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Aim: To evaluate the agreement between six currently available periapical radiography-based methods for measuring the root canal curvatures in mesial roots of mandibular first molars, assessed by two examiners with different proficiency levels., Methodology: Non-endodontically treated mesial roots of 41 human mandibular first molars were radiographed using the parallelling technique. Two independent observers (a specialist in endodontics and radiology and a final-year dental student) assessed their root canal curvature using the methodologies described by Schneider (1971, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 32, 271), Weine (1982, Endodontic therapy), Berbert and Nishiyama (1994, Revista Gaúcha de Odontología, 356), Luiten et al. (1995, Journal of Endodontics, 21, 26), Hankins and ElDeeb (1996, Journal of Endodontics, 22, 123) and Pettiette et al. (1999, Journal of Endodontics, 25, 230). Intra- and inter-examiner reliability was assessed using the intraclass correlation coefficient. The differences in curvature angle measured by the different methods were compared using the one-way anova for repeated measures test, followed by Tukey's post hoc analysis. The effect was calculated using the Cohen's d method. To determine the agreement between methods, the Bland-Altman analysis was used. The significance level was set at 5%., Results: Agreement for the observers was excellent (>0.81) for the six methods considered. For the angle comparisons between methods, the maximum differences were for Schneider versus Weine (35.77°) and Luiten versus Hankins (35.14°), whilst the highest percentage of angles with a difference >10° were Weine versus Luiten and Berbert versus Pettiette (90%) and the comparison Weine versus Hankins presented with the lowest frequency (15%). Excellent agreement was found for five comparisons: Weine versus Luiten (0.940), Berbert versus Pettiette (0.917), Weine versus Pettiette (0.907), Luiten versus Pettiette (0.904) and Berbert versus Luiten (0.812). Compared to Schneider's method, the other methods showed a tendency of increasing difference as the angles became more acute. The other methods exhibited linear differences, remaining constant for smaller and larger angles., Conclusions: Reliability was excellent for all methods assessed separately. Maximum differences in curvature angles were found when comparing Schneider versus Weine and Luiten versus Hankins. Excellent agreement was found for Weine versus Luiten, Berbert versus Pettiette, Weine versus Pettiette, Luiten versus Pettiette and Berbert versus Luiten. In the presence of dilacerations, the method by Schneider was less sensitive., (© 2024 The Author(s). International Endodontic Journal published by John Wiley & Sons Ltd on behalf of British Endodontic Society.)

Background: A comprehensive understanding of the root form and canal anatomy is essential for successful endodontic treatment. This study aimed to evaluate the root canal anatomy of mandibular premolars in the Pakistani population using cone beam computed tomography (CBCT) and to classify the findings with the new classification proposed by Ahmed et al. METHODS: Ethical exemption was obtained from Aga Khan University Hospital, Karachi. A total of 707 CBCT scans from Karachi and Lahore were included, comprising 592 scans from a tertiary care hospital in Karachi and 115 scans from a radiology center in Lahore. The study focused on sound, fully formed mandibular first and second premolars, excluding those with significant caries, restorations, or prior root canal treatments. Scans from different equipment were used, and calibration was achieved between a specialist endodontist and two dental residents. Data was analyzed using the Statistical Package for the Social Sciences (SPSS) software, version 26. Descriptive statistics, Chi-square tests to determine association between the variables, and a significance level set at 5% (p <0.05) were utilized., Results: A total of 2403 mandibular premolars were analyzed. The most common configuration was 1 MPM 1 (82.90%), with rare variations such as 1 MPM 1-3-1 (0.04%) and 2 MPM 1 B1 L2 (0.04%). Single-rooted premolars were predominant (98.87%), and no significant differences were observed when data was stratified by age or gender., Conclusions: This is the first study in Pakistan involving multiple centers and using the classification system by Ahmed et al. to understand the anatomy of mandibular premolars. The findings indicate that while most premolars have a single root and canal, variations exist. These variations highlight the importance of understanding canal morphology for improving the success of endodontic treatment. Future studies should include a larger and more diverse dataset to fully represent the Pakistani population., Competing Interests: Declarations. Ethics approval and consent to participate: This study has been conducted in accordance with the guidelines of the Declaration of Helsinki. Additionally, Ethical exemption (reference no. 2024–10008-29535) was obtained from the Ethical Review Committee at the Aga Khan University before initiating the study. The Ethical Review Committee of Aga Khan University, Karachi waived the informed consent procedure because the study is retrospective in nature. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Mandibular premolars exhibit intricate and diverse root canal anatomy, presenting substantial challenges in endodontic treatment. Uncommon variations, such as the presence of three canals, demand meticulous diagnostic and therapeutic approaches to mitigate the risk of overlooking canals and subsequent treatment failure. This case report highlights three cases of mandibular premolars exhibiting a rare root canal configuration with one mesial and two distal canals, successfully managed using cone beam computed tomography (CBCT) for accurate diagnosis and ultrasonic activation for disinfection. The findings underscore the significance of utilizing three-dimensional imaging and precise canal identification in addressing anatomical anomalies in mandibular premolars, which have been sparsely documented in the existing literature. This report aims to contribute to understanding and managing the rare and complex root canal configurations in endodontics., Competing Interests: Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, A et al.)

Teeth may exhibit a wide range of anatomical variations in their roots and root canal systems, making them challenging to treat in endodontic procedures. Generally, maxillary canines and mandibular premolars present with a single root with one canal, and variations are comparatively rare. Achieving a fluid-impervious seal in endodontic therapy requires thorough debridement and three-dimensional obturation of the root canal system, which is considered a complex micro-neurologic procedure. Clinicians may fail to achieve the successful outcome without a comprehensive understanding of the pulp chamber and root canal system anatomy. We present a report of successful management of previously failed root canal treatment of two such cases, a maxillary canine and a mandibular premolar, with a previously missed second canal due to their uncommon root canal morphological presentation. This report also comprehensively reviews the literature, focusing on the clinically significant anatomical variations and detailing techniques for the effective management of such anomalies in endodontic treatment. The review provides an in-depth explanation of each stage of treatment, including preoperative diagnosis, intraoperative identification of morphological variations, and evidence-based modern endodontic treatment approaches. Emphasis is placed on ensuring a thorough understanding of these steps to achieve successful outcomes in the management of complex cases involving root canal anatomical variations., Competing Interests: Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, AlTamimi et al.)

To achieve success in endodontic treatment, it is essential to have a thorough understanding of the root and canal morphology. While maxillary canines typically have a single root and canal, studies have reported variations in different populations. This case report details the non-surgical endodontic management of a maxillary canine (tooth no. 13) with a Vertucci type 3 canal configuration in a 69-year-old female patient. The patient reported pain in the maxillary right canine (#tooth no. 13) and was diagnosed clinically with apical periodontitis. The patient's dental history revealed an ameloblastoma in the right mandibular region, successfully treated five years ago. Cone beam computed tomography aided the treatment. After completing the root canal treatment (#13) involving the two canals, an incidental loop-type accessory canal was noted. After three years of follow-up, the patient reported being asymptomatic. This paper reports the endodontic management of an uncommon type 3 canal configuration in the maxillary canine. Clinicians must remain aware of canal variations and utilize modern diagnostic tools like cone beam computed tomography to ensure all canals are located and adequately treated., Competing Interests: Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Gehlot et al.)

Background: Knowledge of the anatomy and morphology of root canal orifices and variations are vital elements affecting treatment outcomes., Aim: The objective of this study was to evaluate variations in the number of root canal orifices and their patterns in primary teeth, as identified by both the naked eye and under magnifying loupes., Materials and Methods: Total of 173 primary teeth was scheduled for pulpectomy over a period of 18 months. Two examiners assessed the number and pattern of the root canal orifices. After access cavity preparation, the operator recorded the number of root canal orifices with naked eye, and examiner recorded the same using magnifying loupes (3.5×). After cleaning and shaping, the same protocol was used. Collected data were statistically analyzed using SPSS version 23.0 and compared using a paired t -test., Results: The overall variation in the in the identification of root canal orifices between the naked eye and magnifying loupes (3.005 ± 0.971) was statistically significant after access cavity preparation (P ≤ 0.05)., Conclusion: Magnifying loupes significantly enhances the determination of the number and pattern of root canal orifices in primary teeth. Therefore, the application of magnifying loupes is essential for accurately assessing variations in root canal orifices in primary dentition., Competing Interests: The research is original, not under publication consideration elsewhere, and free of conflict of interest., (© 2024 The Authors.)

Objectives: The aim of this research was to compare the penetration ability of calcium silicate-based sealers (iRoot SP and TotalFill BC HiFlow) and an epoxy resin-based sealer (AH Plus) into the lateral canals using the single-cone (SC) or continuous wave compaction (CW) obturation techniques., Methods: Ninety single-rooted human teeth received canal instrumentation and diaphanisation before artificial lateral canals were created at 3 different root levels. The specimens were randomly allocated into 6 groups based on the combination of obturation technique and sealer used. Radiographic and photographic measurements evaluated the percentage of sealer penetration. Statistical analysis was performed to compare the penetration ability amongst different types of sealers, obturation methods, and root levels., Results: Although TotalFill BC HiFlow sealer combined with the CW technique demonstrated greater sealer penetration at the coronal level (P < .05), the overall penetration ability of iRoot SP, TotalFill BC HiFlow, and AH Plus was not significantly different. The deepest sealer penetration was observed at the apical root level., Conclusions: All sealers showed similar penetration abilities into the lateral canals using the SC or CW techniques in vitro. Calcium silicate-based sealers have comparable penetration ability into lateral canals compared to epoxy resin-based sealers using SC or CW obturation techniques., Competing Interests: Conflict of interest None disclosed., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Mandibular lateral incisors sometimes feature an additional lingual canal, which, if not identified and missed during endodontic treatment, can lead to postoperative pain. Thus, a proper diagnosis of the internal anatomy of a tooth is necessary before treatment begins. Radiovisiography (RVG), a cost-effective and widely employed dental imaging technique, is used in clinics to visualize the internal root structure of teeth. The zoom function of RVG allows for a detailed examination of complex internal anatomical variations, facilitating a more accurate diagnosis and treatment planning process. This case study identified a rare Vertucci Type VII root canal system in a mandibular left lateral incisor using the zoom-in feature of radiovisiography (Vatech, EZ sensor). Additionally, horizontal sectioning was performed, and these sections were imaged to verify the accuracy of digital radiographs in diagnosing such cases as part of a preclinical demonstration for aspiring endodontists., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Jethi et al.)

Knowledge of the root canals configuration is essential for the success of endodontic treatment. The main aim of the systematic review is to determine the number of roots and the number of root canals in maxillary third molars, in addition, where possible, to determine the Vertucci classification. This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines. The study protocol was registered and approved on the International Prospective Register of Systematic Reviews PROSPERO (Reg. No: CRD42022366444) before the start of the study. Twelve studies were included in the analysis, differing in sample origin and methodology. The combined studies were analyzed based on the number of roots, number of canals, and root canal configurations, and the findings were compared with those of other international studies. Analyzing the available research results regarding the root anatomy and canal configuration of the third maxillary molar, the most commonly maxillary third molars had 3 roots (59.00%). Single-rooted teeth (24.20%) or double-rooted teeth (13.80%) were less common. In addition, it was observed that maxillary third molars typically possessed three root canals (47.28%) and the MB (mesiobuccal), DB (distobuccal), and P (palatal) canals most often showed Vertucci Type I (59.53%, 95.83% and 98.61%, respectively) in three-rooted form. Due to the small number of available studies, it is necessary to conduct further analyses taking into account demographic and ethnic differences that may affect the anatomical and morphological structure of the teeth.

Background Understanding root canal anatomy variations, particularly C-shaped canals, is crucial for successful endodontic treatment. This study used clinical and radiographic methods to assess the prevalence and characteristics of C-shaped canals in mandibular second molars in Western Maharashtra. Materials and methods This prospective study was conducted in the western region of Maharashtra, India. The samples included patients requiring endodontic treatment for mandibular second molars. Clinical evaluation was conducted using a surgical endodontic microscope and cone beam computed tomography (CBCT) imaging. Inclusion and exclusion criteria ensured the selection of a focused and homogeneous sample. Data analysis included assessment of unilateral/bilateral occurrence, canal distribution, and cross-sectional characteristics. Results Out of 200 mandibular second molars, 7.5% exhibited C-shaped root canals, with no significant gender differences. Canal distribution varied across coronal, middle, and apical levels, with prevalent configurations being C1, C2, C3, and C4. No significant differences were observed in canal distribution based on root levels. No significant gender differences were found in the presence of grooves on the root surfaces. Conclusion This study provides valuable insights into the prevalence and characteristics of C-shaped canals in mandibular second molars in Western Maharashtra. Further research into histological and genetic aspects can enhance our understanding, leading to improved treatment strategies for complex root canal anatomy variations., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Ethical Committee of Krishna Institute of Medical Sciences, Deemed University issued approval KIMSDU/DR/573. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Shaikh et al.)

Introduction: Large-scale clinical studies on the incidence of middle mesial canals (MMCs) in nonsurgical root canal treatment (RCT) and retreatment of mandibular molars are lacking. The primary aim of this observational study was to determine the incidence of MMCs in mandibular first and second molars that received RCT or nonsurgical retreatment (NSRetx). The secondary aim was to determine factors associated with incidence of MMCs., Methods: Included were 3018 mandibular molars that received RCT (n = 1624) or NSRetx (n = 1394) by 3 endodontists in a private practice. Demographic and procedural data were collected. Bivariate and multivariable (Poisson regression model) analyses were performed., Results: Incidence of MMCs was 8.8% (n = 267). Although the bivariate analysis showed that NSRetx was significantly associated with incidence of MMCs, this association did not reach the threshold for statistical significance after controlling for all covariates (P = .07). Multivariable analysis on the entire cohort showed that incidence of MMCs was significantly associated with younger age (risk ratio [RR] = 1.62; 95% confidence interval [CI], 1.28-2.06), male gender (RR = 1.48; 95% CI, 1.18-1.85), preoperative cone-beam computed tomography (CBCT) (RR = 1.48; 95% CI, 1.17-1.89), and first molar (RR = 2.30; 95% CI:1.74-3.05). Subgroup multivariable analyses revealed that incidence of MMCs was associated with male gender only in the RCT group (RR = 2.26; 95% CI, 1.55-3.30) but not in the NSRetx group (RR = 1.11; 95% CI, 0.82, 1.50); and with preoperative CBCT only in the NSRetx group (RR = 1.78; 95% CI, 1.28, 2.50) but not in the RCT group (RR = 1.10; 95% CI, 0.71, 1.69). Associations with younger age and first molar remained unchanged., Conclusions: Overall incidence of MMCs was 8.8%. Incidence of MMCs was significantly higher in younger patients and in mandibular first molars but was not associated with the type of treatment., (Copyright © 2024 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

This is a unique case of a single-rooted maxillary premolar with two separate canals in bayonet or S-shaped radicular anatomy undergoing post-endodontic reinforcement prior to crown placement. Bayonet-shaped canals present challenges in canal negotiation, cleaning, shaping, and obturation. The complexity of these canals heightens the risk of accidental file breakage and other iatrogenic errors, posing significant challenges. Post-endodontic restoration in S-shaped canals with double curvature poses challenges in precise placement and material adaptation. A novel technique was implicated to preserve the functionality and structural aesthetics of a decayed maxillary first premolar tooth., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Jethi et al.)

Purpose: The aim of this study was to evaluate the prevalence and the morphology of c-shaped root canal(s) in mandibular premolars using cone beam computed tomography (CBCT) images., Materials and Methods: CBCT images of 1095 mandibular premolars were examined at coronal, middle, and apical levels of the root canals. The type, the level, and the position (buccal or lingual) of the c-shaped anatomy were recorded. Absolute counts and percentages of different groups and subgroups of C-shape morphologies were calculated. The Chi-square test was used to compare the prevalence of C-shaped morphology between mandibular first and second premolars. The Z-test for proportions in independent groups was used to analyze the differences in mandibular C-shaped premolar proportions between location (left and right side) and tooth (first or second premolars) (p=0.05)., Results: C-shaped root canal morphology was present in 44 teeth. The percentage of c-shaped morphologies was 6.9% and 1.6% in mandibular first and second premolars, respectively. Comparison of the first and the second premolars showed that C1 type (p=0.008) and C4b type (p=0.013) configurations are more common in the first premolars at the coronal level. In contrast, the C2 type configuration showed significantly higher prevalence in the second premolars (p=0.009). Additionally, the C4c type configuration was significantly frequent on the right premolars at the coronal level (p=0.038)., Conclusion: C-shape canal morphology is a rare but complex anatomic feature in mandibular premolars. Therefore, clinicians should be aware of this complex root canal anatomy for the success of endodontic treatment in mandibular premolar teeth., Competing Interests: Conflict of interest:The authors declared that they have no conflict of interest., (Copyright © 2024 European Oral Research.)

Variations in the root canal anatomy of a maxillary first molar are often challenging to diagnose and treat; thus, clinicians must have a thorough knowledge of the same. This case report highlights the successful nonsurgical endodontic management of a maxillary first molar with an unusual morphology of three roots and six root canals. A total of six root canals (mesiobuccal [MB] 1, MB2, MB3, distobuccal [DB] 1, DB2, and palatal) were detected after initiating root canal therapy and access cavity preparation. Conventional root canal treatment was completed, and postoperative cone-beam computed tomography scanning was done to verify the total number of canals and ensure the adequacy of root canal fillings. Managing such cases with rare variations in the root canal systems could be arduous and thus, clinicians should be well-versed in the methods to identify and manage such complexities to facilitate the successful outcomes of endodontic treatment., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Journal of Conservative Dentistry and Endodontics.)

The description of non-surgical retreatment is to eliminate all previous filling materials and correct any mishaps. An adequate understanding of root and canal morphology is a fundamental requirement for obtaining a favorable outcome in endodontic treatment. The endodontic diagnosis was previously treated through therapy with symptomatic apical periodontitis. Treatment was performed under a dental operative microscope. Gates Glidden (GG) drills size 2 and 3 were used to remove the coronal part of gutta-percha for all canals. A braiding technique with a Hedstrom file size 15 without a solvent was used to remove gutta-percha and separate the file together for the palatal canal whereas the mesiobuccal canal was retreated by ProTaper Retreatment Kit. Proper understanding of root canal morphology and using an endodontic armamentarium could reduce endodontic mishaps. This case report described the successful management of overextended gutta-percha, a separated file, and a missed canal., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Alnassar et al.)

Introduction: A simple tooth extraction method usually involves using elevators and forceps to remove the tooth easily. In contrast, a surgical extraction method requires utilizing a straight handpiece to facilitate the tooth extraction, either removing bone or sectioning the tooth into pieces., Objective: In this research, we aim to diagnose a tooth radiographically before extraction and determine certain factors to observe which extraction method might be more feasible, either simple or surgical., Methodology: This study followed a retrospective cross-sectional study design. The x-ray radiographs (periapical (PA) or panoramic) were collected from the R4 system in the university dental hospital for data collection. Different radiographic influencing factors were measured, such as bone density, bone level, endodontic involvement (RCT/post and core), crowned or remaining root, and root morphology. Statistical associations were performed using SPSS (IBM Corp., Armonk, NY) with a one-way ANOVA test., Results: There were 62 cases with 47 simple and 15 surgical extractions. There was a non-significant (p>0.05) association between the measured factors and the extraction method, either simple or surgical tooth extraction. Although bone density measurements showed a slight tendency toward PA lesions and simple tooth extraction., Conclusion: There was no significant association between the factors and extraction methods. Future research is required to determine whether or not preoperative radiographic evaluation can influence the decision for the tooth extraction method., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Darwish et al.)

Objectives: The aim of this study was to assess cone beam computed tomography (CBCT) as a root canal anatomy diagnostic tool by comparison with micro-CT gold-standard., Materials and Methods: 216 two-rooted mandibular molars were first scanned in a CBCT device (200 μm voxel size) and posteriorly in a micro-CT scanner (19.61 μm). The volumes were sequentially screened to classify main root canal anatomy according to Vertucci classification, and for the presence of lateral canals and apical deltas, in both mesial and distal roots., Results: Both methods revealed a higher prevalence of Vertucci Type II and IV in the mesial root, and Vertucci Type I in the distal root. The percentage of agreement for main root canal anatomy classification between CBCT and micro-CT scores was high (85.2%)., Conclusion: Sensibility to detect both lateral canals and apical deltas with CBCT was low. These results attest to the fact that minor anatomical changes might be difficult to identify with CBCT imaging, hampering its diagnostic value., (© 2024. The Author(s).)

Objectives: This study aimed to determine the effects of 1-rooted mandibular second molar (MnSM) teeth on root canal anatomy complexities of the mandibular central incisor (MnCI), mandibular lateral incisor (MnLI), mandibular canine (MnCn), mandibular first premolar (MnFP), mandibular second premolar (MnSP), and mandibular first molar (MnFM) teeth., Materials and Methods: Cone-beam computed tomography images of 600 patients with full lower dentition were examined. Individuals with 1-rooted MnSMs were determined, and the complexity of root canal anatomy of other teeth was compared with individuals without 1-rooted MnSMs (Group-1; subjects with at least one 1-rooted MnSM, Group-2; subjects with more than a single root in both MnSMs). A second canal in MnCIs, MnLIs, MnCns, MnFPs, and MnSPs indicated a complicated root canal. The presence of a third root in MnFMs was recorded as complicated., Results: The prevalence of 1-rooted MnSMs was 12.2%, with the C-shaped root type being the most prevalent (9%). There were fewer complicated root canals in MnCIs ( p = 0.02), MnLIs ( p < 0.001), and MnFPs ( p < 0.001) in Group 1. The other teeth showed no difference between the groups ( p > 0.05). According to logistic regression analysis, 1-rooted right MnSMs had a negative effect on having complex canal systems of MnLIs and MnFPs. Left MnSMs were explanatory variables on left MnLIs and both MnFPs., Conclusions: In individuals with single-rooted MnSMs, a less complicated root canal system was observed in all teeth except the MnFMs., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported., (Copyright © 2024. The Korean Academy of Conservative Dentistry.)

A novel system to classify root and canal morphology was recently introduced (Ahmed et al. 2017). This systematic review aimed to answer the following research question: Does the Ahmed et al. system provide a more accurate and practical classification of root and canal anatomy compared to other classifications? A literature search was conducted in Google Scholar, Scopus and Wiley Online Library to identify the citation counts for the article entitled 'A new system for classifying root and root canal morphology; doi.org/10.1111/iej.12685'. After removal of duplicates and unrelated articles, 15 studies were included and analysed. All studies compared the Ahmed et al. system with the Vertucci classification. Results revealed that both systems were able to classify simple canal configurations in single-rooted anterior and premolar teeth, disto-buccal and palatal roots of maxillary molars. However, the Ahmed et al. system provided more accurate and comprehensive categorisations of single-rooted teeth with complex canal anatomy, multi-rooted maxillary and mandibular premolars and the mesio-buccal root of maxillary molars. Further evidence on the utility of the Ahmed et al. system is required using other diagnostic devices especially in molars., (© 2023 The Authors. Australian Endodontic Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Endodontology Inc.)

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.

Objectives: This review aims to discuss the implications of anatomy of the root, pulp chamber, and canals on pulpotomy and revitalization procedures (RPs) as treatment alternatives to root canal treatment procedures., Methods: This narrative review was undertaken to address two main questions - why remove vital pulp tissue in teeth with complex canal anatomy when it can be preserved? And why replace the necrotic pulp in teeth with mature roots with a synthetic material when we can revitalize? This review also aims to discuss anatomical challenges with pulpotomy and revitalization procedures., Results: Maintaining the vitality of the pulp via partial or full pulpotomy procedures avoids the multiple potential challenges faced by clinicians during root canal treatment. However, carrying out pulpotomy procedures requires a meticulous understanding of the pulp chamber anatomy, which varies from tooth to tooth. Literature shows an increased interest in the application of RPs in teeth with mature roots; however, to date, the relation between the complexity of the root canal system and outcomes of RPs in necrotic multi-rooted teeth with mature roots is unclear and requires further robust comparative research and long-term follow-up., Conclusions: Whenever indicated, pulpotomy procedures are viable treatment options for vital teeth with mature roots; however, comparative, adequately powered studies with long-term follow-up are needed as a priority in this area. RPs show promising outcomes for necrotic teeth with mature roots that warrant more evidence in different tooth types with long-term follow-ups.  CLINICAL RELEVANCE: Clinicians should be aware of the pulp chamber anatomy, which is subject to morphological changes by age or as a defensive mechanism against microbial irritation, before practicing partial and full pulpotomy procedures. RP is a promising treatment option for teeth with immature roots, but more evidence is needed for its applications in teeth with mature roots. A universal consensus and considerably more robust evidence are needed for the standardization of RPs in teeth with mature roots., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Introduction: This meta-analysis sought to identify the in vivo prevalence and influencing factors of middle mesial canal (MMC) in mandibular first and second molars based on cone-beam computed tomography (CBCT) scans., Methods: MEDLINE/PubMed, Web of Science, Scopus, SciELO, Google Scholar databases/search engines were searched in period between 15 th and 21 st November 2022, to retrieve the in vivo CBCT-based studies that assessed the prevalence of MMC in mandibular first and/or second molars. The studies were strictly assessed using predefined inclusion and exclusion criteria for relevancy and eligibility through screening the title and abstract, and then assessed through reading the full texts using the same criteria. Subsequently, the fulfilled studies were assessed qualitatively using the Newcastle-Ottawa Quality Assessment Scale, and quantitatively using meta-analysis to calculate the pooled prevalence rates of MMC. The publication bias was assessed using funnel plot and Egger's test., Results: Out of 1122 studies, 33 studies comprised of 13,349 and 7624 mandibular first and second molars, respectively, were eligible for inclusion. Twenty studies scored high quality, while 13 scored moderate quality. The global prevalence of MMC in the first molar was 4.4% (95% CI = 0.035-0.053, P < .001), significantly higher than that of the second molar which was 1.3% (95%, CI = 0.008-0.018, P < .001). Gender, molar side, and age were not influencing factors of MMC prevalence., Conclusions: The prevalence of MMC is not uncommon, being higher in the mandibular first molar compared to the mandibular second molar. The prevalence of MMC is not influenced by age, molar's side, and gender., (Copyright © 2023 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Aim: The present study aimed to determine and compare the dentine thickness around the root canals of maxillary molars with fusion using micro-computed tomography (micro-CT)., Methodology: A total of 120 fused maxillary molars having more than a single canal with distinct canal orifices near the cementoenamel junction were selected from a pool of extracted maxillary molars, which were scanned on a micro-CT device (SkyScan 1172, Bruker-microCT). The minimum dentine thickness around the root canals in furcal direction was measured using CTAn software (v.1.18.8 Bruker-microCT) at each millimetre. The specimens were grouped according to their fusion type, and dentine thickness around the canals was compared. The data were statistically analysed using anova and post hoc Tukey-Kramer tests following an assessment of the normality of their distribution with the Kolmogorov-Smirnov test (p < .05)., Results: Dentine thickness showed a statistically significant decrease at 2 mm apical to the orifice level irrespective of fusion type. The minimum dentine thickness values were detected around the second mesiobuccal canal as 0.30 mm at 6 mm below orifice. Dentine thickness around the mesiobuccal canal was significantly greater in fusion type 1 than those of types 2 and 3 (p < .05), while those of distobuccal and palatal canals were significantly thinner in type 3 fusion compared with type 1 or 6 (pDentine thickness showed a statistically significant decrease at 2 mm apical to the orifice level  irrespective of fusion type. The minimum dentine thickness values were detected around the second mesiobuccal canal as 0.30 mm at 6 mm below orifice. Dentine thickness around the mesiobuccal canal was significantly greater in fusion type 1 than those of types 2 and 3 ( CONCLUSION: Minimum dentine thickness values at the danger zone of distobuccal and palatal canals change according to the fusion type in fused maxillary second molars., (© 2023 British Endodontic Society. Published by John Wiley & Sons Ltd.)

Background: The design of minimally invasive access has become a hotspot. This study aimed to evaluate the coronal root canal morphology of permanent maxillary first molars to facilitate the design of endodontic access cavities for minimally invasive linear access., Materials and Methods: A selection of 91 permanent maxillary first molars was evaluated. Three-dimensional tooth models were reconstructed using micro-computed tomography data. Root canal prevalence and coronal root canal landmarks were recorded. The positional coordinates of landmarks in the horizontal plane and the angles and directions of coronal root canal curvature in the horizontal and axial planes were also assessed., Results: The detection rates of the mesiobuccal (MB), distobuccal (DB), and palatal (P) canals were 100%, whereas that of the second mesiobuccal (MB2) canals was 68.1%. All landmarks were located near the central fossa. In the axial plane, the average angles of coronal root canal curvature were DB (27.05°) > MB (25.43°) > P (20.71°) in teeth with three canals, and MB2 (33.20°) > MB (29.61°) > DB (28.40°) > P (23.69°) in teeth with four canals. In the horizontal plane, the average angles were P (78.15°) > DB (42.34°) > MB (32.41°) in teeth with three canals, and P (81.26°) > DB (43.44°) > MB (41.22°) > MB2 (9.41°) in teeth with four canals., Conclusion: In maxillary first molars, coronal root canals tend to converge towards the occlusal surface. The results of this study could be applied to improve the precision of endodontic access cavity designs of minimally invasive access., Competing Interests: The authors have no conflicts of interest relevant to this article., (© 2022 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.)

Missed canals pose a potential risk in the treatment of teeth with anatomical variations, even when multi-angled radiographs have been used. Incomplete mechanical and chemical debridement of the root canal system can lead to treatment failure. Therefore, clinicians must have adequate knowledge of normal root canal systems as well as any possible variations in order to prevent any failure during or after the treatment of teeth with anatomical variations. Any case report of such rare variations would add to this critically required body of knowledge. The current case report presents the diagnosis and endodontic treatment of a maxillary first premolar with one root and three canals (one palatal and two buccal canals, all buccolingually positioned, bifurcating in the apical region), which was different from premolars with 3 canals reported up to now. This configuration describes an unusual root canal system for the maxillary first premolar and does not fit into any of the well-known root canal classification systems., Competing Interests: The authors declare that they have no conflict of interest., (Copyright: © Journal of Dentistry.)

Aim: To evaluate the effects of progressive root canal enlargements on the unprepared surface area and remaining dentine thickness of three-rooted maxillary first premolars with different root configurations., Methodology: Thirty three-rooted maxillary first premolars with three root configurations (n = 10) were selected and scanned in a micro-CT device. The root canals were sequentially enlarged with rotary instruments sizes 30.02 (step 1), 30.04 (step 2) and 30.06 (step 3). After each step, a new scan was taken. Analysed parameters included morphometric measurements (length, volume and surface area), number of static voxels and minimal dentine thickness. Statistical analyses were performed with one-way anova post hoc Tukey tests and paired sample t-test at a significance level of 5%., Results: No statistical differences were observed amongst groups regarding the morphometric parameters and static voxels (p > .05). The minimal dentine thickness of the distobuccal root significantly changed depending on the root configuration (p < .05), whilst no differences were observed in the other roots (p > .05). A great variation in the position of the minimal dentine thickness was observed after preparation. Overall, mean percentage reduction in dentine thickness was higher in the buccal roots than in the palatal root (p < .05). In the mesiobuccal and distobuccal root, the number of slices with minimal dentine thickness lower than 0.05 mm increases 2 to 3 times and 3 to 4 times, respectively, from steps 1 to 3., Conclusions: Instruments sizes 30.02 and 30.04 can be safely and effectively used to enlarge the buccal and palatal canals of three-rooted maxillary first premolars., (© 2022 British Endodontic Society. Published by John Wiley & Sons Ltd.)

Objectives: This study aimed to evaluate the prevalence of apical periodontitis (AP) in the mesiobuccal roots of root canal-treated maxillary molars., Materials and Methods: One thousand cone-beam computed tomography images of the teeth were examined by 2 dental specialists in oral radiology and endodontics. The internal anatomy of the roots, Vertucci's classification, quality of root canal treatment, and presence of missed canals were evaluated; additionally, the correlation between these variables and AP was ascertained., Results: A total of 1,000 roots (692 first molars and 308 second molars) encompassing 1,549 canals were assessed, and the quality of the root canal filling in the majority (56.9%) of the canals was satisfactory. AP was observed in 54.4% of the teeth. A mesiolingual canal in the mesiobuccal root (MB2 canal) was observed in 54.9% of the images, and the majority (83.5%) of these canals were not filled. Significant associations were observed between the presence of an MB2 canal and the quality of the root canal filling and the presence of AP., Conclusions: AP was detected in more than half of the images. The MB2 canals were frequently missed or poorly filled., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported., (Copyright © 2022. The Korean Academy of Conservative Dentistry.)

Objectives: This micro-computed tomography (micro-CT) study analyzed band-shaped isthmuses having their floor at the apical third of the mesiobuccal roots of maxillary molars in terms of 2D and 3D morphological parameters., Materials and Methods: A total of 199 maxillary first molars were scanned with micro-CT. Twenty-seven specimens, confirmed to have a band-shaped isthmus, were further examined in terms of the isthmus length, volume, structure model index (SMI), and surface area. The distance of apical foramina of mesial canals from the isthmus floor and major-minor diameters, roundness, perimeter, and area of the isthmus roof and floor were compared. Statistical analyses were performed with descriptive statistics and t-test with a 5% significance threshold., Results: The band-shaped isthmus frequency was 13.5% and its length reached up to 5.5 mm. The distances of the apical foramina of mesiobuccal canals (MB1 and MB2) from the isthmus floor were similar (p > .05). Isthmus roof and floor showed significant differences in terms of their major diameter and area (p < .05), whereas their minor diameter, roundness, and perimeter values were similar (p > .05)., Conclusion: The band-shaped isthmuses are not rare and can reach through the half of the root length with oval cross-sections in the floor and roof anatomy. The distance between the isthmus floor and apical foramina did not differ between MB1 and MB2., Clinical Relevance: The band-shaped isthmus morphology contributes to the complexity of the apical anatomy of maxillary first molar teeth with various lengths and diameters., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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., (© 2022. The Author(s).)

Root canal curvature and calcification introduce factors that increase the risk of procedural accidents during root canal treatment. The inability to achieve patency to the apical third, asymmetrical dentine removal leading to transportation, perforation, and instrument fracture inside the curved trajectories are some of the procedural problems that might jeopardize the management of intraradicular infection and result in poor treatment outcomes. In fact, curved and constricted canals introduce such complexity that total instrumentation concepts and specially designed instruments have been developed to deal with the challenge. This narrative review seeks to provide and consolidate the principles necessary for understanding the dynamics of curved and constricted canal management and to improve the understanding for future developments in this field., (© 2022 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

The technical execution of root canal treatment procedures demands a thorough understanding and knowledge of root and canal anatomy. Over the decades, and with the aid of various research methods such as staining and clearing, 2D radiographic imaging, sectioning procedures, cone beam computed tomography and micro-computed tomography, many laboratory and clinical studies have been undertaken to understand the root and canal anatomy of the human dentition. This has resulted in a tremendous increase in the body of knowledge with a wide range of qualitative and quantitative presentations of the root and canal anatomy. This review aims to provide a critical analysis for the laboratory and clinical research methods in root and canal anatomy studies. In addition, it aims to identify existing gaps and present insights for directions of future research and ways for translation to clinical endodontics., (© 2022 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Purpose: The prevalence of the middle distal (MD) canal in the mandibular molar is significantly low among countries including the USA, Spain, Turkey, and Jordan; however, analysis of its prevalence and configuration has not been performed in Saudi Arabia. Therefore, we aimed to assess the prevalence and configuration of the MD canal in Saudi Arabia., Methods: A retrospective analysis of 132 cone-beam computed tomography (CBCT) images was performed to evaluate the presence of the MD canal in patients visiting the Radiology Department of The College of Dentistry in King Saud University between July 2018 and July 2019. The canal was examined if it was confluent with the distobuccal (DB) or distolingual (DL) canals, fin, or independent. Moreover, the distances from the MD canal to the DL and DB canals and cementoenamel junction (CEJ) were recorded., Results: One MD canal (0.7%) was observed in 145 teeth. It was confluent with the DL canal. No statistical significance was observed among sex and age. The distances from the MD canal to the DL canal, DB canal, and CEJ were 1.4 mm, 1.9 mm, and 3.1 mm, respectively., Conclusions: The prevalence of the MD canal was significantly low in a Saudi subpopulation (0.7%). Careful evaluation of CBCT images and the pulpal floor is significantly important to detect the MD canal to ensure a good prognosis., (© 2021 The Authors.)

Background The aim of this study was to assess the root morphology of mandibular molar teeth using cone‑beam computed tomography (CBCT) in patients with periodontal disease. Methods In total, 88 patients were included in this study (70 patients with periodontitis and 18 patients with non-periodontitis). This cross-sectional study involved CBCT images taken for patients who visited the dental clinic of Imam Abdulrahman Bin Faisal University (IAU) from January 2019 to March 2021. The following data were analyzed on the mandibular molars: root length, number of root canals, root trunk, distance between roots, accessory canals in the furcation area (ACF), bone loss, and furcation involvement. Results The mesial root was longer than the distal root in the mandibular molars of periodontitis and non-periodontitis patients. A statistically significant difference was observed between non-periodontitis and periodontitis patients regarding the number of mesial root canals of the mandibular first molar; 70% had two root canals in non-periodontitis patients, compared with 86.1% in periodontitis patients (p = 0.04). First molars of non-periodontitis patients had significantly longer root trunks than periodontitis patients (4.65 ± 0.90 compared with 4.09 ± 1.02, p = 0.007). There was a statistically significant difference in bone loss between non-periodontitis and periodontitis patients (0% and 25% for first molars, and 2.8% and 23.6% for second molars, respectively). Accessory furcation canals were 2.9 % in second molars and 7.1 % in first molars in periodontitis patients, which were higher compared with non-periodontitis patients. Conclusions The first molar showed a longer root trunk in non-periodontitis patients than in periodontitis patients. The mean mesial and distal root lengths were also greater in the first than the second molar. Accessory canals in the furcation area were more observed in first molars than in second molars in periodontitis patients compared with non-periodontitis patients., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Madi et al.)

Article Title and Bibliographic Information: Martins JNR et al. Influence of Demographic Factors on the Prevalence of a Second Root Canal in Mandibular Anterior Teeth - A Systematic Review and Meta-Analysis of Cross-Sectional Studies Using Cone Beam Computed Tomography. Arch Oral Biol. 2020 Aug;116:104,749. doi: 10.1016/j.archoralbio.2020.104749., Source of Funding: No funding was obtained for this research TYPE OF STUDY/DESIGN: Systematic review with meta-analysis., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: To investigate the three-dimensional morphology of isthmuses in molars according to their boundary characteristics using micro-computed tomography (micro-CT)., Methods: Micro-CT reconstructed images of 248 molars were evaluated. Isthmuses were classified into four types based on the boundary characteristics: isthmus with roof, isthmus with floor, band-shaped isthmus, and isthmus without boundary. The tooth and root with isthmuses, the number and location of the isthmuses in the root, and the canal configurations were recorded. The maximum of the major diameter of all canal cross-sections in one isthmus (d max ), the minor diameter of the canal in same cross-section (d min ), the distance between the d max cross-section and apex (D m-a ), isthmus length (L i ), and distance from the isthmus ending cross-section to apex (D e-a ) were measured and analysed with a significance threshold set to 5%., Results: Isthmuses were present in 75.4% specimens. The four types of isthmuses were found in various molars and roots. Their distribution in different root locations and canal configurations was significantly different. The d max , d min , L i , and D e-a were analysed according to different molars and different isthmus types; their respective median values were 2.508 mm, 0.07 mm, 3.09 mm, and 3.96 mm., Conclusion: The three-dimensional classification of isthmuses according to the boundary characteristics provides a comprehensive picture of the isthmus in molars. Their corresponding distributions in different molars, location in roots, and canal configurations will be helpful in predicting the type of isthmus based on the tooth position and canal configurations., (© 2021. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Information regarding the canal anatomy especially in complex cases such as C-shaped canals is essential for a successful treatment. In this study, five different methods for identification of C-shaped canal configuration were compared. 108 extracted mandibular molars with fused roots were studied. Radiographic evaluation was carried out using periapical radiography and CBCT. After access cavity preparation, all specimens were evaluated by direct visual examination and then under dental operating microscope. Finally, the actual anatomy of each sample was determined by preparing horizontal cross sections of the roots (1 mm thick) and examining them under stereomicroscope as the gold standard. Among the techniques used, high-resolution CBCT manifested the highest accuracy, whereas periapical radiography had the lowest. All approaches can be useful in reaching a correct diagnosis. CBCT, especially the low-resolution modality, is an effective technique in the diagnosis of C-shaped anatomy., (© 2020 Australian Society of Endodontology Inc.)

This study aimed to determine the prevalence of four-rooted teeth and the corresponding crown, root and canal morphology in maxillary molars. Cone-beam computed tomographic images for 1200 patients were examined, and 1799 maxillary first molar (MFM) and 2123 maxillary second molar (MSM) teeth were evaluated. Statistical analyses were performed at a 5% significance level. Only three MFMs (0.17%) and 30 maxillary MSMs (1.41%) were four-rooted. The most common four-root type was the double palatal root. A higher proportion of four-rooted teeth were observed in men (P < 0.05), and a high percentage of root fusion was seen in these teeth. The palatal half of the crown was wider in teeth with double palatal roots. Although rarely encountered, the diagnosis and proper treatment of these teeth are very important for endodontic success., (© 2020 Australian Society of Endodontology Inc.)

Objectives: This study aimed to investigate the efficacy of ionic and non-ionic-based contrast media ( in vitro study) and the combinatorial effect of chitosan-based endo-radiopaque solution (CERS) ( in vivo study) for visualization of the root canal anatomy., Materials and Methods: In vitr o study (120 teeth): The root canal of maxillary premolars and molars ( in vitro group 1 and 2 respectively, n = 60 each) were analyzed using 4 different contrast media (subgroups: Omnipaque 350, Iopamidol, Xenetix 350, and Urografin 76; n = 15 each) in combination with 5.25% sodium hypochlorite (NaOCl). Based on the results of the in vitro study, in vivo study (80 teeth) was done to compare Xenetix 350 + 5.25% NaOCl with CERS ( in vivo group 1 and 2 respectively, n = 40 each) on maxillary and mandibular premolars and molars. Two endodontists used radiovisiography to assess the depth of ingress and identify the aberrant root anatomy after access cavity preparation, and after initial cleaning and shaping of canals. Kruskal-Wallis test was used for in vitro comparison ( p < 0.05), and Wilcoxon signed-rank test and Mann-Whitney U test for in vivo analysis ( p < 0.01)., Results: In vitro study, Xenetix 350 + 5.25% NaOCl facilitated a significant higher visualization ( p < 0.05). For in vivo study, CERS had a statistically significant depth of ingress ( p < 0.01), and was efficient in identifying the aberrant root canal anatomy of premolars and molars., Conclusions: CERS facilitates better visualization of the root canal anatomy of human premolars and molars., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported., (Copyright © 2021. The Korean Academy of Conservative Dentistry.)

Aim: The aims of this study were to assess the prevalence and configuration of the second mesiobuccal (MB2) canal in the mesiobuccal MB root of permanent maxillary first molars at different root levels in a Saudi sub-population using cone‑beam computed tomography (CBCT) and to measure the inter-orifice distance between MB & MB2 at the pulpal floor level., Materials and Methods: This retrospective study was carried out on CBCT images of Saudi patients seen at King Abdul Aziz University. A total of 106 maxillary first molars were evaluated using a specialized software program (iCAT CBCT software). The prevalence of MB2, canal configuration and location of joining (apical-middle-coronal), if present was calculated. Also, the inter-orifice distance between both canals was measured at the level of the pulpal floor. Chi‑square and one-way analysis of variance (ANOVA) were used., Results: The MB2 canal was found in 92 (86.8%) maxillary first molar teeth. The MB and MB2 canals were joined in 61 (58%) cases, where the location of joining was 14 (23%), 17 (27%), and 31 (50%) in the coronal, middle, and apical third, respectively. The mean inter-orifice distance between both canals at the level of the pulpal floor was 2.52±0.76 mm., Conclusion: The prevalence of MB2 canal in this Saudi sub-population was high. The prevalence decreased as the root canal approached the apical third. There was no correlation between the average distance and occurrence of canal joining. CBCT is useful in detecting and mapping the mesiobuccal root canal system, with a likelihood of enhancing the quality of root canal treatment., Competing Interests: The authors report no conflicts of interest in this work., (© 2021 Al-Habib and Howait.)

Introduction: This cone-beam computed tomographic (CBCT)-based study evaluated the root canal configurations of mandibular anterior teeth in a large Brazilian population, along with the influence of sex and the frequency of symmetry between the contralateral teeth., Methods: Overall, 2543 CBCT scans, including those of 4773 lower central incisors (LCIs), 4835 lower lateral incisors (LLIs), and 4805 lower canines (LCs), were analyzed. The scans were obtained from a private radiologic clinic using the PreXion 3D device (Yoshida Dental Mfg Co, Ltd, Tokyo, Japan) with a 0.14-mm voxel size; exposure parameters of 90 kV, 4 mA, and 19 seconds; and a field of view of 80 × 80 mm. Root canal anatomy was analyzed according to the Vertucci classification. Sex influence on the canal distribution and symmetry between the contralateral teeth were analyzed. The data were analyzed statistically and were considered significant when P < .05., Results: All LCIs and LLIs had 1 root, whereas 2.4% of LCs had 2 roots. Two root canals were observed in approximately 20% of LCIs and LLIs and in approximately 11% of LCs. The most common configuration was type I followed by type III. Bilateral symmetry occurred in a majority of the individuals (ie, 91% in LCIs, 87% in LLIs, and 87% in LCs). No sex influence was noted with LLIs and LCs (P > .05). However, LCIs showed a higher prevalence of 2 canals in men (P < .05)., Conclusions: The prevalence of 2 root canals in the mandibular anterior teeth in Brazilians was approximately 20% for central and lateral incisors and 10% for canines., (Copyright © 2021. Published by Elsevier Inc.)

Purpose: The aim of this study was to evaluate the efficacy of endoscopic visualisation to detect the presence and type of isthmuses within the mesial root canals of mandibular first molar teeth compared with micro-computed tomography (micro- CT) images as reference., Materials and Methods: Thirty-two mesial roots of mandibular first molars presenting isthmuses were selected based on micro-CT scans. In all, 12 type I and 20 band-shaped isthmuses were collected. The specimens were mounted in the posterior socket of dental phantom manikin for endoscopic visualisation. The ability of endoscopes to visualize the presence of isthmuses and distinguish the type of isthmuses was compared. Micro-CT images of the specimens were used as references. Data were analyzed using Fisher's exact tests., Results: Sensitivity of endoscope to detect isthmuses were also calculated for each isthmus type. In 37.5% of the samples, isthmus presence was correctly diagnosed via orthograde endoscopic visualization. Type I istmuses were significantly more detected than band-shaped isthmuses (P<0.05). Endoscope showed higher sensitivity to detect type I isthmus than band-shaped isthmus., Conclusion: The endodontic endoscope could detect type I isthmuses more accurately than band- shaped isthmuses., (Copyright © 2021 European Oral Research.)

Dens invaginatus (DI) is a dental anomaly associated with complex internal anatomy. Our article discusses an unusual maxillary lateral incisor with two DI. The treatment was planned and performed using cone-beam computed tomographic (CBCT) imaging. During clinical and radiographic evaluations, tooth #7 was diagnosed with DI and pulp necrosis with asymptomatic apical abscess. Periapical radiographs of the tooth showed 2 roots and complex internal anatomy. CBCT evaluation revealed tooth #7 had 2 separate cul-de-sacs (that separate the main canal into four portions). Root canal treatment was completed in 2 visits. The tooth was obturated with EndoSeal MTA. At the 6-month re-evaluation, the patient remained asymptomatic and his tooth had remained functional. Clinical and radiographic examination showed tooth #7 had no sensitivity to percussion or palpation, probe depths within normal limits (#3 mm), no mobility and continued improvement of periapical lesion, despite the commencement of orthodontic Rx 3months previous. Radiographic assessment at the one-year follow up showed significant osseous healing of the preoperative lesion even after the orthodontic forces., Competing Interests: ‘None declared’., (© The Author(s).)

Purpose: This study aimed to determine the prevalence of the second mesiobuccal canal in maxillary first molar teeth in a sample of population from Basrah city in the south of Iraq., Patients and Methods: Cone-beam computed tomography (CBCT) images of 353 Iraqi patients from Basrah city were included in the study. These images revealed 691 maxillary first molars, but only 655 of them were included. The images were obtained using a Gendex (GXDP-7000) CBCT machine (Hatfield, PA, USA) and studied for the prevalence of second mesiobuccal canal in the mesiobuccal root canal configuration, according to Vertucci's classification, by scrolling through the images. Pearson's chi-square tests were used to correlate canal type distribution to gender and age. The distributions of canal type on the right and left sides were assessed using the Kendal tau correlation coefficient. A P-value <0.001 was considered highly significant. For intra-examiner reliability analysis, Cohen's kappa test was used., Results: The second mesiobuccal canal was identified in 81.68% of the Iraqi population sample. The most common type was type II (44.58%), followed by type IV (31.30%). Type I occurred in 18.32% of cases. Other types were less frequent., Conclusion: The second mesiobuccal canal occurred in most of the examined samples of the Iraqi population (81.68%), with the most common type being type II, followed by type IV., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Al-Saedi et al.)

Introduction: The purpose of this study was to determine root canal cross-sectional shapes (RCCSSs) of human permanent teeth using new cone-beam computed tomographic (CBCT) software., Methods: RCCSS was determined on CBCT scans of 1400 teeth (422 patients) as follows: (1) circular, (2) conical/pyramidal, (3) oval/long oval, (4) flat/ribbonlike, (5) 8 shaped, (6) C shaped, (7) calcified, (8) trapezoidal, (9) drop shaped, and (10) other shapes. Root canal shapes were evaluated in the coronal and middle thirds, 2 mm below their beginning, and in the apical third, 1 and 2 mm short of the apical foramen. Categoric variables were described as frequencies and percentages and analyzed using the chi-square test. The level of significance was set at P = .05., Results: Maxillary anterior teeth and maxillary first and second premolars had a circular RCCSS at 1 and 2 mm from the apical foramen in more than 45% of the cases. The most frequent RCCSS in the buccal canal of maxillary first premolars at 1 mm from the apical foramen was circular (71%) followed by flat/ribbonlike (10%) and oval/long oval (6%). In mesiobuccal roots of maxillary and mandibular first molars at 1 mm from the apical foramen, the circular shape was found in 52% and 49%, respectively., Conclusions: The RCCSSs in human permanent teeth are variable according to the tooth group and root thirds. The highest frequency of the circular-shaped canal at 1 and 2 mm from the apical foramen was found in maxillary central incisors and mandibular first and second premolars. Oval-shaped canals were detected in practically all tooth groups and root thirds., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to investigate the accuracy of endoscopic visualization to detect root canal anastomoses at the coronal half of the mesial root canals of mandibular molars using micro-computed tomographic (micro-CT) images as reference. Material and methods: Seventy-four mesial roots of mandibular first molars with ( n  = 47) or without ( n  = 27) intercanal anastomosis were selected based on the micro-CT scans of 269 mandibular first molars at a pixel size of 10 µm. The specimens were mounted on the mannequins and their root canals were evaluated using dental operating microscope (DOM) and endoscope. The endoscopic probe was inserted into the main mesial root canals and 2 blinded observers evaluated the presence of a divergence point of anastomosis (where the branching occurs) as 'present' or 'absent'. The scorings were compared with the three-dimensional reconstructed images of the specimens and recorded as 'correct' or 'incorrect' evaluation. Degree of agreement between evaluators was assessed with Kappa test and the accuracy of endoscopic visualization according to the presence and location of anastomosis was compared using Fisher exact tests with a significance threshold at 5%. Results: High inter-examiner reliability was reported (0.91). None of the divergence points were identified using DOM whereas 11 divergence points were detected using endoscope, corresponding the 23.4% of the intercanal anastomoses. The endoscope also showed the absence of an intercanal anastomosis correctly in all of the specimens without an anastomosis. Detectability of a divergence point using endoscope was not affected by its location within the coronal half of root canal ( p  > .05). Conclusions: The endoscopes were able to visualize the divergence points of 23.4% of the intercanal anastomoses located at the coronal halves of root canals.

It is very rare (2%-6% cases) for a mandibular canine to have two root canals and the incidence of finding two roots with two root canals in a mandibular canine that too bilaterally is almost negligible. This case report discusses the presence and multidisciplinary management of such rarest configuration in both mandibular canines of a female patient. This case shows the importance of recognition of anatomical variations in successful accomplishment of root canal treatment., Competing Interests: There are no conflicts of interest., (Copyright: © 2020 Journal of Pharmacy and Bioallied Sciences.)

Introduction: Root morphology and canal anatomy of maxillary molars shows several complexities and variations. Knowledge of these is essential for successful endodontic treatment. This study aimed to investigate the morphology of the maxillary second molars in a Saudi Arabian sub-population in relation to gender, age, and nationality, as well as to analyze the anatomical symmetry between the left and right side in each individual., Methodology: 420 digitized cone-beam computed tomography (CBCT) scans were collected, of which 351 scans met the inclusion criteria. Number of roots and canals at three different levels of the root in each case was counted at all available sides and compared on the basis of the study variables. Statistical significance was set at P  ≤ 0.05., Results: Most of the patients (n = 323, 92%) had three roots, while two roots (n = 23, 6.6%), four roots (n = 4, 1.1%), and one root (n = 1, 0.3%) were less frequently observed. A significant correlation between female patients and the presence of two canals, while male patients showed a higher correlation with the presence of four canals at all levels. There also was a correlation between Saudi participants and the presence of four canals at all levels. No significant correlation in symmetry between the left and right side root canal anatomy was found. There was an inverse relation between the number of canals and age., Conclusion: Considering the limitations in this study, it appears that the Saudi population is more likely to have three- and two-rooted maxillary second molars, with males and females showing greater tendencies to having three and two roots, respectively., Competing Interests: The authors declare no conflicts of interest., (© 2019 The Authors.)

Background: As the complex anatomy of maxillary first molars is one of the major challenges in endodontic therapy, knowledge of the complicated root canal anatomy and configuration is crucial to ensure the success of endodontic treatment and prognosis. This article presents an endodontically managed left maxillary first molar with an unusual palatal root morphology. The available literature on the anatomic variation of maxillary first molars is also reviewed., Case Summary: A 36-year-old man with no medical history presented to the Stomatology Department of Peking University Third Hospital complaining of a toothache during mastication in the maxillary left posterior region for approximately 3 mo. He had a spontaneous and intermittent toothache that had worsened, particularly at night. The diagnosis based on clinical examination, X-ray imaging, and cone beam computed tomography (CBCT) was symptomatic irreversible pulpitis. Nonsurgical endodontic therapy was performed for the left maxillary first molar. Five root canals revealed by CBCT included a special palatal root canal (1-2-1-shaped), two mesiobuccal root canals, and one distobuccal root canal. Evaluation of the CBCT images confirmed the root canal morphology and the clinician performed more effective cleaning, obturation, and therapy. Finally, the tooth was restored using composite resin, and the patient was satisfied with the result., Conclusion: CBCT and a complete review of the literature may be beneficial for investigating the root canal system to achieve a biological and functional therapeutic effect., Competing Interests: Conflict-of-interest statement: The authors declare that they have no conflict of interest., (©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.)

Objective: This study aimed to investigate the root canal system morphology of maxillary first molar mesiobuccal (MB) roots in a Brazilian sub-population using micro-computed tomography., Methods: Ninety-six MB roots were scanned with a micro-CT (Skyscan 1173, Bruker). Three-dimensional images were analyzed regarding the number of pulp chamber orifices, the number and classification of the canals, the presence of accessory canals in different thirds of the root as well as the number and type of apical foramina., Results: A single entrance orifice was found in 53.0% of the samples, two in 43.9% and only 3.1% had three orifices. The second mesiobuccal root canal (MB2) was present at some portion of the root in 87.5% of the specimens. A single apical foramen was present in 16.7%, two in 22.9%, and three or more foramina in 60.4% of the roots. Only 55.3% and 76.1% of the root canals could be arranged by Weine's and Vertucci's classifications, respectively., Conclusion: The number of orifices at the pulp chamber level could not work as a predictor of the MB2 presence. The most prevalent canal configuration was Weine type IV / Vertucci type V. The anatomical complexity of the MB root could not be entirely classified by the current most accepted classifications., Competing Interests: Conflict of interest: The authors declare that they have no conflict of interest., (Copyright: © 2020 European Endodontic Journal.)