. From the place where the radiopaque marker was observed, it was possible to visualize the location of the canal orifice and the distance to the wear point marked by the gutta-percha (Figure 3F) and (Figure 3G). The glide path was obtained using a steel hand file ISO #10 K C-Pilot and #15 K (Dentsply Maillefer, Ballaigues, Switzerland) with the aid of an electronic apical locator (Root-ZX, Morita, Kyoto, Japan) (Figure 3H). After cleaning the pulp chamber with alcohol, Tetric Evo Flow (Ivoclar Vivadent, Amherst, NY, USA) was used for intra-coronal sealing, and restoration was performed with composite resin (3M, ESPE Germany) (Figure 3I).