Special Committee to Revise the Joint AAE/AAOMR Position Statement on use of CBCT in Endodontics. AAE and AAOMR Joint Position Statement: Use of Cone Beam Computed Tomography in Endodontics 2015 Update. Oral Surg Oral Med Oral Pathol Oral Radiol. 2015;120:508-512. [PMID: 26346911 DOI: 10.1016/j.oooo.2015.07.033]

Dens evagination and complete invagination in the same tooth with extraoral fistula: A rare case report

Key Clinical Message

Successful management of a rare case involving both dens evaginatus and dens invaginatus in the same tooth, monitored over a 24-month follow-up.

Abstract

Dens invaginatus (DI) is a congenital dental anomaly characterized by the presence of a tooth that resembles a "tooth within a tooth." Conversely, dens evaginatus (DE) is a developmental anomaly distinguished by an additional tubercle or cusp on the tooth's crown. Both DI and DE can result in pulpal and periapical diseases in the affected tooth. This article presents a case of a healthy 14-year-old male with recurrent swelling under the chin and a wound with pus drainage on the right side of the submental area, associated with his left mandibular lateral incisor affected by both DI and DE. Clinical and radiographic examinations revealed that the tooth was necrotic and had a chronic apical abscess. Cone beam computed tomography (CBCT) confirmed Oehlers' type III DI and a talon cusp on the lingual surface of the same tooth. The patient underwent orthograde endodontic treatment. Passive ultrasonic activation of a 5.25% NaOCl solution and a mixture of Ca(OH)2 and a 2% chlorhexidine solution were utilized to effectively clean and eliminate the persistent pus discharge. After the resolution of the patient's symptoms, the apical third of the root canal and the invaginated space were filled with a plug of mineral trioxide aggregate (MTA), while the remaining root canal was filled using a sealer-based obturation technique. A 24-month follow-up visit revealed complete bone regeneration in the previously affected periradicular tissues.

Is a Pre-Existent Cone-Beam Computed Tomography Able to Detect Metal Dental Posts?

(1) Background: In this study, the efficacy of cone-beam computed tomography (CBCT) in detecting dental posts was compared to periapical radiography. (2) Methods: A retrospective evaluation of 53 patients' periapical radiographs and CBCT images was performed. The presence and type of the intra-canal dental post were initially determined on the periapical images (PA) radiographs' examination and were then compared to the observer's ability to detect the dental post on a CBCT image. The effect of the post's type (metal cast or prefabricated) on its detection on CBCT images was determined. (3) Results: 10.5% of teeth that were identified as having a post on a PA radiograph were not identified as having a post on the CBCT examination (p < 0.05). Approximately 17.6% of teeth that were identified as not having a post on a PA radiograph were identified as having a post on the CBCT examination (p < 0.05). Moreover, 16.3% and 50% of teeth with a prefabricated or cast posts on PA radiographs were falsely identified on the CBCT examination, respectively (p < 0.05). (4) Conclusions: A CBCT image is an insufficient tool for the identification of metal prefabricated and cast posts. A PA image is the recommended radiographic tool for achieving information about the post-endodontic restoration status of teeth candidates for endodontic retreatment in patients with a former CBCT scan.

Treatment outcomes and prognostic factors of the apical barrier technique with premixed calcium silicate-based putty in necrotic permanent teeth with open apices: a retrospective cohort study with up to six years follow-up

OBJECTIVES

To evaluate treatment outcomes of the apical barrier technique with premixed calcium silicate-based putty for treating necrotic permanent teeth with open apices and to identify prognostic factors.

MATERIALS AND METHODS

Permanent teeth with necrotic pulps and open apices treated by the apical barrier technique with premixed calcium silicate-based putty, with a minimum follow-up of 12 months, were included. Treatment outcomes were based on clinical signs, symptoms, and radiographic evaluation. The treatment outcome was dichotomized into success or failure according to strict and loose criteria. The chi-square test (or Fisher's exact test) and multiple logistic regression analysis were used to evaluate possible prognostic factors associated with treatment outcomes.

RESULTS

Seventy-four teeth with a follow-up time of 12-72 months (mean, 25.74 ± 14.36 months) were included in the final evaluation. The success rate was 97.30% using the loose criteria and 66.22% using the strict criteria. Multiple logistic regression analysis indicated that the size of pre-operative periapical lesion (≥ 5 mm) (odds ratio [OR]: 18.96; P = 0.0153) and root canal underfilling (OR: 8.341; P = 0.0448) were significant predictors for treatment failure under the strict criteria.

CONCLUSION

The apical barrier technique with premixed calcium silicate-based putty is a highly successful procedure for treating necrotic permanent teeth with open apices after an observation period of up to 6 years. Treatment success under the strict criteria is primarily affected by the size of the pre-operative periapical lesion and the apical extent of root-filling.

CLINICAL RELEVANCE

Careful case selection and ensuring adequate root filling quality are essential to the successful outcome of the apical barrier technique with premixed calcium silicate-based putty.

Identification and classification of pulp calcifications in posterior teeth according to dental condition using digital panoramic radiography and cone beam CT

OBJECTIVE

To compare digital panoramic radiography (DPR) and cone beam CT (CBCT) in the detection and classification of pulp calcifications in posterior teeth in relation to tooth condition and its location.

METHODS

Two hundred and fifty patients with simultaneous DPR and CBCT scans were selected from a dental image bank. For each posterior tooth, its condition was registered (healthy, restored, or decayed). The presence of calcifications was assessed and classified according to location (coronal or radicular) and type (total obliteration, partial obliteration, narrowing, and no calcification). Chi-square and McNemar tests were used to compare DPR and CBCT results, with a significance level of 5%. DPR diagnostic values were calculated using CBCT as reference.

RESULTS

Decayed and restored teeth showed a significantly (P < .001) higher prevalence of pulp calcifications than healthy teeth in both imaging exams. There was a significant discrepancy between the imaging modalities in the identification of calcifications (P < .001), especially for radicular calcifications of maxillary teeth (DPR = 55.2%; CBCT = 30.9%). In the case of coronal calcifications, there was a greater discrepancy between CBCT and DPR in the mandibular teeth (10.7%) than in the maxillary teeth (7.7%). Overall, DPR presents higher sensitivity (0.855) than specificity (0.483) for pulp calcifications detection.

CONCLUSION

DPR considerably overestimates pulp calcifications in posterior teeth, as compared to CBCT. A higher prevalence of pulp calcifications is related to decayed and restored teeth.

A comparison of virtual reality and three-dimensional multiplanar educational methods for student learning of cone beam computed tomography interpretations

OBJECTIVES

The purpose of this study was to compare student learning of cone beam computed tomography (CBCT) interpretation using immersive virtual reality (VR) and three-dimensional multiplanar (MP) reconstructions.

METHODS

Sixty first-year dental students were randomly allocated to two groups, VR and MP, and underwent a one-on-one educational intervention to identify anatomic structures using CBCT data. All participants completed three multiple-choice questionnaires (MCQs) before (T1), immediately after (T2), and 2 weeks following (T3) the intervention. Additionally, pre-survey, post-survey, NASA Task Load Index (NASA-TLX), and presence questionnaires were completed. Analysis of objective measures of performance on MCQs and subjective data from the questionnaires was completed (α = 0.05).

RESULTS

There was a significant increase in test performance and informational recall between T1-T2 and T1-T3 for VR and MP groups (p < 0.001). However, there were no significant differences in performance on MCQs between T2 and T3. Analysis of the Presence questionnaire indicated that the VR group felt decreased distraction (p = 0.013), increased realism (p = 0.035), and increased involvement (p = 0.047) during the educational intervention when compared with the MP group. Analysis of the NASA-TLX indicated that the VR group experienced more physical demand (p < 0.01) but similar cognitive demand when compared with the MP group. Qualitative responses indicated that the VR group had a more dynamic sense of visualization and manipulation compared to the MP group.

CONCLUSION

Results from this study show that VR is as effective as traditional MP methods of CBCT interpretation learning. Further benefits of VR educational intervention include increased involvement, realism and less distraction.

Worldwide Prevalence of Single-rooted with a Single Root Canal and Four-rooted Configurations in Maxillary Molars: A Multi-center Cross-sectional Study with Meta-analysis

INTRODUCTION

To evaluate the prevalence of single root with a single root canal and four-root configurations in the maxillary first and second molars, and analyze how geographic region, ethnicity, sex, and age impact these outcomes.

METHODS

Researchers from 44 nations examined 26,400 maxillary molars using cone-beam computed tomography scans to gather data on the proportions of single roots with single canals and four-root configurations. All observers underwent prior calibration regarding the step-by-step assessment protocol and anatomical concepts to ensure consistent evaluations across all assessed locations. Tests were conducted to evaluate the intraobserver and interobserver reliability. Demographic data including ethnicity, gender, and age were collected for each participant. The potential impact of imaging voxel size and field-of-view on bias was also assessed. The primary results were depicted as odds ratios and untransformed proportion forest plots with 95% confidence intervals. Additionally, a meta-analysis was performed to compare various subgroups and identify sources of variation among them. Statistical significance was set at 5%.

RESULTS

The prevalence of single-rooted with a single canal and four-rooted configurations in the maxillary first molar was 0.16% and 0.28%, respectively, while in the maxillary second molar, it was 2.56% and 0.83%. Males tended to exhibit lower percentages of single roots with a single canal (P < .05) and higher percentages of four-rooted configurations (P > .05) in the second molar, whereas the African subgroup displayed lower proportions for both configurations. Additionally, in both teeth, single roots with a single canal were more prevalent among older patients. Voxel size and field-of-view did not significantly influence the results (P > .05).

CONCLUSIONS

The proportions of single-rooted with a single canal and four-rooted configurations were low, and demographic factors such as geographic region, ethnicity, sex, and age may have influenced the outcomes for the maxillary second molar.

Construction and Evaluation of an AI-based CBCT Resolution Optimization Technique for Extracted Teeth

INTRODUCTION

In dental clinical practice, cone-beam computed tomography (CBCT) is commonly used to assist practitioners to recognize the complex morphology of root canal systems; however, because of its resolution limitations, certain small anatomical structures still cannot be accurately recognized on CBCT. The purpose of this study was to perform image super-resolution (SR) processing on CBCT images of extracted human teeth with the help of a deep learning model, and to compare the differences among CBCT, super-resolution computed tomography (SRCT), and micro-computed tomography (Micro-CT) images through three-dimensional reconstruction.

METHODS

The deep learning model (Basicvsr++) was selected and modified. The dataset consisted of 171 extracted teeth that met inclusion criteria, with 40 maxillary first molars as the training set and 40 maxillary first molars as well as 91 teeth from other tooth positions as the external test set. The corresponding CBCT, SRCT, and Micro-CT images of each tooth in test sets were reconstructed using Mimics Research 17.0, and the root canal recognition rates in the 3 groups were recorded. The following parameters were measured: volume of hard tissue (V1), volume of pulp chamber and root canal system (V2), length of visible root canals under orifice (VL-X, where X represents the specific root canal), and intersection angle between coronal axis of canal and long axis of tooth (∠X, where X represents the specific root canal). Data were statistically analyzed between CBCT and SRCT images using paired sample t-test and Wilcoxon test analysis, with the measurement from Micro-CT images as the gold standard.

RESULTS

Images from all tested teeth were successfully processed with the SR program. In 4-canal maxillary first molar, identification of MB2 was 72% (18/25) in CBCT group, 92% (23/25) in SRCT group, and 100% (25/25) in Micro-CT group. The difference of hard tissue volume between SRCT and Micro-CT was significantly smaller than that between CBCT and Micro-CT in all tested teeth except 4-canal mandibular first molar (P < .05). Similar results were obtained in volume of pulp chamber and root canal system in all tested teeth (P < .05). As for length of visible root canals under orifice, the difference between SRCT and Micro-CT was significantly smaller than that between CBCT and Micro-CT (P < .05) in most root canals.

CONCLUSIONS

The deep learning model developed in this study helps to optimize the root canal morphology of extracted teeth in CBCT. And it may be helpful for the identification of MB2 in the maxillary first molar.

Is the assessment of the mandibular molar danger zone affected by field of view and voxel size in cone beam computed tomography examinations?

OBJECTIVE

To verify if assessment of the danger zone (DZ) in the mesial root of mandibular molars is affected by field of view (FOV) and voxel sizes in cone beam computed tomography (CBCT) scans.

STUDY DESIGN

Forty mandibular molars were scanned by micro-computed tomography, creating the reference standard. The teeth were then submitted for CBCT scans with FOVs of 10 × 5.5 cm and 5 × 5.5 cm and voxel sizes of 0.4, 0.2, 0.15, and 0.075 mm3. The smallest dentin thickness in the DZ from the mesiobuccal and mesiolingual canals was measured at 2, 4, and 6 mm apical to the root furcation. Descriptive statistics, paired t-tests, and intraclass correlation coefficients were used for statistical analysis with significance established at P < .05.

RESULTS

All CBCT measurements overestimated the DZ dentin thickness (P < .001) compared to the reference standard. The greatest overestimation occurred in the 5 × 5.5 cm FOV with 0.4 mm3 voxels (P = .007). Dentin thickness measured with the 5 × 5.5 cm FOV and 0.075 mm3 voxels was significantly smaller and produced the best ICC value with the reference standard (0.936).

CONCLUSIONS

CBCT overestimates the dentin thickness of the DZ regardless of FOV and voxel sizes. The 5 × 5.5 cm FOV showed the best performance with the 0.075 mm3 voxel size, but it performed poorly with 0.4 mm3 voxels.

Impact of the spatial orientation of the patient's head, metal artifact reduction, and tube current on cone-beam computed tomography artifact expression adjacent to a dental implant: A laboratory study using a simulated surgical guide

Purpose

The aim of this study was to evaluate image artifacts in the vicinity of dental implants in cone-beam computed tomography (CBCT) scans obtained with different spatial orientations, tube current levels, and metal artifact reduction algorithm (MAR) conditions.

Materials and Methods

One dental implant and 2 tubes filled with a radiopaque solution were placed in the posterior region of a mandible using a surgical guide to ensure parallel alignment. CBCT scans were acquired with the mandible in 2 spatial orientations in relation to the X-ray projection plane (standard and modified) at 3 tube current levels: 5, 8, and 11 mA. CBCT scans were repeated without the implant and were reconstructed with and without MAR. The mean voxel and noise values of each tube were obtained and compared using multi-way analysis of variance and the Tukey test (α=0.05).

Results

Mean voxel values were significantly higher and noise values were significantly lower in the modified orientation than in the standard orientation (P<0.05). MAR activation and tube current levels did not show significant differences in most cases of the modified spatial orientation and in the absence of the dental implant (P>0.05).

Conclusion

Modifying the spatial orientation of the head increased brightness and reduced spatial orientation noise in adjacent regions of a dental implant, with no influence from the tube current level and MAR.

The clinical outcomes of vital intact teeth close to large cystic lesions of endodontic origin: A prospective clinical study

AIM

To evaluate the indication of the endodontic treatment for vital intact teeth with the root apex involved in large radicular cystic lesions of endodontic origin.

METHODOLOGY

This prospective cohort study enrolled healthy participants with radicular cysts of endodontic origin and with the root apex of vital intact teeth involved in the bone defect, as determined by cone beam computed tomography (CBCT). Thirty-two sound vital teeth were analysed by thermal (TPT) and electric pulp tests (EPT) before surgery (T0) and 1 week (T1), 2 weeks (T2), 3 months (T3) and 6 months (T4) post-surgery. Student's t-test (p < .05) was used to compare the EPT values at baseline and T4. anova (p < .05) was used to analyse the EPT variations for all maxillary and mandibular teeth. McNemar test (p < .05) was used to compare the results according to variation in EPT values gathering by variation, no variation and no response.

RESULTS

At T1, 75 and 65.7% of teeth responded positively whilst 25 and 34.3% did not respond to EPT and TPT, respectively. The variation of the EPT values between T0 and T1 was observed for 50.0% of teeth, whilst no variation was noticed in 25.0% of teeth. At T4, 90.6 and 87.5% of teeth responded positively whilst 9.4 and 12.5% did not respond to EPT and TPT, respectively. At T4, variation of the EPT values between T0 and T4 was observed for 28.1%, whilst no variation was noticed in 62.5% of teeth. There were no statistical differences in EPT results between T0 and T4 (p > .05), but significant differences were observed for EPT values between T1 and T4 (p < .05), and between mandibular and maxillary teeth. The pulp sensibility of maxillary teeth worsened after surgery, before reverting progressively to T0 values, whilst no statistically significant differences were observed for mandibular teeth at the different time points.

CONCLUSIONS

These data support the inconsistence of the prophylactic endodontic treatment in healthy vital teeth with apex involvement in large cystic lesions of endodontic origin. Post-surgery follow-up with TPT and EPT is recommended to assess pulp status.

A systematic review and meta-analysis of the prevalence and global distribution of middle mesial canals in mandibular molars identified by CBCT

OBJECTIVES

This systematic review and meta-analysis aimed to evaluate the prevalence of middle mesial canal (MMC) in permanent mandibular molars of different populations and regions based on cone-beam computed tomography (CBCT) studies.

MATERIALS AND METHODS

PubMed, Scopus, Embase, Web of Science, and Open-Grey were searched up to October 2023 according to specific keywords. A hand search was conducted on the references of the included studies and articles from three peer-reviewed journals in endodontics. The main variable of interest was the prevalence of MMC. Additional data such as the total number of included cases, age and country of the population, CBCT device information, voxel size, and field of view details were also extracted. Extracted data were analyzed qualitatively with the JBI quality assessment checklist and quantitatively with STATA software.

RESULTS

Of 32,793 studied teeth, the cumulative prevalence of MMC in both mandibular 1st and 2nd molars was 3.11% (95% CI: 2.00-4.44%). The subgroup analysis reveals a prevalence of 4.15% (95% CI: 2.69-5.89%) for mandibular 1st molars and 1.2% (95% CI: 0.2-2.83%) for mandibular 2nd molars. The highest prevalence of MMC in 1st molar was attributed to South Asia (11.24%) and Africa (6.61%).

CONCLUSIONS

The prevalence of MMC varies among regions. Clinicians should be aware of the potential prevalence of MMC, particularly in mandibular first molars, as a missed MMC could result in endodontic failure.

CLINICAL RELEVANCE

The presence of MMCs varies in different geographic regions (0% to 29.7%). Clinicians should always look for MMC when doing an endodontic treatment on mandibular molars, as the presence of this canal is not uncommon. We suggest searching for this canal as if searching for the second mesiobuccal canal of maxillary 1st molars.

Periapical Lesions in Panoramic Radiography and CBCT Imaging-Assessment of AI's Diagnostic Accuracy

Background/Objectives: Periapical lesions (PLs) are frequently detected in dental radiology. Accurate diagnosis of these lesions is essential for proper treatment planning. Imaging techniques such as orthopantomogram (OPG) and cone-beam CT (CBCT) imaging are used to identify PLs. The aim of this study was to assess the diagnostic accuracy of artificial intelligence (AI) software Diagnocat for PL detection in OPG and CBCT images. Methods: The study included 49 patients, totaling 1223 teeth. Both OPG and CBCT images were analyzed by AI software and by three experienced clinicians. All the images were obtained in one patient cohort, and findings were compared to the consensus of human readers using CBCT. The AI's diagnostic accuracy was compared to a reference method, calculating sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and F1 score. Results: The AI's sensitivity for OPG images was 33.33% with an F1 score of 32.73%. For CBCT images, the AI's sensitivity was 77.78% with an F1 score of 84.00%. The AI's specificity was over 98% for both OPG and CBCT images. Conclusions: The AI demonstrated high sensitivity and high specificity in detecting PLs in CBCT images but lower sensitivity in OPG images.

Comparative Analysis of Examination Methods for Periapical Lesion Diagnostics: Assessing Cone-Beam Computer Tomography, Ultrasound, and Periapical Radiography

INTRODUCTION

Periapical lesions of teeth are typically evaluated using periapical X-rays (PA) or cone-beam computer tomography (CBCT); however, ultrasound imaging (US) can also be used to detect bone defects. A comparative analysis is necessary to establish the diagnostic accuracy of US for the detection of periapical lesions in comparison with PA and CBCT.

OBJECTIVES

This study aimed to evaluate and compare the measurement precision of US against PA and CBCT in detecting periapical lesions.

METHODS

This study included 43 maxillary and mandibular teeth with periapical lesions. All teeth were examined clinically, radiographically, and ultrasonographically. Observers evaluated and measured the periapical lesions on CBCT, PA, and US images.

RESULTS

The comparison of lesion size showed that it differs significantly between the different methods of examination. A statistically significant difference was found between CBCT and US (mean difference = 0.99 mm, 95% CI [0.43-1.55]), as well as between CBCT and PA (mean difference = 0.61 mm, 95% CI [0.17-1.05]). No difference was found between the US and PA methods (p = 0.193).

CONCLUSION

US cannot replace PA radiography in detecting pathologies but it can accurately measure and characterize periapical lesions with minimal radiation exposure. CBCT is the most precise and radiation-intensive method so it should only be used for complex cases.

Evaluation of radiographic quality of root canal obturation performed by undergraduate and postgraduate clinical dental students in a Nigerian hospital

Introduction

the three-dimensional fluid-tight obturation of the root canal system ends the endodontic treatment process and the technical quality of obturation of the root canal (RC) is a determinant of the outcome of the treatment. This final stage of RCT is critical in the outcome of treatment, thus the need to have adequate and quality obturation. The audit of the performance of students in this aspect evaluates performances and identifies where there is a need for improvement. Therefore, we set out to evaluate the quality of root canal obturation performed by undergraduate and postgraduate clinical dental students.

Methods

a cross-sectional study that evaluated the root canal obturation performed by undergraduate and postgraduate students in a teaching hospital, for 1 year. The radiographic evaluation was done by calibrated assessors. The radiographs were viewed under magnifying lenses (x3.5). The adequacy of length and homogeneity of the density of obturation were the outcome variables assessed in all the categories of teeth treated among patients who are 18 years and above, seen during the study period.

Results

eighty-four maxillary and 36 mandibular teeth were root-filled in 97 patients with a mean age of 37.6 years ± 14.7 SD. A good proportion (47.5%) of the root fillings were done by the postgraduate doctors. Most of the canals (69.4%) had acceptable lengths while density was acceptable in only 37.7%. Slightly over half of canals with acceptable length (64 out of 127; 50.4%) were reported in teeth with single canals (p=0.000) likewise with density (28;40.6%). Overall acceptable length and root filling density was 28.9% and there was no statistical significance in the performances of the operators in relation to the length of root filling (p=0.109), and density (p=0.55).

Conclusion

the overall acceptable length and root filling density was 28.9% among both undergraduate and postgraduate students. The adequacy of root canal filling may be dependent on experience, the complexity of the tooth, and the method of instrumentation.

Optimizing radiation safety in dentistry: Clinical recommendations and regulatory considerations

BACKGROUND

The value of dental radiographs to oral health care decision making must be balanced with radiation safety to minimize patient exposure and occupational risk of oral health care providers. This review summarizes recommendations and regulatory guidance regarding dental radiography and cone-beam computed tomography. An expert panel presents recommendations on radiation safety, appropriate imaging practices, and reducing radiation exposure.

TYPES OF STUDIES REVIEWED

A systematic search run in Ovid MEDLINE, Embase, and Cochrane Database of Systematic Reviews identified relevant topical systematic reviews, organizational guidelines, and regulatory reviews published in the peer-reviewed literature since 2010. A supplemental search of the gray literature (eg, technical reports, standards, and regulations) identified topical nonindexed publications. Inclusion criteria required relevance to primary oral health care (ie, general or pediatric dentistry).

RESULTS

A total of 95 articles, guidance documents, and regulations met the inclusion criteria. Resources were characterized as applicable to all modalities, operator and occupational protection, dose reduction and optimization, and quality assurance and control.

PRACTICAL IMPLICATIONS

Understanding factors affecting imaging safety and applying fundamental principles of radiation protection consistent with federal, state, and local requirements are essential for limiting patient ionizing radiation exposure, in conjunction with implementing optimal imaging procedures to support prudent use of dental radiographs and cone-beam computed tomographic imaging. The regulatory guidance and best practice recommendations summarized in this article should be followed by dentists and other oral health care providers.

Developmental and Acquired Abnormalities of the Teeth

This review aims to present a detailed analysis of the most common developmental and acquired dental abnormalities, including caries, resorptive lesions, and congenital anomalies of teeth number, size, form, and structure. This review highlights how diagnostic imaging can aid in the accurate identification and management of these conditions.

Cone-beam computed tomography in endodontics: from the specific technical considerations of acquisition parameters and interpretation to advanced clinical applications

The implementation of imaging methods that enable sensitive and specific observation of anatomical structures has been a constant in the evolution of endodontic therapy. Cone-beam computed tomography (CBCT) enables 3-dimensional (3D) spatial anatomical navigation in the 3 volumetric planes (sagittal, coronal and axial) which translates into great accuracy for the identification of endodontic pathologies/conditions. CBCT interpretation consists of 2 main components: (i) the generation of specific tasks of the image and (ii) the subsequent interpretation report. A systematic and reproducible method to review CBCT scans can improve the accuracy of the interpretation process, translating into greater precision in terms of diagnosis and planning of endodontic clinical procedures. MEDLINE (PubMed), Web of Science, Google Scholar, Embase and Scopus were searched from inception to March 2023. This narrative review addresses the theoretical concepts, elements of interpretation and applications of the CBCT scan in endodontics. In addition, the contents and rationale for reporting 3D endodontic imaging are discussed.

Global cone-beam computed tomography adoption, usage and scan interpretation preferences of dentists and endodontists

AIM

This study investigated the adoption of cone-beam computed tomography (CBCT) by dentists and endodontists around the world, including their preferences in endodontic CBCT usage.

METHODOLOGY

An online questionnaire surveyed dental association members in Australia and New Zealand, and endodontic association members in Australia, Britain, Canada, Italy, New Zealand and the USA, about their CBCT training history, considerations in acquisition/interpretation, access to and usage of CBCT, preferred scan interpreter, and preferred endodontic scan settings. Data were analysed with Chi-squared, independent sample t-tests, Cochran's Q and McNemar's tests.

RESULTS

Responses from 578 endodontic specialists or postgraduates (Group E) and 185 non-endodontic dentists (Group NE) were included. Continuing professional education (CPE) was the most common source of CBCT training (69.2%). Factors considered in CBCT acquisition/interpretation included beam hardening (75.4%), radiation exposure (61.1%) and patient movement (58.3%). Group E reported higher CBCT usage (90.8%) than Group NE (45.4%, p < .001) and greater workplace access to CBCT (81.1% vs. 25.9%, p < .001). Scans were interpreted by the respondent in most workplace scans (83.3%) and externally taken scans (60.5%); Group E were significantly more likely to interpret themselves than Group NE. Small field of view (83.6%) and high resolution (86.6%) were most preferred as settings for endodontic CBCTs; Group NE were less likely to choose these settings. There were some geographic variations within Group E.

CONCLUSIONS

CBCT training was most commonly acquired via CPE. Endodontic respondents reported very high CBCT usage and access in the workplace. There are educational implications regarding CBCT limitations, appropriate applications and interpretation.

The Correlation between Intraorifice Distance and the Anatomical Characteristics of the Second Mesiobuccal Canal of Maxillary Molars: A CBCT Study

Introduction

Missing anatomy is one of the main causes of endodontic failures, and accurate knowledge of teeth anatomy is a prerequisite for adequate root canal treatment. The aim of the present cone beam computed tomography (CBCT) study was to describe the anatomical characteristics of the mesiobuccal (MB) root canals of maxillary molars and to understand if a correlation exists between the position of the canal orifices and the anatomical features of the root.

Methods

For the purposes of the study, a total of 100 CBCT scans of maxillary molars with two MB canals were selected and studied. The features of root canal anatomy of the MB root of the same teeth were analyzed and recorded (root length, confluence, and Vertucci classification). The distance between MB1 and MB2 orifices and the palatal orifice were recorded, as well as the distance between the orifices and the line joining the palatal orifice and the others. A statistical analysis was performed by providing descriptive measures, the measure of the correlation between different parameters, and the influence of some of these measures on the presence of a confluence between MB1 and MB2.

Results

It resulted that the most frequent configuration is type II Vertucci. The length measured on the sagittal plane was significantly correlated to the presence of a confluence in the MB root. When the root length was higher than 14.56 mm, the confluence is three times more frequent than when the length is lower (OR = 3.635). The area under the curve (AUC) of the receiver operator characteristic (ROC) curve for length on the sagittal plane was 0.632 (P=0.036).

Conclusions

The presence of a confluence between the MB canals of maxillary molars is correlated to the length of the root that could be measured on the sagittal plane and to the distance between the canal orifices. The relative position of the root canal orifices in relation to anatomic landmarks needs to be further explored.

The association of endodontic prognostic factors with the presence of periapical lesion, its volume, and bone characteristics in endodontically treated molars: a cross-sectional study

BACKGROUND

This study intended to evaluate the association between several endodontic prognostic factors with the presence of periapical lesions (PLs), their volume, and bone characteristics including cortical bone destruction (CBD) and buccal plate bone height (BPBH) in root-filled molar teeth using cone-beam computed tomography.

METHODS

A collection of 143 scans of endodontically treated maxillary/mandibular first or second molars recorded over 8 years, were obtained from a specialized radiology center. Data on prognostic factors including tooth number, gender, jaw type, the status and number of missed canals, obturation length, restoration type, presence of a separated instrument, presence of a post or screw in the canals, and presence of perforation were collected. The assessed outcomes included PL presence, PL volume, CBD, and BPBH. The association between prognostic factors and outcomes was evaluated using multiple logistic regression models with adjusted covariates and multifactorial ANOVA at a significance level of 0.05.

RESULTS

A total of 282 molars from 82 women and 50 men with a mean age of 40.6 ± 12.27 were included. Among those, 139 teeth presented PL with a mean volume of 18.68 mm3. CBD was prevalent in 137 teeth and the mean BPBH appeared to be 9.45 mm. The presence of a missed canal (OR = 10.022, P < .05), underfilled canal (OR = 3.725, P < .05), overfilled canal (OR = 15.859, P = .018), and perforation (OR = 15.261, P = .013) was significantly associated with PLs. None of the prognostic factors could considerably contribute to the CBD (P > .05). The presence of a missed canal was positively associated with the PL volume (P < .05). Similarly, missed canals (P < .05), perforation (P < .05), and separated instruments (P = .004) were associated with a significantly reduced BPBH.

CONCLUSIONS

Overfillings, perforations, missed canals, and underfillings were identified as remarkable predictors of PL, arranged in descending order of their respective impact. The only factor capable of significantly increasing the PL volume was the missed canal. In brief, obturation length errors, perforations, missed canals, and separated instruments were robustly correlated with endodontic failure, which highlights the importance of mitigating the potential for errors by following the fundamentals of endodontics.

Worldwide Assessment of the Root and Root Canal Characteristics of Maxillary Premolars - A Multi-center Cone-beam Computed Tomography Cross-sectional Study With Meta-analysis

INTRODUCTION

This worldwide study examined the root and root canal characteristics of maxillary premolars and explored how demographic factors impact the outcomes.

METHODS

Observers from 44 countries assessed 26,400 maxillary premolars using cone-beam computed tomography and employed a standardized screening method to gather data on multiple canal morphology and 3-rooted configuration (primary outcomes), as well as secondary outcomes related to root and root canal anatomies. Demographic factors such as ethnicity, sex, and age were collected for each participant. The intra- and inter-observer tests ensured observer reliability. Primary outcomes were represented as odds ratios and untransformed proportions accompanied by 95% confidence interval (CI) forest plots. Meta-analysis compared sub-groups and identified sources of heterogeneity (α = 5%).

RESULTS

The overall prevalence of multiple canal morphology in the first premolar was 93.5% (95% CI, 93.3%-94.7%), while in the second premolar, it was 49.7% (95% CI, 44.9%-54.6%). The proportion of 3-rooted configuration was 1.8% (95% CI, 1.4%-2.1%) in the first premolar and 0.4% (95% CI, 0.3%-0.5%) in the second. Asian countries generally displayed fewer roots and root canals, while European nations showed higher counts (P < .05). Males exhibited higher percentages and odds ratios for both outcomes in both premolars. Younger patients demonstrated lower percentages of multiple root canal morphologies (P < .05). Factors such as tooth side, voxel size and field-of-view did not influence the outcomes (P > .05).

CONCLUSIONS

The worldwide assessment of root and root canal characteristics of maxillary premolars has revealed a discernible influence of various factors such as tooth type, geographical region, ethnicity, sex, and age.

Mapping artifacts generated in a tooth adjacent to titanium and zirconia implants located in the endomass and exomass in cone beam computed tomography: an ex vivo study

OBJECTIVE

We evaluated artifact expression in a root adjacent to a dental implant located in the endomass or exomass in cone beam computed tomography (CBCT).

STUDY DESIGN

We placed a single titanium or zirconia implant adjacent to a premolar root in a dried human mandible and acquired CBCT scans using an OP300 Maxio and a Picasso Trio 3D unit exposing a 5x5cm field of view with the implant in the endomass or exomass (implant groups) or without an implant (control group). We measured the mean gray values (MGVs) for 8 lines of interest (LOIs) around the root canal of the premolar and compared the MGVs by analysis of variance, with significance established at P < 0.05.

RESULTS

For the OP300 Maxio scans, the MGVs of both implant groups in the endomass were lower than the MGVs of the control group. In the exomass, the titanium group had MGVs similar to the control group, but the zirconia group produced significantly lower MGVs than control and titanium groups (P <.0001), indicating the presence of hypodense artifacts. For the Picasso Trio 3D scans, the MGVs of both implant groups in the endomass were similar to the MGVs of the control group. In the exomass, the zirconia group generated lower MGVs than control and titanium groups (P <.0001), indicating hypodense artifacts.

CONCLUSIONS

When performing CBCT examination, titanium implants produce less artifact expression in the exomass, and zirconia implants have less artifact expression in the endomass.

Applying the American Association of Endodontists and American Academy of Oral and Maxillofacial Radiology guidelines for cone-beam computed tomography prescription: Impact on endodontic clinical decisions

BACKGROUND

The American Association of Endodontists (AAE) and the American Academy of Oral and Maxillofacial Radiology (AAOMR) developed guidelines for the prescription of cone-beam computed tomographic (CBCT) imaging. The impact of appropriately prescribed CBCT imaging on endodontic diagnosis and treatment (Tx) decisions was examined.

METHODS

The clinical databases at the School of Dentistry at the University of California, Los Angeles, Los Angeles, California, were queried to identify patients referred for CBCT imaging from the postgraduate endodontic clinic over a consecutive 36-month period. Primary and secondary indications for CBCT imaging were recorded. Pre-CBCT uncertainty in diagnosis, Tx of the teeth in question, and post-CBCT changes to the diagnosis and Tx plan were recorded.

RESULTS

CBCT imaging was prescribed for 12% of patients. A total of 442 scans were prescribed to evaluate 526 teeth. Molars accounted for 51% of teeth examined. Overall, CBCT effected a change in periapical diagnosis (21%) and in the Tx plan (69%). The 5 most frequent primary indications for CBCT imaging were, in order, AAE-AAOMR recommendations 7, 9, 2, 12, and 6. The impact of these recommendations on Tx decisions varied from 48% through 93%.

CONCLUSIONS

This study validates the use of the AAE-AAOMR guidelines for prescribing CBCT imaging for endodontic evaluations. CBCT imaging contributed predominantly to Tx decisions rather than diagnostic determinations.

PRACTICAL IMPLICATIONS

This study validates AAE-AAOMR case selection guidelines for CBCT imaging and shows a positive impact of prescription imaging on endodontic decision making.

Global survey of endodontic practice and adoption of newer technologies

AIM

To investigate current endodontic practices, adoption of technologies and continuing education attendance within specialist endodontic practice globally and to identify geographic trends.

METHODOLOGY

A web-based survey of endodontic association members in Australia, Britain, Canada, Italy, New Zealand and the USA on routine treatment preferences, armamentarium and education attendance was conducted. Chi-squared, independent sample t-tests, Cochran's Q test and McNemar's test were performed.

RESULTS

The survey was completed by 543 endodontists or endodontic post-graduate students. Almost all respondents used the dental operating microscope (DOM, 91.3%), engine-driven nickel-titanium instruments (NiTi, 97.6%), electronic apex locators (EAL, 93.0%), cone-beam computed tomography (CBCT, 91.2%) and calcium silicate-based materials (CSBMs, 93.7%). Dental dam was always used by 99.1%. Over half used irrigation adjuncts (81.8%), warm vertical compaction (74.6%) and heat-treated NiTi (60.2%). Geographic comparison between AP (Asia-Pacific, n = 78), AM (Americas, n = 402) and EM (Europe and Middle East, n = 63) was performed. AM and EM preferred single-visit treatment more (p < .001) and used higher sodium hypochlorite concentrations than AP. AM had more access to CBCT in the workplace (86.6%) than AP (65.4%, p < .001) and used CBCT for routine preoperative assessment (39.6%) more than EM (7.3%, p < .001). Almost all of EM used irrigation adjuncts (95.2%), more than AM (78.1%, p = .001). AP used steroid/antibiotic medicaments most (p < .001) and had the highest attendance at continuing education programmes.

CONCLUSION

Several endodontic-specific armamentaria have reached almost complete adoption within global specialist endodontic practice, whilst the continued uptake of newer technologies should be followed over time. Some practising philosophies varied significantly across different geographic regions.

Morphometric relationships in mesio-buccal roots of maxillary first molars in Saudi subpopulation: A CBCT study

This CBCT-based study analysed morphometric relationships in Mesio-Buccal (MB) roots of maxillary first molars (MFM). 133 MFM with two MB canals were assessed and classified using Vertucci's classification. MB roots' length and MB1-MB2 canals inter-orifice distances (IOD) were noted. The data were analysed using SPSS software. The most frequently present canal was type IV (59.4%) followed by type II (40.6%). Mean MB roots' length for canals exhibiting type IV was 9.26 ± 0.21 mm and of those exhibiting type II was 12.8 ± 0.42 mm. Statistically significant relationship was found between MB root length and canal type. Mean IOD for type II and type IV canals was 2.4 ± 0.47 and 3.8 ± 0.21 mm, respectively. Statistically significant relationship was found between IOD and canal type. Length of MB root and IOD had a significant association with canal type present in MFM. This knowledge can enhance clinicians' understanding of canal morphology which can increase predictability and success rate of endodontic treatment.

Prevalence of middle mesial canal using cone beam computed tomography: A systematic review and meta-analysis

Background

The presence of middle mesial canals in mandibular molars are not commonly encountered in daily practice. However, locating and debriding such anatomical variation during the endodontic therapy is essential to avoid endodontic failure. The aim of this systematic review was to identify the overall prevalence of middle mesial canals (MMC) in mandibular molars using cone-beam computed tomography (CBCT), to assess the influence of different gender on the prevalence of MMCs in mandibular molars and to describe the MMC configurations.

Methods

The review protocol was registered in the PROSPERO database (CRD42021238523). The main electronic databases were searched until February 2022 for prevalence studies on root/canal anatomy in mandibular molars using CBCT imaging, in addition to hand-searched scientific articles in peer-reviewed journals and grey literature. The quality of the included studies was assessed using the Joanna Briggs Institute Critical Appraisal tool. Egger's and Begg's tests and Pearson's chi-square test were used for statistical analysis.

Results

From 523 records, 488 studies were excluded after screening the title and abstract. 35 relevant studies were included for full-text assessment and 28 studies were included in the meta-analysis. The overall prevalence of MMC out of the 19,256 teeth was 5.09% (95% CI: 2.894 to 7.784). The prevalence of MMC was 9.79% (95% CI: 4.296 to 17.224) in males and 13.96% (95% CI: 0.541 to 40.737) in females with a statistically significant difference of 4.16% (95% CI: 2.29 to 6.01). The most MMC configuration found in this review to be confluent with the mesiobuccal canal.

Conclusion

The results showed an overall 5.09% prevalence of MMC in mandibular molars, with a significantly high prevalence in female subjects. Additionally, this canal was found to be confluent with the mesiobuccal canal.

Comparison of Curvature Severity Between Sagittal and Coronal Planes of Mesiobuccal Canals in Permanent Maxillary First Molars Using Multiple Complexity-risk Criteria: A CBCT Cross-sectional Study of a Brazilian Subpopulation

INTRODUCTION

This study aimed to compare the curvature severity of mesio-buccal (MB) canals between sagittal and coronal planes using cone-beam computed tomography.

METHODS

In a Brazilian subpopulation, untreated MB1 (n = 141) and MB2 (n = 72) with single curvatures in sagittal and coronal planes were measured to determine their angle and radius (r), plus the prevalence of S-shaped canals was recorded. Curvature severity was defined according to the American Association of Endodontists Case Difficulty Assessment form (AAE) and EndoApp (EA), as well as their modified versions that consider angle and radii (AAE-r, EA-r). Data were converted into mean angle and r, percentage of canals >30°, AAE, EA, AAE-r and EA-r categories. The influence of r on case severity was assessed. Statistical analysis was performed using t-tests and chi-squared tests. The level of significance was set as P ≤ .05.

RESULTS

For single curvatures, significantly higher mean degrees (SD) angles were found in the sagittal views in both canals (MB1 sagittal: 35 [11]; MB1 coronal: 13 [13]; MB2 sagittal: 29 [14]; MB2 coronal: 22 [15] [P < .05]). A greater percentage of angles >30° (MB1: 56.7% vs 6.4%; MB2: 44.4% vs 22.2%) in sagittal planes compared to coronal planes was also found. Conversely, a higher prevalence of S-shaped canals (MB1: 33.3% vs 7.1% MB2: 31.9% vs 15.3%) was observed in coronal planes. Significant differences between AAE and AAE-r were present with greater case severity when radii were considered (P < .05).

CONCLUSIONS

Sagittal planes were associated with more severe single curvatures, while coronal planes had a greater prevalence of S-shaped canals.

A Cone Beam Computed Tomography-Based Investigation of the Frequency and Pattern of Radix Entomolaris in the Saudi Arabian Population

Background and Objectives: An understanding of the anatomical complexity of teeth is a significant factor for a successful endodontic treatment outcome. The aim of this study was to explore the frequency and pattern of distribution of radix entomolaris (RE) in mandibular first molars (MFMs) of a Saudi Arabian subpopulation using CBCT scans. Materials and Methods: This study was conducted at dental clinics of Qassim University from February to May 2023 by evaluating CBCT scans that were previously obtained for diagnostic purposes. Scans of Saudi national patients with bilaterally present MFMs and fully formed root apices were included. Conversely, scans with one/or two missing MFMs, MFMs with incomplete root apices, full- or partial-coverage prosthesis, endodontic treatment, and associated radicular resorption were excluded from study. A total of 303 CBCT scans with 606 bilateral MFMs were analyzed by two calibrated evaluators for the presence of, and type according to Song's typolgy of RE. The data were analyzed using SPPS-24. The descriptive variables were documented as frequencies and percentages. The chi-square test was used to determine the association between the prevalence of RE with the gender, jaw side and age group. Both inter-rater and intra-rater agreements were estimated for detecting and classifying RE using Cohen's kappa test. Results: The sample had 63.7% males and 36.3% females. The prevalence of RE was 6.6%, with Song's type III (57.5%) as the most common variant. Absolute agreement was noted between the raters about the presence of RE and very strong agreement was noted for the classification of the RE. Conclusions: RE is an uncommon finding among the mandibular first molars of the Saudi population without any gender and quadrant predilection. The clinicians' knowledge of the presence and Song's type of RE may contribute towards the enhancement of endodontic treatment outcomes.

Diagnosis of Odontogenic Maxillary Sinusitis by Cone-beam Computed Tomography: A Critical Review

INTRODUCTION

This review aims to provide an up-to-date overview of the current applications of cone-beam computed tomography (CBCT) and other imaging modalities in diagnosing odontogenic maxillary sinusitis (OMS). Furthermore, the clinical operation procedures of radiography modalities in OMS diagnosis were summarized, with the goal of assisting clinicians in improving OMS diagnostic accuracy in clinical practice.

METHOD

A comprehensive review of researches that discussed the applications of radiography modalities in the diagnosis of OMS was conducted. Pertinent information was evaluated and organized for this review.

RESULTS

Cone-beam computed tomography (CBCT) offers a superior, high-resolution, and three-dimensional view of the maxillary tooth-bone-sinus complex compared to conventional radiography modalities. It enables a better understanding and classification of the spatial relationships between root apices/periapical lesions and maxillary sinus. The use of CBCT, combined with the advantages of other radiography modalities and proper image interpretation, is indispensable to enhance OMS diagnostic accuracy and mitigate the risk of missed or misdiagnosis.

CONCLUSION

The significance of CBCT in the diagnosis of oral and maxillofacial conditions has garnered widespread recognition. It provides highly precise diagnostic information and classification basis for OMS. The clinical operation procedures for imaging examination are essential in ensuring the consistency and reliability of the diagnosis.

Endodontic Orthograde Retreatments: Challenges and Solutions

Endodontic orthograde retreatments are considered one of the possible treatment options in case of post-treatment diseases considering the promising results present in the literature. Despite this, a plethora of articles have been published on this topic, and drawing conclusions could be challenging. For this reason, this review aims to summarize the crucial points on each aspect of non-surgical endodontic retreatments, discussing and comparing the current protocols, techniques, materials, and indications. Taking into consideration data from the literature, in terms of diagnosis, CBCT should be considered the first choice, since it can thoroughly affect the diagnosis and treatment plan. Regarding the procedural phases, some conclusions can be drawn: when present, coronal restoration materials such as crowns, partial prostheses, post, and core should be removed; the use of magnification devices, ultrasonic instruments, and an in-depth interpretation of radiographic images with both 2D and 3D images are strongly recommended during the orifice location; additional protocols such as irrigants activation, ultrasonic cleaning, and rotary or reciprocating instrumentation of treated canals are strongly recommended for filling materials removal and to achieve a high-quality chemo-mechanical disinfection; perforations should be treated as soon as possible, and the material of choice to treat them is the MTA or other calcium-silicate-based repair materials; the presence of ledges does not intrinsically reduce the success rate of RCRts if properly managed; in case of instrument fragments, their removal should be considered as the first treatment option, however many variables should be considered to select the proper technique or consider the option of bypassing.

Assessment of the Prevalence of Radix Entomolaris and Distolingual Canal in Mandibular First Molars in 15 Countries: A Multinational Cross-sectional Study with Meta-analysis

AIM

The aim of this study was two-folded: i) to assess the prevalence of Distolingual Canal (DLC) and Radix Entomolaris (RE) in Mandibular First Molars (M1Ms), using Cone Beam Computed Tomography (CBCT) images and ii) to assess the impact of sociodemographic factors on the prevalence of these conditions worldwide.

METHODS

CBCT images were scanned retrospectively and the ones including bilateral M1Ms were included in the study. The evaluation was performed by 1 researcher in each country, trained with CBCT technology. A written and video instruction program explaining the protocol to be followed step-by-step was provided to all observers to calibrate them. The CBCT imaging screening procedure consisted of evaluating axial sections from coronal to apical. The presence of DLC and RE in M1Ms (yes/no) was identified and recorded.

RESULTS

Six thousand three hundred four CBCTs, representing 12,608 M1Ms, were evaluated. A significant difference was found between countries regarding the prevalence of both RE and DLC (P < .05). The prevalence of DLC ranged from 3% to 50%, and the overall prevalence was 22% (95% CI: 15%-29%). RE prevalence ranged from 0% to 12%, and the overall prevalence was 3% (95% CI: 2%-5%). There were no significant differences between left and right M1Ms or between genders for either DLC or RE (P > .05).

CONCLUSION

The overall prevalence of RE and DLC in M1Ms was 3% and 22%. Additionally, both RE and DLC showed substantial bilaterally. These variations should be considered by endodontic clinicians during endodontic procedures in order to avoid potential complications.

Patient shielding during dentomaxillofacial radiography: Recommendations from the American Academy of Oral and Maxillofacial Radiology

BACKGROUND

The American Academy of Oral and Maxillofacial Radiology established an ad hoc committee to draft evidence-based recommendations and clinical guidance for the application of patient contact shielding during dentomaxillofacial imaging.

TYPES OF STUDIES REVIEWED

The committee reviewed monographs and reports from radiation protection organizations and studies that reported radiation dose to gonads, breasts, and thyroid gland from dentomaxillofacial imaging.

RESULTS

Considering the absence of radiation-induced heritable effects in humans and the negligible dose to the gonads and fetus from dentomaxillofacial imaging, the committee recommends discontinuing shielding of the gonads, pelvic structures, and fetuses during all dentomaxillofacial radiographic imaging procedures. On the basis of radiation doses from contemporaneous maxillofacial imaging, the committee considered that the risks from thyroid cancer are negligible and recommends that thyroid shielding not be used during intraoral, panoramic, cephalometric, and cone-beam computed tomographic imaging.

PRACTICAL IMPLICATIONS

This position statement informs and educates the reader on evolving radiation protection practices and provides simple, unequivocal guidance to dental personnel to implement these guidelines. State and local authorities should be contacted to update regulations to reflect these recommendations.

Cone-beam computed tomography-Predictors and characteristics of usage in Australia and New Zealand, a multifactorial analysis

Cone-beam computed tomography (CBCT) is an increasingly used imaging modality. This study aimed to identify the factors that predict its usage amongst endodontists in Australia and New Zealand and describe usage characteristics. Data were collected via an online questionnaire, with analysis including descriptive statistics, cross-tabulation and multifactorial modelling. Ninety-four endodontists completed the questionnaire who were using CBCT for 7 years (median), over half had a CBCT unit in practice, with most prescribing up to 10 scans/month and 55 using a small field of view. Sixty-eight participated in >5 h of CBCT education/year and a third received a specialist-prepared report. The number of prescriptions/month was significantly associated with on-site CBCT units (Exp B: 8.53; 95% CI: 1.46-49.86, p < 0.05) and the number of years of CBCT usage by participants (Exp B: 1.46; 95% CI: 1.17-1.84, p = 0.001). CBCT imaging in endodontics is a useful diagnostic aid to decision making and treatment planning, with widespread acceptance and usage.

Endodontic treatment of an immature maxillary lateral incisor with type II dens invaginatus in an orthodontic patient: A case report

This paper presents a case report of an immature maxillary lateral incisor with type II dens invaginatus, with a periapical lesion. The tooth was treated with MTA apical barrier followed by root filling with thermoplasticised GP and restoration with resin composite. Three-year radiographic follow-up showed healing of the apical lesion and normal clinical parameters.

Age-related changes in the morphology of the root canal system of mandibular first molars: a micro-CT study

OBJECTIVE

This study aimed to evaluate changes on root canal morphology in patients with different ages using micro-CT technology.

MATERIALS AND METHODS

Mandibular first molars (n = 150) were scanned at a pixel size of 13.68 µm, categorized into 3 groups according to patient's age and analyzed regarding configuration, orifices, apical foramina, root length, canal volume, and surface area. Morphological 2D and 3D parameters were evaluated in distal roots with Type I configuration (n = 109) as well as the morphology of isthmuses Types I and III in 68 mesial roots. One-way ANOVA post hoc Tukey and Kruskal-Wallis tests were used for statistical analyses (α = 5%).

RESULTS

A great variation in the canal configuration was found. No difference was observed in roots' length (p > 0.05). Canal volume reduced with age (p < 0.05), while surface area increased (p < 0.05) in patients ≤ 30 years. There was no difference in canal/root length, area, and from foramen to the apex in distal roots with Type I configuration (p > 0.05), but 2D and 3D parameters significantly decreased with age (p < 0.05). Overall, the diameter of the isthmuses' roof reduced with age (p < 0.05). In patients ≥ 31 years with Type III isthmus the distance from the isthmus floor to the foramen of the mesiolingual canal also decreased (p < 0.05).

CONCLUSION

Overall, the internal morphology of the mesial roots of mandibular first molars was more affected by aging than distal canals. The most relevant tested parameter that significantly reduced in both roots was the volume of the root canal systems.

CLINICAL RELEVANCE

A detailed evaluation of fine anatomical aspects of the root canal system of mandibular first molars of patients with different ages showed that the internal morphology of mesial roots is more affected by aging than distal canals.

Prevalence of pulp canal obliteration and periapical pathology in human anterior teeth: A three-dimensional analysis based on CBCT scans

This study aimed to determine the prevalence of pulp canal obliteration (PCO) and its association with periapical pathology (Hypodense areas) in cone-beam computed tomography (CBCT) scans of anterior teeth. A total of 2161 CBCT scans from patients 18 years or older taken between 2000 and 2020 were selected. Patient-, tooth- and scan-related data were registered. Two calibrated evaluators recorded the number of teeth with PCO ≥4 mm in the cervical third of the roots and the presence or absence of periapical hypodensities (PH). The length of the root canal that was calcified was also determined. Logistic regression analysis was used to determine whether any of the recorded factors influenced the presence of PCO and the presence of periapical pathology in teeth presenting with PCO. The only factor significantly related to the presence of PCO was patient age. The prevalence of PH in teeth exhibiting PCO was 10%.

Post-treatment apical periodontitis associated with a missed root canal in a maxillary lateral incisor with two roots: A case report

Missed canals can be a common cause of persistent intraradicular infection and post-treatment apical periodontitis. This article reports on a rare case of a maxillary lateral incisor with two roots exhibiting symptomatic post-treatment apical periodontitis regardless of a radiographically adequate root canal treatment. The second root, which was only revealed by cone-beam computed tomography, had passed unnoticed during the first treatment, and its missed canal was the most likely cause of symptoms and treatment failure. Reintervention including the proper management of the extra root canal and retreatment of the main canal resulted in the resolution of symptoms and periradicular tissue healing. This case report reinforces the need for three-dimensional radiographic diagnosis to search for the cause of post-treatment disease and guide the decision-making process for proper management.

Endodontic management of a double-type IIIB dens invaginatus in a vital maxillary central incisor aided by CBCT: A case report

Type IIIB dens invaginatus presents with diagnostic and treatment related challenges when in need of endodontic management as a consequence of its complex anatomy, especially when presented in a vital tooth with a periapical lesion. Apical periodontitis associated with two type IIIB invaginations in a central maxillary incisor of a 10-year-old patient was diagnosed. A cone-beam computed tomography (CBCT) scan provided essential diagnostic information and steered the treatment plan. The two invaginations were separate, with no communication between them and the pulp. The pulp appeared vital and non-inflamed. Endodontic treatment of the invaginations was carried out without intervention in the pulp. A 4-month follow-up periapical radiograph showed significant shrinkage of the lesion and a 2-year follow-up CBCT scan confirmed its complete healing. The pulp remains vital, responding normally to sensitivity tests. This outcome indicates that preserving the pulp's vitality is achievable through timely diagnosis.

Endodontic Clinical Outcome after Separated Instrument Removal Using a Spinal Needle Technique: A Retrospective Study of Thirty Years of Clinical Experience

INTRODUCTION

Current methods for the removal of separated endodontic instruments (RSI) are not predictable.

METHODS

The primary outcome of this retrospective study was to assess the clinical and radiographic success (CRS) of teeth in case of RSI after a 5-year follow-up. Secondary outcomes were to evaluate (1) the effectiveness in RSI and (2) the risk of root fracture after RSI. The study protocol was registered at ClinicalTrials.gov (ID: NCT05128266). The patients were treated by the same endodontist between January 1991 and December 2019. The RSI was performed under the operative microscope as follows: first, the dentine surrounding the coronal part of the broken instrument was selectively removed by using a small ultrasonic tip to loosen the fragment; then, a modified spinal needle was used to catch and remove the instrument. The 1-, 3-, 5-, and >5-year CRS were recorded. Logistic regression analysis was performed to determine independent predictors of failure (ie, tooth number, type of root canal, shape of the root canal, type of broken instrument, apicocoronal level of the separated instrument, presence of periapical lesions, and root perforations).

RESULTS

A total of 158 teeth were included in this study. Finally, 131 instruments underwent RSI (82.9%). RSI was an independent predictor of CRS after 1-year of treatment (odds ratio: 58.3; 95% confidence interval: 27.42-95.73, P < .05). At the 5-year follow-up, only 10 of 131 teeth (7.6%) failed. All failures were caused by root fracture (10/10) (χ2 test, P < .05). Separated instruments located in the apical third of the root were more difficult to remove (13/49 cases, 26.5%; χ2 test, P < .05).

CONCLUSIONS

The proposed technique can achieve excellent effectiveness in RSI, can achieve a high CRS rate when a periapical lesion is present, is not associated to a significant increase in root fracture incidence, and should be performed with the help of an operative microscope.

Influence of Calcified Canals Localization on the Accuracy of Guided Endodontic Therapy: A Case Series Study

This study aimed to evaluate the precision of the guided endodontic technique applied to calcified canals in anterior teeth in relation to demographic and dental variables. The present observational study was conducted during the period 2020-2021. The patients were consecutive referrals at the Department of Endodontics and Conservative Dentistry of the University Hospital of Siena. The guided endodontics protocol was applied using 0.75 mm diameter burs for the lower teeth and 0.90 mm for the upper teeth. The inclusion criteria were as follows: (i) teeth with pulp canal obliteration (PCO) associated with a periapical lesion (periapical index (PAI) ≥ 2); (ii) teeth with PCO that require the placement of a root canal post for the execution of a prosthetic treatment; (iii) teeth in which surgical treatment was not justified. Socio-demographic characteristics of the patients were recorded and related to the drill path accuracy through the guide in the calcified endodontic canal, evaluated through a radiographic analysis, and classified as optimal (in the center of the root canal) and acceptable (deviated peripherally/tangentially). A logistic regression model was built to predict the factors that influence the poor precision of the technique. Seventeen patients (mean age 48 years) with eighteen calcified single-rooted teeth were enrolled. All teeth were associated with periapical lesions with PAI scores from 2 to 5 (mean PAI: 3.055). From the model, it is evident that the presence of a calcification affecting the apical area of the root increases the probability of being off-center with the bur by about 15 times. In addition, a previous attempt at endodontic treatment and the position in the lower arch increases the probability of non-centrality of the drill, although in a non-statistically significant way. In any of the analyzed cases, the guided endodontic technique applied to PCO did not determine the presence of iatrogenic errors, such as perforations. However, the apical localization of the obliteration increases the probability of being off-center with the drill during the instrumentation phase by about 15 times.

Endodontic Surgery of the Palatal Root of a Maxillary Molar Associated with Simultaneous Management of a Maxillary Sinus Lesion

This case report describes a particular application of endodontic microsurgery with a palatal approach in the presence of a radiopaque lesion inside the maxillary sinus. The patient presented complaining of pain related to the first maxillary molar and events of nasal obstruction and facial pain in the cheek and nasal area. The endodontic orthograde treatment and retreatment were done, respectively, 7 and 4 years earlier. The cone-beam computed tomography (CBCT) scan taken before the treatment showed two separate lesions: one associated with the palatine root of the molar and another one inside the maxillary sinus. The patient agreed to solve both problems in one surgical step: endodontic surgery of the palatine root with palatal access with the simultaneous asportation of a lesion from the maxillary sinus floor. Complete bone healing of the periapical area and the maxillary sinus was visualized on intra-oral radiographs, and CBCT was taken one year after the treatment. As far as the authors know, no one in literature has ever described this approach and solved in such a conservative way both the problems at the tooth and in the maxillary sinus.

Middle mesial canal in mandibular first molar: A narrative review

Purpose

This review aimed to assess the incidence, anatomical characteristics, identification, and clinical management using conventional techniques and advanced tools to manage MMCs successfully.

Methods

Medline/PubMed and Scopus databases were searched using "Middle mesial canal," "Middle mesial root canal," OR "Accessory mesial canal" keywords from 1 January 1970 and 1 February 2023. The most pertinent articles were chosen for the review from the retrieved articles. In addition, relevant articles were added by manually searching the list of references.

Results

The incidence of MMC is noticeable in younger people, and the confluent canal is the most common type. The majority of MMCs merged with mesiobuccal (MB) canals rather than mesiolingual (ML) canals. Clinical management could be employed using the standard endodontics protocol, and recent radiography technologies, magnification, rotary, and obturation materials can facilitate the procedures.

Conclusion

The possibility of the incidence of MMC is not unusual. Detection and thorough debridement followed by obturation of the canal could increase the success rate of clinical outcomes.

CBCT in contemporary endodontics

Cone-beam computed tomography (CBCT) is a three-dimensional imaging modality which can aid endodontic diagnosis and treatment planning. While there are guidelines available describing the indications, there are divergent philosophies on when this technology should be applied in clinical practice. This paper reviews the applications of CBCT including the clinical relevance of parameters which can be assessed, highlights the limitations of this technology, and provides guidance on how to maximise its clinical utility.

Prevalence and morphological analysis of dens invaginatus in anterior teeth using cone beam computed tomography: A systematic review and meta-analysis

OBJECTIVES

To evaluate the prevalence and morphological characteristics of DI using CBCT.

METHODS

A literature search was performed in PubMed, Embase, Scopus, and Web of Science. Inclusion criteria were randomized clinical trials, cross-sectional studies, and prospective and retrospective cohort studies evaluating the morphological characteristics of DI in anterior teeth using CBCT. Three reviewer authors independently screened the studies, applied the eligibility criteria, assessed the risk of bias, and extracted until September (2022). The risk of bias was evaluated using the Joanna Briggs Institute criteria. Meta-analyses of proportions were used for estimate the prevalence DI according to factors at participant and tooth levels.

RESULTS

Six studies were included in the meta-analysis. Among 7373 individuals, a prevalence of 7.45 % of DI was observed (n = 258; τ2 = 0.0096; CI of 4.51-11.3; p < 0.05), with no significant influence of sex. Regarding laterality, unilateral DI showed higher mean prevalence (4.30 %; CI of 2.03-7.33). Among the 382 anterior teeth with DI (0.72 %), the most affected tooth was the upper lateral incisor (5.12 %; n = 329; CI of 2.35-8.86; p < 0.001), type I was the most prevalent (0.59 %; CI of 0.24-1.08) and the presence of open apex and periradicular pathology ranged from 4.3 % to 22.72 % and 3.5-77.92 %, respectively.

CONCLUSIONS

The prevalence of individuals with dens invaginatus was 7.45 %, the most affect tooth was the upper lateral incisor with a prevalence of 5.12 % unilaterally and type I was the most prevalent morphology.

Non-surgical Root Canal Treatment of an Upper First Molar With an Unusual Morphology: A Case Report

This paper presents the unusual morphology of an upper right first molar with two roots, each containing a single canal, in a patient seeking emergency endodontic treatment. Clinical and radiographic examinations revealed the unusual root canal morphology of the tooth, which required further investigation using cone beam computed tomography (CBCT) imaging, which confirmed this unusual anatomical structure. It was also noted that the upper right first molar was asymmetrical to the upper left first molar, which had the normal three-root morphology. The buccal and palatal canals were instrumented using ProTaper Next Ni-Ti rotary instruments and enlarged to ISO size 30, with a taper of 0.7; irrigated with 2.5% NaOCl; filled with gutta-percha using the warm-vertical-compaction technique, with the aid of a dental operating microscope (DOM); and then confirmed via periapical radiograph. The DOM and CBCT are valuable aids that helped us to confirm the endodontic diagnosis and treatment of this unusual morphology.

Influence of CBCT parameters on image quality and the diagnosis of vertical root fractures in teeth with metallic posts: an ex vivo study

Objectives

The aim of this study was to evaluate the influence of peak kilovoltage (kVp) and a metal artifact reduction (MAR) tool on image quality and the diagnosis of vertical root fracture (VRF) in cone-beam computed tomography (CBCT).

Materials and Methods

Twenty single-rooted human teeth filled with an intracanal metal post were divided into 2 groups: control (n = 10) and VRF (n = 10). Each tooth was placed into the socket of a dry mandible, and CBCT scans were acquired using a Picasso Trio varying the kVp (70, 80, 90, or 99), and the use of MAR (with or without). The examinations were assessed by 5 examiners for the diagnosis of VRF using a 5-point scale. A subjective evaluation of the expression of artifacts was done by comparing random axial images of the studied protocols. The results of the diagnoses were analyzed using 2-way analysis of variance and the Tukey post hoc test, the subjective evaluations were compared using the Friedman test, and intra-examiner reproducibility was evaluated using the weighted kappa test (α = 5%).

Results

The kVp and MAR did not influence the diagnosis of VRF (p > 0.05). According to the subjective classification, the 99 kVp protocol with MAR demonstrated the least expression of artifacts, while the 70 kVp protocol without MAR led to the most artifacts.

Conclusions

Protocols with higher kVp combined with MAR improved the image quality of CBCT examinations. However, those factors did not lead to an improvement in the diagnosis of VRF.

Root and canal morphology of mandibular second molars in an Egyptian subpopulation: a cone-beam computed tomography study

BACKGROUND

This study was using Cone beam computed tomography (CBCT) to examine the anatomical variations in mandibular second molars in an Egyptian sub-population.

METHODS

A total of 350 CBCT images (215 females and 135 males, aged 15-65 years) of mandibular second molars were evaluated. Samples were evaluated in terms of: number of roots, number of root canals, roots' cross section as well as prevalence and configurations of C-shaped canals. Statistical analysis was done to highlight differences between different categories and their prevalence among genders (significance level was set at p < 0.05). Data were presented as frequency and percentage values and were analyzed using chi square test followed by pairwise comparisons utilizing multiple Fisher's exact tests with Bonferroni correction. The significance level was set at p < 0.05 within all tests.

RESULTS

Of the 350 mandibular second molars evaluated, 87.2% were non-C-shaped while 12.8% were C-shaped with no gender-based statistically significant differences (χ2 = 0.19, p = 0.656). Most samples had three root canals (80%) followed by two (16%), then one (3.2%), and finally four (0.8%) root canals. Among the non-C-shaped molars, presence of two roots was most common (83.4%) followed by presence of a single root (16.2%), and only one sample (0.2%) had three roots, and this had no correlation with gender (χ2 = 1.86, p = 0.431). In the mesial roots Type IV Vertucci was the most common configuration found (68.8%), while Type I was the most prevalent in the distal roots (91.8%). The long oval configuration was the most commonly found cross section in mesial roots while "oval" was the most prevalent in distal roots.

CONCLUSION

Egyptian sub-population shows highly variable morphological features in mandibular second molars, hence, CBCT is highly recommended on case-to-case conditions.

Assessment of the Prevalence of Middle Mesial Canal in Mandibular First Molar: A Multinational Cross-sectional Study with Meta-analysis

BACKGROUND

An additional canal found in the mandibular first molar (M1M) is the middle mesial canal (MMC), which is often missed during root canal treatment. In this study, the prevalence of MMC in M1M on cone-beam computed tomography (CBCT) images was evaluated in 15 countries, along with the effect of some demographic factors on its prevalence.

METHODS

Deidentified CBCT images were scanned retrospectively, and the ones including bilateral M1Ms were included in the study. A written and video instruction program explaining the protocol to be followed step-by-step was provided to all observers to calibrate them. The CBCT imaging screening procedure consisted of evaluating three planes (coronal, sagittal, and axial) after a 3-dimensional alignment of the long axis of the root(s). The presence of an MMC in M1Ms (yes/no) was identified and recorded.

RESULTS

In total, 6304 CBCTs, representing 12,608 M1Ms, were evaluated. A significant difference was found between countries (P < .05). MMC prevalence ranged from 1% to 23%, and the overall prevalence was 7% (95% confidence interval [CI]: 5%-9%). No significant differences were found between the left and right M1M (odds ratio = 1.09, 95% CI: 0.93, 1.27; P > .05) or between genders (odds ratio= 1.07, 95% CI: 0.91, 1.27; P > .05). As for the age groups, no significant differences were found (P > .05).

CONCLUSIONS

The prevalence of MMC varies by ethnicity, but it is generally estimated at 7% worldwide. Physicians must pay close attention to the presence of MMC in M1M, especially for opposite M1Ms, due to the prevalence of MMC being significantly bilateral.

Outcome and associated predictors for nonsurgical management of large cyst-like periapical lesions: A CBCT-based prospective cohort study

AIM

The aim of this cone-beam computed tomography (CBCT)-based study was to evaluate the outcome of nonsurgical root canal treatment (RCT) performed for the management of large cyst-like periapical lesions (LCPL) and to identify the predictive factors affecting healing.

METHODOLOGY

Fifty-four subjects (77 permanent maxillary anterior teeth) with LCPL (>10 mm) of endodontic origin were included. A single operator performed standardized multi-visit RCT. Patients were clinically and radiographically examined at 6, 12 months, and a CBCT scan was taken at 24 months. Two independent blinded evaluators measured the pre- and postoperative volume of periapical lesions on CBCT scans using ITK snap software (version 3.8.0-beta-20181028-win64). The outcome was assessed as a percentage change in lesion volume and dichotomized as success (resolved/reduced) or failure (unchanged/enlarged). Ten preoperative (gender; age; intraoral draining sinus, soft tissue swelling, tooth discoloration, pulp canal obliteration, open apex, root resorption, cortical bone defect and lesion volume) and four intraoperative (apical extent and density of root filling; number of treatment visits and type of root filling) predictive factors were observed. Bivariate and stepwise multivariable linear regression analysis was performed to identify independent predictors affecting treatment outcomes. The significance level was set at 5%.

RESULTS

A recall rate of 88% was achieved. The success rate of RCT was 82.2% (8.9% resolved, 73.3% reduced). Median lesion volume reduction was 75% (IQR 61%-93%). No pre- or intra-operative factors were related to treatment failure. However, presence of preoperative cortical bone defect (palatal versus no cortical defect, β = -51.5; 95% CI: -86.9 to -16, p = .006) and apical extent of obturation (long versus flush, β = -27.2; 95% CI: -53.8 to -0.6, p = .04) were negatively associated with reduction in lesion volume (%).

CONCLUSION

Large cyst-like periapical lesions may be successfully managed with RCT. Preoperative cortical bone defect and apical extent of obturation may negatively influence osseous healing.

Influence of the technical parameters of CBCT image acquisition on vertical root fracture diagnosis: a systematic review and meta-analysis

OBJECTIVES

To evaluate the influence of image acquisition parameters (voxel, FOV, kVp, mA) on the accuracy of cone-beam computed tomography (CBCT) in detecting vertical root fracture (VRF).

MATERIAL AND METHODS

Searches were performed in 6 main databases and the gray literature, without restrictions of language or date. Observational clinical studies (OCS) and in vitro-extracted teeth (IV) studies were considered eligible for inclusion when investigating the accuracy (sensitivity, specificity) of CBCT in detecting VRF in human teeth. The risk of bias was assessed using QUADAS-2, and a meta-analysis was performed using Review Manager v5.4 software and Jamovi software v1.6.

RESULTS

A total of 60 out of 132 articles was included after fulfilling the eligibility criteria. Of these, 54 were IV studies while 6 were OCS. In the IV studies, it was seen that smaller FOV sizes tended to present higher accuracy values. The meta-analysis of the 6 OCS showed that the overall sensitivity and specificity values for 0.08 mm and 0.1 mm voxels were greater (0.84 and 0.79, respectively) than the sensitivity and specificity values for 0.125 mm and 0.2 mm voxels (0.70 and 0.55, respectively).

CONCLUSIONS

Despite the uncertain risk of bias found for the IV and OCS studies, smaller voxel and FOV sizes seem to provide more accurate VRF detection values when using CBCT.

CLINICAL RELEVANCE

This information is crucial for supporting the clinician when prescribing CBCT in cases of a clinical suspicion of VRF, and contributes to the personalization of the CBCT prescription, thereby ensuring greater accuracy in the VRF diagnosis. Registration This protocol was registered at the PROSPERO database (International Prospective Register of Systematic Review) under registration number CRD42020210118.