Cone Beam Computed Tomography and Radiographs for Endodontics: A Pictorial Illustration of the AAE-AAOMR Position Statement

Rumpa Ganguly BDS, DMD, MS, is an oral and maxillofacial radiologist and a diplomate of the American Board of Oral and Maxillofacial Radiology. She is an associate professor of clinical orofacial sciences and director of the oral and maxillofacial radiology clinic at the University of California, San Francisco, School of Dentistry. Conflict of Interest Disclosure: None Reported.

Mike Sabeti, DDS, MA, is an endodontist and is a diplomate of the American Board of Endodontics. He is a professor of preventive and restorative dental sciences and the program director of the graduate endodontics program at the University of California, San Francisco, School of Dentistry. Conflict of Interest Disclosure: None Reported.

ABSTRACT

Background: Cone beam computed tomography (CBCT) has become an integral part of more challenging and complex endodontic treatments. CBCT may be considered in the presence of specific signs and symptoms when clinical questions are not addressed by conventional 2D radiographic imaging.

Results: This article provides pictorial illustrations of endodontic cases where CBCT, imaging, when performed with appropriate imaging protocol, may lead to informed decision-making regarding treatment approaches of the more challenging endodontic cases. The illustrations are based on recommendations made by the AAE-AAOMR position statement.

Practical implications: This pictorial essay elaborates the recommendations in the joint position statement of the AAE-AAOMR through illustrated case scenarios to help clinicians understand the impact of CBCT on diagnosis and treatment planning.

Key words: Cone beam CT, CBCT, endodontics, AAE-AAOMR position statement recommendations

Radiographic imaging plays a crucial role in endodontic treatment. The goal of radiographic imaging is to acquire high-quality images of the teeth and surrounding structures for diagnosis, treatment and monitoring of care. The most common radiograph ordered for endodontic diagnosis and postoperative follow-up is a periapical radiograph. A diagnostic periapical radiograph made using proper technique and exposure settings displays the width and height of the tooth structure and periapical bone. The apical structures of the teeth such as lamina dura and periodontal ligament space can be depicted accurately and with great clarity provided the projection geometry is accurate for the structures under investigation. Over the past decade, dentistry has witnessed rapid migration from film-based imaging to digital imaging due to the demand for electronic health records and stricter environmental laws for handling, disposing and treating chemicals and materials used in film-based imaging. Digital imaging technology has improved over the last two decades with lower costs and more product availability. However, the inherent limitation of periapical radiography, whether film-based or digital, is the lack of information in the transverse plane or in the buccolingual plane leading to limited diagnostic information in those situations where diagnosis requires a multidimension visualization of the tooth and surrounding structures. Although this information may not be necessary in most routine cases of endodontic treatment, the determination of an existing anomaly or abnormal findings may alter the clinician’s treatment approach. [1] Cone beam computed tomography (CBCT) allows multidimensional visualization of teeth and adjoining anatomy and has transformed endodontic diagnostic capability. [2–4]

Current CBCT machines provide varying options for field of view (FOV), voxel sizes, exposure settings, gantry rotation angle and number of projection frames acquired in a single rotation of the gantry. These factors have an impact on both diagnostic image quality and radiation dose to the patient. Clinicians must exercise discretion and professional judgement to select the most appropriate FOV, voxel size and exposure settings that accomplish the diagnostic objective with the least amount of radiation. An appropriately designed examination ensures that the anticipated diagnostic benefits will outweigh the risks. For endodontic diagnostic purposes, the area of interest is typically limited to a single tooth or the adjacent teeth within a sextant, thus a limited FOV provides adequate coverage. Additionally, endodontic diagnostic assessments involve evaluation of structural details such as lamina dura, PDL space and narrow root canals thus requiring high spatial resolution to accomplish the diagnostic objectives.

This manuscript lists the 14 CBCT imaging recommendations published in the joint position statement of the American Academy of Endodontics (AAE) and the American Academy of Oral and Maxillofacial Radiology (AAOMR). [5] We summarize the essential elements of evidence that form the basis for these recommendations. Using illustrative cases, we demonstrate how proper patient selection and appropriate CBCT imaging provide value in decision-making for a variety of challenging endodontic situations.

Recommendation 1: Intraoral radiographs should be considered the imaging modality of choice in the evaluation of the endodontic patient. [5]

Rationale: For most common pulp and periapical diseases, clinical evaluation and radiologic information provide adequate information for successful diagnosis and management. Intraoral radiographs provide the needed diagnostic benefit at lower radiation and cost.

A 36-year-old-female presented for root canal treatment of the mandibular incisors. Clinical exam of teeth Nos. 23–26 revealed porcelain fused to metal crowns in place. These teeth were not sensitive to percussion or palpation and did not respond to a cold test. A periapical radiograph was made with the crowns in place and again after their removal. The periapical radiographs showed widening of the apical periodontal ligament (PDL) space of these teeth with a periapical radiolucent area of teeth Nos. 24 and 26 consistent with apical rarefying osteitis (granuloma or cyst). Root canal treatment was performed successfully based on the diagnostic information available in these periapical radiographs (FIGURES 1).

Recommendation 2: Limited FOV CBCT should be considered the imaging modality of choice for diagnosis in patients who present with contradictory or nonspecific clinical signs and symptoms associated with untreated or previously endodontically treated teeth. [5]

Rationale: Studies have shown that periapical lesions appear earlier in CBCT images compared to periapical radiographs. [6] Success of endodontic treatment is higher when teeth are treated before appearance of radiographic signs of periapical disease. [6] Studies have also shown higher detection rates of primary endodontic disease with CBCT when compared with periapical radiography both via in vivo and ex vivo studies. [8–12] Further, CBCT is better than periapical imaging for differentiation of atypical odontalgia from symptomatic apical periodontitis. [13,14]

A 62-year-old female presented with a persistent periapical radiolucent lesion of tooth No. 21 post-endodontic treatment. Periapical radiographs and CBCT from over a two-year period were reviewed. There was a periapical radiolucent area associated with teeth Nos. 21 and 22 that appeared to have minimally reduced in size over the two years since the endodontic treatment of tooth No. 21. A limited FOV CBCT was obtained and compared to a previous CBCT from a year prior to investigate the possibility of a fracture of tooth No. 21, but no evidence of a fracture was noted. Clinical exam revealed that teeth Nos. 21 and 22 were negative to percussion and palpation with no mobility. The probing depths were within normal limits with no bleeding upon probing. No swelling or sinus tract was noted. The patient presented with contradictory or nonspecific clinical signs and symptoms for tooth No. 21. A definitive diagnosis could not be reached based on the clinical and radiographical evaluation. A biopsy was ordered to determine the confirmatory diagnosis of the periapical lesion (FIGURES 2).

Recommendation 3: A limited FOV CBCT should be considered the imaging modality of choice for initial treatment of teeth with the potential for extra canals and suspected complex morphology, such as mandibular anterior teeth, maxillary and mandibular premolars and molars and dental anomalies. [5]

Rationale: The inherent limitations of 2D imaging in displaying anatomical variations of roots and the root canal system may lead to lack of complete data for a successful root canal therapy. Data from CBCT showed a strong correlation with sectioning and histologic examination of teeth depicting the actual number of roots and canals; [14,15] specificity and sensitivity in detecting the second mesiobuccal (MB2) canal is higher with CBCT than with intraoral radiography. [17]

A 61-year-old female presented with pain in the lower anterior region. On clinical exam, teeth Nos. 23 and 24 were sensitive to percussion and palpation with grades 1 to 2 mobility. A periapical radiograph revealed a periapical radiolucent area with loss of lamina dura of teeth Nos. 23 and 24. There appeared to be a radiolucent area superimposed over the apical half of the root of tooth No. 24. A limited FOV CBCT revealed a large periapical radiolucent area around teeth Nos. 23 and 24. Tooth No. 24 also had large external resorption at midroot level on the lingual. No buccal bone was present on tooth No. 24. Widening of the PDL space was seen on teeth Nos. 23 and 24. Tooth No. 23 had been endodontically treated previously and seemed to have a lingual canal that was inadequately prepared and filled (FIGURES 3).

Recommendation 4: If a preoperative CBCT has not been taken, limited FOV CBCT should be considered as the imaging modality of choice for intra-appointment identification and localization of calcified canals. [5]

Rationale:

■ Anatomical variations exist among different types of teeth. The success of nonsurgical root canal therapy depends on identification of canals, cleaning, shaping and obturation of root canal systems as well as the quality of the final restoration.

■ 2D imaging does not consistently reveal the actual number of roots and canals. In studies, data acquired by CBCT showed a very strong correlation between sectioning and histologic examination. [15,16]

■ In a 2013 study, CBCT showed higher mean values of specificity and sensitivity when compared to intraoral radiographic assessments in the detection of the MB2 canal. [17]

A 64-year-old male presented to our clinic with a chief complaint of “I have pain in my upper left jaw.” Clinical exam revealed that tooth No. 14 was negative to a thermal test, positive to percussion and palpation and no swelling or sinus tract was noted. There was no mobility of tooth No. 14 and probing depths were within normal limits. A periapical radiograph of tooth No. 14 revealed a periapical radiolucent area with loss of lamina dura consistent with apical rarefying osteitis. Clinically, tooth No. 14 was diagnosed as necrotic with symptomatic apical periodontitis. The tooth was anesthetized and isolated with a rubber dam and root canal treatment was initiated, but the clinician was unable to locate the mesiobuccal (MB) canals due to calcification of the canals. A limited FOV CBCT was acquired for further investigation and both MB1 and MB2 were identified and negotiated (FIGURES 4).

Recommendation 5: Intraoral radiographs should be considered the imaging modality of choice for immediate postoperative imaging. [5]

A 45-year-old-female presented for an 18-month follow-up postendodontic treatment of tooth No. 5. The patient was asymptomatic. A periapical radiograph showed normal trabecular pattern and density of periapical bone of endodontically treated tooth No. 5. The comparison of the progressively reducing size of the periapical radiolucent lesion of tooth No. 5 in the pretreatment, immediate postoperative and 18-month follow-up periapical radiographs can be made (FIGURES 5).

Recommendation 6: Limited FOV CBCT should be considered the imaging modality of choice if clinical examination and 2D intraoral radiography are inconclusive in the detection of vertical root fracture. [5]

Rationale: CBCT has been shown to exhibit higher sensitivity (88%) and specificity (75%) in detection of vertical root fractures in a clinical study where definitive fracture was diagnosed at the time of surgery. [18] Several in vivo and laboratory studies have also found CBCT to have higher accuracy, specificity and sensitivity in detection of vertical root fractures, identified through its consequent periradicular bone loss. [19,20] However, detection of fracture is dependent on the size of the fracture, the presence of artifacts caused by endodontic filling material and the spatial resolution of the CBCT image. Nevertheless, the use of CBCT may improve the odds of obtaining an accurate diagnosis that can affect both the choice of treatment options and the outcome.

A 77-year-old male patient presented with a fractured mesio-occlusal (MO) amalgam restoration of tooth No. 2 and an isolated deep probing depth of 14 mm. Cold test was negative, percussion was positive and no tooth mobility was detected on clinical testing. A periapical radiograph of tooth No. 2 showed an ill-defined periapical radiolucent area with loss of lamina dura and widening of the PDL space. The lesion appeared to extend into the maxillary sinus. The floor of the maxillary sinus appeared intact but elevated. The roots appeared superimposed over one another, although no peripheral bone loss along the roots was seen. Small FOV CBCT volume of tooth No. 2 was made for further assessment. Axial and coronal CBCT views revealed a vertical root fracture extending mesiodistally between the MB and DB roots. Extensive periodontal bone loss was noted along all the roots extending apically with disruption of the floor of the maxillary sinus as noted in coronal and sagittal CBCT slices. Soft tissue thickening was noted in the adjoining maxillary sinus representing odontogenic sinusitis (FIGURES 6).

Recommendation 7: Limited FOV CBCT should be the imaging modality of choice when evaluating the nonhealing of previous endodontic treatment to help determine the need for further treatment, such as nonsurgical, surgical or extraction.

Rationale: A higher number of periapical lesions was reported with posttreatment recall CBCT imaging (25%) compared to periapical radiographs (12%), according to a study by Liang et al. [21] These results concur with similar studies. [22–24] Additionally, 80% of apparently short root fillings based on periapical radiographs appeared flush on CBCT. Periapical radiographs revealed voids in endodontic filling in 16% of cases whereas CBCT revealed voids in 46% of cases. [21] The accuracy of diagnosis reached with CBCT was approximately twice that of periapical radiographs. A change in diagnosis and treatment plan was noted in 56% to 66% of cases in a study comparing periapical radiographs and CBCT imaging, and in 62% of cases, treatment plan modifications were made due to additional information acquired from the CBCT data. [25]

A 38-year-old male presented with a chief complaint of pain and swelling in the maxillary left posterior region for the past month while on antibiotics. A clinical exam revealed that tooth No. 14 was tender on percussion and palpation associated with swelling of the surrounding soft tissues. Tooth No. 14, which had a full-coverage ceramic restoration, had been endodontically treated. A limited FOV CBCT volume revealed a previous apicoectomy of the MB root system with a long bevel and blunting of the apex of the MB root. A radiolucent area associated with the surgical endodontic access site of the MB root system was noted. No instrumentation of the MB2 canal was noted. Tooth No. 14 was diagnosed as an acute apical abscess with previous root canal treatment (RCT) and apicoectomy. RCT was recommended due to a missed MB2 canal (FIGURES 7).

Recommendation 8: Limited FOV CBCT should be the imaging modality of choice for nonsurgical retreatment to assess endodontic treatment complications, such as overextended root canal obturation material, separated endodontic instruments and localization of perforations. [5]

Rationale: The 3D spatial location of a separated instrument or perforation and its relationships to vital structures are important elements for treatment planning and for prognosis.

A 41-year-old presented with previously treated tooth No. 30 with a distobuccal sinus tract. Clinical exam revealed that the tooth was slightly tender to percussion and negative to palpation. The porcelain fused to metal crown was intact. A gutta percha point was used to trace the sinus tract to the distal root in a periapical radiograph. The periapical radiograph of tooth No. 30 revealed a radiolucent area surrounding mesial and distal root apices. Extruded sealer was noted at the apex of the mesial canal. Tooth No. 30 was diagnosed as previously treated with chronic apical abscess. Limited FOV CBCT imaging revealed radiolucent areas surrounding mesial and distal apices. Extruded sealer was noted beyond the MB apical foramen. One untreated distal canal was noted (FIGURES 8A).

A 63-year-old female presented with an endodontically treated tooth No. 18 that remained symptomatic with tenderness on percussion and palpation. Tooth No. 18 was diagnosed as previously treated with symptomatic apical periodontitis. A periapical radiograph showed foreign material extending beyond the distal root apex of tooth No. 18 and a periapical radiolucent lesion consistent with apical rarefying osteitis (abscess, granuloma or cyst). A limited FOV CBCT volume revealed a linear high-density object consistent with a separated instrument in the distal root apex, which extended into the periapical region (FIGURES 8B).

A 50-year-old female presented with an endodontically treated tooth No. 3. A periapical radiograph of tooth No. 3 showed a periapical radiolucent area associated with the mesial root with widening of the periodontal ligament (PDL) space. The apical third of the mesial root was devoid of endodontic filling material. The tooth was sensitive to percussion and palpation. Clinically, tooth No. 3 was diagnosed as previously treated with symptomatic apical periodontitis. A limited FOV CBCT was acquired. The reconstructed thin section panoramic view showed the periapical radiolucent area with peripheral bone loss along the mesial root. There was also transportation and perforation of the MB2 root at the midroot level as shown in the axial and sagittal CBCT images (FIGURES 8C).

Recommendation 9: Limited FOV CBCT should be considered as the imaging modality of choice for presurgical treatment planning to localize root apex/apices and to evaluate the proximity to adjacent anatomical structures. [5]

Rationale: The use of CBCT has been recommended for treatment planning of endodontic surgery. [26,27] CBCT visualization of the true extent of periapical lesions and their proximity to important vital structures and anatomical landmarks is superior to that of periapical radiographs. Potential morbidity from inadvertent violation of vital anatomic boundaries is high.

A 68-year-old female presented with pain in the left posterior region of the mandible. Tooth No. 19 was tender on palpation and percussion and had swelling of the adjacent soft tissues. Tooth No. 19 responded negatively to a cold test. A periapical radiograph revealed widening of the apical PDL space and a periapical radiolucent area that was surrounded by sclerosis of the trabecular bone consistent with sclerosing osteitis. A clinical diagnosis of necrotic pulp with acute apical abscess and possible osteomyelitis was made. A limited FOV CBCT of tooth No. 19 confirmed the periapical radiolucent area with surrounding sclerosis consistent with sclerosing osteitis or focal sclerosing osteomyelitis. Additionally, a moderate caliber accessory neurovascular channel or a nutrient canal was noted extending from the distal root to the inferior alveolar nerve canal (FIGURES 9A). The risk of paresthesia following treatment was reviewed and communicated to the patient.

A 68-year-old male presented for a five-year recall postendodontic treatment of tooth No. 18. The patient was asymptomatic. Tooth No. 18 tested normal on palpation, percussion and mobility testing. An isolated 10 mm pocket was noted lingual to the tooth. A periapical radiograph revealed a radiolucent area associated with the mesial and distal root apices that was stable in size on comparing with previous images. The tooth was diagnosed as an endodontically treated tooth with asymptomatic apical periodontitis. A limited FOV CBCT of tooth No. 18 was made to further investigate S the reason for the deep pocket. CBCT revealed previous endodontic treatment of tooth No.18 with three obturated canals. Obturation appeared adequate in length, taper and density. Radiolucent areas around the mesial and distal apices were noted with perforation of the lingual cortical plate distal to the roots. A fracture line was identified on the pulpal floor extending from the mesial root to the distal canal. The radiolucent lesion measured approximately 8 mm by 8 mm by 8 mm and was in close proximity to the inferior alveolar nerve canal (FIGURES 9B).

A 61-year-old male presented with a sinus tract on tooth No. 13. The tooth had been treated with nonsurgical root canal therapy. Tooth No. 13 was diagnosed with chronic apical abscess. A periapical radiograph of tooth No. 13 showed an endodontically treated tooth No. 13 with a periapical radiolucent lesion, however, the full extent of the lesion could not be seen in this radiograph. A limited FOV CBCT was acquired. CBCT images showed an expansile radiolucent lesion associated with the apex of tooth No. 13 close to the maxillary sinus. The floor of the sinus adjacent to the lesion was displaced with extreme thinning and possible perforation. Loss of the buccal cortex adjacent to the lesion was noted. Soft tissue thickening in the maxillary sinus adjoining the periapical lesion of tooth No. 13 was noted and consistent with sinusitis (FIGURES 9C).

Recommendation 10: Limited FOV CBCT should be considered as the imaging modality of choice for surgical placement of implants. [5,28]

A 50-year-old female presented for presurgical planning of dental implant placement in the area of missing teeth Nos. 12 and 13. A periapical radiograph of the region showed a normal trabecular pattern of bone with no evidence of pathosis; however, the assessment of the quantity of available bone in the region and the location of the floor of the maxillary sinus could not be assessed from this image. A limited FOV CBCT was acquired. The axial image slice of the CBCT showed the length of the edentulous span and the reference line perpendicular to the arch in the image referred to the location of the cross-sectional CBCT image slice. The cross-sectional image slice is vital to the preoperative assessment of the dental implant site. This image slice shows the morphology of the residual alveolar ridge in the buccolingual plane, the location of the floor of the maxillary sinus and the orientation of the long axis of the residual alveolar ridge. The measurement of the available height from the floor of the sinus and width of the residual alveolar ridge near the alveolar crest is shown in the image slice (FIGURES 10).

Recommendation 11: Limited FOV CBCT should be considered the imaging modality of choice for diagnosis and management of limited dentoalveolar trauma, root fractures, luxation and/or displacement of teeth and localized alveolar fractures in the absence of other maxillofacial or soft tissue injury that may require other advanced imaging modalities. [29]

A 62-year-old male presented with a swelling in the facial aspect of tooth No. 8. The patient reported that tooth No. 8 was endodontically treated several years prior following a facial trauma. A periapical radiograph revealed an endodontically treated tooth No. 8, obturated to the apex but with widening of the apical PDL space and a radiolucent area mesial of the apical region of this tooth. The lesion had progressively increased in size over the years as seen in comparison radiographs. A limited FOV CBCT revealed a horizontal fracture line in the buccal aspect of the root, 5 mm from the apex. Bone loss was noted on the facial, lingual and mesial surfaces of tooth No. 8 presenting as a wide radiolucent area around the root with the loss of facial cortex. Bone loss was seen in the vicinity of the noted horizontal fracture (FIGURES 11). Endodontic diagnosis was previous endodontic treatment with acute apical abscess and a horizontal fracture.

Recommendation 12: Limited FOV CBCT is the imaging modality of choice in the localization and differentiation of external and internal resorptive defects and the determination of appropriate treatment and prognosis. [30,31]

A 65-year-old- male presented with a chief concern of, “I was told I need to see endodontists to see if they can save my tooth.” A periapical radiograph showed an ovoid radiolucent area in the cervical region of tooth No. 11. The shadow of the pulp could be distinguished from the ovoid radiolucent area. A limited FOV CBCT of tooth No. 11 was acquired. CBCT images showed a radiolucent area in the cervical region of tooth No. 11 with palatal entry involving the palatal tooth surface and continuity with the pulp consistent with invasive external resorption. Clinically, there appeared to be a pinkish area that was in communication with the lesion with the palatal point of entry (FIGURES 12).

Recommendation 13: In the absence of clinical signs or symptoms, intraoral radiographs should be considered the imaging modality of choice for the evaluation of healing following nonsurgical and surgical endodontic treatment. [32]

For most typical endodontic management, clinical and historical information and periapical radiographs provide adequate information to assess successful treatment outcome.

Recommendation 14: In the absence of signs and symptoms, if limited FOV CBCT was the imaging modality of choice at the time of evaluation and treatment, it may be the modality of choice for follow-up evaluation. In the presence of signs and symptoms, refer to Recommendation 7. [32]

Evaluation of the periapical bone is one component in endodontic outcome assessment. Clinicians may use judgement and, where appropriate, use CBCT imaging to facilitate evaluation of post-treatment changes, as necessary.

CBCT imaging has the potential to provide information of value to a successful outcome of endodontic treatment. However, appropriate patient selection is a key element to its effective use. The AAE-AAOMR recommendations for patient selection provide guidance to selecting the most appropriate situations that would likely benefit from CBCT imaging. It is also important to recognize that CBCT information may be inconclusive or may not provide the anticipated additional information. Beyond patient selection and optimization of the imaging protocol, the value of the diagnostic imaging is provided by the dentist’s evaluation and interpretation of the findings. Dentists who use CBCT imaging must be skillful in interpreting these images. This requires knowledge of the radiographic anatomy, pathology and an understanding of the CT image formation. For example, the dentist must recognize that artifacts generated by metallic dental restorations, implants and high-attenuation endodontic restorative materials can negatively impact image interpretation. Such artifacts manifested as streaks and dark bands are referred to as “beam hardening artifacts.” Some vendors provide software tools that manipulate CT image reconstruction to reduce the appearance of these artifacts. However, such approaches also alter and can potentially decrease diagnostic information. Dentists who use these tools must be aware of these inadvertent effects and apply such image correction tools with caution.

This pictorial essay demonstrates that the recommendations in the joint AAE- AAOMR position statement on the use of CBCT in endodontics are a rational and effective approach to implementing CBCT technology in endodontics. Although CBCT is associated with higher radiation levels than traditional periapical radiography, this technology offers vital information to improve the diagnosis of the dental clinician in keeping with the ALARA principle of radiation protection for better patient outcomes. The benefits of additional information obtained with CBCT may in many cases justify the increase in radiation exposure.

REFERENCES

1. Roda RS. Can use of cone beam computed tomography have an effect on endodontic treatment? J Calif Dent Assoc 2018 Apr;46 (4):237–46.

2. Lofthag-Hansen S, Huumonen S, Grondahl K, Grondahl HG. Limited cone beam CT and intraoral radiography for the diagnosis of periapical pathology. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007 Jan;103(1):114–9. doi: 10.1016/j.tripleo.2006.01.001. Epub 2006 Apr 24.

3. Low KM, Dula K, Burgin W, von Arx T. Comparison of periapical radiography and limited cone beam tomography in posterior maxillary teeth referred for apical surgery. J Endod 2008 May;34(5):557–62. doi: 10.1016/j. joen.2008.02.022.

4. Patel S, Dawood A, Mannocci F, Wilson R, Pitt Ford T. Detection of periapical bone defects in human jaws using cone beam computed tomography and intraoral radiography. Int Endod J 2009 Jun;42(6):507–15. doi: 10.1111/j.1365- 2591.2008.01538.x. Epub 2009 Mar 2.

5. Fayad MI, Nair M, Levin MD, Benavides E, Rubinstein RA, Barghan S, Hirschberg CS, Ruprecht A. AAE and AAOMR joint position statement — use of cone beam computed tomography in endodontics 2015 update. Oral Surg Oral Med Oral Pathol Oral Radiol 2015 Oct;120(4):508–12. doi: 10.1016/j. oooo.2015.07.033. Epub 2015 Aug 3.

6. De Paula-Silva FW, Wu MK, Leonardo MR, da Silva LA, Wesselink PR. Accuracy of periapical radiography and cone beam computed tomography scans in diagnosing apical periodontitis using histopathological findings as a gold standard. J Endod 2009 Jul;35(7):1009–12. doi: 10.1016/j. joen.2009.04.006.

7. Friedman S. Prognosis of initial endodontic therapy. Endod Topics 2002;2:59–98.

8. Patel S, Wilson R, Dawood A, Mannocci F. The detection of periapical pathosis using periapical radiography and cone beam computed tomography — part 1: Preoperative status. Int Endod J 2012 Aug;45(8):702–10. doi: 10.1111/j.1365- 2591.2011.01989.x. Epub 2011 Dec 21.

9. Abella F, Patel S, Duran-Sindreu F, Mercad M, Bueno R, Roig M. Evaluating the periapical status of teeth with irreversible pulpitis by using cone beam computed tomography scanning and periapical radiographs. J Endod 2012 Dec;38(12):1588–91. doi: 10.1016/j.joen.2012.09.003.

10. Cheung G, Wei L, MvGrath C. Agreement between periapical radiographs and cone beam computed tomography for assessment of periapical status of root filled molar teeth. Int Endod J 2013 Oct;46(10):889–95. doi: 10.1111/ iej.12076. Epub 2013 Feb 26.

11. Sogur E, Grondahl H, Bakst G, Mert A. Does a combination of two radiographs increase accuracy in detecting acid-induced periapical lesions and does it approach the accuracy of cone beam computed tomography scanning? J Endod 2012 Feb;38(2):131–6. doi: 10.1016/j. joen.2011.10.013. Epub 2011 Dec 6.

12. Patel S, Dawood A, Mannocci F, Wilson R, Pitt Ford T. Detection of periapical bone defects in human jaws using cone beam computed tomography and intraoral radiography. Int Endod J 2009 Jun;42(6):507–15. doi: 10.1111/j.1365- 2591.2008.01538.x. Epub 2009 Mar 2.

13. Nixdorf D, Moana-Filho E. Persistent dento-alveolar pain disorder (PDAP): Working towards a better understanding. Rev Pain 2011 Dec;5(4):18–27. doi: 10.1177/204946371100500404.

14. Pigg M, List T, Petersson K, Lindh C, Petersson A. Diagnostic yield of conventional radiographic and cone-beam computed tomographic images in patients with atypical odontalgia. Int Endod J 2011 Dec;44(12):1092–101. doi: 10.1111/j.1365- 2591.2011.01923.x. Epub 2011 Jul 26.

15. Blattner TC, George N, Lee CC, Kumar V, Yelton CGJ. Efficacy of CBCT as a modality to accurately identify the presence of second mesiobuccal canals in maxillary first and second molars: A pilot study. J Endod 2010 May;36(5):867– 70. doi: 10.1016/j.joen.2009.12.023. Epub 2010 Feb 21.

16. Michetti J, Maret D, Mallet J-P, Diemer F. Validation of cone beam computed tomography as a tool to explore root canal anatomy. J Endod 2010 Jul;36(7):1187–90. doi: 10.1016/j. joen.2010.03.029. Epub 2010 May 13.

17. Vizzotto MB, Silveira PF, Arús NA, Montagner F, Gomes BP, Da Silveira HE. CBCT for the assessment of second mesiobuccal (MB2) canals in maxillary molar teeth: Effect of voxel size and presence of root filling. Int Endod J 2013 Sep;46(9):870–6. doi: 10.1111/iej.12075. Epub 2013 Feb 26.

18. Edlund M, Nair MK, Nair UP. Detection of vertical root fractures by using cone beam computed tomography: A clinical study. J Endod 2011 Jun;37(6):768–72. doi: 10.1016/j. joen.2011.02.034. Epub 2011 Apr 13.

19. Metska ME, Aartman IH, Wesselink PR, Özok AR. Detection of vertical root fracture in vivo in endodontically treated teeth by cone beam computed tomography scans. J Endod 2012 Oct;38(10):1344–7. doi: 10.1016/j. joen.2012.05.003. Epub 2012 Jun 30.

20. Brady E, Mannocci F, Wilson R, Brown J, Patel S. A comparison of CBCT and periapical radiography for the detection of vertical root fractures in non-endodontically treated teeth. Int Endod J 2014 Aug;47(8):735–46. doi: 10.1111/ iej.12209. Epub 2013 Dec 11.

21. Liang H, Li Gang, Wesselink P, Wu M. Endodontic outcome predictors identified with periapical radiographs and cone-beam computed tomography scans. J Endod 2011 Mar;37(3):326–31. doi: 10.1016/j.joen.2010.11.032.

22. Christiansen R, Kirkevang L-L, Gotfredsen E, Wenzel A. Periapical radiography and cone beam computed tomography for assessment of the periapical bone defect one week and 12 months after root-end resection. Dentomaxillofac Radiol 2009 Dec;38(8):531–6. doi: 10.1259/dmfr/63019695.

23. Estrela C, Bueno MR, Leles CR, Azevedo BC, Azevedo JR. Accuracy of cone beam computed tomography, panoramic and periapical radiographic for detection of apical periodontitis. J Endod 2008 Mar;34(3):273–9. doi: 10.1016/j.joen.2007.11.023. Epub 2008 Jan 31.

24.Moura MS, Guedes OA, Alencar AH, Azevedo BC, Estrela C. Influence of length of root canal obturation on apical periodontitis detected by periapical radiography and cone beam computed tomography. J Endod 2009 Jun;35(6):805– 9. doi: 10.1016/j.joen.2009.03.013.

25. Ee J, Fayad IM, Johnson BR. Comparison of endodontic diagnosis and treatment planning decisions using cone beam volumetric tomography versus periapical radiography. J Endod 2014 Jul;40(7):910–6. doi: 10.1016/j.joen.2014.03.002. Epub 2014 Apr 16.

26. Venskutonis T, Plotino G, Tocci L, Gambarini G, Maminskas J, Juodzbalys G. Periapical and Endodontic status scale based on periapical bone lesions and endodontic treatment quality evaluation using cone-beam computed tomography. J Endod 2015 Feb;41(2):190–6. doi: 10.1016/j.joen.2014.10.017. Epub 2014 Dec 10.

27. Low KM, Dula K, Bürgin W, Arx T. Comparison of periapical radiography and limited cone beam tomography in posterior maxillary teeth referred for apical surgery. J Endod 2008 May;34(5):557–62. doi: 10.1016/j. joen.2008.02.022.

28. Tyndall D, Price J, Tetradis S, Ganz S, Hildebolt C, Scarf W. Position statement of the American Academy of Oral and Maxillofacial Radiology on selection criteria for the use of radiology in dental implantology with emphasis on cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol 2012 Jun;113(6):817–26. doi: 10.1016/j. oooo.2012.03.005.

29. May JJ, Cohenca N, Peters OA. Contemporary management of horizontal root fractures to the permanent dentition: diagnosis, radiologic assessment to include cone beam computed tomography. Pediatr Dent Mar–Apr 2013; 35(2):120–4.

30. Estrela C, Bueno MR, De Alencar AH, Mattar R, Valladares Neto J, Azevedo BC, De Araújo Estrela CR. Method to evaluate inflammatory root resorption by using cone beam computed tomography. J Endod 2009 Nov;35(11):1491–7. doi: 10.1016/j.joen.2009.08.009.

31. Durack C, Patel S, Davies J, Wilson R, Mannocci F. Diagnostic accuracy of small volume cone beam computed tomography and intraoral periapical radiography for the detection of simulated external inflammatory root resorption. Int Endod J 2011 Feb;44(2):136–47. doi: 10.1111/j.1365- 2591.2010.01819.x. Epub 2010 Nov 17.

32. Fayad MI, Nair M, Levin MD, Benavides E, Rubinstein RA, Barghan S, Hirschberg CS, Ruprecht A. AAE and AAOMR Joint Position Statement. Use of cone beam computed tomography in endodontics — 2015/2016 update. f3f142zs0k2w1kg84k5p9i1o-wpengine.netdna-ssl. com/specialty/wp-content/uploads/sites/2/2017/06/ conebeamstatement.pdf.

THE CORRESPONDING AUTHOR, Rumpta Ganguly BDS, DMD, MS, can be reached at rumpta.ganguly@ucsf.edu.