Special Committee to Revise the Joint AAE/AAOMR Position Statement on use of CBCT in Endodontics. 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;120:508-512. [PMID: 26346911 DOI: 10.1016/j.oooo.2015.07.033]

Microsurgical endodontic treatment of the upper molar teeth and their relationship with the maxillary sinus: a retrospective multicentric clinical study

PURPOSE

To assess the clinical and radiographic success rate of microsurgical endodontic treatment of upper molar teeth in relationship with the maxillary sinus, with 12 months follow-up.

METHODS

Patients treated with microsurgical endodontic treatment of upper molar teeth in the period between 2017 and 2019 were recruited from two dental clinics according to specific selection criteria. The outcomes were determined based on clinical and radiographic results taken three, six and 12 months post-operatively, compared with those taken immediately before and after surgery. Clinical and radiographic outcomes were recorded. The distance between the most apical part of the root and of the lesion to the maxillary sinus was measured on CBCT images before the surgery. Patient-related outcomes were recorded.

RESULTS

Out of 35 patients evaluated, 21 were selected according with the selection criteria for a total of 27 roots and 29 canals treated. After 12 months, 18 patients showed a complete healing whereas three demonstrated incomplete healing. Consequently, the success rate in this study was 85.7% after one year. In 28.5% (6 patients) there was a perforation of the Schneiderian membrane that didn't seem to affect the outcome. All patients kept the molar one year later. The pain level decreased significantly over the time during the first week after surgery.

CONCLUSION

Microsurgical Endodontic treatment of the upper molar teeth should be considered a valid and predictable treatment option even in case of Schneiderian membrane perforation. Future clinical studies with a larger sample size are needed to compare the results obtained.

Root canal morphology and symmetry of mandibular second premolars using cone-beam computed tomography

OBJECTIVES

The current study aims to investigate the morphology and symmetry of root canals of mandibular second premolar teeth via Cone-Beam Computed Tomography (CBCT) among a sample of the Saudi population.

METHODS

A total of 1200 CBCT images were examined in the study. The number of roots in the mandibular second premolars was identified, and canal configurations were classified according to Vertucci classification. Bilateral symmetry and association between gender and number of roots and root canal configuration were investigated using a chi-square test was utilized for data analysis and p value was set at 0.05 for significance.

RESULTS

Of the total 2400 Mandibular second premolars, 98.33% were single rooted and 1.67% were double rooted. The prevalence of double roots in females on the right side was significantly higher than that on the left side (p = 0.017), but the opposite was found among males. Only Type I and II canal configurations showed significant differences regarding gender and sides. 98.0% of teeth showed the symmetrical number of roots in both genders. The symmetry in canal configuration was 96.7% in males and 97.3% in females and 99.1% was Type I in both sides, 0.5% Type III, and 0.3% Type IV in both sides.

CONCLUSIONS

The root morphology of mandibular second premolars in the Saudi population demonstrated a high degree of variability. The vast majority of mandibular premolars have a single root with one canal and a low prevalence of two rooted teeth. Contralateral mandibular second premolars exhibited great symmetry of roots and root canal configuration.

Endodontic length measurements using cone beam computed tomography with dedicated or conventional software at different voxel sizes

The aim of this study is to investigate the accuracies and the agreements of the 3D Endo software, conventional CBCT software Romexis Viewer at three voxel sizes, and the EAL ProPex Pixi in endodontic length measurements. Three hundred and twenty-nine root canals in 120 intact human extracted molars were accessed. The actual lengths (AL) and electronic lengths (EL) were measured using the ruler and electronic apex locator (EAL), respectively. Teeth were scanned using the CBCT at different voxel sizes (0.075, 0.10, and 0.15 mm). Root canal lengths were measured using 3D Endo with proposed length (3D-PL) by software, corrected length (3D-CL), Romexis Viewer. The Fisher's exact test, paired t-test and Bland-Altman plots were calculated to detect the agreements of the four methods with AL measurements. The ProPex Pixi measurements obtained the highest accuracy in the range of ± 0.5 mm. There was agreement between the 3D-PL and the 3D-CL with AL measurements at voxel size of 0.15 mm and at voxel size of 0.10 mm, respectively. The CBCT Romexis Viewer measurements agreed with AL at three voxel sizes. The conventional CBCT measurements using Romexis Viewer and dedicated software did not reach to the 100% accuracy in the range of ± 0.5 mm.

Assessment of Perceptions of Cone-beam Computed Tomography and Endodontic Treatment in a Military Population

INTRODUCTION

Cone-beam computed tomographic (CBCT) imaging has had a significant impact in endodontic diagnosis and treatment planning. Previous studies have investigated provider attitudes and the use of CBCT technology, but little is known about patients' perceptions of the use of CBCT imaging in endodontics. This study assessed the perceptions of patients within a military population regarding the application of CBCT imaging for endodontic treatment.

METHODS

One hundred three consecutive, volunteer patients who were treated in a military dental treatment facility and prescribed a CBCT study according to the American Association of Endodontists/American Academy of Oral and Maxillofacial Radiology guidelines were given a Likert-type survey that recorded an initial level of knowledge and attitudes regarding the use of CBCT in endodontics. After standardized patient education in the form of a 2-minute video presentation describing the applications and risks associated with CBCT technology, CBCT volumes were acquired. A second survey was administered to record the patients' perceptions of the benefits and risks associated with CBCT imaging.

RESULTS

After the video, 75% of the participants had a more positive opinion of CBCT technology; 56% felt that CBCT imaging was essential, and 44% felt it was beneficial. Fifty percent of the participants reported CBCT imaging having less radiation than they previously thought, whereas 11% thought it was more radiation. A total of 85% would seek out a provider who uses CBCT imaging if treatment is needed in the future.

CONCLUSIONS

When presented with basic information, most patients within a military population perceive CBCT imaging to have an important role in endodontic treatment.

Assessment of Mesiobuccal Canal Configuration, Prevalence and Inter-Orifice Distance at Different Root Thirds of Maxillary First Molars: A CBCT Study

Aim

The aims of this study were to assess the prevalence and configuration of the second mesiobuccal (MB2) canal in the mesiobuccal MB root of permanent maxillary first molars at different root levels in a Saudi sub-population using cone‑beam computed tomography (CBCT) and to measure the inter-orifice distance between MB & MB2 at the pulpal floor level.

Materials and Methods

This retrospective study was carried out on CBCT images of Saudi patients seen at King Abdul Aziz University. A total of 106 maxillary first molars were evaluated using a specialized software program (iCAT CBCT software). The prevalence of MB2, canal configuration and location of joining (apical-middle-coronal), if present was calculated. Also, the inter-orifice distance between both canals was measured at the level of the pulpal floor. Chi‑square and one-way analysis of variance (ANOVA) were used.

Results

The MB2 canal was found in 92 (86.8%) maxillary first molar teeth. The MB and MB2 canals were joined in 61 (58%) cases, where the location of joining was 14 (23%), 17 (27%), and 31 (50%) in the coronal, middle, and apical third, respectively. The mean inter-orifice distance between both canals at the level of the pulpal floor was 2.52±0.76 mm.

Conclusion

The prevalence of MB2 canal in this Saudi sub-population was high. The prevalence decreased as the root canal approached the apical third. There was no correlation between the average distance and occurrence of canal joining. CBCT is useful in detecting and mapping the mesiobuccal root canal system, with a likelihood of enhancing the quality of root canal treatment.

Effect of a formalin-based fixation method on bone mineral content in human ex-vivo specimens

OBJECTIVE

Histopathology of formalin-fixated human ex-vivo specimens may be used as reference standard for evaluation of diagnostic index tests like CBCT or MRI. The aim was to estimate changes in bone mineral content (BMC) over time in human ex-vivo bone specimens fixated in a formalin-based solution for 24 h followed by storage in an alcohol-based medium for six months, assessed by dual-energy X-ray absorptiometry (DXA).

METHODOLOGY

Bone specimens (n = 19) from human ex-vivo mandibles donated for science were included. BMC was measured by DXA before fixation (D₀), after 24 h of immersion fixation in a formalin-based solution (D₁), and hereafter every 30 days (M₁-M₆) during storage in a 30% ethanol-based storage medium for 6 months. Changes in BMC from D₀ to D₁ and from D₀ to M₆ were calculated and mean change in BMC estimated.

RESULTS

Mean change in BMC from D₀ to D₁ was -0.73% (95% CI -1.75%; 0.29%), and from D₀ to M₆ -1.19% (95% CI -2.14%; -0.23%).

CONCLUSIONS

No changes in BMC of ex-vivo human bone specimens were found after 24 h formalin-based immersion fixation. After six months storage in an ethanol-based medium, BMC mean loss of 1% was detected. In this range, changes in BMC are not clinically relevant.

Conservative endodontic management using a calcium silicate bioceramic sealer for delayed root fracture: A case report and review of the literature

BACKGROUND

The success rate of conservative endodontic management for root fracture varies greatly based on different methods used. It has been rarely reported that calcium silicate-based materials are applied in root fracture treatment.

CASE SUMMARY

A 38-year-old male patient presented with spontaneous pain from the upper left anterior teeth for 1 wk. The spontaneous pain was subsequently relieved, but pain on mastication persisted for 3 d. The patient had a dental trauma from a boxing match 15 years ago. Cone beam computed tomography showed that the maxillary left central incisor had oblique fracture lines and a radiolucent lesion around the fracture line. The tooth was diagnosed with an oblique root fracture with no healing and symptomatic apical periodontitis. In the following conservative endodontic management, the coronal and apical fragments of the canal both were chemo-mechanically prepared and obturated using a single cone gutta-percha with iRoot SP (Innovative BioCreamix Inc, Vancouver, Canada), a new calcium silicate-based bioceramic root canal sealer. At follow-ups at 1, 6, 12, and 24 mo, the patient was asymptomatic and the radiolucency around the fracture line was healing radiographically.

CONCLUSION

Conservative root canal treatment is an alternative treatment in some cases of oblique root fracture with no healing. The application of bioceramic sealers and single core obturation techniques may also be essential to obtain an excellent outcome.

Diagnosis and Management of Apical Fenestrations Associated with Endodontic Diseases: A Literature Review

Apical fenestration describes a window-like opening of the alveolar bone that involves the root apex of the associated tooth. Mucosal fenestration is a similar defect of the overlying mucosa and, when presented with a concomitant apical fenestration, may expose the root apex to the oral environment. A fenestration may arise from physiological and pathological processes. Although its presence does not necessitate treatment per se, these lesions have significant clinical implications when associated with endodontic diseases. Apical fenestrations associated with endodontic infections are relatively uncommon and can easily be overlooked or misdiagnosed. A thorough understanding of these lesions is key for timely diagnosis and successful management. The aim of this study was to review the epidemiology, aetiological factors, characteristics, management methods and potential outcomes of apical fenestrations associated with endodontic diseases. A search of online databases for relevant studies was conducted. With the inclusion of hand searched articles, 20 articles, consisting of case reports and series, were identified, and the key characteristics of each case were summarised. Apical fenestrations were found to be most commonly associated with maxillary teeth and almost always occur on the buccal aspect of the alveolar bone. Clinicians may consider the possibility of an apical fenestration with concurrent endodontic pathology when patients present with non-healing sinus tracts, exposed tooth apices and/or persistent pain after endodontic treatment, particularly on palpation and mastication. Clinical signs and symptoms can vary, hence cone-beam computed tomography is an important tool for diagnosis. The management involves surgically restoring a favourable anatomical configuration of the root apex in relation to the alveolar bony housing and may be combined with guided tissue regeneration and/or grafting procedures. Sloughing, reopening and infection are potential complications. The literature on apical fenestrations associated with endodontic diseases is limited, thus further research is needed to develop evidence-based guidelines for the diagnosis and management of these lesions.

Application of image processing techniques to aid in the detection of vertical root fractures in digital periapical radiography

OBJECTIVES

To present an image processing framework to improve the detection of vertical root fractures (VRFs) in digital periapical radiography.

MATERIALS AND METHODS

Thirty endodontically treated human teeth (15 of them fractured with a metal post inserted into them, and 15 for the control) were enclosed in a dry mandible and radiographed individually. The proposed framework was applied to the raw data, as a preprocessing step, and was composed of four stages: geometric adjustment and negative, denoising, adaptive contrast enhancement, and gamma correction. The contrast-to-noise ratio (CNR) and sharpness of the image's VRF region were used for the objective evaluation of the method. In addition, five examiners evaluated the original and enhanced images, using a 5-point scale to assess confidence.

RESULTS

The objective results showed that the proposed framework increased the CNR of the VRF region by 173% compared to the standard preprocessing method provided by the detector's manufacturer. The results found by the human observers indicated that the area under the curve (AUC) and sensitivity of the diagnosis of VRF significantly increased by 4% and 17% (p ≤ 0.05), respectively, when the examiners evaluated the image with the proposed method concomitantly with the image available in the commercial software. However, the specificity was reduced.

CONCLUSIONS

The proposed image processing framework can be used as an additional tool to that provided by the manufacturer to increase the sensitivity and AUC of the diagnosis of VRF.

CLINICAL RELEVANCE

The proposed method can be easily used in clinical practice to aid VRF detection, since it does not incur high computational costs and does not increase the radiation dose applied to the patient.

Mesiobuccal and Palatal Interorifice Distance May Predict the Presence of the Second Mesiobuccal Canal in Maxillary Second Molars with Fused Roots

INTRODUCTION

The aim of this study was to evaluate if the configuration of canal orifices can predict the presence of a second mesiobuccal canal (MB2) in maxillary second molars with fused roots.

METHODS

Maxillary second molars with fused roots (N = 150) were scanned in a micro-computed tomographic device (pixel size = 9 μm) and evaluated regarding the root fusion type and the incidence of the MB2 canal. The centers of the canal orifices were connected, and the angles formed by the intersection of these lines as well as their distances were measured and statistically compared (1-way analysis of variance). Specimens were then assigned to 2 groups according to the presence (n = 65) or absence (n = 50) of the MB2 canal and compared regarding the angles and interorifice distances using the Welch t test. A binary logistic regression model estimated the association between the interorifice distance, the fusion type, and the presence of the MB2 canal, whereas receiver operating characteristic curve analysis was performed to evaluate the diagnostic abilities of significant variables. The significance level was set at 5%.

RESULTS

The most common fusion types were 1 and 6, and MB2 canal incidence was 47.3%. No statistical difference was observed in the angles or interorifice distances among teeth with different fusion types (P > .05). Distances from the mesiobuccal (MB) to the distobuccal and palatal (P) canal orifices as well as the MB and P angles were significantly higher in the presence of an MB2 canal (P < .05). A binary logistic regression model revealed that MB-distobuccal and MB-P distances were significant in the presence of an MB2 canal (P < .05). Receiver operating characteristic analysis indicated that MB-P distance had acceptable diagnostic accuracy for the prediction of MB2 canal presence. Sensitivity (specificity) calculated from the MB-P distances of 4.0, 4.5, and 5.0 mm were 89.2% (36.5%), 76.9% (58.4%), and 44.4% (71.4%), respectively.

CONCLUSIONS

MB-P interorifice distance is a strong predictor of the presence of the MB2 canal in maxillary second molars with fused roots.

[Imaginology in the diagnosis and planning of root duct systems: an updated review]

Root canal systems present a varied morphological conformation for each group of teeth. Several authors have described the anatomical conformation and its variants in different classifications, including the main, collateral, lateral, secondary, accessory, interduct, recurrent, apical delta and interradicular cavus canals. Currently, radiology still does not allow visualization of all these structures. However, proper use of imaging techniques together with the use of new 3D equipment for adjustments of acquisition parameters with adequate software and algorithms allows greater image precision, facilitating diagnosis and the planning of the most adequate approach for endodontic treatments. The objective of this article was to conduct a review of the literature to identify new concepts and useful imaging tools for better diagnoses.

Comparison of Cone Beam Computed Tomography and Digital Radiography in Detecting Separated Endodontic Files and Strip Perforation

The separation of endodontic files and strip perforation are among procedural intraoperative complications which may ultimately lead to the failure of root canal treatment. The aim of the present study was to compare the diagnostic potential of cone beam computed tomography (CBCT) and digital periapical radiographs in detecting separated rotary files and strip perforation in filled canals. Fifty human mandibular molars were selected for this study. The teeth were randomly divided into two groups based on endodontic errors (i.e., file separation and strip perforation). In each group, 25 of 50 mesial canals were randomly chosen for simulating the errors, while the other 25 canals were considered as the control group. In group one, a simulation of the separation of rotary files was performed using ProTaper F2 files. Strip perforation of the root canals in group two was achieved by number 2 and 3 Gates Glidden drills in the coronal third of the root canals. Digital periapical radiographs in two different horizontal angles and high-resolution CBCT scans were obtained from the teeth mounted on a dry human mandible with simulated soft tissue covering. Three experienced observers who were unaware of the study groups evaluated the digital periapical and CBCT image sets in two separate readings. Intraobserver and interobserver agreements, as well as accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were calculated and compared. Intraobserver and interobserver agreements ranged from poor to excellent and poor to good, respectively. The accuracy, sensitivity, specificity, PPV, and NPV for digital radiography in detecting separated files were 0.950, 0.813, 0.957, 0.929, and 0.880, respectively. The same values for CBCT were 0.747, 0.667, 0.900, 0.833, and 0.783, respectively. For the diagnosis of strip perforation, these values were 0.855, 0.800, 0.909, 0.889, and 0.833 for periapical radiography and 0.955, 1.000, 0.920, 0.926, and 1.000 for CBCT. In conclusion, CBCT was superior for diagnosing strip perforation of the filled root canals, while digital periapical radiographs performed better in the detection of separated rotary files.

Guided Endodontics for Managing Severely Calcified Canals

Endodontic treatment of teeth with pulp canal obliteration presents a challenge given the high likelihood of procedural errors and complications during treatment. These drawbacks can be avoided by using a personalized 3-dimensional (3D) guide designed by overlaying a cone-beam computed tomographic scan with an intraoral scan of the patient. This 3D guide enables the clinician to obtain a straight access to the obliterated root canal.This article described guided endodontics in managing 7 severely obliterated teeth using both virtually designed 3D guides and a customized 1-mm-diameter cylindrical bur. This treatment approach was demonstrated to be safe and fast and can be considered as a predictable technique for the location of calcified canals, thus minimizing complications.

Correlation of objective image quality and working length measurements in different CBCT machines: An ex vivo study

To investigate potential correlations between objective CBCT image parameters and accuracy in endodontic working length determination ex vivo. Contrast-to-noise ratio (CNR) and spatial resolution (SR) as fundamental objective image parameters were examined using specific phantoms in seven different CBCT machines. Seven experienced observers were instructed and calibrated. The order of the CBCTs was randomized for each observer and observation. To assess intra-operator reproducibility, the procedure was repeated within six weeks with a randomized order of CBCT images. Multivariate analysis (MANOVA) did not reveal any influence of the combined image quality factors CNR and SR on measurement accuracy. Inter-operator reproducibility as assessed between the two observations was poor, with a mean intra-class correlation (ICC) of 0.48 (95%-CI  0.38, 0.59) for observation No. 1. and 0.40 (95%-CI 0.30, 0.51) for observation No. 2. Intra-operator reproducibility pooled over all observers between both observations was only moderate, with a mean ICC of 0.58 (95%-CI 0.52 to 0.64). Within the limitations of the study, objective image quality measures and exposure parameters seem not to have a significant influence on accuracy in determining endodontic root canal lengths in CBCT scans. The main factor of variance is the observer.

Comparison of Cone-beam Computed Tomography and Periapical Radiography to Determine the Proximity of Periapical Lesions to Anatomical Structures in Premaxillary Area prior to Surgical Endodontics: A Clinical Study

Aim

In the anterior maxillary region when periapical (PA) surgery is contemplated, knowledge of relation between root apices and lesion, spatial relationship of tooth root to adjacent anatomical structures is essential. The aim of this study was to compare cone-beam computed tomography (CBCT) and PA radiography to determine the proximity of PA lesions to anatomical structures in the premaxillary area for decision-making before apical surgery.

Materials and methods

Twenty subjects were selected. Three endodontists viewed PA radiographs and CBCT images. These observers (1) determined proximity of lesion to anatomical structures and (2) made decisions on treatment based on each imaging modality. Chi-square test was used to check the relationship between the treatment plans given by PA radiographs and CBCT images. Reliability of the observations was evaluated using intraclass correlation (ICC).

Results

Significant difference was noted in the treatment plan selected by the observers using the two modalities (p < 0.05).

Conclusion

After the lesions were observed with CBCT, there was an increase in the number of teeth involved with the lesion. A change in the observer's treatment plan was recorded after viewing the CBCT scans.

How to cite this article

Sheth K, Kapoor S, Daveshwar S, et al. Comparison of Cone-beam Computed Tomography and Periapical Radiography to Determine the Proximity of Periapical Lesions to Anatomical Structures in Premaxillary Area prior to Surgical Endodontics: A Clinical Study. Int J Clin Pediatr Dent 2020;13(4):322-326.

Endodontic Length Measurements Using Different Modalities: An In Vitro Study

INTRODUCTION

The aim of this study was to investigate and compare the accuracy of the 3D Endo software, conventional CBCT software Romexis Viewer, and the EAL E-Pex Pro in WL determination.

MATERIALS AND METHODS

Three hundred and two root canals in 110 intact human extracted molars were accessed. The actual lengths (ALs) were measured. Root canal lengths were measured using 3D Endo with proposed length (3D-PL) by software, correct length (3D-CL), Romexis Viewer, and the E-Pex Pro. The percentages of the measurements in the range of ±0.5 mm to the AL were compared using the Fisher's exact test. The paired t test and Bland-Altman plots were calculated to detect the agreement of the four methods with the AL measurements. The statistical significance was set at P<0.05.

RESULTS

The accuracies in the range of ±0.5 mm to the AL were 83.8%, 86.7%, 48.3%, and 99.7% for 3D-PL, 3D-CL, Romexis Viewer, and E-PexPro, respectively. There were agreements between 3D-PL and Romexis Viewer with the AL measurements.

CONCLUSION

The CBCT measurements using 3D Endo with the proposed length by the software and Romexis Viewer with the voxel size of 0.15 mm agreed with the AL measurements of the root canals.

Preoperative Estimation of Endodontic Working Length with Cone-Beam Computed Tomography and Standardized Paralleling Technique in comparison to Its Real Length

An accurate estimation of the working canal length is essential for successful root canal treatment. This study is aimed at investigating the diagnostic accuracy of root canal length estimation on cone-beam computed tomography (CBCT) scans and digital paralleling radiographs (PAs), using the real canal length as a gold standard, and at evaluating the influence of canal curvature on this estimation. Sixty extracted human premolar teeth were selected for this study. Root canal length measurement was performed on CBCT scans (NewTom, Giano, Verona, Italy) and digital paralleling radiography (EzRay Air W; Vatech, Korea). The real working length was established by subtracting 0.5 mm from the actual canal length. No significant difference was found between CBCT and digital paralleling radiography. There was a tendency for underestimation of the root canal length measured on the CBCT images in 52 (86.7%) of the examined teeth and overestimation in 5 teeth (8.3%). All the digital radiographs slightly overestimated the real canal length. The analysis revealed a strong correlation between the estimation from moderate to severe curvature for digital radiography and CBCT images. Preoperative working length estimation can be made closest to its real clinical canal length on the standardized paralleling technique, using a long (16-inch) target-receptor distance.

The efficacy of five different techniques in identifying C-shaped canals in mandibular molars

Information regarding the canal anatomy especially in complex cases such as C-shaped canals is essential for a successful treatment. In this study, five different methods for identification of C-shaped canal configuration were compared. 108 extracted mandibular molars with fused roots were studied. Radiographic evaluation was carried out using periapical radiography and CBCT. After access cavity preparation, all specimens were evaluated by direct visual examination and then under dental operating microscope. Finally, the actual anatomy of each sample was determined by preparing horizontal cross sections of the roots (1 mm thick) and examining them under stereomicroscope as the gold standard. Among the techniques used, high-resolution CBCT manifested the highest accuracy, whereas periapical radiography had the lowest. All approaches can be useful in reaching a correct diagnosis. CBCT, especially the low-resolution modality, is an effective technique in the diagnosis of C-shaped anatomy.

Clinical decision-making and importance of the AAE/AAOMR position statement for CBCT examination in endodontic cases

AIM

To compare conventional radiographic and cone beam computed tomography (CBCT) findings with reference to the American Association of Endodontics and American Academy of Oral and Maxillofacial Radiology (AAE/AAOMR) joint position statement and to determine the effect of the CBCT on the initial diagnoses and treatment plans in a single-centre Postgraduate Endodontic Programme.

METHODOLOGY

The clinical CBCT scans of patients, treated at the Endodontic Department of the University of British Columbia, were reviewed for CBCT referrals by comparing them with corresponding radiographs. The features considered were periapical lesions, missed/extra canals, root fractures, complex anatomy, calcified canals and root resorption of tooth/teeth in question. Reasons for the CBCT prescriptions were assigned to 3 groups: to formulate the primary diagnosis, to confirm the diagnosis achieved by clinical examination and conventional radiographs, and to assist in treatment planning. Variables were compared statistically using chi-square and McNemar tests.

RESULTS

A total of 128 CBCT examinations were performed on 110 patients. No CBCT examination was performed more than once on the same tooth. Overall, 76% of CBCT examinations were performed on previously root filled teeth. CBCT images revealed a significantly higher incidence of periapical lesions (P = 0.002), missed canals (P < 0.001), vertical root fractures (P = 0.004) and complex anatomy (P = 0.008) than periapical radiographs. CBCT was prescribed most frequently to assist surgical treatment planning (62%) rather than for generating a diagnosis (9%) or confirming diagnoses (29%). Both the diagnosis (P = 0.001) and the treatment plan (P = 0.005) initially made by examining periapical radiographs were altered significantly by the subsequent CBCT examination by revealing information such as new periapical lesions, missed canals or involvement of buccal or lingual cortical bone.

CONCLUSION

CBCT examinations were prescribed mainly to assist treatment planning rather than for diagnosis. The majority of CBCT examinations were performed on previously root filled teeth. The additional information obtained from CBCT scans resulted in the alteration of the initial diagnoses as well as subsequent treatment plans in 59 out of 128 cases.

Management of Root Fenestration Using Buccal Decortication and Guided Tissue Regeneration: A Case Report and 3-dimensional Analysis

The management of patients with apical fenestration and clinical symptoms has always been limited to apical root resection and placement of the root tip within the bony crypt. This result would often present resolution of clinical symptoms based on a few case studies. In this case report, we present a case in which apical resection alone did not resolve the patient's discomfort; on the contrary, it resulted in further bone loss and persistence of clinical symptoms. A corrective surgery was performed with the use of guided bone regeneration in conjunction with decortication of the cortical plate to induce bleeding. The patient symptoms resolved within a few weeks after the surgery, and the follow-up scan showed apical root coverage. Three-dimensional analysis was performed to compare the bony changes between the 2 surgeries and showed a significant amount of bone gain of around 200 mm³ and a 2-mm linear bone gain opposite the distobuccal root. The case presents a conservative approach to manage root fenestration of the buccal plate without further compromising the root apex.

Missed canals in endodontically treated maxillary molars of a Brazilian subpopulation: prevalence and association with periapical lesion using cone-beam computed tomography

OBJECTIVES

To evaluate the prevalence of missed canals in endodontically treated maxillary molars through cone-beam computed tomography (CBCT) images and to verify their association with the presence of periapical lesions.

MATERIAL AND METHODS

Three oral radiologists evaluated 633 maxillary molars in CBCT exams regarding number of roots, number of root canals, number of missed canals, anatomic identification of missed canals, presence of periapical lesions, and root location of the periapical lesions. Data were statistically analyzed at a 5% significance level.

RESULTS

Descriptive statistical analysis showed that among 395 first molars, 218 had at least one missed canal, and 186 (46.5%) had a missed canal and periapical lesion simultaneously. Of these, 72.4% (134) of the missed canals were only mesiobuccal 2 (MB2). Among 238 s molars evaluated, 121 presented at least one missed canal, and 104 (43.6%) had a missed canal and periapical lesion simultaneously. Of these, 81.7% (85) of the missed canals were only MB2. The chi-squared test showed an association between the presence of missed canals and periapical lesions for 1st and 2nd maxillary molars. Teeth that presented a missed canal showed an odds ratio (OR) of 2.57 (p < 0.0001) of being associated with a periapical lesion. Missed canal occurrence was positively related to the number of root canals (z = 13.06, p < 0.0001), meaning when the number of root canals is higher, there is a higher probability of missed canal occurrence. According to the model calculated prediction, for a one-unit increase in the number of canals, the probability of missed canals increases by 4.22%.

CONCLUSIONS

It was concluded that MB2 was the most frequently missed canal, associated with the presence of periapical lesions in endodontically treated maxillary molars.

CLINICAL RELEVANCE

Professionals' negligence of anatomical root variations has been contributed to the high prevalence of missed canals, leading to failures in endodontic treatment. Their association with periapical lesion occurrence emphasizes the importance of correct detection and instrumentation of these canals.

Concentrated Growth Factor - Surgical Management of Large Periapical Lesion Using a Novel Platelet Concentrate in Combination with Bone Graft

Although endodontic therapy is typically successful, in approximately 10%-15% of the cases, symptoms can persist or reoccur. Periapical surgery is the preferred treatment of choice in failed root canal therapy, chronic periapical lesion, persistent apical periodontitis, etc., i.e., when conventional treatment modalities fail. Over the past few decades, although the list of indications for endodontic surgery has diminished, there exist definite cases in which the tooth cannot be retained without surgery. This case report, however, sheds light on the incorporation of a novel autologous platelet concentrate-concentrated growth factor (CGF) coupled with an osseograft in surgical endodontic procedure to ensure a swift and successful recovery of the periapical region subjected to extensive lesions. The use of an osseograft combined with CGF has numerous advantages as well due to the formation of sticky bone. There are no articles published in the literature with respect to the potent application of CGF and bone graft (sticky bone) in large periapical lesions to aid in the reparative process. In this case report, the 1-year follow-up radiographs and cone-beam computed tomography showed complete healing of the hard and soft-tissue lesions that conform to achieving repair and regeneration at a rapid rate in extensive periapical lesions.

Concentrated Growth Factor: A Novel Platelet Concentrate for Revascularization of Immature Permanent Teeth-A Report of Two Cases

This article elucidates the utilization of a novel platelet concentrate-concentrated growth factor (CGF) for rapid and successful healing outcome in regenerative endodontics. This case report focusses on two cases: 23-year-old and 21-year-old patients with incomplete root formation and periapical lesion. Case 1 and case 2 are classified as stage IV and stage II, respectively, in accordance with Cvek's classification of open apex and had varied outcomes. The extent of open apex, root dentin thickness, and lesion were assessed using periapical radiograph and CBCT. Revascularization procedure was carried out after obtaining patient consent. Following bleeding induction, CGF was prepared, placed, and condensed using pluggers in the root canal space, followed by the placement of mineral trioxide aggregate (MTA) up to the level of CEJ. At 1-year follow-up, apical closure with increased root dentin thickness and reduced periapical radiolucency was evident.

Accuracy of mean grey density values obtained with small field of view cone beam computed tomography in differentiation between periapical cystic and solid lesions

AIM

To determine if small and medium field of view (FOV) cone beam computed tomography (CBCT) adjusted grey density values can be used to distinguish between periapical cystic and solid lesions.

METHODOLOGY

Fifty-seven patients with periapical lesions having retrievable small or medium FOV CBCT images and biopsy samples were included. Two oral and maxillofacial pathologists examined the biopsy samples to provide the gold standard diagnosis of cystic or solid lesion. From the CBCT images, two independent examiners recorded the minimum adjusted grey density value of each lesion twice. Intra-examiner and inter-examiner reliability of the measurements were analysed, and sensitivity, specificity and accuracy of the minimum grey values in distinguishing a solid from cystic lesion were calculated. A receiver operating curve for diagnostic ability of adjusted grey density values to differentiate between periapical cystic and solid lesions was obtained, and the area under the curve (AUC) was calculated.

RESULTS

The intra- and inter-examiner reliability of the grey density values of the lesions and dentine were excellent. The AUC was 0.44 (P-value = 0.45). The adjusted grey density value with the greatest accuracy for differentiating between cystic and solid lesions had an accuracy, sensitivity and specificity of 0.54, 1.00 and 0.075, respectively.

CONCLUSIONS

Small FOV CBCT adjusted grey density values obtained by the device used in the study could not distinguish between periapical cystic and solid lesions. Further developments in CBCT devices are needed to improve the accuracy of grey density measurements.

Acemannan Used as an Implantable Biomaterial for Vital Pulp Therapy of Immature Permanent Teeth Induced Continued Root Formation

Direct pulp-capping, a vital pulp therapy, is used to protect and preserve pulp vitality by applying a biomaterial on the pulp exposure site. Acemannan, a polysaccharide extracted from Aloe vera, induces osteodentin-bridge formation to cover the exposure site in vivo. We evaluated the effect of acemannan sponges on partial pulpotomized permanent teeth with caries or accident-induced pulp exposure (n = 50). After removing infected dentin and inflamed pulp tissue, the teeth were randomly divided into acemannan or control (mineral trioxide aggregate (MTA) groups (n = 25). The teeth were examined immediately after treatment (baseline) and at 6- and 12-month follow-ups for clinical and cone beam computed tomography (CBCT) examination. The three-dimensional tooth length and root apex area were simulated to determine treatment success. We found that the overall success rate in the acemannan and MTA groups from baseline to 12-month follow-up was 90.91% and 95.65%, respectively, with no significant difference between the two groups (p > 0.05). In the success teeth in both groups, the root length increased, and the apex area significantly decreased (p < 0.05), indicating continued root formation. Our results suggest that acemannan is a promising low-cost biomaterial for partial pulpotomy treatment for immature permanent teeth requiring vital pulp therapy.

Guided Endodontic Treatment of Calcified Lower Incisors: A Case Report

A 52-year-old female patient was diagnosed with chronic periapical periodontitis associated with severely calcified lower central incisors. Radiographic examination revealed no visible root canal in the coronal-third of the root. After choosing the guided endodontic treatment, an intraoral scan (Trios, 3shape, Copenhagen, Denmark), in conjunction with a cone beam computed tomography (CBCT) scan, was taken in order to design and fabricate a printed guide. Virtual implant software was used to visualize the surgical access into the sclerosed root canals. After locating the canals, the guide was removed, and the teeth were treated under a rubber dam. The guided approach allows predictable, efficient endodontic treatment of teeth presenting calcified canals, with minimal removal of sound dentine and less risk of root perforations.

An investigation into dose optimisation for imaging root canal anatomy using cone beam CT

OBJECTIVES

To identify a dose as low as diagnostically acceptable and a threshold level of image quality for cone beam CT (CBCT) imaging root canals, using maxillary first molar (M1M) second mesiobuccal (MB2) canals of varying complexity for two CBCT scanners.

METHODS

Dose-area product (DAP) and contrast-to-noise ratio (CNR) were measured for two scanners at a range of exposure parameters. Subjective-image-quality assessment at the same exposures was performed for three M1Ms of varying MB2 complexity, positioned in an anthropomorphic phantom. Nine raters (three endodontists, three dental radiologists and three junior staff) assessed canal visibility, using a 5-point confidence scale rating.

RESULTS

Identification of simple-moderate MB2 canal complexity was achieved at a range of protocols, with DAP values of ≥209.3 and ≥203.2 mGy cm² and CNRs of 3 and 7.6 for Promax^®3D and Accuitomo-F170^® respectively. For complex canal anatomy, target subjective image quality was not achieved, even at the highest DAP values for both scanners. Junior staff classified significantly more images as undiagnostic compared with senior staff (p = 0.043).

CONCLUSIONS

In this first study to address optimisation of CBCT imaging of root canal anatomy, a similar threshold dose for both scanners was identified for M1Ms with simple-moderate MB2 canal complexity. Increasing dose to enhance visualisation of more complex canal anatomy was ineffective. Selection of standard protocols (while avoiding lower kV/mA protocols) instead of high-resolution scans was a practical means of reducing patient dose. CNR is not a transferable measure of image quality.

Cone-beam computed tomography and its applications in dental and maxillofacial radiology

Cone-beam computed tomography (CBCT) was first used in dental and maxillofacial radiology (DMFR) at the end of the 1990s. Since then, it has been successfully established as the standard three-dimensional radiographic imaging technique in DMFR, with a wide variety of applications in this field. This manuscript briefly reviews the background information on the technology and summarises available data on effective dose and dose optimisation. In addition, typical clinical applications and indications of the technique in DMFR are presented.

3D Assessment of Endodontic Lesions with a Low-Dose CBCT Protocol

Background: Cone beam computed tomography (CBCT) is often used in different fields of dental science, especially in complex anatomical districts like the endodontic one. The aim of this study is to propose a low-dose CBCT protocol useful in cases of endodontic lesions. Methods: The device used was a MyRay Hyperion X9-11x5; the low dose setting of the machine was 90 Kv, 27 mAs, CTDI/Vol 2.89 mGy. The absorbed organ doses have been evaluated with an anthropomorphic phantom loaded with thermoluminescent dosimeters positioned at the level of sensitive organs like brain, bone marrow, salivary glands, thyroid, esophagus, oral mucosa, extrathoracic airways, and lymph nodes. Equivalent and effective doses have been calculated; the last one has been calculated using the recommendations approved by the Main Commission of ICRP (International Commission Radiological Protection) in March 2007. For the assessment of image quality, five senior clinicians, independent and experienced clinicians, were asked to state if CBCT scans were accurate enough to assess endodontic lesions. Results: The use of a low-dose CBCT acquisition produced the lowest organ dose (5.01 microSv) at the level of the esophagus. Image quality has been considered accurate enough for endodontic diagnostic needs. Conclusions: CBCT low-dose protocol can be used over the standard one in endodontic special cases because it provides a significantly lower radiation dose to the patients while ensuring good image quality. However, further studies are necessary to evaluate the opportunity of low-dose CBCT exams in endodontic clinical practice.

Biomarker for Asymptomatic Apical Periodontitis in Gingival Crevicular Fluid: aMMP-8

Objectives  Asymptomatic apical periodontitis (AAP) is one of the most widespread chronic inflammatory diseases in the field of dental medicine. Active matrix metalloproteinase (aMMP-8) previously demonstrated diagnostic potential as a biomarker for AAP in gingival crevicular fluid (GCF). The aim of this study was to determine the levels and diagnostic accuracy of aMMP-8 in GCF from teeth with AAP.

Materials and Methods  In this cross-sectional study, GCF samples were obtained from teeth with AAP (sample group, n = 31) and their contralateral teeth (control group, n = 31). Clinical and cone beam computed tomography (CBCT) parameters were used for the diagnosis and assessment of AAP and the determination of clinically healthy marginal periodontal tissues. One pool GCF sample per tooth was obtained from the whole crevice’s perimeter. aMMP-8 levels were determined by enzyme-linked immunosorbent assay (ELISA).

Statistical Analysis  Wilcoxon signed ranks test and Spearman rank correlation coefficient (rs) were used as statistical tools. The significance level was set at p < .05.

Results  The two groups demonstrated biomarker levels corresponding to a healthy marginal periodontal tissue. aMMP-8 levels were statistically and significantly higher in the samples collected from teeth with AAP. Lesions with greater volume showed correspondingly larger diameters. No statistically significant correlation between aMMP-8 levels and lesions’ volume or diameter was discovered.

Conclusion  GCF composition is modified by AAP only to a minimal extent. Further research is needed to substantiate the utilization of aMMP-8 as a potential biomarker for the diagnosis of the disease as well as to explore its relationship with other biomarkers.

Microscopic removal of type III dens invaginatus and preparation of apical barrier with mineral trioxide aggregate in a maxillary lateral incisor: A case report and review of literature

BACKGROUND

Invaginated teeth pose greater challenges in clinical management because of their complex configuration. With advancements in equipment and materials, such as the dental operation microscope, cone-beam computed tomography and mineral trioxide aggregate, the preservation rate of type III dens invaginatus could be greatly increased.

CASE SUMMARY

This case report presented a 31-year-old woman with complaints of spontaneous swelling and pain in the right maxillary lateral tooth. With the aid of cone-beam computed tomography, type III dens invaginatus with apical periodontitis was diagnosed and confirmed. Three-visit endodontic treatment was performed. In the first visit, the invagination was carefully removed under the dental operation microscope, and chemomechanical preparation was done. In the second visit, mineral trioxide aggregate apical barrier surgery was performed in this tooth. In the third visit, the canal was finally obturated with thermoplastic gutta-percha to recover the crown morphology. A 26-mo follow-up revealed a satisfied outcome both in the radiographic and oral examinations.

CONCLUSION

In this case, removal of the entire abnormal structure provided great convenience for the follow-up treatment. When confronted with the same clinical case in the future, we can take a similar approach to address it.

The anatomical relationship between the roots of erupted permanent teeth and the mandibular canal: a systematic review

PURPOSE

This study reviewed the literature on the position of the mandibular canal (MC) relative to the root apices (RA) of neighbouring teeth using cone beam computed tomography (CBCT).

METHODS

The authors searched the PubMed, Scopus, EBSCO Dentistry and Oral Sciences Source, Cochrane and Lilacs databases for relevant English-language articles with no year limitations published through January 25, 2018.

RESULTS

The search identified 888 articles, 12 of which met the inclusion criteria. Three groups were found based on the measuring method: the shortest distance from the RA to the MC, the vertical distance from the RA to the MC, or the distance from the RA to the superior cortical bone of the MC. In the first and second groups, the shortest distances to the canines, first premolars, second premolars, first molars, second molars, and third molars were 3.8 mm, 4.76 mm, 1.65 mm, 1.23 mm, 0.64 mm, and 1.28 mm, respectively. In the third group, the shortest distances to the second premolars, first molars, and second molars were 2.71 mm, 3.82 mm, and 1.4 mm, respectively.

CONCLUSIONS

The distance from the MC to the RA was generally shorter in females and younger people, with decreasing distances in patients over 60 years old, and depended on the tooth type.

TRIAL REGISTRATION

The protocol for this systematic review was registered on PROSPERO (CRD42018085478).

Can Cone-beam Computed Tomography Change Endodontists' Level of Confidence in Diagnosis and Treatment Planning? A Before and After Study

INTRODUCTION

This study evaluated the influence of cone-beam computed tomography (CBCT) on endodondists' level of confidence in their diagnosis of endodontic cases and their treatment plans.

METHODS

Twenty clinical cases with periapical radiographs and small-volume CBCT scans were classified according to the American Association of Endodontists guidelines. Information was provided on patient clinical history, and both extraoral and intraoral examinations were simulated. Fifteen endodontists filled out 2 questionnaires. In the first (Q1), the clinical description and a periapical radiograph were presented, followed by the questions. Thirty days later, they answered a second questionnaire (Q2) containing the same clinical description and CBCT. Their confidence in diagnosis and treatment planning was analyzed before and after receiving the tomographic images. Responses were recorded on a 5-point Likert scale, and the Wilcoxon test was used to investigate before and after levels of confidence in diagnosis and treatment planning.

RESULTS

The CBCT images influenced confidence in diagnosis and treatment planning of endodontic cases classified as complex (Wilcoxon test; P ≤ .05). There was a substantial change in the treatment planned in both moderate and complex cases after CBCT. Case complexity did not affect the participants' decision to request complementary information through CBCT.

CONCLUSIONS

In complex cases, CBCT increased endodontists' confidence to diagnose and plan treatment, when compared with periapical radiographs. Endodontists tended to recommend intervention when periapical images were supplemented with CBCT. CBCT proved to be an imaging method that influences endodontists' preoperative evaluation and treatment choice.

Electronic processing of digital panoramic radiography for the detection of apical periodontitis

INTRODUCTION

This study aimed to evaluate the accuracy of both digital complete and small portion of panoramic radiography (PAN) in the detection of clinically/surgically confirmed asymptomatic apical periodontitis (AP) lesions with and without endodontic treatment.

METHODS

A total of 480 patients/teeth including 120 AP with and without endodontic treatment, and 120 healthy periapex with and without endodontic treatment were detected via CBCT using the periapical index system. Each diseased and healthy patient underwent PAN first and a CBCT scan within 40 days. All 480 cases were assessed by four different methods, as follows: complete PAN with clinical examination of each tooth available and not available, respectively, and small portion of PAN in which a root with crown and root without crown were displayed, respectively. Periapical index system was also used to assess AP by PAN. Accuracy for both complete and small portion of PAN with respect to CBCT was analyzed.

RESULTS

The overall accuracy of the four methods for teeth with endodontic treatment (73.4) was higher than teeth without endodontic treatment (66.6). Accuracy of complete PAN and portion of PAN was 71.3 and 68.7, respectively. As regards teeth without endodontic treatment, accuracy was higher for complete PAN in the upper/lower incisive area and for small portion of PAN in the upper molar area. No difference was found in teeth with endodontic treatment.

CONCLUSION

Complete and small portion of PAN showed greater accuracy in the upper/lower incisive area and upper molar area of untreated teeth, respectively, whereas no difference was found in treated teeth.

[Vital pulp preservation treatment in mandibular right first molar with vertical root fractures: a case report]

This case presents vertical root fracture with vital pulp in mandibular right first molar. Examinations of the history, clinical tests, laser Doppler flowmetry, and radiographs revealed that the tooth showed positive response to electric pulp testing and was normal compared with the healthy control tooth. This study aimed to use a novel vital preserving surgical technique (microapical surgery and nanometer bioactive materials) to make an effective therapeutic decision for the vital tooth with vertical root fracture.

Surgically-oriented anatomical study of mandibular premolars: A CBCT study

Background

The knowledge of root canal anatomy and of the anatomical relationship should be considered mandatory when planning surgical endodontics. The aim of the study was to investigate the anatomical features of mandibular premolars, evaluating their relationship with mental nerve.

Material and Methods

CBCT scans were evaluated recording the number of roots, root canal configuration and the relationship with mental nerve of 100 mandibular premolars. After simulating a resection of 3 mm of the root, the shape and the number of canals, and the distance to the buccal and lingual bone plate and to the mental foramen was evaluated.

Results

The one root - one canal configuration was the most common configuration. The mental foramen was located at the level of MSPs in 40% cases, and it was between MSP and MFP in 46% of cases. The distance between the apex and the vestibular plate was lower than the distance to the lingual one.

Conclusions

We found a significant heterogeneity in the anatomy of mandibular premolars. CBCT could be considered important when planning surgical endodontics in this region. Key words:Cone-Beam Computed Tomography, bicuspid, root canal, root canal therapy, apicoectomy, mandibular nerve.

Accuracy and Reliability of Root Crack and Fracture Detection in Teeth Using Magnetic Resonance Imaging

INTRODUCTION

Magnetic resonance imaging (MRI) has the potential to aid in determining the presence and extent of cracks/fractures in teeth because of better contrast without ionizing radiation. The objectives were to develop MRI criteria for root crack/fracture identification and to establish reliability and accuracy in their detection.

METHODS

MRI-based criteria for crack/fracture appearance was developed by an MRI physicist and a panel of 6 dentists. Twenty-nine human adult teeth previously extracted after a clinical diagnosis of a root crack/fracture were frequency matched to 29 controls. Samples were scanned using an in vivo MRI protocol and the reference standard (ie, ex vivo limited field of view cone-beam computed tomographic [CBCT] imaging). A blinded, 4-member panel evaluated the images with a proportion randomly retested to establish intrarater reliability. Overall observer agreement, sensitivity, and specificity were computed for each imaging modality.

RESULTS

Subjectively, MRI has increased crack/fracture contrast and is less prone to artifacts from radiodense materials relative to CBCT imaging. Intrarater reliability for MRI was fair to excellent (κ = 0.38-1.00), and for CBCT imaging, it was moderate to excellent (κ = 0.66-1.00). Sensitivity for MRI was 0.59 (95% confidence interval [CI], 0.39-0.76; P = .46), and for CBCT imaging, it was 0.59 (95% CI, 0.59-0.76; P = .46). Specificity for MRI was 0.83 (95% CI, 0.64-0.94; P < .01), and for CBCT imaging, it was 0.90 (95% CI, 0.73-0.98; P < .01).

CONCLUSIONS

Despite advantages of increased contrast and the absence of artifacts from radiodense materials in MRI, comparable measures of sensitivity and specificity (to limited field of view CBCT imaging) suggest MRI quality improvements are needed, specifically in image acquisition and postprocessing parameters. Given the early stage of technology development, there may be a use for MRI in detecting cracks/fractures in teeth.

Novel low-dose protocols using cone beam computed tomography in dental medicine: a review focusing on indications, limitations, and future possibilities

OBJECTIVES

A narrative review on the potential use of low-dose protocols for cone beam computed tomography (CBCT) was conducted to identify indications and their relevance for various dental disciplines.

MATERIALS AND METHODS

Google Scholar was searched using the words "low-dose CBCT". Reviews, consensus papers, clinical studies, and experimental studies were eligible for the initial screening process, but for data extraction only original articles were selected. Similar search procedures were then performed with the additional search words "pedo," "ortho," "endo," "implant," "perio," and "oral surgery." Furthermore, references of included articles were examined to identify further relevant articles.

RESULTS

After screening, 27 publications remained for the data extraction process. Low-dose protocols have been reported for specialties such as pediatric dentistry (evaluating orofacial clefts, periapical lesions, impacted teeth, and autotransplantation), orthodontics (cephalometric analysis and interim assessment of treatment results), endodontics (detecting root fractures, resorptions and periapical bone loss), implant dentistry (planning implant insertion, evaluating peri-implant fenestration and dehiscence), periodontology (assessing periodontal structures), and oral and maxillofacial surgery (assessing mandibular third molars and TMJs). Nevertheless, most of the literature available is related to non-clinical studies. Furthermore, there is a lack of position statements or guidelines from authoritative bodies regarding the use of low-dose protocols in dental medicine.

CONCLUSIONS

Low-dose protocols for CBCT imaging seem to have potential in various disciplines in dental medicine ranging from pediatric dentistry to oral and maxillofacial surgery. Dose reduction is usually achieved by mAs reduction, use of partial rotations, reduced number of projections, and larger voxel sizes, but seldom by kV reduction.

CLINICAL RELEVANCE

Albeit low-dose protocols have potential to result in a reduction of dose exposure for 3D imaging due to dental indications, there is a need to more clearly specify indications and limitations to avoid indiscriminate use of standard and high-dose CBCT scans in the future on the lines of ALARA/ALADA principles.

Fused roots of maxillary molars: characterization and prevalence in a Latin American sub-population: a cone beam computed tomography study

Objectives

The upper molars generally have three roots; therefore, different combinations of fusion can occur, increasing the possibility of finding more complex root canal systems. The purpose of this study was to evaluate the prevalence and characterization of fused roots in first and second maxillary molars using cone-beam computed tomography (CBCT) in a Colombian population.

Materials and Methods

A total of 1274 teeth were evaluated, of which 534 were maxillary first molars and 740 were maxillary second molars. Axial sections were made at the cervical, middle, and apical levels to determine the prevalence of root fusion and the types of fusion.

Results

Overall, 43% of the molars (n = 551) presented some type of fused root. Root fusion was present in 23.4% of the maxillary first molars. The most frequent type of fused root was type 3 (distobuccal-palatal; DB-P) (58.9%). Root fusion was observed in 57.6% of the maxillary second molars, and the most prevalent type of fused root was type 6 (cone-shaped) (45.2%). Of the maxillary molars, 12.5% were classified as C-shaped.

Conclusion

Within the limitations of this study, there was a high prevalence of fused roots in maxillary molars in the Colombian population, mainly in the maxillary second molars. In first molars, the most common type of fused root was type 3 (DB-P) and in second molars, the most common type was type 6 (cone-shaped). Additionally, molars with root fusion presented variation at different levels of the radicular portion, with implications for treatment quality.

A Novel Prefabricated Grid for Guided Endodontic Microsurgery

INTRODUCTION

This study aimed to introduce a novel method using cone-beam computed tomographic (CBCT) imaging and prefabricated grids to guide apical access during endodontic microsurgery and to compare its accuracy with that of the nonguided method.

METHODS

Forty-two roots from human cadaver jaws were selected. Twenty-one were randomly assigned to the experimental group (grid based) and their contralateral counterparts to the control group (nonguided). Preoperative CBCT images were used to design a drill path that intended to reach the palatal/lingual aspect of the roots without attempting to complete the osteotomy or to resect the entire root end. In the experimental group, prefabricated metal grids used during imaging and surgery acted as a reference in the design and drilling. Postoperative CBCT volumes were superimposed on the preoperative volumes, and the distances between the actual drill paths and the target points were measured. A dichotomized outcome of success versus failure was also recorded and compared. Statistical analysis was performed using the paired t test and Fisher exact test.

RESULTS

The mean deviation of the drill paths from the target points was 0.66 mm ± 0.54 mm (mean ± standard deviation) for grid-based drilling and 1.92 mm ± 1.05 mm (mean ± standard deviation) for nonguided drilling (P < .001). Grid-based drilling was on average 1.27 mm (95% confidence interval, 0.81-1.72 mm) closer to the target point than nonguided drilling. The probability of successful drilling was also significantly higher with grids than without grids (P = .02).

CONCLUSIONS

The proposed method of guided osteotomy and root-end resection using prefabricated grids was more accurate than the nonguided method.

C-shaped canals in first and second mandibular molars from Brazilian individuals: A prevalence study using cone-beam computed tomography

Introduction

The study aimed to evaluate, through in vivo tomographic analysis, the prevalence of C-shaped canals in mandibular first and second molars of Brazilian individuals, analyzing its frequency by thirds of the roots, and in contralateral teeth.

Methods

Images of 801 mandibular molars (379 first molars and 422 second molars) from 334 Brazilian individuals (142 men and 192 women) were identified through 1544 cone beam computed tomography (CBCT) exams, obtained from a private oral radiologic clinic. The cross-sectional configurations were analyzed to determine the frequency of C-shaped canals at three different axial levels and classified in categories by three experienced endodontists independently.

Results

The incidence of C-shaped canals was 181 (23%). Considering the type of tooth, 91 (24.01%) were identified in the first molars, and 90 (21.32%) were found in the second molars. The incidence was significantly higher in female individuals (P < 0.05) for both first and second molars. The most common C-shaped canal configurations were: C1 (89.01% for first molars and 90% second molars), followed by C2 (8.79% for first molars and 6.66% for second molars) and C4 (2.19% for the first molars and 3.33% for the second molars). Bilateral C-shaped canals were significantly higher than unilateral for both first and second molars (P < 0.01).

Conclusions

The prevalence of C-shaped canals in mandibular molars of the Brazilian individuals was higher than previously reported for both mandibular first (24.01%) and second molars (21.32%). The incidence was significantly higher in female individuals and the coronal portion of the roots. The classic C-shaped format “C1” was the most frequent anatomical configuration. Furthermore, the prevalence of bilateral C-shaped canals was higher for the first molar (61.70%) and lower for the second molar (38.29%).

Cone Beam Computed Tomography

In the last several decades, the need for 3D images in dentistry have developed. Computerized tomography was first introduced mainly with the advent of implantology, but its use remained limited to a small number of specialists, due to its indications, access and dose radiation. In the late 90's, a new technology using a cone-shaped beam and a reciprocating detector, which rotates around the patient 360 degrees and acquires projected data in a single rotation, namely the cone beam computerized tomography (CBCT), invaded dentistry, making the perception of 3D easily acceptable to dentists and their patients.

Endodontic management of the maxillary first molars with two root canals: A case report and review of the literature

BACKGROUND

The complex anatomy of the maxillary first molars has always been a major challenge for complete root canal treatment in endodontic therapy. Here, we present two cases of maxillary first molars, each with only two root canals, which have been rarely reported. We also perform a literature review of maxillary first molar anatomy.

CASE SUMMARY

The two patients were referred to the hospital after 1) finding a cavity in their tooth with a color change and, 2) a toothache during mastication, respectively. Both of these cases were diagnosed as apical periodontitis by X-ray imaging and cone beam computed tomography (CBCT). Non-surgical endodontic therapy was performed with the assistance of a dental operating microscope (DOM). CBCT showed rare but accurate images of both patients, each with two root canals and two roots in their maxillary first molars. Both roots were located in the buccal in the palatal direction, and each root had only one clear root canal. In addition, each maxillary first molar in both patients was symmetrical to that on the opposing side with only two separate root canals. Non-surgical endodontic therapy was performed with the assistance of a DOM. Finally, the teeth were restored using composite resin and the patients were satisfied with the results.

CONCLUSION

Making full use of CBCT and DOM would contribute to helping dentists make correct diagnoses and successfully treat teeth with rare root canal morphologies.