The role of imaging in endodontics

Abstract

Dental radiography is an essential tool in endodontics for determination of diagnosis, treatment planning and monitoring of treatment outcome. Conventional two-dimensional imaging remains the most commonly used and the standard method of radiographic imaging in endodontics due to accessibility and low radiation exposure. The use of cone beam computed tomography is increasing worldwide due to the benefits of three-dimensional visualisation of the teeth under investigation and surrounding structures. Its use, however, should be considered on a case-by-case basis, taking into consideration the benefits and increased dose of radiation in line with published guidelines.

Fig. 1

a) Discharging sinus adjacent to the lower right second molar 47 (responsive to cold testing). b) Size 20 gutta-percha point inserted into the sinus. c) IOPA of the image in (b) showing the gutta percha point tracking to the peri-radicular lesion of the lower right first molar (46)

Fig. 2

a, b) Showing a lower left first molar (36) using paralleling technique and an angled IOPA radiograph revealing evidence of a radix molaris. More information was required before commencing endodontic treatment in this case and hence a low volume CBCT of the 36 was taken which confirmed the complex anatomical features. c, d) Coronal view and sagittal view

Fig. 3

a, b, c) Series of periapical radiographs showing radiolucency related to apices of the 11, 12, and 13. d) Maxillary occlusal radiograph showing a large non-corticated radiolucency in relation to the apices of the 11, 12, 13, and 14 in a patient with a history of trauma to the anterior teeth. This case was of a complex nature requiring surgical intervention and a CBCT was needed for planning purposes. e, f) The CBCT images, sagittal view and coronal view clearly demonstrate the extent of the lesion

Fig. 4

Patient presented with symptoms of apical periodontitis with clinical tenderness to percussion from all three extensively restored molars. No other clinical signs of inflammation were detected and pulp testing was inconclusive. a) The periapical radiograph did not show any clear evidence of pathology; the area of interest is masked by the zygomatic arch. b) A small FOV CBCT revealed a large periapical radiolucency associated with the 27

Fig. 5

a) IOPA radiograph of lower incisors showing a mixed radiolucent-radiopaque appearance of the lesion located at the apices of the lower anterior teeth. The lamina dura associated with the 31, 41 and 42 are lost. All teeth tested positive with sensibility testing and a diagnosis of FCOD made. Endodontic treatment is not indicated. The teeth are vital. b) IOPA radiograph of the 35 and 36 (same patient as Figure 5a) showing a large radiolucent area in relation to apices of 35 and also 36. The 35 distal restoration has secondary caries. Both teeth tested positive with sensibility testing, further confirming a diagnosis of FCOD. Endodontic treatment is not indicated. The teeth are vital

Fig. 6

a) IOPA showing the 22 with a dens invaginatus (Oehlers' Classification Type I) and talon cusp. b) Sagittal view from CBCT of the same tooth showing the full extent of the lesion

Fig. 7

Patient presented with symptomatic upper left first molar (26), with tenderness on palpation above the mesio-buccal root. a) IOPA radiograph of endodontically treated 26 and 27. b) CBCT coronal view of the mesio-buccal root of the 26 showing the root canal filling is off centre, untreated MB2, and periapical radiolucency

Fig. 8

a) Periapical view of the lower right second premolar, first second and third molars. b) Estimation of canal curvature, left to right; extreme (light blue), moderate(red), slight (green) and straight canal (dark blue). The angle is formed at the intersection of the two lines

Fig. 9

a) IOPA radiograph showing inflammatory resorption of the distal root of the 36 and periapical radiolucency of mesial and distal canals. b) CBCT axial slice showing the extent of the lesion, perforating the buccal cortical plate. c) Coronal view revealing severe curvature of the disto-lingual canal in the bucco-lingual plane which is not evident on the IOPA radiograph

Fig. 10

a) IOPA showing an attempted access of a calcified canal, tooth 21. b) CBCT sagittal view of the tooth showing a large labial perforation rendering the tooth non-restorable

Fig. 11

a) IOPA of the 21 with a threaded post which appears to be well-aligned in the mesial and distal planes. b) CBCT sagittal view of the same tooth showing the post is misaligned with near palatal perforation. Note the beam-hardening artefact mimicking a fracture line

Fig. 12

a) IOPA of the 46 showing signs of ECR. b) Sagittal CBCT section. c) Axial CBCT section of the 46 revealing extensive cervical resorption with portal of entry located in the distal interproximal region. Patel et al. classification: 2CP. Surgical access and treatment poses a significant risk to the adjacent tooth and therefore, it was planned for an extraction

Fig. 13

a) The 21. Resorption detected on IOPA. b) Axial CBCT section showing the extent of circumferential spread. c) CBCT sagittal section reveals the apical extension in relation to the marginal bone, and proximity to the pulp. d) Endodontic treatment and surgical repair of the perforation was completed. Patel et al. classification: 2BP

Fig. 14

a) IOPA view of the 22 with internal resorption and artefact evident on film; ‘crease'. b) Sagittal view of CBCT section showing the bucco-palatal extent of the lesion and also evidence of canal apical to resorptive lesion. c) IOPA following obturation. Image courtesy of Abdulrahman Mataqi

Fig. 15

a, b) Working length determination in teeth with loss of apical constriction due to incomplete root development and external inflammatory resorption

Fig. 16

IOPA of upper left first premolar (24) with complex anatomy; three canals. a) Working length radiograph with three size 10k files in situ also confirmed with EAL. b) Cone fit radiograph (F1 ProTaper gold matching cones) used to confirm the lengths before final obturation. c) Final obturation (thermoplasticised technique). Image courtesy of Abdullah Alenezi

Fig. 17

Lower right first molar (46), mesial tube shift allowing visual separation of files in mesial root. Note two different designs of file have been used in the mesial canals to further differentiate between the buccal and lingual canals

Fig. 18

a) IOPA showing a rotated and calcified 31. Following attempted access and troughing with ultrasonics under a dental microscope, a CBCT was taken. b, c) Axial and sagittal views showing a near perforation. This provided adequate information for the clinician to re-align the access to locate the canal. d) Cone fit IOPA showing the canal was successfully re-negotiated

Fig. 19

a) Working length radiograph of first mesiobuccal with severe curvature using a 20k file. b) Subsequent master cone radiograph revealing a strip perforation ‘straightening' of the canal following instrumentation with ProTaper Gold F2

Fig. 20

a) Small FOV CBCT showing curved mesio-buccal root with perforation. The scan reveals the proximity of the sinus, adjacent roots, the amount of bone preparation required to expose the mesio-buccal root. b) Depth of resection required for removal. The root was obturated with biodentine and resected surgically. c) Two-year postoperative IOPA radiograph showing signs of bone regeneration

Fig. 21

a) IOPA of lower left first molar (36) with a gutta-percha tracer inserted in buccal sinus. Diagnosis: necrotic pulp, symptomatic chronic apical abscess. Considered a high-complexity endodontic case due to inflammatory resorption of the distal root and loss of apical constriction. Periapical radiolucencies present on both mesial and distal root. b) One-year review following endodontic treatment. The distal canal was obturated with mineral trioxide aggregate due to apical gauge ISO 70. IOPA radiograph exposed reveals signs of regeneration of the peri-radicular tissues. Image courtesy of Abdullah Alnaami

Fig. 22

a) IOPA radiograph revealing periapical lesion extending into the furcation area. b) 12-month follow-up IOPA radiograph revealing complete bone regeneration