Canal Anatomy Research Articles

A PATH LESS LOOKED FOR - MIDDLE MESIAL CANAL : CASE SERIES

Knowledge of pulp anatomy of mandibular molar is crucial for endodontic treatment success. There are innumerable causes for endodontic failures but missed canals comes out to be the most common. Each canal contains irregular and hidden regions, which have to be accessed during endodontic therapy. The advent of latest technological advancements in the field of dentistry leads to the identification of the variable root canal anatomy that helped in increasing the success rate. The present case series portrays the successful management of the middle mesial canals with different anatomical configuration in case of mandibular molars.

Guided endodontic treatment in a region of limited mouth opening: a case report of mandibular molar mesial root canals with dystrophic calcification

BackgroundThe endodontic treatment of calcified root canals in molars is a challenging and time-consuming procedure. Even with the aid of a surgical microscope, the risk of root perforation is high, especially in the furcation area. The purpose of this study is to report the Computer-Aided-Design and Manufacturing (CAD–CAM) workflow, the innovative strategies for the template ideation, and the guided endodontic treatment of a mandibular molar with dystrophic calcification in the mesial root canals.Case presentationA 58-year-old female patient, ASA I, was referred to endodontic treatment in the right first mandibular molar for prosthetic reasons. The mesiobuccal and mesiolingual canals appeared obliterated in the radiographic images. The absence of dental crown, tooth inclination, and the limited mouth opening of the region contributed to a poor visual reference of the tooth in the dental arch and the direction of the remaining lumens of the canals. Despite using surgical microscopy, the conventional technique led to the deviation of the mesiobuccal canal towards the furcation area. The obliteration of both mesial root canals was confirmed using the Cone Beam Computer Tomography. The clinical history associated with the tomography diagnosis was compatible with dystrophic calcifications in the pulp canals. The patient was submitted to an intra-oral scanning as well. The Digital Imaging and Communications in Medicine data (DICOM) were segmented. The Standard Tessellation Language (STL) files were processed following the CAD–CAM workflow, aiming to create two different endodontic templates with a new open design concept. The templates with open design allowed direct visualization of the operative field, irrigation, and dentin debris removal. The strategy of the guidance sleeves niche as half-cylinders allowed the drill insertion in a limited mouth opening region.ConclusionsThe digital planning and guided access permitted to overcome the case limitations and then re-establish the glide path following the original anatomy of the root canals. The guided endodontic represents a personalized technique that provides security, reduced risks of root perforation, and a significant decrease of the working time to access obliterated root canals even in the mesial root canal of mandibular molars, a region of limited mouth opening.

Vascular and neurosensory evaluation in relation to lingual canal anatomy after mandibular midline implant installation in edentulous patients

ObjectivesThe aim of this study is to investigate vascular and neurosensory complications in edentulous patients following the installation of mandibular midline single implants in relation to lingual canals.Materials and methodsAfter performing a cone beam computed tomography scan for the 50 recruited patients, the relationship between the potential implant site and the lingual canals was assessed, and all vascular and neurosensory complications were recorded.ResultsSix patients (12%) reported profuse bleeding during implant placement, and 13 (26%) reported transient neurosensory changes, which were resolved after 3 months. According to the virtual implant planning, 44 patients (88%) would have their implants touching the lingual canals, six of them reported vascular changes (14%), and 12 out of 44 patients reported neurosensory changes (27%). For the six patients who would have their implants not touching the lingual canals, one patient reported transient neurosensory changes.ConclusionsThe mandibular lingual canals are constant anatomic landmarks. Injury to the supra-spinosum lingual canals may occur during midline implant placement, depending on the implant length and the bone height.Clinical relevanceDespite that injury to the supra-spinosum lingual canals during implant insertion does not result in permanent vascular or neurosensory complications, caution is required to avoid the perforation of the lingual cortices.

Endodontic Management of Malpositioned Canine with Two Canals and Subgingival Caries

Mandibular canines are considered the cornerstone of the dental arch. Their importance is demonstrated by their efficient masticatory function and maintaining the stability of the dental arch. An intimate relationship exists between gingival health and the restoration of the tooth. Every effort must be made to maintain the tooth in its functional and esthetic form, in harmony with surrounding soft tissues. Successful endodontic treatment depends upon the knowledge of the clinician and his ability to identify and manage variations in canal anatomy. Canines show variations in their canal anatomy. A conservative approach to canal orifice is significant in maintaining the inherent strength of the tooth. The present case report presents endodontic management of a mandibular rotated canine having two canals and subgingival caries that need to be restored by minimal surgical intervention.

Endodontic Management of bilateral two rooted mandibular second premolar: A case report

Mandibular second premolar usually exhibit the basic one root and one canal anatomy. This case report describes successful endodontic management of bilateral mandibular second premolar with two separate roots with an uncommon mesial and distal morphological location, which leads us to conclude that clinician should be aware of variations while treating mandibular premolars.

Analysis of root morphology and internal anatomy of 400 maxillary first premolars using cone-beam computed tomography in an Indian Dravidian subpopulation: An ex vivo study.

There have been numerous cone-beam computed tomography (CBCT) studies done over the years to analyze the canal configurations among various racial and ethnic population groups. Several of these studies have highlighted a certain consistency in the incidence of particular features within these population subsets. The study aimed to analyze the root morphology and canal configurations of the maxillary first premolar (Mx1PM) in the Indian Dravidian subpopulation using CBCT. This study involved a retrospective analysis of 200 CBCT scans, which included 400 Mx1PM. The CBCT images were evaluated, and the number of roots and canal configurations was recorded as per the Vertucci's classification. Variations in the number of roots and canal anatomies were statistically interpreted using the Chi-square test of association with the significance level set at P < 0.05. Among the 400 Mx1PM studied, 116 (29%) teeth displayed single roots and 284 (71%) showed the presence of two roots. The single-rooted premolars revealed a varied canal configuration with a predominance of Vertucci's Type II configuration in around 53.4% of the Mx1PM. The two-rooted premolars revealed 100% Type I canal configuration. The Mx1PM studied predominantly showed the two-rooted morphology with independent canals in each root. There was no significant difference between the teeth on either side of the same arch. The CBCT is an excellent nondestructive modality that can help us study the internal anatomy of pulp space accurately.

Comparative evaluation of shaping ability of sequential rotary, single rotary, and single reciprocating file systems in simulated curved canals using cone-beam computed tomography: An in vitro study

Comparative evaluation of shaping ability of sequential rotary, single rotary, and single reciprocating file systems in simulated curved canals using cone-beam computed tomography: An in vitro study

Assessment of Knowledge, Attitude and Practice of C-shaped Root Canals among Dental Students and Dentists in the Makkah Region of Saudi ArabiaA Cross-sectional Study

Introduction: Thorough management of root canal anatomy and its variants is important for good prognosis of endodontic treatment. C-shaped root canal is one such important variation in root canal anatomy. Due to the complex nature of C-shaped root canals the clinicians should be familiar with this variation to achieve better success rate in endodontic treatment. Aim: To assess Knowledge, Attitude and Practice (KAP) among dental students and dentists of the Makkah region of the Kingdom of Saudi Arabia towards C-shaped root canals. Materials and Methods: A cross-sectional questionnaire survey was conducted for a period of five months from 25th September 2020 to 25th February 2021 in Dentistry program of Ibn Sina National College for Medical Studies, Jeddah using a selfstructured, close-ended, multiple-choice questionnaire consisting of 21 questions. The questionnaire was sent using online to 503 Dental students and Dentists of Makkah region of Saudi Arabia. The study population was selected using convenient random sampling. The questionnaire was constructed and validated with the help of five endodontics with adequate teaching and clinical experience. The data were analysed using IBM Statistical Package for the Social Sciences (SPSS) version 22.0 and descriptive statistics followed by Chi-square test was applied to test of variables in the questionnaire. Results: In the study population ,68.4% (n=344) were males and 31.6% (n=159) were females, 25.2% (n=127) were undergraduate students and 74.7% (n=376) were graduate dentists, 63.2% (n=318) believe most commonly C-shaped root canals are found in mandibular second molars, 49.3% (n=248) have strongly agreed that they are proficient in diagnosing C-shaped root canals, 75.7% (n=381) have agreed that knowledge of canal anatomy will be helpful during access preparation of C-shaped root canals,48.5% (n=244) felt use of crown down technique will be effective in managing C-shaped root canals,72.8% (n=366) felt multiple visit endodontics is needed for successful management of C-shaped root canals and 25.8% (n=130) felt use of thermoplasticised gutta-percha compaction will be helpful in obturation. Conclusion: Knowledge of anatomical variations of root canal system and the use of advanced endodontic instruments and techniques will enable the dentists to handle difficult root canal cases thoroughly for good prognosis of dentition.

Evaluation of the Root Canal Morphology of Human Teeth by Cone Beam Computed Tomography and Micro-Computed Tomographic - A Systematic Review with Meta-analysis.

Introduction:To thoroughly plan and execute any dental treatment, the anatomy of the dental root canals is of prime significance. Hence, in this systemic review, we intend to evaluate the cone beam computed and micro-computed tomographic presentations of the root canal morphologies of the secondary teeth.Materials and Methods:We conducted the search for the data from the online sources such as the “EMBASE,” “Pubmed,” “Scopus,” and other sources. Only human studies were collected. Terms searched were cone beam computed tomography (CBCT), micro-computed tomography, permanent teeth, and root canal morphology. The data extraction and meta-analysis were based on the PRISMA guidelines.Results:A total of 170 studies were initially considered for the study. After the application of the inclusion and the exclusion criteria, only ten studies were qualified for the study. In 2 studies, the comparison was done between the conical beam and the microtomograhic views for assessing the root canal anatomies. There were, however, three studies that did not conclude any significant relation between the two imaging systems. When the risk of bias was calculated for the ten studies, there were only low and moderate for the ten included studies. The pooled prevalence among the genders were 21.4% (14.0%–24.6% confidence interval [CI] 95%) and 25.3% (20.0%–30.7% CI 95%), respectively, with high heterogeneity values (= 99.30% and 98.50%, respectively), but no statistical significance (P > 0.05).Conclusion:Both the imaging systems CBCT and the microtomography can be used with accuracy in the evaluation of the anatomic variations of the human root canal. However, a definition is dependent on the voxel size.

Evaluation of centralization ability and canal transportation of root canals prepared with three commercially available pediatric rotary files.

The complex root canal anatomy of primary root canals is considered to be most challenging. The quality of the root canal preparation plays a significant role in the success of endodontic treatment. Now, there are very few root canal instruments that are capable of cleaning the canal three dimensionally. To evaluate the efficacy of root canal instruments, various technologies have been used; one of the most reliable strategies was cone-beam computed tomography (CBCT). The aim of this study is to compare the centralization ability and canal transportation of three commercially available pediatric rotary file systems using CBCT analysis. Thirty-three extracted human primary teeth with a minimum 7 mm root length were randomly divided into three groups (group I - Kedo-SG Blue, group II - Kedo-S Square, and group III - Pro AF Baby Gold). Biomechanical preparation was done according to the manufacturers instructions. Pre- and postinstrumentation CBCT images were taken for each group to evaluate the remaining dentin thickness thereby assessing the centering ability and the canal transportation ability of different file systems. Significant difference was noticed in canal transportation and centering ability between the three tested groups. Mesiodistal canal transportation was significant at all three levels, whereas buccolingual canal transportation was significant only at the apical third of the root. However, Kedo-SG Blue and Pro AF Baby Gold showed lesser canal transportation compared to Kedo-S Square rotary file system. Mesiodistal centering ability was significant at cervical and apical thirds of the root with Kedo-S Square rotary file system maintaining less canal centricity. All three file systems tested in the study were effective in removing the radicular dentin. However, Kedo-SG Blue and Pro AF Baby Gold rotary file systems showed comparatively less canal transportation and more centering ability than Kedo-S Square rotary file system.

Root canal anatomy and morphology evaluation of mandibular molars according to gender by cone-beam computed tomography in Iranian population

Introduction: This study aimed to evaluate anatomy and morphology of mandibular permanent molars using cone-beam computed tomography (CBCT) in a selected Iranian population.Methods and Materials: CBCT images of 638 first and second mandibular molars (322 of males and 316 of females) were included in this in vitro study. Number of roots and root canals, Vertucci’s configuration of each root, radix paramolaris (RP), radix entomolaris (RE), and C-shaped canals were determined in both genders. Data were analyzed by Pearson-Chi square test using SPSS (V.22) software (P = 0.05).Results: The most common configuration of distal roots were type I for both genders. Among 266 first molars, 97.3% teeth had two roots, 0.75% had RP and 1.87% had RE. All RP and RE were type I. C-shaped canals were found in 1.12% teeth and all were in male population, significantly at the left side (P=0.045). Among 372 second molars, 94.08% had two roots, 0.53% had RP and 0.26% had RE. The prevalent canal configuration of mesial roots was type III (52.96%) with significant difference between right (P=0.006) and left (P=0.049). C-shaped canals were found in 5.64% of second molars and more specifically detected in male group. Significant difference was observed between two genders in the right (P=0.024) and the left (P=0.009).Conclusion: Vertucci’s type III and type II were the most prevalent configurations in mesial roots while for distal roots the predominant configuration was type I. RE, RP, and C-shaped channels were not common in mandibular molars between Iranian population and their prevalence were higher among male population.

A comparative study of cyclic fatigue of 6 endodontic systems. An in vitro study.

BackgroundMechanical preparation and the formation of space for adequate obturation are included in root canal shaping, but the complex root canal anatomy may be affect it. Manufacturers have created different alloys like M-Wire, Blue-Wire, Gold-Wire or R-phase. Objective: This investigation was performed to verify the null hypothesis that there were not significant differences between size 25 instruments ESP Files Thermoflex, Protaper Ultimate, Protaper Next, Blueshaper, One Curve and 2Shape about cyclic fatigue and length of broken fragments. Material and Methods180 new size 25 files of the systems investigated were selected (n=30). Files were used with Endo Mate DT endo motor with speed and torque recommended by manufacturers, holding the instruments with clamping mechanism, with passive adjustment, glycerine and without pressure in a stainless-steel block. The time was calculated in seconds until fracture. Number of fatigue cycles was determined as (Resistance (s) x Speed)/60. Separated fragment lengths were calculated with digital Vernier caliper. Statistical analysis was carried out with the SPSS 18 programme at a 95% confidence level, using Levene´s Test to compare variances, Welch’s Test to compare means, and Games-Howell´s Test to reveal differences between groups. ResultsLevene’s Test determined no equal variances (P<0.05). Welch’s Test and ANOVA (P<0.05) showed significant differences in cyclic fatigue and separated fragment lengths. Games-Howell’s and Bonferroni´s Test established significant differences in multiple comparisons (P<0.05). ConclusionsESP Files Thermoflex was superior in cyclic fatigue. About separated fragment lengths, ESP Files Thermoflex, Protaper Ultimate and Blueshaper obtained longer lengths. Key words:Cyclic fatigue, continuous movement, separated fragment lengths, rotary systems.

A Comparative Evaluation of Antimicrobial Efficacy of Triphala and Calcium Hydroxide as Intracanal Medicament: An In Vitro Study.

Background:The goal for placement of intracanal medicament during pulpal therapy procedures is to eradicate the bacteria and the exotoxins from the infected root canal, thereby preventing and controlling pulpal and periradicular infections. Chemo-mechanical preparation is considered an essential step in root canal disinfection; but to accomplish the total elimination of bacteria in highly complex root canal anatomy is difficult. Intracanal medicaments help eliminate bacteria by remaining in the root canal, and calcium hydroxide has been recommended as one of the most effective antimicrobial dressings during endodontic therapy. The herbal agents offer an alternative to synthetic compounds. They have been considered either non-toxic or less toxic. The rapid increase in antibiotic-resistant strains and side effects caused by synthetic drugs have prompted researchers to look for herbal alternatives.Aim and Objective:The in vitro study aims to evaluate and compare the antibacterial activity of triphala and calcium hydroxide against Enterococcus faecalis as an intracanal medicamentMaterials and Methods:The antimicrobial efficacy of triphala and calcium hydroxide was evaluated against E. faecalis cultured and incubated for various time frames in 42 intact, caries-free, human, single-rooted teeth with straight roots and mature apices. The comparison of the number of counted colonies after each incubation time and based on the type of drug used inside the canal is evaluated using non-parametric Kruskal–Wallis test and Mann–Whitney U test, respectively. Statistical analysis was done using SPSS version 14.0.Results:Efficacy of calcium hydroxide against Enterococcus faecalis was best in the first 72-hr time duration compared with triphala. Triphala showed significant antimicrobial activity against Enterococcus faecalis that was closely parallel to the calcium hydroxide group in one week. Calcium hydroxide and triphala had complete eradication of Enterococcus faecalis in a given one-month time duration.

Comparative Evaluation of Chlorhexidine and Cetrimide as Irrigants in Necrotic Primary Teeth: An In vivo Study.

Context:Disinfection of the root canal system by biomechanical preparation and profuse irrigation is especially important in primary teeth due to its complex pulp canal anatomy. Appropriate selection of irrigating solution should be done in terms of tissue dissolving capacity, antibacterial efficacy, and palatability when treating pediatric cases.Aim:The aim of the study was to compare the antibacterial efficacy of 2% chlorhexidine (CHX), 0.2% cetrimide (CTR), and 0.2% CHX + 0.2% CTR against anaerobic bacteria and to test the influence of CTR added to CHX on its antibacterial action.Materials and Methods:Seventy-five teeth that were selected for the study were divided into three groups: Group I (2% CHX), Group II (0.2% CTR), and Group III (0. 2% CHX + 0.2% CTR). Samples collected before and after irrigation were immediately processed and microbial growths were quantified.Statistical Analysis:Intergroup comparison was done using one-way analysis of variance and Newman–Keuls multiple post hoc procedures and intragroup comparison was done using paired t-test.Results:When the mean values of Group I were compared with Group II, the data were statistically not significant (P = 0.2341), whereas Group I showed a significant difference when compared with Group III (P = 0.0107). When the mean values of Group II and Group III were compared, the data were found to be statistically not significant (P = 0.0805).Conclusion:The efficacy of 2% CHX was found to be slightly superior when compared with that of 0.2% CTR, but the difference was not statistically significant. However, a significant difference was found between 2% CHX and combination irrigants.

Relationship between root canal merging and presence of C-shaped canal in fused rooted maxillary molar teeth

Objective: This study aimed to evaluate the prevalence of root fusion and the incidence of C-shaped canals inmaxillary first molar (MFM) and maxillary second molar (MSM) teeth using cone-beam computed tomography.Material and Methods: In this study, a total of 1233 MFMs and 1406 MSMs from 802 patients were analyzed.First, the number of fused rooted teeth and the type of root fusion were determined. Subsequently, incidenceand number of C-shaped canals were ascertained according to the type of fusion, location, position, and levelof canal merging in teeth with fused roots. Six types were established according to the C-shape configurationsobserved. Presence of root fusion and the C-shaped canal according to gender, age, and tooth position wereevaluated by chi-square test. Values with p&lt; 0.05 were considered significant in statistical tests. Results: Theincidence of fusion in the MFM and MSM teeth was 6.16% and 22.40%, respectively. Only three MFMs (0.24%)and 3.77% of the MSMs had C-shaped canals. While the incidence of fusion was higher in women (p&lt; 0.05),the C-shaped morphology was not affected by sex (p&gt; 0.05). Individuals over the age of 50 years had a lowerincidence of C-shaped canals (p&lt; 0.05). Conclusion: C-shaped canal morphology was more commonly associatedwith complex types of root fusion involving three roots; 16.83% of MSMs with fused roots had C-shaped canals.KEYWORDSCanal merging; Cone-beam computed tomography; C-shaped root canal; Root canal anatomy; Root fusion.

Root canal morphologies of mandibular premolars in Southeast Anatolian population: Evaluation of CBCT

Background/Aim: This study aimed to evaluate the root canal morphology of mandibular first and second premolars with the aid of cone-beam computed tomography (CBCT) in the Southeast Anatolian population. Material and Methods: The study examined a total of 1258 mandibular first and second premolars using cone-beam computed tomography images of 370 randomly selected patients who applied to the Department of OralDental and Maxillofacial Radiology of Faculty of Dentistry, Dicle University due to various indications. The total number of roots and root canals, canal symmetry and correlations between the right and left side of the mandible, and the prevalence in men and women were recorded. Data was analzyed using the Chi-Square and Fisher's Exact tests. Canal configurations were evaluated based on the Vertucci classification. Results: The evaluation of CT images of a total of 370 individuals showed that 88.89% of the first premolars and 98.45% of the second premolars were symmetrical. The canal anatomy of the first premolars suggested that 85.98% of the premolars were of Type I, 12.02% were of Type V, and 2% were of Type III based on the Vertucci classification. On the other hand, the canal anatomy of the second premolars revealed that 98.83% were of Type I, 0.67% were of Type V, and 0.5% were of Type III. Conclusions: The prevalent morphology of the multiple canals was Type V, except for the Vertucci classification Type I in the mandibular first premolars. Limited number of canal variations were observed in the mandibular second premolars.

The Effect of Glide Path Preparation on Root Canal Shaping Procedures and Outcomes.

The ‘glide path’ in non-surgical root canal treatment refers to a smooth radicular tunnel from the root canal orifice to its terminus. Its establishment is aimed at creating sufficient space to facilitate the subsequent and safer use of engine-driven nickel titanium (NiTi) shaping files. Glide paths were originally prepared using stainless steel hand files to, at least, a loose International Organisation for Standardisation (ISO) size 10 or larger. However, the advent of engine-driven NiTi instrumentation has led to the availability of many engine-driven NiTi glide path files. The aims of this review were to assess the effects of engine-driven and manual glide path preparation (GPP) on root canal shaping procedures and outcomes. An online search of the PubMed, Embase, Scopus and ScienceDirect databases was conducted and 32 studies were identified. The published literature suggests the use of engine-driven glide path files to be beneficial in maintaining the original root canal anatomy, reducing preparation time, decreasing apical extrusion of debris and causing less postoperative pain. However, there was no difference between engine-driven and manual GPP with regards to the physical strain exerted on the shaping files. Future research focused on clinical outcomes is needed to help ascertain the clinical benefits for patients.

Cone-beam computed tomographic analysis of root canal morphology of permanent mandibular incisors - Prevalence and related factors.

Objectives:To investigate the prevalence of additional canals and the occurrence of oval canals in apical third area of mandibular permanent incisors of Saudi sub-population.Methods:This study was conducted from November 2020 to May 2021 at College of Dentistry, Qassim University. For the investigation purpose of this study, 314 scans were analyzed within the age limits of 13 to 70 years. The root canal morphology, presence of oval canals, number of roots, and prevalence of various canal configurations based on age, gender and bilateral symmetry were recorded. The obtained data was statistically analyzed using SPSS software.Results:The mandibular central incisors (CI) exhibited, significant difference between Type-I, II, III and IV canal configurations and Type-I, II, III and V canal configurations (p < 0.05). For the mandibular lateral incisor (LI), significant difference was found between Type-I, II, III, IV and VII canal configurations (p < 0.05). The cumulative prevalence of oval canals in mandibular incisors was found to be 46.6%. For both mandibular CI and LI, the prevalence of Type-I canals was significantly higher in males as compared to females (p < 0.05). Conversely, significantly higher prevalence of Type-III canals was noted for females as compared to males (p < 0.05). No significant difference was found in the prevalence of different canal configurations on the left and the right side of the mouth.Conclusion:In this study, multiple canals were prominently recognized with Type-III mandibular incisors dominating this feature. Oval canals were predominantly found in single canal especially Type-III. This research suggests variability in canal morphology among different populations. Knowledge of these aberrant canal anatomies is useful for the clinician to achieve a favorable endodontic outcome.

Retrospective investigation of root canal anatomy and morphology of permanent teeth on CBCT images

Retrospective investigation of root canal anatomy and morphology of permanent teeth on CBCT images

CBCT-based assessment of root canal treatment using micro-CT reference images.

PurposeThis study compared the root canal anatomy between cone-beam computed tomography (CBCT) and micro-computed tomography (micro-CT) images before and after biomechanical preparation and root canal filling.Materials and MethodsIsthmus-containing mesial roots of mandibular molars (n=14) were scanned by micro-CT and 3 CBCT devices: 3D Accuitomo 170 (ACC), NewTom 5G (N5G) and NewTom VGi evo (NEVO). Two calibrated observers evaluated the images for 2-dimensional quantitative parameters, the presence of debris or root perforation, and filling quality in the root canal and isthmus. The kappa coefficient, analysis of variance, and the Tukey test were used for statistical analyses (α=5%).ResultsSubstantial intra-observer agreement (κ=0.63) was found between micro-CT and ACC, N5G, and NEVO. Debris detection was difficult using ACC (42.9%), N5G (40.0%), and NEVO (40%), with no agreement between micro-CT and ACC, N5G, and NEVO (0.05<κ<0.12). After biomechanical preparation, 2.4%-4.8% of CBCT images showed root perforation that was absent on micro-CT. The 2D parameters showed satisfactory reproducibility between micro-CT and ACC, N5G, and NEVO (intraclass correlation coefficient: 0.60-0.73). Partially filled isthmuses were observed in 2.9% of the ACC images, 8.8% of the N5G and NEVO images, and 26.5% of the micro-CT images, with no agreement between micro-CT and ACC, and poor agreement between micro-CT and N5G and NEVO. Excellent agreement was found for area, perimeter, and the major and minor diameters, while the roundness measures were satisfactory.ConclusionCBCT images aided in isthmus detection and classification, but did not allow their classification after biomechanical preparation and root canal filling.