The potential applications of cone beam computed tomography in the management of endodontic problems

Management of a permanent maxillary first molar with unusual crown and root anatomy: a case report

The aim of this article was to showcase the endodontic management of a maxillary first molar with an unusual crown and root anatomy. Clinical diagnosis of the roots and root canal configuration was confirmed by a cone-beam computed tomography (CBCT) and the detection of the canals was made using a dental operating microscope. CBCT images revealed the presence of 5 roots with Vertucci type I canal configuration in all, except, in the middle root which had 2 canals with type IV configuration. The 6 canal orifices were clinically visualized under the dental operating microscope. Clinicians should familiarize themselves with the latest technologies to get additional information in endodontic practice in order to enhance the outcomes of endodontic therapy.

External cervical resorption-part 1: histopathology, distribution and presentation

External cervical resorption (ECR) is the loss of dental hard tissue as a result of odontoclastic action. It is a dynamic process that involves periodontal, dental and in later stages pulpal tissues. Over the last two decades, ECR has attracted increased interest; this is in part due to novel micro-CT and histopathological techniques for its assessment and also improved radiographic detection using CBCT. This literature review will cover the aetiology, potential predisposing factors, histopathology and diagnosis of ECR. Part 2 will cover the management of ECR.

The prevalence of second canals in the mesiobuccal root of maxillary molars: A cone beam computed tomography study

The aim of this study was to determine the prevalence of MB2 canals in permanent maxillary molars utilising CBCT; in patients attending a university hospital. A total of 200 patient scans, (100 female and 100 male patients), were enrolled in the study. In total, 800 teeth were analysed, and teeth with additional canals in their MB roots (MB2) were identified. First maxillary molar teeth exhibited the highest prevalence of MB2 canals, 92% and 87%, for teeth 16 and 26, respectively. Second maxillary molar teeth showed a lower prevalence of MB2 canals, 69% and 65%, for the 17 and 27, respectively. There were no associations of significance between the prevalence of MB2 canals and patient age or gender. Root morphology and anatomy of permanent maxillary first and second molar teeth was found to be highly variable. The prevalence of additional canals in the MB roots is a frequent finding which has previously been underreported.

Diagnostic accuracy of cone-beam computed tomography scans with high- and low-resolution modes for the detection of root perforations

Purpose

This study compared the diagnostic accuracy of cone-beam computed tomography (CBCT) scans obtained with 2 CBCT systems with high- and low-resolution modes for the detection of root perforations in endodontically treated mandibular molars.

Materials and Methods

The root canals of 72 mandibular molars were cleaned and shaped. Perforations measuring 0.2, 0.3, and 0.4 mm in diameter were created at the furcation area of 48 roots, simulating strip perforations, or on the external surfaces of 48 roots, simulating root perforations. Forty-eight roots remained intact (control group). The roots were filled using gutta-percha (Gapadent, Tianjin, China) and AH26 sealer (Dentsply Maillefer, Ballaigues, Switzerland). The CBCT scans were obtained using the NewTom 3G (QR srl, Verona, Italy) and Cranex 3D (Soredex, Helsinki, Finland) CBCT systems in high- and low-resolution modes, and were evaluated by 2 observers. The chi-square test was used to assess the nominal variables.

Results

In strip perforations, the accuracies of low- and high-resolution modes were 75% and 83% for NewTom 3G and 67% and 69% for Cranex 3D. In root perforations, the accuracies of low- and high-resolution modes were 79% and 83% for NewTom 3G and was 56% and 73% for Cranex 3D.

Conclusion

The accuracy of the 2 CBCT systems was different for the detection of strip and root perforations. The Cranex 3D had non-significantly higher accuracy than the NewTom 3G. In both scanners, the high-resolution mode yielded significantly higher accuracy than the low-resolution mode. The diagnostic accuracy of CBCT scans was not affected by the perforation diameter.

Prevalence of C-shaped canal system in mandibular first and second molars in a Saudi population assessed via cone beam computed tomography: a retrospective study

OBJECTIVES

The purpose of this study was to determine the prevalence of the C-shaped root canal configuration, location of the longitudinal groove, sex differences, and unilateral/bilateral presence in mandibular first and second molars in a Saudi population using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT images for the mandibular first and second molars of 487 patients (a total of 529 first molars and 681 s molars) were evaluated. The teeth were assessed for the presence of C-shaped root canals according to Fan criteria. Subdivisions were also made according to sex, direction of the longitudinal groove, and unilateral/bilateral presence.

RESULTS

Only one C-shaped mandibular first molar was observed (0.19%), whereas 62 second molars (9.1%) exhibited C-shaped anatomy. Unilateral presence of the C-shaped root canal system was more common (53.85%). Female patients had a higher prevalence than males. Longitudinal grooves were most commonly found on the root lingual surface (58.1%).

CONCLUSIONS

The prevalence of the C-shaped canal configuration in a Saudi Arabian population was 0.19% in the mandibular first molar and 9.1% in the mandibular second molar. Longitudinal groove prevalence was highest on the lingual surface. Women had a significantly higher prevalence of the C-shaped canal configuration than men. Patients with unilateral presence of the C-shaped canal configuration were more common than those with bilateral presence.

CLINICAL RELEVANCE

Tooth type, patient sex, and ethnicity can help clinicians predict the prevalence of the C-shaped canal system in mandibular molars.

Cone-beam computed tomography analysis of root canal morphology in mandibular first molars in a Chinese population: a clinical study

Background

The aim of this study was to evaluate the root canal morphology of mandibular first molars in a Chinese population by using cone-beam computed tomography (CBCT).

Methods

In this study, CBCT images of 900 mandibular first molars were evaluated for the following details: (1) number of roots, (2) number of apical foramina, (3) frequency distribution of root canal configurations defined in accordance with Vertucci’s classification, and (4) frequency of occurrence of middle mesial (MM) canal.

Results

Overall, 74.9% of the evaluated mandibular first molars possessed two roots, and 55.4% exhibited three apical foramina. The evaluated teeth exhibited a relatively high prevalence of type IV canals in mesial (M) roots (76.8%) and type I canals in the distal (D) (79.4%), distobuccal (DB) (98.7%), and distolingual (DL) (100%) roots. There were no significant differences in the number of roots, incidence of apical foramina, or distribution of different canal configurations of mandibular first molars between men and women (P > 0.05). 1.9% of mandibular first molars possessed three mesial canals, and the highest frequency of occurrence of MM canals (4.1%) was among Chinese people below the age of 30 years.

Conclusions

CBCT scanning facilitates identification of the root canal system. In order to increase the success rate of treatment, it is important to obtain information about the variable morphology of root canals before endodontic treatment.

Trial registration

TJSKE20160412. Registered 12 April 2016.

Diagnostic validity of CT to assess degenerative temporomandibular joint disease: a systematic review

OBJECTIVES

The aim of this systematic review was to answer the focus question: "In subjects with degenerative joint disease (DJD) of the temporomandibular joint (TMJ), what is the diagnostic validity of CT or cone-beam CT (CBCT) compared with clinical protocols"?

METHODS

DJD should be assessed through clinical diagnosis according to RDC/TMD or DC/TMD. Search strategies were specifically developed to the following electronic databases: Cochrane, Latin American And Caribbean Health Sciences (LILACS), PubMed (including Medline), Scopus and Web of Science. Furthermore, partial grey literature search through Google Scholar, OpenGrey and ProQuest was performed. The risk of bias was evaluated using the second version of Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2).

RESULTS

The databases search revealed 454 records. After applying the eligibility criteria, four studies were included in this review. All studies were methodologically acceptable, although none of the them fulfilled all criteria of risk of bias according to QUADAS-2. Despite there were some high values for sensitivity and specificity, they were not homogeneous between studies. Regarding specificity outcomes, there were three studies with poor values and only one considered as excellent.

CONCLUSIONS

CBCT could be a good image to evaluate DJD progression over time, but should not be used as a screening tool in healthy individuals.

Accuracy of Cone-beam Computed Tomographic Image Interpretation by Endodontists and Endodontic Residents

INTRODUCTION

Limited field cone-beam computed tomography (CBCT) imaging has become a modality frequently used by endodontists to evaluate the teeth and surrounding tissues of their patients. Accurate image interpretation is vital to obtain needed treatment information as well as to discern coincidental findings that could be present. The goal of this study was to determine the accuracy of CBCT volume interpretation when performed by endodontists and endodontic residents.

METHODS

Eighteen deidentified limited field CBCT scans were obtained and evaluated by an oral and maxillofacial radiologist and an endodontist experienced in reading CBCT images. Their collective findings were combined as the "gold standard" of interpretation for this investigation. Using standard CBCT software, 4 practicing endodontists and 5 second-year endodontic residents evaluated each scan and recorded any notable findings and whether or not each scan warranted referral to a radiology specialist. Their interpretations were then compared with the gold standard to determine accuracy and any significant differences among the groups.

RESULTS

The overall accuracy was 58.3% for endodontists and 64.3% for residents. Paired t tests showed no statistically significant differences in accuracy between the 2 groups for findings in teeth or in bone, but residents were significantly better for maxillary sinus findings. Endodontists agreed with the gold standard 38.9% of the time and residents 49.8% of the time on necessity of referral. The Cohen kappa coefficient showed moderate agreement between the groups.

CONCLUSIONS

Endodontists and residents had similar accuracy in CBCT scan evaluation. More training and experience are warranted for both groups in order to maximize image assessment accuracy.

An in vitro study to find the incidence of mesiobuccal 2 canal in permanent maxillary first molars using three different methods

Aim:

In-vitro study was done to evaluate the incidence of MB2 canals using three different methods (CBCT, CLINICAL ANALYSIS AND DENTAL LOUPES) and to compare the efficacy of the three methods in identifying the incidence of MB2 canals in maxillary permanent first molars.

Materials and Methods:

The study sample consisted of 120 extracted intact permanent maxillary molars. These extracted teeth were subjected to CBCT. Later the teeth were access opened with naked eye to find the incidence of MB2 canal, and then the teeth were visualised under dental loupe to locate MB2 canal if they were missed under naked eye. Results was statistically analysed by Mc Nemar's tests with Bonferroni correction, Chi square test and Cochran's Q test.

Result:

CBCT showed high incidence (68.3%) of MB2 canal in maxillary first molars and it showed to be a reliable method in detecting MB2 canal. When compared to dental loupe (52.5%) and naked eye (25%), the dental loupe improved the detection of MB2 canal.

Conclusion:

Within the parameter of this study in detecting the incidence of MB2 canal, using CBCT dental loupes and naked eye, detection of MB2 canal was significantly higher with CBCT followed by dental loupe and least with naked eye.

The Incidence of Second Mesiobuccal Canals Located in Maxillary Molars with the Aid of Cone-beam Computed Tomography

INTRODUCTION

Many endodontic treatment failures in maxillary molars result from missed second mesiobuccal (MB2) canals. An MB2 canal orifice is present in as many as 95% of maxillary molars, but these canals are not always located during endodontic procedures. Additional tools, such as cone-beam computed tomographic (CBCT) imaging, may be needed to locate these canals in maxillary molars. Hence, the aims of this study were to investigate the frequency of use of CBCT imaging during the treatment of maxillary molars and to evaluate the influence of its use on the detection of MB2 canals.

METHODS

Endodontic treatment records, digital intraoral radiographs (when present), and CBCT images from all maxillary first and second molars treated at the University of Washington, Seattle, WA, between 2010 and 2014 (N = 886) were reviewed. Statistical analysis was performed to assess differences between the groups.

RESULTS

Overall, an MB2 canal was found in 55.8% of the maxillary molars studied, and CBCT imaging assisted in detecting 11.7% of these canals. CBCT imaging was used in 16.5% of the cases treated and was used significantly more for retreatment cases. CBCT imaging was used preoperatively in 5.6% of cases, and the data show that significantly more MB2 canals were located when a preoperative CBCT image was available. More MB2 canals were located in first molars without full-coverage crowns.

CONCLUSIONS

The data show that CBCT imaging is a valuable tool in locating MB2 canals. Based on the results of his study, the use of CBCT imaging could be warranted when treating maxillary molars.

The prevalence and distribution of radiopaque, calcified pulp stones: A cone-beam computed tomography study in a northern Taiwanese population

Background/purpose

Presence of pulp stones increase the difficulty of locating canal orifice during endodontic treatment. This study aims to determine the prevalence of pulp stones in a northern Taiwanese population through analysis of cone beam computed tomography (CBCT).

Materials and methods

A total of 144 patients and 2554 teeth were used in the present study which were collected from a CBCT image archive. To determine the presence of pulp stones, images of pulp chamber and root canals were analyzed in the sagittal, axial and coronal planes and from the occlusal to apical direction. Correlations between pulp stones and gender, age, tooth type, dental arch or side were also examined.

Results

Of the 144 patients, 120 patients (83.3%) and 800 (31.3%) teeth were found to have one or more pulp stones through CBCT examination. Prevalence of pulp stones between dental arches and tooth types were significantly different (P < 0.001). Pulp stones were found to be the most prevalent in first molars (50.0%) and most scarce in first premolars (18.8%). There was no significant correlation between pulp stones and gender, increasing age, or dental sides.

Conclusion

Pulp stones are more frequent in maxillary teeth compared to mandibular teeth. Pulp stones in molar teeth were significantly more common than premolars and incisors. CBCT could be a sensitive tool to detect pulp stones, especially simplifying identification of pulp stones in radicular pulp. Knowledge of pulp stones distribution can aid dentists in clinical endodontic treatment.

Prevalence of Three Rooted Permanent Mandibular First Molars in Haryana (North Indian) Population

Background:

Mandibular first molars typically have two roots but sometimes a supernumerary root presents distolingually called as radix entomolaris (RE).

Aim:

The present study evaluated the prevalence of permanent mandibular first molars featuring a distolingual root in Haryana (North India).

Materials and Methods:

Five hundred patients possessing bilateral mandibular first molars were selected for this study. The intraoral periapical radiographs were taken. The radiographs of these patients were evaluated under optimal conditions. A total of 1000 mandibular first molars were screened, and the incidence of three-rooted mandibular first molars, RE and the correlation between left and right side occurrence and between either gender were recorded.

Statistical Analysis:

The binary logistic regression test and Pearson's Chi-square test were used for statistical analysis.

Results:

The prevalence of three-rooted permanent mandibular first molars was 13% of the patients examined and 8.3% of the teeth examined. There was no statistically significant difference between gender and side of occurrence (P ≥ 0.05). The bilateral incidence of a symmetric distribution was 27.6 (18/65) among the RE teeth examined.

Conclusion:

RE is considered as an Asiatic trait. The occurrence of this macrostructure in the Haryana (North India) population was found to be 13%. The clinician must thoroughly examine the radiographs before the initiation of endodontic therapy.

Impact of cone-beam computed tomography scan mode on the diagnostic yield of chemically simulated external root resorption

INTRODUCTION

The aim of this in-vitro study was to evaluate the influence of cone-beam computed tomography scans on the diagnosis of chemically simulated external root resorption.

METHODS

One hundred extracted anterior teeth were selected. Subsurface demineralization was induced on a limited area of the apical third of the root of 49 teeth. Each tooth was placed in an empty socket of a partially edentulous dry mandible. Cone-beam computed tomography images were obtained according to 3 protocols: (1) half scan, 0.40-mm voxel size; (2) full scan, 0.40-mm voxel size; and (3) full scan, 0.125-mm voxel size. Three observers evaluated the images. Sensitivity, specificity, accuracy, and area under the curve were compared with the Cochran Q and Mann-Whitney U tests.

RESULTS

Protocol 3 had the highest sensitivity (81.63%), accuracy (80.67%), and area under the curve (0.807). There were statistically significant differences between protocol 3 and the other 2 protocols (P <0.001). The specificity of protocol 1 (84.97%) was greater than that of protocols 2 (69.93%) and 3 (79.74%); however, a statistically significant difference was found only between protocols 1 and 2 (P = 0.005).

CONCLUSIONS

A more dedicated, high-resolution scan should be acquired when one intends to investigate the early stage of external root resorption during orthodontic treatment. However, this does not imply that all orthodontic patients should be subjected to high-dose cone-beam computed tomography scans.

Invasive cervical resorption and the oro-facial cleft patient: a review and case series

Introduction Invasive cervical resorption (ICR) has an unknown aetiology, yet it exhibits very aggressive behaviour compared with typical external root resorption, posing a high risk of tooth loss.Aim To investigate the number of patients at the Dublin Cleft Prosthodontic Department with an oro-facial cleft who experienced ICR and to identify any possible aetiological factors.Materials and method A retrospective investigation of all oro-facial cleft patients treated at the Dublin Cleft Prosthodontic Department, St James's Hospital, Dublin. All patients' clinical and radiological records were reviewed. Patients where tooth loss became inevitable due to Class 4 ICR were analysed.Results From 588 oro-facial cleft patients, 14 (2.38%) patients with ICR were identified. Of these eight (57%) were female and six (43%) were male. Mean age at diagnosis was 28 years (range = 16-49 years). Cleft type: six (42.1%) unilateral cleft lip and palate, eight (57.9%) bilateral cleft lip and palate. Seventeen ICR affected teeth in total, with eleven (65%) maxillary central incisors, two (12%) maxillary lateral incisors, four (23%) maxillary canines, and one (7%) central, lateral and canine affected. Some, (N = 10, 71.4%) presented with ICR resulting in immediate tooth loss. Other patients (N = 4, 28.6%) developed ICR during or following prosthodontic treatment at the Cleft Centre. Tooth loss for this cohort, though not immediate, was inevitable. All had undergone fixed orthodontic appliance treatment and twelve had received dento-alveolar bone grafts. A number (N = 7, 50%) had undergone osteotomy, two (14%) had received night guard vital dental whitening and one had a history of trauma.Conclusions ICR, given its aggressive nature and ill-understood aetiology, poses significant treatment challenges. The most severe form of ICR (Class 4) leads inevitably to tooth loss. The slow-moderate progression of ICR may explain the late presentation found in this study, reinforcing the importance of long-term follow-up of this special dental care group.

Analyses of anatomical relationship between mandibular third molar roots and variations in lingual undercut of mandible using cone-beam computed tomography

Background/purpose

Anatomical features of the lingual undercut region is a potential factor that might increase the risk of displacement of a tooth or fragment. The aim of this study was to report the normal anatomical relationship of impacted lower third molar roots to the lingual cortex and soft tissues of mandible and anatomical variations of lingual balcony in the impacted third molar region.

Materials and methods

One hundred impacted third molars (54 males, 46 females) from 65 (31 men, 34 women) patients were evaluated for this study using cone-beam computed tomography. Three measurements [bone thickness, angle (Ang) 1 and Ang 2] were recorded on the coronal section slices of cone-beam computed tomography images; in these images, the impacted third molar root was closest to the lingual soft tissues.

Results

The average distance between the tooth root and the lingual outer cortical bone layer (bone thickness) was 1.03 mm. The averages of Ang 1 and Ang 2 were 140.61° and 153.44°. Ang 1 and Ang 2 of female patients were larger than those of male patients.

Conclusion

The narrow angulation of the lingual balcony region and the relationship between roots and lingual soft tissues should be noted to avoid undesirable complication of displacement of a tooth or fragment into sublingual, submandibular, and pterygomandibular spaces. There was no relation in the floor of the mouth between the position of the impacted third molar roots and different lingual undercut angulation variations.

Common Operative Procedural Errors and Clinical Factors Associated with Root Canal Treatment

Abstract Operative procedural errors must be well analyzed in order to avoid influence negatively the root canal treatment (RCT) prognosis. The successful RCT prevents tooth loss and avoids pain and apical periodontitis. This review aimed to categorize common operative procedure errors and clinical factors associated with RCT. Based on this, will be approached common errors of procedures within the clinical operative sequence: endodontic treatment planning, pulp and periapical disease diagnosis, anaesthesia, access cavity preparation, isolation with rubber dam, root canal preparation, root canal filling and retreatment, restoration of endodontically treated teeth, postoperative pain, follow up of endodontically treated teeth. The professional must remind that in each phase of RCT an operative error may have adverse implication on prognosis, and these errors characterize risk factors to failure. The knowledge of probable operative procedural errors and its consequences are essentials to avoid future problems to the tooth health.

Characteristics and treatment of invasive cervical resorption in vital teeth. A narrative review and a report of two cases

Invasive cervical resorption (ICR) is a significant defect of the root surface where the hard dental tissues are undermined and become translucent due to the resorptive granulomatous tissue. It is mainly detected on radiographs. The radiographic appearance of ICR is asymmetrical radiolucency with irregular margins and an unchanged root canal. The purpose of this study is to present a comprehensive review together with the characteristics and the treatment of ICR through two cases which were followed-up for 36 months. In both cases the teeth were vital and the management consisted of raising a flap, granulomatous tissue removal, thorough debridement, restoration of the resorptive defect by placing a suitable filling material and follow-up examinations. Our results indicate that the specific treatment protocol has very positive outcomes. After 36 months pulpal vitality tests revealed a healthy pulp, and clinical and radiographic examination confirmed a stable periodontal condition.

Detection of Fractured Endodontic Instruments in Root Canals: Comparison between Different Digital Radiography Systems and Cone-beam Computed Tomography

INTRODUCTION

This study compared the detection of fractured instruments in root canals with and without filling by periapical radiographs from 3 digital systems and cone-beam computed tomographic (CBCT) images with different resolutions.

METHODS

Thirty-one human molars (80 canals) were used. Root canals were divided into the following groups: the control group, without fillings; the fracture group, without fillings and with fractured files; the fill group, filled; and the fill/fracture group, filled and with fractured files. Digital radiographs in ortho-, mesio-, and distoradial directions were performed in 2 semidirect systems (VistaScan [Dürr Dental, Beitigheim-Bissinger, Germany] and Express [Instrumentarium Imaging, Tuusula, Finland]) and a direct system (SnapShot [Instrumentarium Imaging]). CBCT images were acquired with 0.085-mm and 0.2-mm voxel sizes. All images were assessed and reassessed by 4 observers for the presence or absence of fractured files on a 5-point scale. The sensitivity, specificity, and accuracy were calculated.

RESULTS

In the absence of filling, accuracy values were high, and there were no statistical differences among the radiographic techniques, different digital systems, or the different CBCT voxels sizes. In the presence of filling, the accuracy of periapical radiographs was significantly higher than CBCT images. In general, SnapShot showed higher accuracy than VistaScan and Express.

CONCLUSIONS

Periapical radiographs in 1 incidence were accurate for the detection of fractured endodontic instruments inside the root canal in the absence or presence of filling, suggesting that this technique should be the first choice as well as the direct digital radiographic system. In the presence of filling, the decision to perform a CBCT examination must take into consideration its low accuracy.

Comparison of Cone Beam Computed Tomography and Multi Slice Computed Tomography Image Quality of Human Dried Mandible using 10 Anatomical Landmarks

INTRODUCTION

Cone Beam Computed Tomography (CBCT) has gained a broad acceptance in dentomaxillofacial imaging. Computed Tomography (CT) is another imaging modality for diagnosis and preoperative assessments of the head and neck region.

AIM

Considering the increased radiation exposure and high cost of CT, this study sought to subjectively assess the image quality of CBCT and Multi Slice CT (MSCT).

MATERIALS AND METHODS

A dry human mandible was scanned by five CBCT systems (New Tom 3G, Scanora, CRANEX 3D, Promax and Galileos) and one MSCT system. Three independent oral and maxillofacial radiologists reviewed the CBCT and MSCT scans for the quality of 10 landmarks namely mental foramen, trabecular bone, Periodontal Ligament (PDL), dentin, incisive canal, mandibular canal, dental pulp, enamel, lamina dura and cortical bone using a five-point scale.

RESULTS

Significant differences were found between MSCT and CBCT and among the five CBCT systems (p<0.05) in visualization of different anatomical structures. A fine structure such as the incisive canal was significantly less visible and more variable among the systems in comparison with other anatomical landmarks such as the mental foramen, mandibular canal, cortical bone, dental pulp, enamel and dentin (p<0.05). The Cranex 3D and Promax systems were superior to MSCT and all other CBCT systems in visualizing anatomical structures.

CONCLUSION

The CBCT image quality was superior to that of MSCT even though some variability existed among different CBCT systems in visualizing fine structures. Considering the low radiation dose and high resolution, CBCT may be beneficial for dentomaxillofacial imaging.

Evaluation of Root Fracture in endodontically treated Teeth using Cone Beam Computed Tomography

AIM

Our objective was to perform an in vitro evaluation of root fracture in endodontically treated teeth using two cone beam computed tomography (CBCT) machines.

MATERIALS AND METHODS

The sample comprised 86 single-rooted human premolars that had been fractured by a universal testing machine. The tomographic images were acquired using an Orthopantomograph OP300^® and an Orthophos XG 3D^® and evaluated by three examiners, by means of specific software. The teeth were classified into presence or absence of root fracture, then the root third where the fracture occurred, was determined. With regard to the detection of the fracture, the Kappa statistic was used for intra and interexaminer repro-ducibility at two distinct points in time. Chi-squared test was employed to analyze the sensitivity and specificity of the two tomographs (p < 0.05).

RESULTS

The results showed a good or excellent Kappa index between examiners. As for the absolute frequency, the sensitivity (0.6) of the Orthophos XG 3D^® equipment was superior, while specificity (0.91) was higher with the Orthopantomograph OP300^®. On the receiver operating characteristics curve, moderate performance was found with an accuracy of 0.73 (OrthopantomographOP300^®) and 0.74 (Orthophos XG 3D^®) respectively. As far as the location of the root fracture is concerned, moderate agreement was verified using the Kappa statistic (k = 0.56).

CONCLUSION

Although the regular CBCTs represent the imaging examination of choice for assisting root fracture diagnosis in endodontically treated teeth, their performance in this study demonstrated an imprecise diagnosis of fractures in a good many cases, irrespective of the tomography machine used.

CLINICAL SIGNIFICANCE

An early and precise detection of root fractures is of the utmost clinical importance, but the radiopaque and/or metallic filling materials in the CBCT viewing field may generate artifacts, known as the beam-hardening effect, which could compromise root fracture detection.

Topographic analysis of the maxillary premolars relative to the maxillary sinus and the alveolar bone using cone beam computed tomography

OBJECTIVE

The purpose of the present study was to elucidate the anatomic characteristics of the maxillary premolars for the planning of dental treatment using cone beam computed tomography (CBCT).

STUDY DESIGN

CBCT images were obtained for 150 maxillary premolars in 68 patients. The internal angle formed by the long axis of the maxillary premolars and the long axis of the alveolar bone was evaluated on the cross-sectional images. The vertical relationships between the maxillary premolars and the maxillary sinus were classified into 5 categories. The bone width and internal angle were compared among the images classified into the 5 categories.

RESULTS

The internal angle was 25.5 ± 6.9° at the maxillary first premolars. The incidence of Type I in the maxillary first premolars was 46.7%. In the maxillary second premolars, the incidence of Type I (14.7%) was significantly lower than the total incidence of Types II, III, IV, and V (85.3%). Type I had the significantly largest internal angle (28.0 ± 7.7°) among all types for the maxillary first premolars.

CONCLUSION

When considering dental treatment in the maxillary premolars, one should observe the inclination of the maxillary premolars to the alveolar bone as well as the position of the inferior wall of the maxillary sinus.

Detection of Second Mesiobuccal Canals in Maxillary First Molars Using a New Angle of Cone Beam Computed Tomography

Background

The localization of the additional canal orifice is one of the primary factors influencing the success of endodontic treatment. To deal with this problem, several techniques that each have their own advantages and disadvantages have been discussed in the literature.

Objectives

The aim of the present in vitro study was to review a new approach to localizing second mesiobuccal (MB2) canals in maxillary first molars using cone beam computed tomography (CBCT).

Patients and Methods

The CBCT scans of 296 patients who were referred to the department of dentomaxillofacial radiology were included in the study. The presence of MB2 canals, the angle formed by the mesiobuccal, distobuccal, and palatal root canal orifices (∠MDP), and the angle formed by the mesiobuccal, distobuccal, and MB2 canal orifices (∠MDMB2) were evaluated on the axial section. Pearson correlation and multiple linear regression methods were used for all predictions. All of the analyses were performed using SPSS for windows version 22.0. A two-sided P value < 0.05 was defined as statistically significant.

Results

Of the 468 first molars, MB2 canals were observed in 296 subjects (141 females and 155 males). There were no statistically significant differences between females and males (P = 0.300). The ∠MDP and ∠MDMB2 were detected and evaluated. A moderate positive correlation was found between the ∠MDP and the ∠MDMB2. To predict the ∠MDMB2 values, it was shown that the ∠MDMB2 increased by 0.420 degrees when the ∠MDP increased by 1 degree. If the ∠MDP was greater than 90.95 degrees, there was a 78% probability that MB2 canals could be found.

Conclusion

The determination of the presence of MB2 in the maxillary first molars may be carried out using CBCT scans. If the ∠MDP was 91 degrees or greater, there was considered to be a higher probability that MB2 canals would be found in the endodontic cavity. Due to the positive correlation between the ∠MDP and the ∠MDMB2, the localization of MB2 canals may be easily performed in relation to the main MB canal.

Cone-Beam Computed Tomography contrast validation of an artificial periodontal phantom for use in endodontics

Validation of image processing techniques such as endodontic segmentations in cone-beam computed tomography (CBCT) is a challenging issue because of the lack of ground truth in in vivo experiments. The purpose of our study was to design an artificial surrounding tissues phantom able to provide CBCT image quality of real extracted teeth, similar to in vivo conditions. Note that these extracted teeth could be previously scanned using micro computed tomography (μCT) to access true quantitative measurements of the root canal anatomy. Different design settings are assessed in our study by comparison to in vivo images, in terms of the contrast-to-noise ratio (CNR) obtained between different anatomical structures. Concerning the root canal and the dentine, the best design setup allowed our phantom to provide a CNR difference of only 3% compared to clinical cases.

Cone beam computed tomography aided diagnosis and treatment of endodontic cases: Critical analysis

Although intraoral radiographs still remain the imaging method of choice for the evaluation of endodontic patients, in recent years, the utilization of cone beam computed tomography (CBCT) in endodontics showed a significant jump. This case series presentation shows the importance of CBCT aided diagnosis and treatment of complex endodontic cases such as; root resorption, missed extra canal, fusion, oblique root fracture, non-diagnosed periapical pathology and horizontal root fracture. CBCT may be a useful diagnostic method in several endodontic cases where intraoral radiography and clinical examination alone are unable to provide sufficient information.

Apicoectomy of maxillary anterior teeth through a piezoelectric bony-window osteotomy: two case reports introducing a new technique to preserve cortical bone

Two case reports describing a new technique of creating a repositionable piezoelectric bony window osteotomy during apicoectomy in order to preserve bone and act as an autologous graft for the surgical site are described. Endodontic microsurgery of anterior teeth with an intact cortical plate and large periapical lesion generally involves removal of a significant amount of healthy bone in order to enucleate the diseased tissue and manage root ends. In the reported cases, apicoectomy was performed on the lateral incisors of two patients. A piezoelectric device was used to create and elevate a bony window at the surgical site, instead of drilling and destroying bone while making an osteotomy with conventional burs. Routine microsurgical procedures - lesion enucleation, root-end resection, and filling - were carried out through this window preparation. The bony window was repositioned to the original site and the soft tissue sutured. The cases were re-evaluated clinically and radiographically after a period of 12 - 24 months. At follow-up, radiographic healing was observed. No additional grafting material was needed despite the extent of the lesions. The indication for this procedure is when teeth present with an intact or near-intact buccal cortical plate and a large apical lesion to preserve the bone and use it as an autologous graft.

The accuracy of linear measurements of maxillary and mandibular edentulous sites in cone-beam computed tomography images with different fields of view and voxel sizes under simulated clinical conditions

PURPOSE

The objective of this study was to investigate the effect of varying resolutions of cone-beam computed tomography images on the accuracy of linear measurements of edentulous areas in human cadaver heads. Intact cadaver heads were used to simulate a clinical situation.

MATERIALS AND METHODS

Fiduciary markers were placed in the edentulous areas of 4 intact embalmed cadaver heads. The heads were scanned with two different CBCT units using a large field of view (13 cm×16 cm) and small field of view (5 cm×8 cm) at varying voxel sizes (0.3 mm, 0.2 mm, and 0.16 mm). The ground truth was established with digital caliper measurements. The imaging measurements were then compared with caliper measurements to determine accuracy.

RESULTS

The Wilcoxon signed rank test revealed no statistically significant difference between the medians of the physical measurements obtained with calipers and the medians of the CBCT measurements. A comparison of accuracy among the different imaging protocols revealed no significant differences as determined by the Friedman test. The intraclass correlation coefficient was 0.961, indicating excellent reproducibility. Inter-observer variability was determined graphically with a Bland-Altman plot and by calculating the intraclass correlation coefficient. The Bland-Altman plot indicated very good reproducibility for smaller measurements but larger discrepancies with larger measurements.

CONCLUSION

The CBCT-based linear measurements in the edentulous sites using different voxel sizes and FOVs are accurate compared with the direct caliper measurements of these sites. Higher resolution CBCT images with smaller voxel size did not result in greater accuracy of the linear measurements.

Effects of voxel size and resolution on the accuracy of endodontic length measurement using cone beam computed tomography

An accurate determination of the working length is indispensable for successful endodontic treatment. The aim of this study was to determine the influence of the voxel size and resolution of CBCT on measuring root canal working length. Thirty extracted single-rooted permanent teeth were used for this study. The working lengths of the teeth were determined by a researcher inserted a K-file into each canal until the tip became visible through the major foramen. The file was withdrawn until its tip was seen at the level of the coronal-most border of the major foramen under. The rubber stop was adjusted to the occlusal reference and the distance from the stop to the false tip was measured with digital calipers and recorded as the actual working length. The CBCT images were obtained with a Planmeca ProMax 3D Mid (Planmeca, Helsinki, Finland) using four sets of settings: from voxel size 0.5mm to voxel size 1.0mm. These measurements were compared with actual lengths (as a control group) using Analysis of Variance and the Dunnett Post Hoc Test. The Pearson correlation coefficient (r) and 95% confidence intervals were calculated to compare all measurement methods. The significance level was set at P<0.05. No significant difference was found among CBCT groups and working length. A highest correlation was found between the actual length and smallest voxel size and highest CBCT measurements (r=0.94). CBCT imaging can be used endodontic working length measurement and the smallest voxel size and highest resolution yielded more accurate results.

Abbott P. A Clinical Update on the Different Methods to Decrease the Occurrence of Missed Root Canals

One of the main causes of endodontic treatment failure is the clinician's inability to localize all the root canals. Due to the complex anatomy of the root canal system, missed canals are not uncommon. There are several strategies to decrease the possibility of missed root canals starting with good pre-operative radiographies. In order to overcome the limitations of conventional radiographies, cone-beam computed tomography (CBCT) can be considered. A correct access cavity preparation is of pivotal importance in localizing the orifices of the root canals. Furthermore, ultrasonics are very important devices to find missed canals. Increasing magnification and illumination enhance the possibility of finding all root canals during root canal treatment. The purpose of the present paper was to review all of the above techniques and devices.

Management of Oehler's Type III Dens Invaginatus Using Cone Beam Computed Tomography

Dens Invaginatus is a dental malformation that poses diagnostic difficulties in the clinical context. This anomaly may increase the risk of pulp disease and can potentially complicate endodontic procedure due to the aberrant root canal anatomy. Compared to conventional radiographs, three-dimensional images obtained with Cone Beam Computed Tomography (CBCT) are invaluable in the diagnosis of the extent of this anomaly and in the appropriate treatment planning. Oehler's classification (1957) for Dens Invaginatus (DI) into three types depending on the depth of the invagination has been used for treatment planning. Of the three types Type III DI is characterized by infolding of the enamel into the tooth up to the root apex and is considered as the most severe variant of DI and hence the most challenging to treat endodontically, due to the morphological complexities. This report describes a case of Oehler's Type III DI in a necrotic permanent maxillary lateral incisor in which CBCT images played a key role in diagnosis and treatment planning. The case was managed successfully by a combination of nonsurgical and surgical endodontic therapy with orthograde and retrograde thermoplastic gutta percha obturation.

Accuracy of Digital Subtraction Radiography in the Detection of Vertical Root Fractures

INTRODUCTION

The objective of this study was to evaluate the accuracy of digital subtraction radiography in the diagnosis of vertical root fractures (VRFs).

METHODS

Twenty decoronated uniradicular human teeth were placed in the alveoli of a dry mandible and radiographed twice, first without (unfilled roots) and then with (filled roots) a gutta-percha cone placed into the root canal. Roots were then removed from the dry mandible, and vertical fractures were created with the aid of a universal testing machine. The fractured roots were repositioned in the mandibular alveoli and again radiographed twice. Radiographic images were subtracted by using the Regeemy software in 3 test situations: group 1, initial radiographic images of unfilled roots and images of fractured or non-fractured unfilled roots; group 2, initial radiographic images of unfilled roots and images of fractured or non-fractured filled roots; and group 3, initial radiographic images of filled roots and images of fractured or non-fractured filled roots. Three examiners evaluated all the original digital radiographs, as well as the subtracted images, for the presence or absence of VRFs. Numerical data were subject to statistical analysis with the use of receiver operator characteristic (ROC) curves.

RESULTS

The areas under the ROC curve for groups 1, 2, and 3 were 0.86, 0.73, and 0.66, respectively. For the original digital radiographs, areas under the ROC curve were 0.80 (without gutta-percha) and 0.73 (with gutta-percha). No statistically significant differences were found between subtracted and original images.

CONCLUSIONS

Digital subtraction radiography could be considered as an alternative tool for the investigation of VRFs because of its comparable diagnostic accuracy to existing methods.

Endodontic Management of a Mandibular Incisor Exhibiting Concurrence of Fusion, Talon Cusp and Dens Invaginatus using CBCT as a Diagnostic Aid

Teeth with aberrant anatomy present a challenge to the endodontist. Advanced tools like cone beam computed tomography aid in exploring the details of endodontic architecture in such cases. The aim of this case report is to highlight the advantage of CBCT in endodontic management of teeth with multiple dental anomalies. A mandibular lateral incisor associated with an extraoral sinus tract revealed unusual clinical anatomy. A provisional diagnosis of type III dens in dente was made based on radiographic findings. Considering the complex anatomy, CBCT was advised to get a confirmatory diagnosis. The anatomic details revealed by CBCT differed significantly from the provisional diagnosis. A final diagnosis of concurrence of fusion with a supernumerary tooth, talon cusp and type II dens invaginatus was established and endodontic treatment of the concerned tooth was carried out. Non-surgical endodontic treatment resulted in successful resolution of the sinus tract and healing of the periapical lesion. CBCT, thus proves to be an excellent diagnostic tool for management of teeth with unusual anatomy, paving way for a conservative treatment free of endodontic mishaps.

Characterization of successful root canal treatment

Knowing the outcome of root canal treatment (RCT) is determinant to substantiate the clinical decision making process, especially when RCT is weighed against the extraction of natural teeth or replacement by prosthetic elements. The ideal scenario in all clinical situations should combine healing/prevention of disease (apical periodontitis) and the functional retention of the tooth. Understanding the risk factors associated with endodontic failure is a key factor to increase the chances of success. The logical action is to reverse the existing disease, which requires intervention to neutralize the bacterial invasion and disrupt the bacterial biofilm within the complex anatomy. Success is more predictable when the immune host defenses are favorable. However, success has different meanings to the dentist, to the patient and to the tooth itself. The life of an endodontically treated tooth depends on the accuracy of the diagnosis and planning, excellence of disinfection, instrumentation and filling procedures (antimicrobial strategies, root canal shaping and coronal and apical seal) and finally the rehabilitation management. The interpretation of constant or intermittent pain and/or discomfort associated with apical periodontitis (AP) in endodontically treated tooth may be suggestive of endodontic failure. The success features of RCT, namely absence of pain, regression of AP, tight seal of canal and coronal spaces, and recovery of tooth function, must be reevaluated over time. In case of doubt between success and failure, cone beam computed tomography (CBCT) could be indicated for detection and precise localization of AP. The possibility of map reading on CBCT images characterizes the real multidimensional structure, providing accurate information on the presence, absence or regression of AP. The survival of an endodontically treated tooth implies understanding the biological and mechanical outcomes as multifactorial events over the individual's life span. The objective of this review of literature is to discuss relevant factors associated with patient's health, tooth and dentist that could account for a successful RCT.

Evaluation of root morphology and root canal configuration of premolars in the Turkish individuals using cone beam computed tomography

OBJECTIVE

The aim of the present study is to assess the root and root canal morphology of maxillary and mandibular premolars in a Turkish population by using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

In this study, CBCT images of 2134 premolars (987 maxillary, 1147 mandibular) were obtained from 404 patients. Details of gender, age, number of roots and canals, and canal configuration in each root were recorded. The canal configuration was classified and evaluated according to Vertucci's criteria.

RESULTS

The majority of maxillary premolars had two separate roots; although, three roots were identified in 1% of maxillary first premolars. However, most of the mandibular premolars had a single root. The two canals (69.9%) and type I (62.6%) and type II (34.1%) configuration for upper first premolar, one canal (82.1%) and type I (77.6%) canal configuration for second premolar was the most prevalent root canal frequency. The most prevalent root canal frequency was the one canal (96.2%) and type I (94.2%) and type V (3.2%) configuration for mandibular first premolar, one canal (98.9%) and type I (98.9%) canal configuration for second premolar. There was no difference in the root canal configurations and the numbers of canals between the left and the right side of both females and males (P > 0.05).

CONCLUSIONS

Recognition of morphology and anatomy of the root canal system is one of the most important factors for successful endodontic treatment. Preoperative CBCT examination allows determination of root canal configuration of premolar teeth and helps clinicians in root canal treatment.

Cone-beam computed tomography study of the root and canal morphology of mandibular permanent anterior teeth in a Chongqing population

OBJECTIVE

To investigate the root and canal morphology of permanent mandibular anterior teeth in a Chongqing population using cone-beam computed tomography (CBCT).

METHODS

CBCT images of 1,725 patients in a Chongqing population were selected, and a total of 9,646 mandibular anterior teeth were analyzed. The number of root canals and the canal configurations were investigated.

RESULTS

In total, 0.3% (11/3,257) of lateral incisors and 0.8% (26/3,014) of canines had double roots, and 3.8% (127/3,375) of central incisors, 10.6% (345/3,257) of lateral incisors, and 4.2% (127/3,014) of canines had multi-root canals. The difference in the incidence of multi-canals in lateral incisors between female and male was statistically significant. The frequency of multi-canals in the different age groups was 5.0% for central incisors for ages 21-30 years, 14.7% for lateral incisors for ages 41-50 years, and 8.1% for canines for ages 41-50 years.

CONCLUSION

With the limitations of the current study, we found that a high percentage of mandibular anterior teeth had multiple canals in the studied Chinese Chongqing population. The current data may provide clinicians practicing in Chongqing with a more thorough understanding of root canal morphology.