Use of cone beam computed tomography in endodontics

Digital Determination of Curvature of Root Canals of Extracted Teeth

Introduction: Determination of the curvature of root canals at present is accomplished by complicated or expensive methods. Therefore, there is a need to develop a new digital method by which this curvature can be determined quickly, easily and accurately.

The aim of this in-vitro study is to determine the angles of curvature of the root canals of extracted teeth by comparing a new digital method of measurement with an established digital method.

Material and Methods: Forty-eight (48) root canals of extracted teeth were studied to achieve the goal. In all roots, curvature is measured by three methods: Method 1 – new digital photographic method and special Software (Screen Protractor); Method 2 – a new digital radiography method and special software (Screen Protractor); Method 3 – approved method, digital by X-ray and special Software (Durr dental).

Results: The mean degrees of the measured curvature of the root canals in all three groups are similar and are about 22°. There are no statistically significant differences between them (p > 0.05).

Conclusion: This shows that the new digital photographic and x-ray methods for measuring root curvature can accurately determine the curve angle for extracted teeth.

Intraoral Scanner, Three-Dimensional Imaging, and Three-Dimensional Printing in the Dental Office

The use of 3-dimensional (3D) cone-beam computed tomography (CBCT) imaging in the dental office has become a common imaging modality. The authors present an overview of multiple treatments that would benefit from the use of this technology. From preoperative, intraoperative, to postoperative patient management, 3D technology plays a vital role in the dental practice. With the incorporation of 3D CBCT, intraoral scanners, and 3D printing, a dental provider can accurately plan and execute the treatment with greater confidence. The contemporary dentist, however, has many options for incorporating the digital workflow based on the specific practice needs.

Evaluation of artificial intelligence for detecting periapical pathosis on cone-beam computed tomography scans

AIM

To verify the diagnostic performance of an artificial intelligence system based on the deep convolutional neural network method to detect periapical pathosis on cone-beam computed tomography (CBCT) images.

METHODOLOGY

images of 153 periapical lesions obtained from 109 patients were included. The specific area of the jaw and teeth associated with the periapical lesions were then determined by a human observer. Lesion volumes were calculated using the manual segmentation methods using Fujifilm-Synapse 3D software (Fujifilm Medical Systems, Tokyo, Japan). The neural network was then used to determine (i) whether the lesion could be detected; (ii) if the lesion was detected, where it was localized (maxilla, mandible or specific tooth); and (iii) lesion volume. Manual segmentation and artificial intelligence (AI) (Diagnocat Inc., San Francisco, CA, USA) methods were compared using Wilcoxon signed rank test and Bland-Altman analysis.

RESULTS

The deep convolutional neural network system was successful in detecting teeth and numbering specific teeth. Only one tooth was incorrectly identified. The AI system was able to detect 142 of a total of 153 periapical lesions. The reliability of correctly detecting a periapical lesion was 92.8%. The deep convolutional neural network volumetric measurements of the lesions were similar to those with manual segmentation. There was no significant difference between the two measurement methods (P > 0.05).

CONCLUSIONS

Volume measurements performed by humans and by AI systems were comparable to each other. AI systems based on deep learning methods can be useful for detecting periapical pathosis on CBCT images for clinical application.

Root canal segmentation in cone-beam computed tomography

Aim: The purpose of this study was to compare root canal volumes (RCVs) obtained by means of cone beam computed tomography (CBCT) to those obtained by micro-computed tomography (micro-CT) after applying different segmentation algorithms. Methods: Eighteen extracted human teeth with sound root canals were individually scanned in CBCT and micro-CT using specific acquisition parameters. Two different images segmentation strategies were applied to both acquisition methods (a visual and an automatic threshold). From each segmented tooth, the root canal volume was obtained. A paired t-test was used to identify differences between mean values resulted from the experimental groups and the gold standard. In addition, Pearson correlation coefficients and the agreement among the experimental groups with the gold standard were also calculated. The significance level adopted was 5%. Results: No statistical differences between the segmentation methods (visual and automatic) were observed for micro-CT acquired images. However, significant differences for the two segmentation methods tested were seen when CBCT acquired images were compared with the micro-CT automatic segmentation methods used. In general, an overestimation of the values in the visual method were observed while an underestimation was observed with the automatic segmentation algorithm. Conclusion: Cone beam computed tomography images acquired with parameters used in the present study resulted in low agreement with root canal volumes obtained with a micro-CT tomography gold standard method of RCV calculation.  

Cone-beam computed tomographic analysis on root and canal morphology of mandibular first permanent molar among multiracial population in Western European population

Objectives:

In the present study, confluent canals in the mandibular first molar's mesial root were investigated in an Italian population by means of cone-beam computed tomography (CBCT).

Materials and Methods:

A total of 200 molars, selected from the CBCT examinations of 130 patients who required this type of X-ray study as part of their dental treatment, were examined. The evaluated parameters were number of canals, root canal system configuration, presence of apical confluences, distance between confluences and apical foramina, which canal had a higher degree of curvature, and symmetry between left and right elements in the same individual.

Statistical Analysis Used:

Percentages of the cases were reported.

Results:

All the examined roots presented two canals. In 59% of cases, a Vertucci Type IV canal configuration was observed, while in 41% of cases, a Type II configuration was observed. Apical confluences were present in 41% of cases. The average distance between confluences and apical foramina was 2.85 mm. When confluences were present, the mesiobuccal canal showed a higher degree of curvature in 78% of cases. Symmetry in Vertucci configuration was seen in 88% of cases.

Conclusions:

Apical confluences in the mesial roots of mandibular molar can be present in a significantly high number of cases, and their recognition is essential to prevent the iatrogenic errors during canal instrumentation.

Prevalence of C-shaped mandibular molars in the Portuguese population evaluated by cone-beam computed tomography

Objective:

The purpose of this study was to evaluate the prevalence of first and second C-shaped mandibular molars in a Western European population of Portuguese Caucasians.

Materials and Methods:

Patients having both routine panoramic radiograph and presurgical cone-beam computed tomography (CBCT) exams were selected. The CBCT examination was performed at five different axial levels and the mandibular molars were classified as C-shape according to the Fan criteria. Differences between genders, age groups, left and right side, type of tooth, and root concavity side were determined. The molars were classified as nonfused roots (NFRI–II), FRI–III, or single root with single canal (SS) groups, using the panoramic radiograph. The prevalence of C-shaped anatomy was calculated to each group.

Results:

A total of 1783 teeth (695 first molars and 1088 second molars) from 792 patients were included in the study. The prevalence of C-shaped configurations was 0.6% and 8.5% to mandibular first and second molars, respectively. The differences between gender, teeth, and root concavity direction were considered statistically significant (P < 0.05). The FR had a significantly higher rate of C-shapes when compared to NFR (P < 0.05). Intrarater reliability was 93.6%.

Conclusions:

The FR radiographic appearance may be considered a predictor of this anatomy. Second mandibular molars and females had a higher incidence ratio. Apparently, the mandibular C-shaped anatomy is more common in the population of this study than that has been previously reported for the European population.

Multidisciplinary Treatment Approach for Perforated Internal Root Resorption: Three-Year Follow-Up

Internal root resorption (IRR) is described as a resorptive defect of the internal aspect of the root caused by odontoclastic activity associated chiefly with chronic pulp inflammation and trauma. An important variation to consider is the presence of a root perforation, although it is rare. This paper defines the use of CBCT in the diagnosis and combined nonsurgical and surgical multidisciplinary management and follow-up of a maxillary central incisor with perforating IRR in a 9-year-old female patient. At 3-year follow-up, clinical and radiographic findings of the case were satisfactory.

Investigation using cone beam computed tomography analysis, of radicular grooves and canal configurations of mandibular premolars in a Turkish subpopulation

OBJECTIVE

To conduct an in vivo evaluation of prevalence of root canal configurations, lengths of C-shaped canals, prevalence and depths of radicular grooves (RGs), in mandibular first and second premolars in a Turkish subpopulation using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT images of 327 first and 264 second premolars were included. Canal configurations, locations, lengths, and types of C-shaped canals, and RGs were evaluated on CBCT images. Data were statistically analyzed (P < 0.05).

RESULTS

First and second premolars were classified as follows: type I, (83.8%, 97.72%); type V, (12.22%, 0.76%); type III, (3.06%, 0.76%); and other types. RGs were exhibited by 14.68% of first and 2.27% of second premolars (P < 0.05). Incidence of complex canals (types III, V and other types, 89.8%) in first premolars with RGs was significantly higher versuswithout RGs (P < 0.05). C-shaped configuration was exhibited by 4.58% of first (80% semilunar-type), and 1.13% of second premolars (P < 0.05). All first premolars with C-shaped canals showed RGs and complex canals.

CONCLUSIONS

Complex canals and RGs frequently co-exist in mandibular premolars. C-shaped canals are not common in mandibular premolars, and mostly located in middle thirds. Type V is the most prevalent complex canal configuration in first premolars, and frequently associated with a C-shaped semilunar-type anatomy.

Symmetry of root and root canal morphology of mandibular incisors: A cone-beam computed tomography study in vivo

Background

Aim of this study was to analyze the root canal configuration in mandibular central and lateral incisors in vivo using cone-beam computed tomography (CBCT) imaging.

Material and Methods

A total of 487 mandibular central incisors and 491 mandibular lateral incisors from 250 patients were examined using CBCT imaging, previously taken for diagnosis and treatment. The number of roots, root canal system configuration, presence of apical confluences, distance between confluences and radiographic root end, symmetry between left and right elements were recorded and statistically analyzed.

Results

All the examined teeth presented only one root. No significant differences were found between the prevalence of two root canals in mandibular central incisors (219 teeth, 45%) compared to lateral incisors (211 teeth, 43%).

Conclusions

The percentage of Vertucci type II configuration was higher than expected, being more frequent than type III. Type I was the prevalent, while other configurations were present but rare. Key words:Cone-beam computed tomography, mandibular incisors, root canal anatomy, confluences.

Accuracy of linear measurements on CBCT images related to presurgical implant treatment planning: A systematic review

OBJECTIVE

The aim of this systematic review was to identify, review, analyze, and summarize available evidence on the accuracy of linear measurements when using maxillofacial cone beam computed tomography (CBCT) specifically in the field of implant dentistry.

MATERIAL AND METHODS

The search was undertaken in April 2017 in the National Library of Medicine database (Medline) through its online site (PubMed), followed by searches in the Cochrane, EMBASE, ScienceDirect, and ProQuest Dissertation and Thesis databases. The main inclusion criterion for studies was that linear CBCT measurements were performed for quantitative assessment (e.g., height, width) of the alveolar bone at edentulous sites or measuring distances from anatomical structures related to implant dentistry. The studies should compare these values to clinical data (humans) or ex vivo and/or experimental (animal) findings from a "gold standard."

RESULTS

The initial search yielded 2,516 titles. In total, 22 studies were included in the final analysis. Of those, two were clinical and 20 ex vivo investigations. The major findings of the review indicate that CBCT provides cross-sectional images that demonstrate high accuracy and reliability for bony linear measurements on cross-sectional images related to implant treatment. A wide range of error has been reported when performing linear measurements on CBCT images, with both over- and underestimation of dimensions in comparison with a gold standard. A voxel size of 0.3 to 0.4 mm is adequate to provide CBCT images of acceptable diagnostic quality for implant treatment planning.

CONCLUSIONS

CBCT can be considered as an appropriate diagnostic tool for 3D preoperative planning. Nevertheless, a 2 mm safety margin to adjacent anatomic structures should be considered when using CBCT. In clinical practice, the measurement accuracy and reliability of linear measurements on CBCT images are most likely reduced through factors such as patient motion, metallic artefacts, device-specific exposure parameters, the software used, and manual vs. automated procedures.

Direct Restorations, Endodontics, and Bleaching: Materials and Techniques Used by General Dentists of New Zealand

Background

To investigate the selection and use of direct restorative materials, endodontic techniques adopted, and approaches to bleaching by general dentists in New Zealand.

Methods

A questionnaire comprising 19 sections and 125 questions was distributed via mail to 351 general dentists in New Zealand who were selected, at random, from the Dental Council of New Zealand's 2016 register.

Results

A total of 204 questionnaires were returned, of which 188 were usable. Direct resin composite was the most commonly used material for occlusoproximal cavity restorations in premolars (93.7%) and permanent molars (85.2%). Resin-modified glass ionomer cements (34%) and resin composite materials (31.4%) were more commonly used in the restoration of deciduous molars. Home-based vital bleaching was provided by a significant number of dentists (86%), while only 18% provided practice-based bleaching. Cold lateral condensation was the most commonly used obturation technique (55.8%), and 83% of respondents reported using rubber dam for treatments.

Conclusions

The findings from this study indicate that dentists in New Zealand are adapting to new materials and technologies to provide high quality care to their patients. Aesthetic treatments such as bleaching have become an integral part of general dental practice.

Three-rooted maxillary first premolars incidentally detected on cone beam CT: an in vivo study

PURPOSE

To explore the incidence and analyze the morphology of three-rooted maxillary first premolars (MFPs) incidentally detected on cone beam computed tomography (CBCT) scans.

METHODS

Of 1328 patients who underwent CBCT scans of the maxilla, only patients with three-rooted MFPs were selected. Morphological features, including the lengths and diameters of palatal, mesiobuccal (MB) and distobuccal (DB) roots, the positions of bucco-palatal (B-P) bifurcations, the distances between root canal bifurcations and cementoenamel junctions (CEJs) and the distances between the apical thirds of the roots, were measured. The canal configuration and the visibility of root canals were also evaluated.

RESULTS

A total of 16/1328 (1.2%) patients had one or two three-rooted MFPs, and a total of 22/2656 (0.8%) three-rooted MFPs were enrolled. The lengths and diameters of palatal roots were significantly greater than those of other roots. The positions of B-P bifurcations were located mainly at the middle third of the root. The median distances between root canal bifurcations and CEJs were 3 mm for B-P bifurcations and 5.2 mm for MB-DB bifurcations. The distance between MB and DB roots was significantly shorter than the distances between other root pairs. All teeth had a type VIII canal configuration. Palatal roots exhibited the best visibility of root canals, whereas the worst visibility was observed within DB roots. A gender-related relationship was observed only for the lengths of the roots.

CONCLUSIONS

The occurrence of three-rooted MFPs is not unusual; therefore, preoperative CBCT evaluation could be suggested whenever endodontic procedures are planned on an MFP.

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.

Cone-beam Computed Tomographic Analysis of Canal Transportation and Centering Ability of Single-file Systems

INTRODUCTION

The purpose of this study was to compare canal transportation and the centering ability of Reciproc (VDW, Munich, Germany), WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), and EdgeFile (EdgeEndo, Albuquerque, NM) rotary systems using cone-beam computed tomographic imaging.

METHODS

Ninety mesiobuccal mandibular first molar uncalcified canals with at least a 19-mm length, a canal curvature of 15°-30° (the Schneider method), and a mature apex were selected. Canals were randomly divided into 3 groups of 30 teeth, and canal preparation with the Reciproc, WaveOne, and EdgeFile systems was performed according to the manufacturers' instructions. Cone-beam computed tomographic images were taken before and after instrumentation in the same position. Apical transportation was calculated in the distances of 2, 3, and 4 mm from the apex. Kruskal-Wallis and Mann-Whitney U tests were used to statistically analyze the data.

RESULTS

The mean canal transportation was significantly lower with EdgeFile (P < .001) followed by the WaveOne rotary system. Moreover, the centering ability of the EdgeFile system was higher than that of the WaveOne and Reciproc systems.

CONCLUSIONS

The EdgeFile rotary system showed the lowest transportation in both the mesiodistal and buccolingual directions and the highest centering ability. The Reciproc system showed the highest transportation and the lowest centering ability.

Impact of voxel size and scan time on the accuracy of three-dimensional radiological imaging data from cone-beam computed tomography

PURPOSE

Three-dimensional (3D) radiological imaging plays an important role in surgical planning used in modern dentistry. The aim of this study was to optimize imaging parameters with a special focus on voxel size and scan time.

MATERIAL AND METHODS

A virtual 3D master model of a macerated human skull was generated using an industrial optical noncontact white light scanner. The skull was X-rayed with cone-beam computed tomography that was applied using different settings for voxel size and acquisition time (voxel edge length of 0.3 mm, scan times 4.8 s and 8.9 s; voxel edge length of 0.2 mm, scan times 14.7 s and 26.9 s). The scan was repeated 10 times at each setting. The CBCT scans were converted into 3D virtual models (actual value), which were superimposed with the 3D master model (reference value) to detect absolute differences.

RESULTS

The mean value of deviation increased with increasing voxel size and decreasing scan time. For a voxel edge length of 0.3 mm, the mean values of deviation were 0.33 mm and 0.22 mm with scan times of 4.8 s and 8.9 s, respectively. For a voxel edge length of 0.2 mm, the mean deviations were 0.16 mm and 0.14 mm with scan times of 14.7 s and 26.9 s, respectively.

CONCLUSIONS

When using small voxel sizes, the scan time does not have a significant impact on image accuracy and therefore the scan time can be shortened. However, for larger voxel sizes, shorter scan times can lead to increased inaccuracy.

Combined endodontic and periodontal management of a class 3 invasive cervical resorption in a mandibular first molar

Dental radiography and cone-beam computed tomography revealed the left mandibular first molar in a 68-year-old female patient with Heithersay Class 3 invasive cervical resorption (ICR). The inhibition of ICR progression and environmental improvement in and around the affected tooth through combined endodontic and periodontal treatments led to a favorable clinical outcome.

A cone-beam computed tomography study of the mesial cervical concavity of maxillary first premolars

OBJECTIVE

To investigate the mesial cervical concavity of maxillary first premolars and its relationship with root and canal configuration using cone-beam computed tomography (CBCT).

DESIGN

Images of maxillary first premolars (n = 1056) were collected from patients (n = 601) who had undergonein vivo CBCT scanning. The root and canal number and morphology were evaluated. The following measurements of the mesial cervical concavity of the maxillary first premolars were evaluated in section images: dentine thickness (in concavity at the cemento-enamel junction), concavity angle, depression depth (distance from mesial dentinal surface at concavity to mesial proximity), concavity position (distance from mesial dentinal wall at invagination to the top of the mesial marginal ridge). The reliability of the data was analyzed with an unpaired Student's t test and Fisher's exact test.

RESULTS

The percentages of maxillary first premolars with one root, two, and three roots were 55.5%, 43.7%, and 0.8% respectively. Mesial cervical concavity was recorded in 64.5% of single-root maxillary premolars. The prevalence of two-root maxillary first premolars with mesial cervical concavity was 73.8%. The means of the aforementioned four measurements were 1.705, 147.9, 1.640, and 5.247 mm. The values of dentine thickness (mm), depression depth (mm), and concavity position (mm) of the mesial cervical concavity were largest in two-root maxillary first premolars. The smallest concavity angle of the mesial cervical concavity was found in three-root maxillary first premolars.

CONCLUSIONS

There is a high prevalence of mesial cervical concavity among maxillary first premolars. The mesial root concavity is more prevalent in single-rooted maxillary first premolars when there are two canals present, and its prevalence and degree of concavity increase with the number of roots.

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.

Second Root Canal in Mandibular Incisors: an Ex Vivo Cone-Beam Computed Tomography (CBCT) Study

Background/Aim: To analyze the internal morphology of mandibular incisors with two root canals using cone-beam computed tomography (CBCT). Material and Methods: 289 (143 central and 146 lateral) extracted intact mandibular incisors were radiographed for detection of a second root canal. The teeth presenting a second root canal were imaged with CBCT and evaluated regarding: root canal type, the distance of the cementoenamel junction (CEJ) to the bifurcation of the canals and the distance of the canal fusion to the apical foramen (in teeth in which canals rejoined). Results: Out of 143 central and 146 lateral mandibular incisors, 41 (28.7%) and 44 (30.1%) teeth respectively showed a second root canal. Types II, III, V and an additional type to Vertucci’s classification were identified. Type III was the most prevalent and presented in 30 (73.2%) central and 34 (77.3%) lateral mandibular incisors with two root canals. The mean values of the distance of the CEJ to the canal bifurcation were 4.2 mm and 4.0 mm for central and lateral mandibular incisors respectively. The mean values of the distance of the canal fusion to the apical foramen 5.5 mm and 5.1 mm for central and lateral mandibular incisors respectively. Conclusions: Mandibular incisors with two root canals mainly present with Vertucci’s Type 3 canal configuration. The canal bifurcation was identified mostly at the coronal and middle thirds of the root, while the canal fusion occurred in the middle third of the root.

Evaluation of remaining dentin thickness and fracture resistance of conventional and conservative access and biomechanical preparation in molars using cone-beam computed tomography: An in vitro study

Aim:

The present study aimed to compare the remaining dentin thickness (RDT) and fracture resistance of conventional and conservative access and biomechanical preparation in molars using cone-beam computed tomography (CBCT).

Methodology:

A total of 60 freshly extracted human molars were selected and were randomly divided into two groups of conventional and conservative access preparation group (n = 30). Samples were subjected to pre-CBCT scan at the pericervical region for the measurement of total dentin thickness. For the conventional group, samples were accessed and biomechanical preparation was done using K3 XF file. For conservative group, samples were accessed using CK microendodontic burs using a dental operating microscope and biomechanical preparation was done using self-adjusting file. After obturation and postobturation with nanohybrid composite restoration, samples of both groups were subjected to post-CBCT scan at pericervical region for the measurement of RDT. The samples were then loaded to fracture in the Instron Universal Testing Machine, and the data were analyzed using paired sample t-test and independent sample t-test.

Results:

The mean RDT was less in conventional group than conservative group. Pericervical dentin was preserved more in conservative group. The statistical difference among both the experimental group was highly significant (<0.001). The mean load at fracture was less in conventional group than conservative group (<0.001).

Conclusion:

Coronal dentin was conserved in molars when accessed through conservative than through conventional. The dentin conservation afforded an increased resistance to fracture in conservative group which is doubled the fracture resistance in conventional group.

The Evaluation of Root Fracture with Cone Beam Computed Tomography (CBCT): An Epidemiological Study

Background

The aim of this study was evaluation of the cone-beam computed tomography (CBCT) image of 50 patients at the ages of 8-15 suspecting root fracture and root fracture occurred, exposed to dental traumatic. In additionally, this study was showed effect of crown fracture on root fracture healing.

Material and Methods

All of the individuals included in the study were obtained images with the cone-beam computed tomography range of 0,3 voxel and 8.9 seconds.(i-CAT®, Model 17-19, Imaging SciencesInternational, Hatfield, Pa USA).The information obtained from the history and CBCT images of patients were evaluated using chi-square test statistical method the mean and the distribution of the independent variables.

Results

50 children, have been exposed to trauma, was detected root fracture injury in 97 teeth. Horizontal root fracture 63.9% of the 97 tooth, the oblique in 31.9%, both the horizontal and oblique in 1.03%, partial fracture in 2.06% ,and both horizontally and vertical in 1.03% was observed.The most affected teeth, respectively of, are the maxillary central incisor (41.23% left, right, 37.11%), maxillary left lateral incisor (9.27%), maxillary right lateral incisor (11.34%), and mandibular central incisor (1.03%).

Conclusions

Crown fractures have negative effects on spontaneous healing of root fractures. CBCT are used selected as an alternative to with conventional radiography for diagnosis of root fractures. In particular, ıt's cross-sectional image is quite useful and has been provided more conveniences seeing the results of diagnosis and treatment for clinician. Key words:Root fracture, CBCT, Epidemiolog.

Role of Cone Beam Computed Tomography in Diagnosis and Treatment Planning in Dentistry: An Update

Accurate diagnosis and treatment planning are the backbone of any medical therapy; for this reason, cone beam computed tomography (CBCT) was introduced and has been widely used. CBCT technology provides a three-dimensional image viewing, enabling exact location and extent of lesions or any anatomical region. For the very same reason, CBCT can not only be used for surgical fields but also for fields such as endodontics, prosthodontics, and orthodontics for appropriate treatment planning and effective dental care. The aim and clinical significance of this review are to update dental clinicians on the CBCT applications in each dental specialty for an appropriate diagnosis and more predictable treatment.

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.

Disappearance of Intracanal Medication: A Preliminary Clinical Finding from Retrospective Review of Teeth with Vertical Root Fracture

Objective:

The purpose of this article was to report the finding of the disappearance of intracanal medication as a supporting evidence of vertical root fracture (VRF) through non-surgical intervention.

Methods:

A retrospective review of the dental records of patients seen by an endodontist in a private endodontic office from September 2013 to September 2016 was conducted by the same endodontist. Cases that met the inclusion and exclusion criteria were assigned as the subjects of this study, and data were extracted from their clinical and radiographic records. Patient’s demographic features, pre-operative signs and symptoms, details of rendered clinical procedures, follow-up visits, clinical and radiographic findings were recorded. Seventeen teeth for which non-surgical exploratory re-treatment was initiated were included in this study. Calcium hydroxide-based intracanal medication was placed for 2-4 weeks. Obturation of the root canals was performed if the tooth showed improvement of clinical signs and symptoms. If not, a cone-beam computed tomography (CBCT) scan was proposed to the patient to rule out VRF.

Results:

After the non-surgical re-treatment was initiated, 13 teeth showed improvement of clinical symptoms and the re-treatment was therefore completed. The remaining 4 teeth presented with unresolved clinical presentations (deep pocket, presence of sinus tract and/or tender to percussion and palpation). Four teeth showed partial disappearance of intracanal medication where VRF was confirmed using CBCT in 3 teeth and with a conventional periapical (PA) radiograph in 1 tooth.

Conclusion:

The disappearance of intracanal medication during non-surgical intervention was often associated with VRF. Thus, this feature may serve as an aid in diagnosing VRF.

Root Canal Morphologies of Mesiobuccal Roots of Maxillary Molars using Cone beam Computed Tomography and Periapical Radiographic Techniques in an Iranian Population

AIM

The aim of this study was to evaluate the accuracy of the results of cone beam computed tomography (CBCT) examinations, confirm the presence or absence of the second mesiobuccal (MB2) root canal in maxillary first and second molars, estimate the distance between the root canal orifices, observe the root types based on Vertucci classification system, and make comparisons between CBCT and periapical techniques in relation to the identification of the root canal form and the second root canal of the MB root.

MATERIALS AND METHODS

The CBCT and periapical radiographic data from the Department of Maxillofacial Radiology were used to select 156 individuals (78 females and 78 males) for the evaluation of the anatomy of maxillary first and second molars.

RESULTS

The prevalence rate of the second root canal in the MB root in the maxillary first molars was 55.1%, with 44.1 and 63.3% in females and males respectively. The prevalence rate in maxillary second molars was 23.7%, with 15.7 and 30.2% in females and males respectively. In addition, the longest and shortest distances between the root canal orifices were 2.4 and 0.3 mm respectively, with a mean of 1.3 mm.

CONCLUSION

There was a significant difference between the results of periapical and CBCT radiographic techniques in relation to the presence or absence of the second root canal in the MB roots of maxillary first and second molars (p < 0.01), with better results being provided by the CBCT technique.

CLINICAL SIGNIFICANCE

The results of CBCT images about the existence of the second root canal in the MB roots of maxillary first and second molars are more reliable, and we can use this technique in the finding of additional canals in the clinic. Keyword: Cone beam computed tomography, Dental radiography, Root canal therapy.

Correlation between sagittal condylar guidance angles obtained using radiographic and protrusive occlusal record methods

PURPOSE

This study compared the SCGAs measured in three types of radiographic images (panoramic, CBCT panoramic-section, and CBCT cross-section images) with values measured using the protrusive occlusal record.

MATERIALS AND METHODS

SCGAs were measured in 20 patients on a semi-adjustable articulator using the protrusive interocclusal record. Panoramic and CBCT images were obtained. SCGAs were measured on CBCT images in panoramic and cross sections. In all of the radiographic images, SCGAs were measured using the Frankfort horizontal reference line and the mean curvature line. The most-superior and most-inferior points of the curvatures were identified to determine the mean curvature line. Each measurement was performed twice by two operators independently. The data were analyzed by the t-test, Pearson's correlation test, and Cronbach's α using SPSS (α=.05).

RESULTS

The mean right and left SCGAs were as follows: protrusive occlusal record (30.1 and 30.2 degrees, respectively), panoramic (38.9 and 38.7 degrees), CBCT panoramic sections (35.4 and 36.8 degrees), and CBCT cross sections (35.3 and 36.1 degrees). The SCGAs differed significantly among the groups. The Pearson coefficients for the correlations with the protrusive occlusal record measurements on the left and right sides were as follows: panoramic (0.834 and 0.791, respectively), CBCT panoramic-section (0.918 and 0.837), and CBCT cross-section (0.918 and 0.845) images.

CONCLUSION

Strong correlations were found between SCGAs obtained using radiographic images and the protrusive occlusal record.

Use of Cone-Beam Computed Tomography in the Diagnosis and Treatment of an Unusual Canine Abnormality

Diagnosis and treatment planning are important for successful endodontic treatment. We report a 24-year old male who presented to the Government Dental College in Kozhikode, Kerala, India, in 2015 with pain in his right upper canine. A digital periapical radiograph indicated the presence of a supernumerary tooth superimposing the root of the canine. However, cone-beam computed tomography (CBCT) confirmed that the supernumerary tooth was an illusion and that the canine root had a sharp invagination involving the labial and pulpal dentin surfaces, with evidence of periapical bone destruction. A blunt resection was performed at the level of the invagination and the resected end was filled with a dentin substitute. At a one-year follow-up, the patient was asymptomatic and the periapical region appeared to be healing well. This report highlights the importance of CBCT in visualising abnormal canine morphology, thus allowing appropriate endodontic treatment.

Diagnostic Accuracy of Periapical Radiography and Cone-beam Computed Tomography in Identifying Root Canal Configuration of Human Premolars

INTRODUCTION

The aim of this study was to assess the diagnostic accuracy of periapical radiography (PR) and cone-beam computed tomographic (CBCT) imaging in the detection of the root canal configuration (RCC) of human premolars.

METHODS

PR and CBCT imaging of 114 extracted human premolars were evaluated by 2 oral radiologists. RCC was recorded according to Vertucci's classification. Micro-computed tomographic imaging served as the gold standard to determine RCC. Accuracy, sensitivity, specificity, and predictive values were calculated. The Friedman test compared both PR and CBCT imaging with the gold standard.

RESULTS

CBCT imaging showed higher values for all diagnostic tests compared with PR. Accuracy was 0.55 and 0.89 for PR and CBCT imaging, respectively. There was no difference between CBCT imaging and the gold standard, whereas PR differed from both CBCT and micro-computed tomographic imaging (P < .0001). CBCT imaging was more accurate than PR for evaluating different types of RCC individually. Canal configuration types III, VII, and "other" were poorly identified on CBCT imaging with a detection accuracy of 50%, 0%, and 43%, respectively. With PR, all canal configurations except type I were poorly visible.

CONCLUSIONS

PR presented low performance in the detection of RCC in premolars, whereas CBCT imaging showed no difference compared with the gold standard. Canals with complex configurations were less identifiable using both imaging methods, especially PR.

Predoctoral and Postdoctoral Education on Cone-Beam Computed Tomography

OBJECTIVES

As the use of cone beam computed tomography (CBCT) in dentistry continues to grow, questions related to appropriate radiation safety, training, and interpretation arise. Recognizing this need, the American Dental Association published an advisory statement for the safe use of CBCT in dentistry and recommended that guidelines for appropriate training be established. The purpose of this study was to assess radiation safety concerns related to CBCT and identify voids in current education on CBCT for the predoctoral dental curriculum and continuing dental education.

METHODS

A survey was mailed to general practitioners, oral surgeons, and periodontists in the Georgia Dental Association (n = 415).

RESULTS

One hundred twenty-one surveys were received for a response rate of 29%. Sixty-eight percent of practitioners reported using CBCT, with 89% having used it for over 2 years. Few (12.4%) had experience with CBCT in dental school. Interest in continuing dental education on CBCT was reported at 59.8% and 43.6% for current users and nonusers of CBCT, respectively. Approximately 50% reported using precautionary radiation safety measures, and the methods used were varied.

CONCLUSIONS

Although a higher survey return rate would allow for stronger evidence, this project identified some areas of education voids including radiation safety and the factors that contribute to patient dose; CBCT basics including instruction on the limitations of CBCT; CBCT anatomy and pathology with additional time dedicated to the paranasal sinuses; and interpretation.

Indications for cone beam computed tomography in children and young patients in a Turkish subpopulation

BACKGROUND

Cone beam computed tomography (CBCT) imaging is widely used in children; however, it remains controversial because of the health effects of radiation.

AIM

This retrospective study investigated the indications for CBCT and dentomaxillofacial pathologies in paediatric patients.

MATERIALS AND METHODS

CBCT images of 329 paediatric patients (i.e., aged <18 years) were investigated retrospectively. CBCT images were obtained with five fields of view (FOV). CBCT indications were categorised as surgery and orthodontics. The effects of age, sex, and FOV were evaluated. The level of significance was P = 0.05.

RESULTS

The most common orthodontic indications were malocclusion and dentomaxillofacial anomalies (38.5%), followed by the localisation of impacted teeth (33.1%). There was no relationship between sex and indications. There were significant associations between age groups and malocclusion and dentomaxillofacial anomalies, localisation of impacted teeth, and trauma. The face was the most frequently imaged region, followed by the jaws (maxilla and mandible).

CONCLUSION

The most common indication for CBCT was malocclusion and dentomaxillofacial anomalies in the primary and permanent dentition age groups, whereas the localisation of impacted teeth was the most common indication in the mixed dentition age group. Generally, CBCT was indicated in orthodontics and surgery.

Feasibility of Cone-beam Computed Tomography in Detecting Lateral Canals before and after Root Canal Treatment: An Ex Vivo Study

INTRODUCTION

The study objective was to evaluate the effectiveness of cone-beam computed tomographic (CBCT) imaging for the detection of lateral canals (LCs) in endodontically treated premolars.

METHODS

Two evaluators classified 80 extracted premolars into 2 groups based on the absence (n = 40) or presence (n = 40) of LCs according to micro-computed tomographic analysis. The extracted teeth were fixated in a human mandible and scanned with CBCT imaging. Subsequently, each tooth was endodontically treated, and CBCT scans were repeated. Three experienced examiners evaluated all images randomly. Receiver operating characteristic curves were compared using the McNemar test, and sensitivity, specificity, positive predictive value, and negative predictive value (NPV) were obtained.

RESULTS

The area under the receiver operating characteristic curve values were 0.58 and 0.49 before and after root canal treatment, respectively. These values were statistically significantly different (P < .001). Before root canal treatment sensitivity, specificity, positive predictive value, and negative predictive value were 55%, 52%, 55%, and 56%, whereas after root canal treatment the values were 33%, 61%, 46%, and 48%, respectively.

CONCLUSIONS

LC detection in nontreated teeth presented low accuracy, whereas among treated teeth CBCT imaging showed no efficacy. The results suggest that CBCT imaging is not an effective diagnostic tool for LC detection.

Cone Beam CT in Diagnosis and Surgical Planning of Dentigerous Cyst

Diagnosis and preoperative planning are critical in the execution of any surgical procedure. Panoramic radiography is a routine method used in dentistry to assist clinical diagnosis; however, with this technique 3D anatomical structures are compressed into 2D images, resulting in overlapping of structures which are of interest in the diagnosis. In this study we report the case of a patient who presented with a dentigerous cyst of expressive dimensions in the body of the mandible region. The surgery was planned and executed after observing the margins of the lesion by Cone Beam Computed Tomography (CBCT). We conclude that CBCT is a precise method to help diagnosis; it provides greater accuracy in surgical treatment planning through 3D image display, allowing more effective results.

Automatic detection of tooth cracks in optical coherence tomography images

PURPOSE

The aims of the present study were to compare the image quality and visibility of tooth cracks between conventional methods and swept-source optical coherence tomography (SS-OCT) and to develop an automatic detection technique for tooth cracks by SS-OCT imaging.

METHODS

We evaluated SS-OCT with a near-infrared wavelength centered at 1,310 nm over a spectral bandwidth of 100 nm at a rate of 50 kHz as a new diagnostic tool for the detection of tooth cracks. The reliability of the SS-OCT images was verified by comparing the crack lines with those detected using conventional methods. After performing preprocessing of the obtained SS-OCT images to emphasize cracks, an algorithm was developed and verified to detect tooth cracks automatically.

RESULTS

The detection capability of SS-OCT was superior or comparable to that of trans-illumination, which did not discriminate among the cracks according to depth. Other conventional methods for the detection of tooth cracks did not sense initial cracks with a width of less than 100 μm. However, SS-OCT detected cracks of all sizes, ranging from craze lines to split teeth, and the crack lines were automatically detected in images using the Hough transform.

CONCLUSIONS

We were able to distinguish structural cracks, craze lines, and split lines in tooth cracks using SS-OCT images, and to automatically detect the position of various cracks in the OCT images. Therefore, the detection capability of SS-OCT images provides a useful diagnostic tool for cracked tooth syndrome.

Prevalence of Extra Roots in Permanent Mandibular First Molars in Iranian Population: A CBCT Analysis

Introduction:

Having knowledge about the anatomy of root canal system is essential for success of endodontic treatment. The present study used cone-beam computed tomography (CBCT), to evaluate the prevalence of third root in mandibular first molars in a selected Iranian population.

Methods and Materials:

A total of 386 CBCT images from subjects referred to oral and maxillofacial radiology department of dental faculty of Tabriz University of Medical Sciences from 2011 to 2013 were selected and evaluated for this study and the cases with well-developed permanent mandibular first molars were included. The 3D images were reconstructed in axial cross sections and evaluated by two endodontists for the presence of the third extra lingual (radix entomolaris) or buccal (radix paramolaris) root. The chi-squared test was used to evaluate the relationship between gender and bilateral incidence of extra roots in mandibular first molars.

Results:

The distribution of three-rooted mandibular first molars with an additional root was 3%, (3.53% in female and 2.50% in male patients). There was no significant relationship between gender and bilateral occurrence of three-rooted mandibular first molars.

Conclusion:

The occurrence of three-rooted mandibular first molars in Iranian population is not uncommon which should be taken into consideration by the dental practitioners during root canal treatment of these teeth.

The Extent of the Crack on Artificial Simulation Models with CBCT and Periapical Radiography

Background

The aim of this study was to investigate the extent of the crack of a cracked tooth on an artificial simulation model with Periapical Radiography (PR) and cone beam computed tomography (CBCT) in vitro, providing the basis for early diagnosis and an appropriate treatment plan.

Methods

Forty-four teeth with different extents of artificial cracks, created by exposure to liquid nitrogen after hot water at 100°C, were collected. They were subjected to PR and CBCT. Micro-computed tomography (micro-CT) examination, regarded as a relatively more accurate measurement than others, was used to measure and record the crack depth. Three observers, an endodontic graduate student, an experienced endodontist, and an experienced radiologist, examined the PR and CBCT results independently, and the presence or absence of cracks with PR and CBCT were respectively recorded. The external consistency ICC with 95% confidence interval (95% CI) was used to analyze the consistency among the graduate student, endodontist, and radiologist; ROC curves were used for the analysis of diagnostic performance of both radiographic modalities for tooth cracks with crack depth.

Results

For the interpretation of the PR results, there were statistically significant differences among the three different observers (P < 0.001), and the interpretation of the CBCT results (P < 0.001). In the group of results read by the graduate student, the sensitivity of diagnosis with CBCT and PR was 77.27% and 22.73%, respectively (P < 0.001). In the group of results read by the endodontist, the sensitivity of diagnosis with CBCT and PR was 81.81% and 8.19%, respectively (P < 0.001). In the group of results read by the radiologist, the sensitivity of diagnosis with CBCT and PR was 88.64% and 11.36%, respectively (P < 0.001). As for CBCT diagnosis, the critical value for the graduate, endodontist, and radiologist was 3.20 mm, 2.06 mm, and 1.24 mm, respectively. For the PR diagnosis, the critical value for the graduate, endodontist, and radiologist was 6.12 mm, 6.94 mm, and 6.94 mm, respectively.

Conclusions

Within the limitations of this study, on an artificial simulation model of cracked teeth for early diagnosis, we recommend that it would be better for a cracked tooth to be diagnosed by a radiologist with CBCT than PR, CBCT with a minimum depth of 1.24 mm.

Effectiveness of three methods for evaluating root canal anatomy of mandibular incisors

This study compared the effectiveness of clinical observation, clinical microscopic observation, and tooth-clearing technique in determining the number of canals in mandibular incisors. Root canal ramifications were also analyzed. Using clinical and microscopic analyses, we determined the number of canal entrances in 277 mandibular incisors. In addition, tooth-clearing technique was used to determine the number of canals and frequency of ramifications in the samples. The kappa coefficient was used to compare the different methods with regard to frequency of canals. Most teeth had one canal entrance. The proportion of teeth with two canals was 23.5% by tooth-clearing analysis, 5.8% by clinical microscopy, and 1.1% by clinical analysis. A large number of samples had some type of ramification (40.1%), and most ramifications were present in teeth with two canals. The most frequent ramification was lateral canals (8.3%). Clinical microscopy improved identification of a second canal in mandibular incisors. However, it did not identify second canals in all teeth with two canals. (J Oral Sci 58, 347-351, 2016).

Computed tomography: Will the slices reveal the truth

With the advances in the field of imaging sciences, new methods have been developed in dental radiology. These include digital radiography, density analyzing methods, cone beam computed tomography (CBCT), magnetic resonance imaging, ultrasound, and nuclear imaging techniques, which provide high-resolution detailed images of oral structures. The current review aims to critically elaborate the use of CBCT in endodontics.