Cone beam computed tomography in Endodontics - a review

Classification of Caries Based on CBCT: A Deep Learning Network Interpretability Study

This study aimed to create a caries classification scheme based on cone-beam computed tomography (CBCT) and develop two deep learning models to improve caries classification accuracy. A total of 2713 axial slices were obtained from CBCT images of 204 carious teeth. Both classification models were trained and tested using the same pretrained classification networks on the dataset, including ResNet50_vd, MobileNetV3_large_ssld, and ResNet50_vd_ssld. The first model was used directly to classify the original images (direct classification model). The second model incorporated a presegmentation step for interpretation (interpretable classification model). Performance evaluation metrics including accuracy, precision, recall, and F1 score were calculated. The Local Interpretable Model-agnostic Explanations (LIME) method was employed to elucidate the decision-making process of the two models. In addition, a minimum distance between caries and pulp was introduced for determining the treatment strategies for type II carious teeth. The direct model that utilized the ResNet50_vd_ssld network achieved top accuracy, precision, recall, and F1 score of 0.700, 0.786, 0.606, and 0.616, respectively. Conversely, the interpretable model consistently yielded metrics surpassing 0.917, irrespective of the network employed. The LIME algorithm confirmed the interpretability of the classification models by identifying key image features for caries classification. Evaluation of treatment strategies for type II carious teeth revealed a significant negative correlation (p < 0.01) with the minimum distance. These results demonstrated that the CBCT-based caries classification scheme and the two classification models appeared to be acceptable tools for the diagnosis and categorization of dental caries.

Factors Influencing Non-Surgical Root Canal Treatment Outcomes in Mandibular Second Molars: A Retrospective Cone-Beam Computed Tomography Analysis

Background/Objectives: This study aimed to investigate the influence of the root canal morphology and various treatment variables on the outcomes of root canal treatments (RCTs) in mandibular second molars, assessed through cone-beam computed tomography (CBCT) imaging. Methods: A total of 150 CBCT images were examined, comprising 100 cases of persistent endodontic infections and 50 of previously treated root canals with normal apices in the mandibular second molars. CBCT was utilized to evaluate the root canal configuration, the radiographic quality of coronal restorations and treated canal systems, and the presence of periapical lesions. Statistical analyses were performed to explore the correlations between these factors. Results: The presence of a C-shaped root canal configuration did not demonstrate a significant correlation with periapical lesions (p = 0.05). Factors influencing endodontic treatment outcomes included missing canals (p = 0.018), underfilling or overfilling (p = 0.045), and inadequate coronal restoration (p = 0.006). Missing a canal was identified as the variable most significantly associated with periapical lesions (OR = 3.103). Inhomogeneous root canal obturation was more commonly observed in C-shaped root canals (p < 0.001). Conclusions: Regardless of the root canal morphology of mandibular second molars, successful RCT depends on thorough disinfection to eliminate any untreated canals, precise three-dimensional filling of the canals at the correct working length, and a securely sealed coronal restoration to prevent leakage.

Pericervical Dentin Metrics in Mandibular First Molars Determined with Digital Periapical Radiography and Cone-beam Computed Tomography

INTRODUCTION

Pericervical root dentin is decisive for the long-term mechanical integrity of root-filled teeth. Current treatment protocol does not include a customized step to determine the pretreatment residual pericervical root dentin.

OBJECTIVE

To determine and compare the residual root dentin and canal width using digital periapical radiography (DPR) and cone-beam computed tomography (CBCT) at the apical limit of the pericervical area (PCA) in mandibular first molars.

METHODS

DPR and CBCT images of 60 patients with age between 22 and 76 years were used to determine (a) the mesiodistal widths of the root canal (pericervical dimensions [PCL]-C) and the root (PCL-R) of mandibular first molars at the apical limit of the PCA and (b) the intracanal distance from the apical limit of the PCA to the radiographic apex (intracanal distance [ICD]). The correlation between the PCL and ICD measurements obtained from DPR and CBCT were evaluated.

RESULTS

Values between 0.10-0.80 mm and 0.00-1.10 mm were obtained for PCL-C using DPR and CBCT respectively (95% CI). The PCL values between 0.90-2.30 mm and 0.00-2.30 mm were obtained from DPR and CBCT respectively (95% CI). The ICD ranged between 4.6-12.3 mm in DPR and 4.40-12.0 mm in CBCT (95% CI). The comparative analysis showed differences from -0.9 to 0.5 mms for PCL and -2.00 to 1.5 mms for ICD between DPR and CBCT techniques respectively.

CONCLUSION

The PCL and ICD determined from DPR and CBCT provided the pericervical dentin metrics that could be utilized clinically as a guideline for decision-making in endodontic treatment.

Root canal morphology of anterior permanent teeth in Jordanian population using two classification systems: a cone-beam computed tomography study

BACKGROUND

Adequate knowledge of root canal morphology and its variation is essential for success of root canal treatment and to overcome treatemnt failure. The aim of this study was to investigate the root and canal morphology of mandibular anterior teeth using 2 classification systems.

METHODS

3342 lower anteriors were evaluated from 557 CBCT scans. The images were examined in sagittal, axial and coronal views using a CS 3D imaging software (V3.10.4, Carestream Dental). Demographic data recorded, the number of roots and canal's morphology were described according to Vertucci and Ahmed classifications.

RESULTS

Frequency of Type I configuration was significantly the highest in incisors and canines (76%, N = 2539), followed by Type III (20.6%, N = 687). Type II (1.1%, N = 37), IV (1.1%, N = 37), and V (0.3%, N = 11) were rarely encountered. 0.9% (N = 31) of the teeth could not be classified with the Vertucci System. The frequency of 2 roots (2MA in Ahmed classification) which has no correspondence in the Vertucci classification, was 1.1% (N = 38), it was significantly higher in canines and in females (35 canines and 3 laterals). A moderate correlation in root canal morpology was found between the left and right sides (V > 0.30). 80% (N = 2538) of the teeth did not exhibit any divergence/merging. The bifurcation level occurred mostly in the middle third of the root.

CONCLUSIONS

One fourth of anterior teeth had variation from the simple type I canal configuration and therefore requires attention during treatment. The new classification system offers a more accurate and simplified presentation of canal morphology.

CLINICAL RELEVANCE

The prevalence and mid root bifurcation of second canal in lower anteriors requires attention to ensure adequate quality root canal treatment without compromising the integrity of teeth.

Prevalence and Association of Calcified Pulp Stones with Periodontitis: A Cone-Beam Computed Tomography Study in Saudi Arabian Population

This study aimed to identify the prevalence and association of periodontitis and pulp stone (PS) along with the clinical variables. This study assessed the cone-beam computed tomography (CBCT) records to identify the presence of PS and clinical periodontitis records were used to determine the stages of periodontitis. The Chi-square test was used to evaluate the relationship between study parameters. Logistic regression was used to determine the association between PS and periodontitis. A total of 228 CBCT records were conveniently selected for this study based on the inclusion and exclusion criteria. Cohen's kappa analysis showed near to perfect scores for both examiners. The Chi-square test showed that CBCT records from the age range 41-50 years, male patients, and stage II of periodontitis prevalently showed pulp stones; however, there were no significant differences observed between the PS and clinical variables. However, gender, involvement of tooth, and stages of periodontitis showed significant distribution of the PS. Logistic regression showed that the stages of periodontitis showed no significant association with PS in patients with periodontitis. Moreover, multivariate odds ratio adjustment did not alter the outcome. Periodontitis is not associated with the presence of PS in the current population.

The Role of Three-Dimensional Imaging (CBCT) in Enhancing Diagnostic Accuracy in Endodontics: A Randomized Controlled Trial

Background

In the field of endodontics, accurate diagnosis is pivotal for successful treatment outcomes. This randomized controlled trial (RCT) explores the potential of cone-beam computed tomography (CBCT) as a tool to enhance diagnostic accuracy in endodontic procedures.

Materials and Methods

An RCT was conducted with a sample of 120 patients presenting with endodontic issues. The patients were divided into two groups: Group A received traditional two-dimensional radiography, while group B underwent CBCT scans. The diagnostic accuracy was assessed by comparing the radiographic findings with the clinical evaluation by experienced endodontists.

Results

The results indicated a significant improvement in diagnostic accuracy in the CBCT group (group B) with an arbitrary value of 88% accuracy, compared with the traditional radiography group (group A) with only 65% accuracy. The CBCT group showed a clearer visualization of root canal anatomy, periapical lesions, and the presence of additional canals, contributing to the enhanced diagnostic capability.

Conclusion

This RCT demonstrates that CBCT significantly enhances diagnostic accuracy in endodontics compared with traditional two-dimensional radiography. The improved visualization of root canal anatomy and periapical regions allows for more precise treatment planning, ultimately leading to better treatment outcomes.

Bacteriologic Conditions of the Apical Root Canal System of Teeth with and without Posttreatment Apical Periodontitis: A Correlative Multianalytical Approach

INTRODUCTION

This study used a correlative multianalytical approach to investigate the bacteriologic conditions in the apical root canal system of treated teeth with or without apical periodontitis and their correlation with the technical quality of the previous root canal obturation and the presence and volume of apical periodontitis lesions.

METHODS

Root apexes were obtained from recently extracted root canal-treated teeth with (n = 23) and without (n = 22) apical periodontitis lesions as demonstrated by cone-beam computed tomographic examination. The root apexes were sectioned and subjected to micro-computed tomographic (micro-CT) scanning. The specimens were cryopulverized, and DNA extracted from the powder was used as a template in real-time polymerase chain reaction assays to quantify total bacteria and members of the Streptococcus genus and Actinobacteria phylum. The bacteriologic findings were compared between the 2 groups and also evaluated for associations with cone-beam computed tomographic and micro-computed tomographic data.

RESULTS

Bacteria were detected in all apical canal samples except 1. The mean counts of total bacteria, streptococci, and actinobacteria did not differ significantly between teeth with or without apical periodontitis (P > .05). Streptococcus levels were significantly lower by 80% in the apical canals of teeth with small lesions compared with those without lesions (P < .05). The limit of filling >2 mm short was significantly associated with more total bacterial counts compared with canals filled 0-2 mm short (P < .05). An adequate coronal restoration was significantly associated with lesser counts of Streptococcus (P < .05).

CONCLUSIONS

Comparable bacterial loads were observed in the apical canal system of treated teeth with and without apical periodontitis, suggesting that factors other than only the total bacterial levels may also influence the development and progression of apical periodontitis. Bacteria were found in the apical canal in virtually all cases with a high prevalence of streptococci and actinobacteria. Streptococci counts were significantly higher in the apical canal of teeth with inadequate restorations and teeth with no lesions. Underfilled canals showed higher bacterial counts.

Effect of photodynamic therapy on the healing of periapical lesions after root canal retreatment: 1-year follow up randomized clinical trial

BACKGROUND

The aim of this randomized clinical trial was to evaluate the effects of photodynamic therapy (PDT) after traditional activated final irrigation protocol (ultrasonically activated irrigation, UAI) on periapical lesion healing after single-visit root canal retreatment.

METHODS

We included 36 patients with asymptomatic chronic apical periodontitis with periapical lesions larger than 5 mm and teeth sensitive to percussion and palpation, who had previous root canal treatment. All patients who signed informed consent underwent cone-beam computed tomography (CBCT) to determine and calculate the preoperative volume of the periapical lesion. Patients were randomly distributed into two groups according to the final disinfection protocol: Group 1; UAI (NaOCl, EDTA, and NaOCl), Group 2; UAI + PDT. All patients underwent single-visit root canal retreatment using rotary instrumentation and standardized irrigation (3 %NaOCl) by the same endodontist. The root canals were filled with epoxy resin-based sealer and single-cone gutta-percha, followed by control radiography. After one year, a new CBCT scan of the teeth was performed to calculate the reduction in the initial periapical lesion as a measure of periapical healing. For the statistical analysis, the chi-square test variants, Fisher's exact test and the Fisher-Freeman-Halton test were used at the level of significance set at 5 %.

RESULTS

There were no significant differences between the groups in terms of age, sex, preoperative and postoperative lesion volume (p > 0.05), and reduction of periapical lesion volume (median, 86.98 % for UAI and 79.72 % for UAI+PDT) (p = 0.970). Additional use of PDT after UAI did not contribute to the healing of periapical lesions.

CONCLUSION

The UAI and UAI+PDT protocols had equal effects on healing of periapical lesion.

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.

Morphology of pulpal mineralizations: A scoping review

OBJECTIVE

The aim of this scoping review was to summarize and discuss the morphological features and associated factors of pulpal mineralizations (PMs) as described within the literature.

DATA

The study protocol was registered on the Open Science Framework platform and is available at the following link: https://osf.io/hfqwe. This scoping review was developed according to the PRISMA-ScR guidelines.

SOURCES

A literature search of four electronic databases was performed in SCOPUS, MEDLINE (PubMed), EMBASE and Word of Science, with the last search on May 29, 2023. Study selection was completed by two reviewers independently. Data was extracted regarding study characteristics, types, and features of PM and associated factors.

STUDY SELECTION

Of 1016 studies initially identified ten which qualified were included in this scoping review. Systemic and local factors that result in pulpal insult can contribute to the development of PMs. Three forms of PM have been reported, pulp stones, diffuse mineralizations, and mineralized ectopic connective tissue, with discrete and diffuse mineralization being the two clinically relevant forms. The different forms of PMs exhibit dissimilar morphological features.

CONCLUSION

Pulpal mineralizations exist in two clinically relevant forms: diffuse and discrete mineralizations and are likely associated with a pulpal insult.

CLINICAL SIGNIFICANCE

Understanding the morphology of dental pulp mineralization is the first step to expanding the knowledge of pulp mineralization and could result in improved diagnosis of endodontic pathosis.

Clinical management of external cervical resorption: A systematic review

This review investigated whether any therapeutic options influenced the outcome of treatment for teeth with external cervical resorption. Out of 870 articles identified by an electronic search, 60 clinical case reports and six case series were included. No randomised clinical trials were found. Risk of bias was assessed using Joanna Briggs Institute's tools. External surgical intervention was the preferred method of accessing the lesions. Removal of resorptive tissue was most often achieved mechanically. Bioactive endodontic cements were the preferred materials for restoring teeth. The outcome measures were based on clinical and radiographic parameters. Of the cases included in the review, no specific treatment approach had a superior outcome in relation to Heithersay's classification. Furthermore, due to the absence of randomised clinical trials, and the low level of evidence associated with case reports/case series, it was not possible to define the optimum clinical treatment for external cervical resorption.

Internal Morphology of Mandibular Second Premolars Using Micro-Computed Tomography

To examine root canal morphology of mandibular second premolars (Mn2P) of a mixed Swiss-German population by means of micro-computed tomography (micro-CT). Root canal configuration (RCC) of 102 Mn2P were investigated using micro-CT unit (µCT 40; SCANCO Medical AG, Brüttisellen, Switzerland) with 3D software imaging (VGStudio Max 2.2; Volume Graphics GmbH, Heidelberg, Germany), described with a four-digit system code indicating the main root canal from coronal to apical thirds and the number of main foramina. A total of 12 different RCCs were detected. 1-1-1/1 (54.9%) was most frequently observed RCC, followed by 1-1-1/2 (14.7%), 1-1-2/2 (10.8%), 1-2-2/2 (4.9%), 1-1-3/3 (3.9%), 1-1-1/3 (2.9%), 2-1-1/1 (2.9%) and less frequently 1-1-2/3, 1-2-1/2, 2-1-2/2, 1-1-2/5, 1-1-1/4 with each 1.0%. No accessory foramina were present in 35.3%, one in 35.3%, two in 21.6%, three and four in 2.9%, and five in 2.0%. In 55.9% Mn2Ps, accessory root canals were present in apical third and 8.8% in middle third of a root. Connecting canals were observed less frequently (6.9%) in apical and 2.9% in the middle third, no accessory/connecting canals in coronal third. Every tenth tooth showed at least or more than three main foramina. Almost two thirds of the sample showed accessory root canals, predominantly in apical third. The mainly single-rooted sample of Mn2Ps showed less frequent morphological diversifications than Mn1Ps.

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.

Conservative management of double teeth in molar teeth with pulp or periapical disease: a report of five cases and literature review

BACKGROUND

Double teeth are usually the result of an abnormality in the developing tooth germ. Double teeth can occur in either the primary or permanent dentition, with the majority of cases concerning permanent teeth reported in the anterior teeth and less frequently in the molar teeth.

CASE PRESENTATION

This report illustrates five cases of double teeth in molars with pulp and periapical disease, including one case of geminated teeth and four cases of fused teeth. Radiographic findings revealed the presence of extra teeth on the buccal aspect of the molar in five cases, with or without communication between the two root canal systems. Root canal treatment was performed by using CBCT and a dental operating microscope. The treatment outcome was good in all five cases.

CONCLUSION

The diagnosis and treatment of double teeth requires special attention. The root canal system should be carefully explored to obtain a full understanding of the anatomy, allowing it to be fully cleaned and obturated. Proper anatomical structure analysis prior to treatment facilitates the development of an appropriate treatment plan, thereby increasing the likelihood of successful treatment both aesthetically and functionally.

Investigation of mandibular second molar root and canal morphology in a Black South African population using cone-beam computed tomography and two classification systems

PURPOSE

To investigate the root and canal morphology of mandibular second molars, including anatomical variations, in a Black South African population using two classification systems.

METHODS

Cone-beam computed tomography images of 386 teeth were evaluated. The number of roots and canal configurations were categorized using the classifications of Vertucci (with modifications by Sert and Bayirli) and Ahmed et al. (including the modified Melton classification). Relationships between variables were assessed using Fisher's exact test (P < 0.05).

RESULTS

Mandibular second molars were predominantly two-rooted (91.7%). The majority of teeth had three canals including Type IV mesial (41.2%) and Type I (75.1%) distal (Ahmed et al. configuration: 2MDM M2 D1). Three or more canals were present in almost one-fifth of mesial (n = 72/386, 18.6%) and a small number of distal (n = 21/386, 5.4%) roots. Males displayed additional canals more frequently in the distal root (P = 0.02). C-shaped anatomy was found in 5.7%. Among the C-shapes, the most common was Melton's Type III in the coronal (50%), middle (81%) and apical (72%) thirds.

CONCLUSION

In this population, mandibular second molar teeth exhibited diverse morphology, which would have clinical significance for endodontic practitioners. The Ahmed et al. classification provided a better description than the Vertucci classification.

A conceptual review on reconstructive peri-implantitis therapy: Challenges and opportunities

OBJECTIVES

The current strategies to reconstruct lost peri-implant tissues due to the disease have been largely unpredictable. The aim of this conceptual review is to discuss relevant biological and biomechanical challenges of applying reconstructive means to treat peri-implantitis. Additionally, opportunities to improve treatment predictability are presented.

MATERIAL AND METHODS

A narrative review was conducted to fulfill the aim.

RESULTS

The four interrelated negative conditions hampering effective reconstruction are: inferior tissue perfusion, unfavorable bone topography, ineffective surface treatment, and unstable wound. First, peri-implant tissues resemble scars with reduced cellularity and vascularity, coupled with the absence of the periodontal ligament plexuses and the avascular implant and biomaterials, maintaining primary closure is a challenge, which is critical for regeneration. Second, defect morphology and bone topography surrounding implants determine the reconstructive potential. Unfortunately, noncontained defects are frequently encountered, with a combination of suprabony (horizontal bone loss) and infrabony (vertical usually involving circumferential bone loss) defects. Third, current attempts for implant surface decontamination are insufficient due to inaccessible macrostructure and rough surfaces in the micro-scale. Histologic evaluation has shown bacteria aggregation and calcified deposits around implants. Lastly, wound stability is difficult to achieve due to inherent soft tissue biomechanical quality and quantity deficiencies and mobile bone particulates. Opportunities to tackle the abovementioned challenges include the use of novel imaging technologies, such as high-frequency dental ultrasound and laser speckle imaging to evaluate tissue perfusion, soft tissue quality/quantity, and bone topography pre-surgically. The use of the operating microscope could allow better visualization and removal of etiologic factors. Strategies to improve soft tissue quality may include preoperative control of soft tissue inflammation and the potential use of biologics. Methods such as fixation to stabilize the biomaterials could be beneficial.

CONCLUSIONS

A more nuanced understanding of the current challenges and opportunities can lead to more effective preoperative and postoperative care protocols, ultimately improving the success rate of reconstructive procedures.

Cone beam computed tomography analysis of the root and canal morphology of the maxillary second molars in a Hail province of the Saudi population

Background

The goal of the present research was to employ CBCT imaging to assess the root and canal anatomy of maxillary second molars in a population from the Hail province of Saudi. The effects of gender and side were taken into account.

Methods

The investigation included a sample size of 499 completely developed right and left untreated maxillary second molars obtained from 250 Saudi people. The root morphology of each tooth was evaluated. The examination also included an analysis of the canal morphology for each tooth, utilizing Vertucci's categorization. The effect of genders as well as sides was recorded. Results were analyzed using the Chi-square test.

Results

464 teeth had three roots (93.0%), whereas 20 teeth (4.0%) had two roots. One root was recorded in 7 (1.4%) of the study sample, whilst 8 (1.6%) had four roots. Although there were no significant differences between the left and right sides (p = .075), gender had a significant influence on the number of roots (p = .030). 240 M (48.1%) had three canal orifices, and 247 (49.5%) had four root canal orifices. Eight molars (1.6%) had two canal orifices, while one and five canal orifices were found in 3 (0.6%) and one (0.2%), respectively. Gender had a significant impact on the number of root canal orifices (p = .039). The observed differences in the orifices of the root canals between the left and right sides were not statistically significant (p = .059). The prevalence of MB2 in maxillary second molars was found to be 49.7%. In the mesiobuccal root, the Vertucci type I configuration had the highest canal frequency (50.3%), followed by the Vertucci types II (14.4%), IV (13.8%), V (12.0%), and III (7.6%), and VI (1.8%). The prevalence of Vertucci type I canal configurations was found to be higher in the distobuccal root (99.4%) and palatal root (98.2%) of maxillary second molars.

Conclusions

Significant variations in root canal anatomy were observed within the Saudi population. The majority of the subjects from Saudi Arabia in this study exhibited the presence of maxillary second molars with three roots. Approximately half of the sample under investigation exhibited the presence of the four canals.

Root and canal morphology of maxillary second molars in a Black South African subpopulation using cone-beam computed tomography and two classifications

This study investigated the root and canal morphology of maxillary second molars in a Black South African population using high-resolution cone-beam computed tomography. In total, 386 maxillary second molar teeth were evaluated and described according to the classifications of Vertucci (with the additions of Sert and Bayirli), as well as Ahmed et al. Root number, fusions and canal morphology were recorded. Relationships between morphology, sex and age were assessed using Fisher's exact test (p < 0.05). Maxillary second molars were predominantly three-rooted (96.1%), with root fusion observed in 14%. No relationships between sex, age and canal morphology were found. Additional canals were observed in 67.4% of mesiobuccal roots. The Ahmed et al. classification provided a better overall description of the morphology. In this population, maxillary second molar teeth exhibited a diversity of root and canal morphology. Complex variations may render endodontic management more difficult and increase the possibility of missed anatomy.

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.

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.

Root canal treatment planning by automatic tooth and root canal segmentation in dental CBCT with deep multi-task feature learning

Accurate and automatic segmentation of individual tooth and root canal from cone-beam computed tomography (CBCT) images is an essential but challenging step for dental surgical planning. In this paper, we propose a novel framework, which consists of two neural networks, DentalNet and PulpNet, for efficient, precise, and fully automatic tooth instance segmentation and root canal segmentation from CBCT images. We first use the proposed DentalNet to achieve tooth instance segmentation and identification. Then, the region of interest (ROI) of the affected tooth is extracted and fed into the PulpNet to obtain precise segmentation of the pulp chamber and the root canal space. These two networks are trained by multi-task feature learning and evaluated on two clinical datasets respectively and achieve superior performances to several comparing methods. In addition, we incorporate our method into an efficient clinical workflow to improve the surgical planning process. In two clinical case studies, our workflow took only 2 min instead of 6 h to obtain the 3D model of tooth and root canal effectively for the surgical planning, resulting in satisfying outcomes in difficult root canal treatments.

Location of the Second Mesiobuccal Canal of Maxillary Molars in a Brazilian Subpopulation: Analyzing Using Cone-beam Computed Tomography

AIM

This study aimed to evaluate the spatial location of the second mesiobuccal canal (MB2) of maxillary molars (MMs), using cone-beam computed tomography (CBCT), in a Brazilian subpopulation.

MATERIALS AND METHODS

The CBCT examination of 250 patients performed on the Eagle 3D device was analyzed, totaling 787 MMs. Using the Radiant Dicom Viewer software, measurements were made of the distances, in millimeters (mm), between the first mesiobuccal canal (MB1), MB2, and palatal (P) canal inputs, from the axial sections. The Image J software evaluated the angle formed by the lines. The data obtained were analyzed statistically by Fisher's exact and Chi-square tests with a significance of 5%.

RESULTS

The prevalence of MB2 canals observed was 76.44 and 41.73% in the first and second molars (1MMs and 2MMs), respectively (p < 0.05). The average of the distances and angles performed, for the location of the MB2 canals of the analyzed teeth, were MB1-P = 5.83 mm, MB1-MB2 = 2.31 mm, and MB2 for the intersection of the connecting distance from MB2-T = 0.90 mm. The average angle formed between the MB1-P and MB1-MB2 distances was 25.89° and 19.68° for the 1MMs and 2MMs, respectively. It was also observed that 91.4 and 75.4% of the maxillary 1MMs and 2MMs, respectively, presented the MB2 canals mesially located at the line connecting the MB1-P canals (p < 0.0001).

CONCLUSION

The MB2 canals were located mesially to the MB1 canal with an average distance of 2 mm between the canals.

CLINICAL SIGNIFICANCE

The anatomical knowledge of the spatial location of the MB2 canal in different ethnicities is important for the planning and execution of endodontic treatment.

The morphology of permanent maxillary first molars evaluated by cone-beam computed tomography among a Yemeni population

BACKGROUND

The study's objective was to use CBCT to ascertain the root and root canal anatomy of the permanent maxillary first molars in a Yemeni population. It was considered how gender affected the prevalence of root canal morphology.

METHODS

A sample of 373 CBCT records of maxillary permanent first molars belonging to 373 Yemeni individuals (162 males and 211 females) aged between 12 and 65 years were included in this study. Using CBCT on the teeth, the root form and canal morphology for each root based on Vertucci's classification were evaluated. The distribution of MB2 occurrence was documented. The prevalence and resemblance of the men and females were investigated. The Chi-square test was performed to evaluate the findings.

RESULTS

Of the 373 maxillary first molars studied, the three separated root form was found in 94.9% of the studied MFMs while the two fused and one separate root form was found in 4.5%. The majority of the three-rooted MFMs (82.6%) had more than three root canals (four canals in 77.2% and five canals in 5.4%). The prevalence of MB2 was as high as 82.3% of the three-rooted MFMs. Vertucci type II configuration was the most frequent canal type (25%) followed by Vertucci type III (23.1%) and Vertucci type I (17.7%) in the mesiobuccal root. Vertucci type I was the most prevalent canal configuration in the distobuccal root and palatal root of the three-rooted MFMs (96% and 99.5%, respectively).

CONCLUSIONS

The maxillary first molars' root canal morphology indicated notable variations among a Yemeni population. The maxillary first molars of most of the Yemeni participants in this study had three roots and four canals. In light of the high occurrence of MB2 (82.3%) in permanent maxillary first molars, our findings emphasize the need of searching for and using cutting-edge techniques to locate the MB2 canals. Males outnumbered females in proportion.

Evaluation of the contour of edentulous jaw sections in the transversal plane and the buccolingual vertical-level disparity in CBCT and panoramic radiography images: a retrospective comparative study

PURPOSE

This study investigates whether edentulous jaw sections in the planned implant position exhibit jaw contours funnel-shaped or exhibit pronounced retraction of the jaw (unusual jaw contours) in the transversal plane of the three-dimensional (3D) images, not visible in two-dimensional (2D) images.

METHODS

A total of 335 patients with an edentulous section of the jaw that required dental implants were selected. Anonymised radiologic patients' data were collected, comprising cone-beam computed tomography (CBCT) images of the edentulous jaw sections. In the first stage, unusual jaw contours were examined, including funnel-shaped or pronounced retraction of the jaw and hypodense regions with an undercut and/or bone deficit. In the second stage, the variation in the height of the alveolar ridge between the lingual and buccal contour in the edentulous jaw sections was assessed.

RESULTS

The CBCT images of an unusual jaw contour were observed in 8 cases (2.4%) in the maxilla on the left and 10 cases (3%) in the maxilla on the right. In the mandible, a jaw contour deviates in 39 cases (12.1%) on the left side and 39 cases (12.1%) on the right side. A height difference was detected in the upper jaw in 307 cases and the lower jaw in 265 cases. The discrepancy was 2.09 mm (± 2.25 mm) in the maxilla and 3.97 mm (± 3.45 mm) in the mandible.

CONCLUSIONS

The CBCT scan provides useful information to avoid complications in the preoperative planning phase and surgical planning in implant dentistry.

Patient-centric outcome assessment of endodontic microsurgery using periapical radiography versus cone beam computed tomography: A randomized clinical trial

AIM

This study aimed to evaluate whether utilizing additional cone beam computed tomography (CBCT) imaging has any effect on quality of life and healing outcome following periapical surgery compared with periapical radiographs (PR).

METHODOLOGY

The study was registered in ClinicalTrials.gov (NCT04333940). In this parallel group randomized controlled trial, 52 patients (88 teeth) with persistent apical periodontitis and periapical radiographic evidence of periapical lesion were randomly assigned to either PR or CBCT group. The primary predictor was the type of the imaging method (PR only or with additional CBCT). The primary outcome was patient's quality of life during the first week after periapical surgery and the secondary outcomes were duration of surgery and healing outcome at 12-month follow-up. Participants of both groups received periapical surgery based on the pre-surgical plan provided by the radiographic imaging methods. Quality of life (QoL) was assessed using Modified Shugars questionnaire. Radiographic analysis for healing was conducted using Molven's criteria and modified PENN 3D criteria. The categorical data between groups were analysed using the Chi-square test, whilst intragroup comparisons were analysed using the McNemar test. The average scores for each component of QoL (oral functions, general functions, pain, swelling and other symptoms), combined QoL scores (overall average of values of 13 variables) and analgesic usage on each day were calculated and analysed.

RESULTS

At 12 months of follow-up, fifty patients were evaluated. Participants in PR group reported significantly more swelling on first three days compared with CBCT group. The analgesic use was higher in the PR group on 2nd and 3rd day (Mann-Whitney U test with Bonferroni correction; p < .007). A significant difference in the limitation of general functions was observed at the second day (p < .07) with the higher values in the PR group. The combined QoL score between the two groups was found to be non-significant. However, none of the patients experienced intraoperative complications or neurovascular exposure. The mean surgical time was lesser in the CBCT group (p < .05). Radiographic healing revealed a success rate of 96.2% for the PR group and 95.8% for the CBCT group with no significant difference between the groups.

CONCLUSION

Participants in the CBCT group experienced substantially less early postoperative swelling and limitation in general functions, in comparison with the PR group. However, preoperative CBCT had no effect on other QoL parameters and intraoperative complications in medium-risk patients. Furthermore, CBCT did not exhibit any added advantage over periapical radiography in terms of assessing healing outcome following endodontic microsurgery. CBCT offered surgically relevant anatomic information for pre-surgical planning and ensured the treatment rendition with a significantly reduced operative time.

Prevalence and correlation of C-shaped root canals of mandibular premolars and molars in Eastern Chinese individuals

The aim of this study was to investigate the prevalence, correlation, and differences of C-shaped root canals (CSRCs) morphology in permanent mandibular premolars and molars in Eastern Chinese individuals using cone-beam computed tomography (CBCT). A total of 8000 mandibular first premolars (MFPs), mandibular second premolars (MSPs), mandibular first molars (MFMs), and mandibular second molars (MSMs) CBCT images from 1000 patients (692 females and 308 males) were collected. The prevalence, correlation, bilateral/unilateral presence, the morphology of CSRCs, level of canal bifurcation, gender differences, and location of radicular grooves (RGs) were evaluated. The prevalence of CSRCs in MFPs, MSPs, MFMs and MSMs were 10.25%, 0.25%, 0.55% and 47.05%, respectively. The prevalence of CSRCs in MFPs of males was higher than that in females, while the prevalence of CSRCs in MSMs of females was higher than that in males (P < 0.05). The bilateral symmetry presence of CSRCs in MSMs was significant but not in MFPs, MSPs, and MFMs. RGs were predominantly found on the mesiolingual (ML) surface of premolars and the lingual surface of molars. There was a high prevalence of CSRCs in MFPs and MSMs in the Eastern Chinese population, but there was no correlation. The prevalence of CSRCs in MFPs and MSMs differ significantly by gender (P < 0.05).

Endodontic treatment of the maxillary first molar with palatal canal variations: A case report and review of literature

BACKGROUND

Root canal variations frequently occur in maxillary first molars, which greatly affects the success of its treatment. The second mesiobuccal (MB) root canal is the most common root canal variation. However, only a few studies have been conducted on palatal root canal variations. Herein, we report the presence of two separate root canals in a palatal root of the maxillary first molar.

CASE SUMMARY

A 39-year-old woman complained of pain in the maxillary right region for 1 year, which recently worsened. Clinical examination revealed a poorly restored right maxillary first molar and caries detected at the filling marginal. Cold and heat test results indicated severe pain in the right maxillary first molar. The patient was diagnosed with irreversible pulpitis, and subsequently, root canal treatment (RCT) was performed. In total, five root canals were found in the maxillary first molar, including two separate root canals in the palatal root. RCT was successfully performed using an endodontic microscope and cone-beam computed tomography (CBCT). The CBCT image revealed a vertucci type I canal morphology in the distobuccal root, while the MB and palatal root canals were type Ⅳ. At the 1-mo follow-up, the maxillary first molar was completely asymptomatic, and the X-ray results indicated a successful RCT. Finally, the ceramic crown restoration was performed.

CONCLUSION

An endodontic microscope and CBCT are useful in effectively identifying and treating root canal variations.

Retreatment of a C-shaped maxillary second molar: case reports and literature review

The root canal systems of maxillary second molar (MSM) variations are complicated, especially the prevalence of fused roots and consequent merged and C-shaped canals, which represent a clinical challenge because canal configurations can be irregular and unpredictable. The purpose of this article was to present 2 cases with a C-shaped configuration diagnosed during root canal retreatment and perform a literature review of this MSM anatomy. Case 1 reports that two palatal root canals fused into a C-shaped configuration that finally formed an apical foramen, which was classified as Type D. Case 2 reflects the fusion of the distobuccal canal and palatal canal into a C-shaped configuration and the configuration was Type C, which was first reported in a case report. Nonsurgical retreatments were proposed and conducted. Evaluation at a 24-month recall revealed that the two patients were symptom-free, and radiographic examination revealed normal periapical tissue. This report serves to remind clinicians of the complexities of the root canal system and that possible anatomic variation should always be anticipated when formulating an effective root canal treatment plan. The use of CBCT imaging coupled with an operative dental microscope will be helpful in locating and identifying supernumerary canals when a preoperative periapical radiograph shows signs of a fused-rooted MSM.

Use of scaffolds and regenerative materials for the treatment of immature necrotic permanent teeth with periapical lesion: Umbrella review

BACKGROUND

Current treatment of immature necrotic permanent teeth with a periapical lesion is regenerative endodontics, which is based on tissue engineering under the triade of stem cells, scaffolds and bioactive molecules.

OBJECTIVES

This Umbrella Review was aimed to evaluate the success of scaffold and regenerative materials used for the treatment of these teeth, in terms of apical closure, tooth length increase, widening of root canal walls, tissue vitality and periapical lesion repair.

METHODS

An extensive literature research was carried out in the Medline, ISI Web of Science, and Scopus databases for relevant systematic reviews matching the keyword search strategy. Based on inclusion and exclusion criteria, reviewers independently rated the quality of each study to determine their level of evidence. Methodological quality assessment of each article was obtained using A Measurement Tool to Assess Systematic Reviews (AMSTAR)-2 tool, and risk of bias was assessed with the Risk of Bias in Systematic Reviews (ROBIS) tool.

RESULTS

After removing duplicates, 155 articles were found; from which 133 were excluded for being non-relevant and 15 other due to exclusion criteria. One more was discarded after methodological quality evaluation, for a total of six articles remaining. The most common scaffold used was the blood clot, others used were poly lactic-co-glycolic acid and platelet-rich fibrin matrix. The most common regeneration material used was Mineral Trioxide Aggregate (MTA), followed by Biodentine. An increase in tooth length and widening of root canal walls were reported in all selected studies with different proportions, as well as periapical lesion repair. ROBIS analysis showed that only one article had low bias, two were classified as unclear bias, while the remaining three had high risk of bias.

DISCUSSION

An exhaustive literature search was carried out applying language filters, high-quality indexed journals, year of publication, which ensures the best quality articles were included. Blood clot was the most used scaffold as is the most easy to place inside the canal and does not require to extract blood from the patient. The use of MTA and Biodentine as sealing materials has been associated with thickening of canal walls, apical closure and reduced signs and symptoms of apical periodontitis. However, most of the included reviews assessed were case reports and only in a few of them were clinical trials included. There is also a lack of risk of bias analysis in most reviews.

CONCLUSION

The blood clot is the most common scaffold used for inducing regeneration during the treatment of immature necrotic teeth. Tooth length increase and widening of root canal walls are the most common criteria used in the studies as success indicators. MTA and Biodentine did not show differences in the results analysed. Quality assessment and bias risk evaluation showed that it is necessary to design better studies with rigorous methodology to recommend a trustable and predictable protocol for the treatment of immature necrotic permanent teeth with periapical lesions.

REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO) CRD42021248404.

Morphologic Analysis of Condyle among Different Disc Status in the Temporomandibular Joints by Three-dimensional Reconstructive Imaging: A Preliminary Study

OBJECTIVES

Morphological study is a common approach in the field of anterior disc displacement (ADD) pathology; however, analysis based on three-dimensional reconstructive imaging has not been investigated. This study investigated the association between ADD and the status of the mandibular condyle and articular fossa.

METHODS

Thirty-four patients were divided into three groups: normal articular disc position (NADP), anterior disc displacement with reduction (ADDwR), and anterior disc displacement without reduction (ADDwoR). Multiple grouped comparisons of three different disc statuses were performed by Kruskal-Wallis H test and variance analysis respectively. Receiver-operating characteristic curve was plotted to assess the diagnostic efficacy of the morphological parameters. Multivariate logistic regression analysis was used to investigate the interfering factors of ADD.

RESULTS

The condylar volume (CV) and condylar superficial area (CSA) in the NADP, ADDwR, and ADDwoR groups exhibited obvious changes (P < 0.05). Both CV and superior joint space (SJS) presented a good diagnostic accuracy for NADP-ADDwoR [area under the curve (AUC)_CV = 0.813; AUC_SJS = 0.855)], and ADDwR-ADDwoR (AUC_CV = 0.858; AUC_SJS = 0.801). CSA presented a good diagnostic accuracy for ADDwR-ADDwoR (AUC = 0.813). A multivariate logistic ordinal regression model showed that the CV [odds ratio (OR) = 1.011; regression coefficient (RC) = 0.011, P = 0.018], SJS (OR, 8.817; RC = 2.177; P < 0.001), and medial joint space (MJS) (OR, 1.492; RC = 0.400; P = 0.047) had a significantly impact on the groups.

CONCLUSION

CV, CSA, SJS, and MJS were significantly associated with the different disc status, and the condyle in ADD exhibited 3-dimensionally altered dimensions. They could be considered as promising biometric markers to assess the ADD.

Evaluation of Root Canal Configuration of Maxillary and Mandibular First Molar by CBCT: A Retrospective Cross-Sectional Study

Adequate knowledge of root canal morphology along with its probable variations is imperative to acquire successful endodontic treatment. This retrospective cross-sectional study aimed to investigate the root canal configuration of maxillary and mandibular first molar using Cone-Beam Computed Tomography (CBCT) among patients in Al-Ahsa region, Saudi Arabia. A total of 377 samples were included, out of which 123 CBCT (I-CAT Vision QTM) scans with intact all first permanent molars were selected in this study and scanned in sagittal, axial, and coronal views by using BlueSkyPlan software. The number of canals in each root and their configuration according to the Vertucci classification system was evaluated. Statistical analysis was analyzed using SPSS version 21 (IBM). Chi-square test was applied to evaluate the association of root canal morphology and mandibular and maxillary first molars with respect to gender. Out of 123 CBCT scans, 59 (48.0%) were males and 64 (52.0%) were females; the mean age was 26.95 ± 10.65 years. The mesiobuccal root of bilateral maxillary first molar had Type-I (87.0%) of Vertucci classification followed by Type-IV (9.8%). Additionally, all mesiobuccal roots (100%) of the left mandibular first molar had Type-I of Vertucci’s classification. A significant association has been observed between gender and a number of canals in bilateral maxillary first molars. Females showed a significantly higher prevalence of three-root canal configuration in maxillary first molars of both sides compared four canals found most commonly in males (p = 0.004). This study concluded that the majority of maxillary and mandibular permanent first molars had three roots and three canals with Type-I Vertucci’s classification in patients belonging to the Al-Ahsa region of the Saudi Arabia. It was also proved that gender is significantly associated with the number of canals in a bilateral maxillary molar.

Fiber Post Removal Using a Conservative Fully Guided Approach: A Dental Technique

This report describes the usefulness of an endodontic template for the removal of a fiber post. A 40-year-old man presented with discomfort in the maxillary left canine. Clinical and radiographic examinations showed tooth #23 with a permanent core material retained with fiber post along with a persistent apical radiolucency. Among the various treatment modalities, nonsurgical root canal retreatment with fiber post removal using a conservative fully guided approach was proposed. After obtaining both the cone-beam computed tomographic images and the cast surface scan, their data were merged using implant planning software (ImplaStation for Windows x64 Bit Beta Version, ProDigiDent, Miami, Florida, USA) and superimposed. The drilling space was planned based on the location, diameter, and apical extent of the fiber post and was virtually overlapped and transferred clinically using a resin template to drill through the fiber post. With guides in position over the rubber dam, drilling was made with increments of 2 mm using a size 4 long-shank round bur (Thomas, Bourges, France) until it exposed the coronal gutta-percha. As soon as the canal was located, K3 rotary files (Sybron Endo, Orange, USA) were used along with chloroform to remove the old obturating materials. Then, additional shaping and cleaning were done with ProTaper Next rotary files (Dentsply Sirona, Ballaigues, Switzerland), sizes X2 and X3, and 5.25% NaOCl irrigation, respectively. The root canal was then dried with paper points and obturated with gutta-percha and AH Plus sealer (Dentsply Sirona, Ballaigues, Switzerland) using the continuous-wave compaction technique. Finally, the tooth was temporarily restored using the double seal technique with zinc oxide and zinc sulfate-based temporary material (Cavit W; 3M ESPE, St. Paul, MN, USA) and resin-modified glass ionomer material (Photac Fil; ESPE, Norristown, PA, USA) filling materials and referred for the final restoration.

Comprehensive evaluation of root and root canal morphology of mandibular second molars in a Saudi subpopulation evaluated by cone-beam computed tomography

BACKGROUND

The study's goal was to use Cone Beam Computed Tomography (CBCT) to assess the root and root canal anatomy of mandibular second molars with C-shaped root canal configurations in residents of the Hail district. The impact of gender and side on the frequency of root canal morphology was considered.

METHODS

The sample size for this study was 304 untreated mandibular second molars with completely developed roots on the right and left sides. Using CBCT on the teeth, the root form and canal morphology for each root are based on Vertucci's classification. The occurrence of canals in the shape of a C. The prevalence and resemblance of the left and right sides or men and females were investigated. The Chi-square test was performed to evaluate the findings.

RESULTS

Of the 304 mandibular second molars studied, 286 teeth had two roots (94.1%), whilst 13 (4.3%) were C-shaped root canal systems. 77 molars (25.3%) had two canal orifices, 219 (72.0%) had three canal orifices, and six (2.0%) and one (0.3%) had four and five root canal orifices, respectively. Type IV was the most common for mesial root, accounting for 57.7% of the sample (n = 176). For distal root, the most common occurrence was type I, which occurred 282 times (96.60%). The most prevalent root canal morphology was the presence of two canals in the mesial root and one canal in the distal root of teeth with two distinct roots (variant 3). (69.4%). The overall prevalence of C-shaped root canal systems is (4.3%) (n = 13).

CONCLUSIONS

The patient's race is an undeniable factor that influences root canal anatomy. The root canal morphology of mandibular second molars revealed significant differences between Saudi subpopulations. The majority of mandibular second molars had two roots and three root canals. When treating these molars, the presence of a C-shaped root canal system must be taken into account.

Is the quality of root canal filling obtained by cone-beam computed tomography associated with periapical lesions? A systematic review and meta-analysis

AIM

To evaluate the influence of root canal filling quality on periapical lesion status using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

The bibliographic search was conducted in electronic databases of PubMed, Embase, Scopus, and Web of Science without restrictions related to the year of publication and language. Inclusion criteria were prospective or retrospective cohort studies that followed periapical pathosis for, at least, 1 year. Three reviewers independently evaluated the eligibility for inclusion, extracted data, and assessed the risk of bias. The quality of the studies was based on the Newcastle-Ottawa Scale. This meta-analysis was performed to evaluate the quality of treatment by the homogeneity and apical extension of the filling.

RESULTS

Of the 1179 studies initially recovered, six cohort studies were included, out of which four were considered with a low risk of bias. The results showed that the absence of gaps in the filling reduced the chance of unhealed periapical lesions by 2.39 times (RR = 2.39; 95% CI: 1.62-3.53; p < 0.00001; I² = 55%). An apical filling extension of 0-2 mm below the apex also contributed significantly to the absence of unhealed periapical lesions (RR = 1.49; 95% CI: 1.15-1.94; p = 0.003; I² = 2%).

CONCLUSION

The homogeneity and apical extension of the filling influenced the presence of unhealed periapical lesions in endodontically treated teeth evaluated using CBCT.

CLINICAL RELEVANCE

Apical extension of the filling ranging between 0 and 2 mm short of the apical foramen and the homogeneity of the filling without gaps are directly related to the success rate of root canal treatment.

Outcomes of Primary Root Canal Therapy: An updated Systematic Review of Longitudinal Clinical Studies Published between 2003 and 2020

Background

A comprehensive effort to evaluate outcomes of primary root canal therapy (RCT) between 1966 and 2002 was published by Ng et al. (2007, International Endodontic Journal, 40, 921; 2008, International Endodontic Journal, 41, 6). Changes in endodontic materials and treatment methods warrant an updated analysis of outcomes.

Objectives

This study aimed to (1) quantify the success rates of primary RCT published between 2003 and 2020; and (2) investigate the influence of some characteristics known/suspected to be associated with treatment outcomes.

Methods

An electronic search was performed in the following databases (01‐01‐2003 to 12‐31‐2020): Pubmed, Embase, CINHAL, Cochrane and Web of Science. Included study designs were longitudinal clinical studies (randomized control trials, cohort studies, retrospective observational studies). Studies with at least twelve‐months of post‐operative review and success rates based on clinical and radiographic criteria were analysed. The terms ‘strict’ (complete resolution of periapical lesion) or ‘loose’ (reduction in size of existing periapical lesion) were used to describe the outcome criteria. Weighted, pooled success rates were calculated. Random effects meta‐regression models were used to investigate potential sources of statistical heterogeneity. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to evaluate for quality assessment of the included studies.

Results

Forty‐two studies were included in the review. Meta‐analyses showed that the weighted pooled success rates were estimated to be 92.6% (95% CI: 90.5%–94.8%) under ‘loose criteria’ and 82.0% (95% CI: 79.3%–84.8%) under ‘strict’ criteria. The most significant areas of study heterogeneity were year of publication and qualification of operator. The majority (64.29%) of studies were considered to be of low quality of evidence.

Discussion

Biological factors continue to have the most significant impact on RCT outcomes. The technological method of instrumentation had no significant effect. The quality of evidence was based primarily on study design and only randomized control trials were considered to be ‘high’ quality of evidence.

Conclusions

The reported success rates show improvement over time. Weighted success rates for studies with a minimum of four‐years follow‐up had better outcomes, compared to those with less than four years, when ‘strict criteria’ were used.

Registration

PROSPERO database (CRD42021226311).

Prognostic Predictors of Endodontic Microsurgery: Radiographic Assessment

Objective

This study aimed to compare the healing outcomes of endodontic microsurgery (EMS) using 2-dimensional (2D) and 3-dimensional (3D) radiographic evaluation in a Chinese population. The prognostic factors of EMS were identified according to the 2D and 3D healing classifications.

Materials and methods

The teeth (n = 82) were studied using 2D and 3D radiographic examinations. The 2D and 3D healing criteria were used to evaluate the healing outcome. Prognostic factors were investigated based on healing outcomes. Data were analysed using SPSS, and P < .05 was considered significant.

Results

There were significant differences between 2D and 3D healing outcomes (P = .004). For the 3D images, age older than 45 years was found to be a significant negative predictor (P = .005).

Conclusions

Cone-beam computed tomographic images provided more precise evaluation of periapical lesions and healing outcomes of EMS than conventional periapical radiographs. Age (>45 years) of the patients exhibited a significant influence on the healing outcome of EMS as determined using 3D images.

Diagnosis Efficacy of Cone-Beam Computed Tomography in Endodontics—A Systematic Review of High-Level-Evidence Studies

Introduction: The integration of clinical inspection and diagnostic imaging forms the basis for endodontic diagnosis, decision making, treatment planning, and outcome assessments. In recent years, CBCT imaging has become a common diagnostic tool in endodontics. CBCT should only be used to ensure that the benefits to the patient exceed the risks. As such, our aim in this study was to evaluate the high level diagnostic efficacy studies and their risk of bias. Methods: A systematic search of the literature was conducted to identify studies evaluating the use of CBCT imaging in endodontics. The following databases were searched: Medline (PubMed), Scopus, and Cochrane Central. The identified studies were subjected to rigorous inclusion criteria. Studies considered as having a high efficacy level were then subjected to a risk of bias assessment using the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. Results: Initially, 1568 articles were identified for possible inclusion in the review. Following title and abstract assessment, duplicate removal, and a full-text evaluation, 22 studies were included. Of those studies, 2 had a low risk of bias and 20 had a high risk of bias. Six studies investigated non-surgical treatment, eight investigated surgical treatment, two investigated both non-surgical and surgical treatment, and six studies investigated diagnostic thinking or decision making. Conclusion: The evidence for the influence of CBCT on decision making and treatment outcomes in endodontics is predominantly based on studies with a high risk of bias.

A comparative study on mandibular premolar root canal morphology employing cone-beam computed tomography and microcomputed tomography imaging

Aim:

The present study was to investigate the root canal morphology of mandibular premolars in Malaysian population using cone-beam computed tomography (CBCT) and microcomputed tomography (micro-CT) scanned images.

Materials and Methods:

Sixty selected mandibular premolars were evaluated in vitro and the root canal morphologies of the samples were categorized based on Vertucci's classification. The position of apical foramen, presence, and location of lateral canal, as well as prevalence of apical delta, were also determined.

Results:

Invariably, Type I variety (Vertucci's classification) was the most frequent root canal morphology followed by Type V and Type III after micro-CT imaging. CBCT investigation also revealed Type I as the most numerous; however, the second most common configuration was Type III followed closely by others. There was a moderate agreement in Vertucci's classification of root canal configuration and also prevalence of apical delta (kappa: 0.516 and 0.550, respectively). However, only a fair agreement (kappa: 0.289) was observed between CBCT and micro-CT on the prevalence of lateral canal.

Conclusion:

CBCT should be cautiously used in determining root canal configuration as deficiencies were evident and revealed during micro-CT imaging.

Reproducibilidad y validez de criterio de dos técnicas radiográficas para variaciones de premolares mandibulares comparadas con CBCT

Introducción: La existencia de variaciones anatómicas ocasiona fracasos en tratamientos endodónticos, por lo que es importante diagnosticarlas. El objetivo fue determinar la reproducibilidad y la validez de criterio de las radiografías con placa de fósforo y la radiovisografía con sensor para identificar las variaciones anatómicas detectadas por tomografía computarizada de haz cónico (CBCT) en premolares inferiores. Métodos: En 140 premolares se obtuvieron imágenes por CBCT, radiografía y radiovisografía. Se realizó lectura independiente por dos endodocistas, evaluándose la clasificación de Vertucci y las ramificaciones. Se determinó la reproducibilidad intraobservador e interobservador. Se calcularon sensibilidad, especificidad y áreas bajo la curva operador-receptor (AUC) utilizando como estándar de oro la CBCT. Resultados: La reproducibilidad intraobservador e interobservador fue mayor para radiografía. Para la Clase I de Vertucci, la radiografía presentó mayor sensibilidad (94,7%), especificidad (64,9%) y AUC (0,795) que la radiovisiografía (89,3%, 62,2% y 0,757, respectivamente), al igual que para la Clase V (Radiografía 69,2%, 93% y 0,811; Radiovisiografía 50%, 84,2% y 0,671, respectivamente). Ninguna de las técnicas aportó al diagnóstico de la Clase III (AUC <0,5). Las ramificaciones fueron infrecuentes (2,9%) y su detección fue baja (Sensibilidad 25% para radiografía y 0% para radiovisiografía). Discusión: Este es el primer estudio que evalúa la reproducibilidad y validez de estas dos técnicas radiográficas comparadas con la CBCT para la detección de variaciones anatómicas en dientes. Conclusiones: La radiografía con placa de fósforo presentó mayor reproducibilidad y validez para el diagnóstico de las Clase I y V de Vertucci, que fueron las variaciones más frecuentes.

Present status and future directions: Endodontic management of traumatic injuries to permanent teeth

The prognosis of traumatized teeth depends largely on the fate of the pulp and its treatment. This review aims to update the present status on the endodontic management of traumatic injuries to permanent teeth and to identify relevant research areas that could contribute to an improvement in diagnosis and treatment of traumatized permanent teeth. Future research should pay greater attention to (1) diagnostic methods to assess the perfusion of the pulp and enhance detection of tooth cracks and initial signs of root resorption; (2) improved materials for vital pulp treatment; (3) studies focusing on type and duration of splinting after root fractures; (4) antiresorptive intracanal medication in case of posttraumatic pulp necrosis and infection-related resorption and (5) long-term data on the apical barrier technique compared to revitalization.

Frequency of root fenestration in a Greek subpopulation: A cone beam computed tomography clinical study

This cone beam computed tomography (CBCT) study aimed to assess the root fenestration (RF) frequency in healthy, intact teeth and analyse their features in a Greek subpopulation. 432 CBCT scans were examined. 5486 teeth were evaluated for RF prevalence. RF prevalence and distribution were recorded for each jaw, tooth group, as well as patient age and sex. RF symmetry, distribution to the affected root surface and the effects of age and sex were evaluated. The prevalence of RF ranged from 0.57% (central incisors) to 7.18% (first premolars) and from 0.48% (second premolars) to 10.79% (lateral incisors) for the maxilla and the mandible, respectively. No symmetrical occurrence of RF was detected. Most RF patients presented one or two defects in both jaws. Types I and IV were the most prevalent in the maxilla, while Types III, II and V were the most prevalent in the mandible. No statistical difference was detected between different sexes and age groups (P > 0.05).

Canal Configuration of Maxillary Premolars in Cukurova Population: A CBCT Analysis

Background/Aim: Aim of this study was to evaluate the anatomy of root-canal systems and numbers of permanent maxillary premolars’ roots and canals, using cone beam computed tomography scans.

Material and Methods: In this retrospective and observational study, maxillary right/left and first/second premolars of patients who were screened with cone beam computed tomography for various reasons in a Turkish dental school, were examined. Evaluated parameters were age, gender, canal configuration (Vertucci classification) and numbers of roots and canals. Chi-square test was used for statistical analysis. The level of significance was set at p<0.05.

Results: A total of 1086 maxillary premolars including 555 first premolars and 531 second premolars were examined in 331 patients (186 female, 145 male). Presence of two roots was shown in 75% of first premolars. 76.3% of second premolars were found to have a single root. Most common canal configuration was type IV (73.2%) for first premolars and type II (32.4%) for second premolars. There was a significant relationship between gender and numbers of first and second premolars’ roots and canals.

Conclusions: High heterogeneity of maxillary premolar root-canal system anatomy should be considered during endodontic treatment.

Is periapical surgery follow-up with only two-dimensional radiographs reliable? A retrospective cohort type sensitivity study

Background

Two-dimensional (2D) radiographic techniques are commonly used for assessing lesion prognosis after endodontic surgery. The present retrospective cohort study analyzes the sensitivity and ability of different radiographic techniques in obtaining area and volume measurements of periapical lesions.

Material and Methods

Preoperative and follow-up (6-48 months) periapical and panoramic radiographs (index test) and cone-beam computed tomography (CBCT) images (reference standard) were selected from an endodontic microsurgery database. Sensitivity was analyzed independently by two examiners. The areas of the 2D radiographic images and CBCT volumes were studied using Itk-Snap software and Romexis viewer.

Results

The sample comprised 105 patients and 105 teeth, with a mean follow-up of 21 months (range 6-48). Preoperatively, CBCT detected all the periapical areas, periapical radiography detected 67, and panoramic radiography detected 60. Postoperatively, of the 52 cases in which CBCT detected remains of the periapical area, periapical radiography detected 22, and panoramic radiography detected 17. The measurements of the areas obtained by the 2D methods, and the volumes obtained by CBCT, had to be transformed into linear measures for comparison purposes. The measurements were found to be significantly different in both the preoperative and the follow-up images.

Conclusions

 Periapical radiography showed greater sensitivity than panoramic radiography, both preoperatively and at follow-up. The lesions measured with CBCT were larger, with significant differences than as evidenced by the periapical and panoramic radiographs.

Key words:Periapical radiography, panoramic radiography, CBCT, sensitivity, treatment outcome, size of periapical radiolucency, area, volume.

Evaluation of the relation between the pulp stones and direct restorations using cone beam computed tomography in a Turkish subpopulation

Objectives

This study aimed to assess the presence of pulp stones through an examination of cone beam computed tomography images and correlate their prevalence with age, sex, dental arch and side, tooth type, and restoration type and depth.

Materials and Methods

Cone beam computed tomography images obtained from 673 patients and archival data on 11,494 teeth were evaluated. The associations of pulp stones with age, sex, dental arch and side, tooth type, and restoration type and depth were noted. All the measurements were subjected to a χ² test and one sample χ² test (p < 0.05).

Results

In the study group, 163 (24.2%) patients and 379 (3.3%) teeth had at least one pulp stone. The pulp stone frequency in those aged 30–39 years was significantly greater than in those aged 18–29 and ≥ 60 years, and the frequency was higher in females than in males (p < 0.05). The highest prevalence of pulp stones was found in maxillary dental arches and molar teeth (p < 0.05). Pulp stones were significantly more common in medium-depth restorations (p < 0.05).

Conclusions

Maxillary molar teeth, medium-depth restorations, individuals aged 30–39 years and females had a greater percentage of pulp stones.

Micro-Computed Tomography-Guided Artificial Intelligence for Pulp Cavity and Tooth Segmentation on Cone-beam Computed Tomography

INTRODUCTION

This study proposes a novel data pipeline based on micro-computed tomographic (micro-CT) data for training the U-Net network to realize the automatic and accurate segmentation of the pulp cavity and tooth on cone-beam computed tomographic (CBCT) images.

METHODS

We collected CBCT data and micro-CT data of 30 teeth. CBCT data were processed and transformed into small field of view and high-resolution CBCT images of each tooth. Twenty-five sets were randomly assigned to the training set and the remaining 5 sets to the test set. We used 2 data pipelines for U-Net network training: one manually labeled by an endodontic specialist as the control group and one processed from the micro-CT data as the experimental group. The 3-dimensional models constructed using micro-CT data in the test set were taken as the ground truth. The Dice similarity coefficient, precision rate, recall rate, average symmetric surface distance, Hausdorff distance, and morphologic analysis were used for performance evaluation.

RESULTS

The segmentation accuracy of the experimental group measured by the Dice similarity coefficient, precision rate, recall rate, average symmetric surface distance, and Hausdorff distance were 96.20% ± 0.58%, 97.31% ± 0.38%, 95.11% ± 0.97%, 0.09 ± 0.01 mm, and 1.54 ± 0.51 mm in the tooth and 86.75% ± 2.42%, 84.45% ± 7.77%, 89.94% ± 4.56%, 0.08 ± 0.02 mm, and 1.99 ± 0.67 mm in the pulp cavity, respectively, which were better than the control group. Morphologic analysis suggested the segmentation results of the experimental group were better than those of the control group.

CONCLUSIONS

This study proposed an automatic and accurate approach for tooth and pulp cavity segmentation on CBCT images, which can be applied in research and clinical tasks.