Impact of Multiple Individualized Guides on the Management of Obliterated Root Canals in a Maxillary First Molar: A Case Report.

The purpose of this investigation was to study the prevalence of fused roots, C‐shaped roots, C‐shaped root canal orifices and C‐shaped root canals in the maxillary molars of a Chinese population. A total of 305 first molars and 309 second molars were collected in Taiwan. The teeth were demineralized and placed in methyl salicylate to make them transparent. Root fusion was examined and the pulp chamber floor was checked for C‐shaped orifices. Chinese ink was then injected into the root canal system to demonstrate possible C‐shaped canals. The maxillary first molars had the palatal root fused with the mesiobuccal root in 0.3% of the cases, and with the distobuccal root in 2.0%. Teeth with C‐shaped roots existed in only 0.3% of maxillary first molars, while 6.2% of the maxillary first molars and 40.1% of the maxillary second molars had fused roots. The maxillary second molars had the palatal root fused with the mesiobuccal root in 18.1% and with the distobuccal root in 2.6%; the palatal root was fused with the mesiobuccal and distobuccal root in 8.1% of the material. The maxillary second molars had a C‐shaped root in 4.5% and C‐shaped root canal orifices with C‐shaped root canals in 4.9% of the cases. Fused roots or incompletely separated roots are common in the maxillary second molars amongst Chinese people, while C‐shaped roots and root canals in maxillary molars are not frequently seen.

Second mesiobuccal root canal in maxillary molars—A systematic review and meta-analysis of prevalence studies using cone beam computed tomography

ObjectivesThis study aimed to investigate the incidence and location of the second mesiobuccal root (MB2) canal in maxillary molars with the aid of various measuring points and lines using cone-beam computed tomography (CT).Materials and MethodsA total of 205 images of patients who underwent cone-beam CT examinations between 2011 and 2015 as part of their dental diagnosis and treatment were included. There were 76 images of the maxillary first molar and 135 images of the maxillary second molar. Canal orifices were detected at −1 mm from the top of the pulpal floor on cone-beam CT images. Image assessment was performed by 2 observers in reformatted image planes using software. Assessments included measurement of the distance between the MB1 and MB2 canals, and the angles between the lines connecting the MB1-MB2 and distobuccal (DB)-palatal (P) canals. The data were analyzed using the student's t-test.ResultsThe prevalence of the MB2 canal was 86.8% in the first molar and 28.9% in the second molar. The angle between the lines connecting the MB1-MB2 and DB-P canals was 2.3° ± 5.7° in the first molar and −3.95° ± 7.73° in the second molar. The distance between the MB1 and MB2 canals was 2.1 ± 0.44 mm in the first molar and 1.98 ± 0.42 mm in the second molar.ConclusionsThe angles between the lines connecting the MB1-MB2 and DB-P canals was almost parallel. These findings may aid in the prediction of the location of the MB2 canal orifice.

Key Clinical MessageA major cause for endodontic failure is the inability to treat all anatomy. Studies report endodontic retreatments contain 42% missed canals. This case illustrates dentin preservation of a molar with an uninstrumented mesiobuccal‐3 canal revealed post‐GentleWave Procedure. Efficient cleaning and disinfection with maintained healing to 18 months is demonstrated.

ObjectivesThe purpose of this study was to investigate the incidence of root fusion and C-shaped root canals in maxillary molars, and to classify the types of C-shaped canal by analyzing cone-beam computed tomography (CBCT) in a Korean population.Materials and MethodsDigitized CBCT images from 911 subjects were obtained in Chosun University Dental Hospital between February 2010 and July 2012 for orthodontic treatment. Among them, a total of selected 3,553 data of maxillary molars were analyzed retrospectively. Tomography sections in the axial, coronal, and sagittal planes were displayed by PiViewstar and Rapidia MPR software (Infinitt Co.). The incidence and types of root fusion and C-shaped root canals were evaluated and the incidence between the first and the second molar was compared using Chi-square test.ResultsRoot fusion was present in 3.2% of the first molars and 19.5% of the second molars, and fusion of mesiobuccal and palatal root was dominant. C-shaped root canals were present in 0.8% of the first molars and 2.7% of the second molars. The frequency of root fusion and C-shaped canal was significantly higher in the second molar than the first molar (p < 0.001).ConclusionsIn a Korean population, maxillary molars showed total 11.3% of root fusion and 1.8% of C-shaped root canals. Furthermore, root fusion and C-shaped root canals were seen more frequently in the maxillary second molars.

Introduction: Knowledge on variations in the root canal system is essential for a successful endodontic treatment. Objective: To present a case of identification of root canals in the maxillary left first molar, including the fourth root canal in the mesiobuccal root, using cone beam computed tomography (CBCT). Conclusion: The CBCT system proved to be relevant in providing important information on the root canal system for the planning of endodontic treatment in cases of persistent infection or access difficulties.

The knowledge on the complex anatomy of the maxillary first molar and location of extra canals are essential for diagnosis and endodontic treatment success. Objective: The purpose of this study was to report a clinical case showing a varied number of root canals in maxillary molars with the aid of the operating microscope (OM). Case report: The endodontic retreatment of the right maxillary first molar with unusual anatomical variation was performed, displaying three canals in the mesiobuccal root (MB), a root canal in the distobuccal root (DV) and a root canal in the palatal root (P). To remove the resin core inside pulp chamber with and without the aid of dental operating microscope, a high-speed drill and ultrasonic tip (diamond round) was used, respectively, for the refinement of the pulp chamber walls. The dental operating microscope was used during the access surgery, location, negotiation of canals and checking of the completion of all stages of the retreatment. Subsequently, the cleaning, shaping and filling of the root canal system was completed. The presence of three canals in the mesiobuccal root, one in the distobuccal root and one in the palatal root was found. Conclusion: Variations in the number of canals could be confirmed during the surgery access in endodontic retreatment cases with the aid of dental operating microscope.

Background and objective: Root canal variations can be a challenge to detect and manage when performing root canal therapy, and failure to detect these variations in the root canals of the teeth will lead to unsatisfactory results of the treatment. An important tool for observing the root canal anatomy of teeth that are indicated for root canal treatment is cone beam computed tomography (CBCT). The objective of this study is to find out the rate of anatomical variations in the root canals of maxillary premolars and molars using CBCT among a Kurdish subpopulation in Erbil, Iraq. Materials and method: Data were collected from five dental clinics and radiographic centers in Erbil City. A total of about 690 CBCT images were used for the study, after applying the exclusion criteria, 205 CBCT images were included for the study. maxillary premolars and molars were examined for the number of roots, number of canals, and presence of root canal variations. Results: The prevalence of the second mesiobuccal (MB2) canal in maxillary first molars (MFM) was 47.8%, while in maxillary second molars (MSM), it was 18.05%. The prevalence of the second distobuccal (DB2) canal in (MFM) was 1.46%, with three recorded cases, while none of the (MSM) had a (DB2) canal. Additionally, only 2 cases (0.98%) in MSM had two palatal canals, whereas no such cases were recorded in MFM. A single case of MFM (0.49%) was recorded with two roots and canals, whereas in (MSM), 10 cases (4.88%) had two canals. In maxillary first premolars, five cases (2.44%) were reported with three roots and canals (molarized premolars). Similarly, five cases (2.44%) had a single canal, while 195 cases (95.12%) had two canals: one buccal and one palatal. In maxillary second premolars, 135 cases (65.85%) had two canals (buccal and palatal), and 70 cases (34.15%) had a single canal. Conclusion: There is a wide range of variations among maxillary molars and premolars, which need careful diagnostic evaluation to prevent missing canals during root canal treatment. Keywords: Anatomical variations, second mesiobuccal canal (MB2), Second distobuccal canal (DB2), Three rooted premolars (Molarized premolars), Second palatal canal (P2), Cone Beam Computed Tomography (CBCT), Erbil city

AimMinimally invasive dentistry has been facilitated by advances in instruments and restorative materials. This study aims to compare the change in the shaping ability of the RECIPROC blue rotary system in both traditional and conservative access cavities, using cone beam computed tomography (CBCT).Material and methodsSixty root canals of 20 artificial maxillary molars were assigned into two groups (n=30 root canals) according to the access cavity design used: Group I: traditional access cavity (TAC) and Group II: conservative access cavity (CAC). CBCT scans of samples were made before and after root canal preparation using the RECIPROC blue rotary system. The shaping parameters are evaluated in root canal transportation and the centering ability. Three CBCT sections per tooth were analyzed at 3, 6, and 9 mm from the apex to assess the canal transportation and centering ability at three levels, apical, middle, and coronal thirds. Data were analyzed using the GraphPad Prism (GraphPad Software, San Diego, CA).ResultsThe results of this study showed a significant difference in transportation within the coronal and middle thirds. However, in apical thirds, there were no significant differences. Both groups observed a significant difference in the centering ability in the coronal third.ConclusionWithin the limitations of this study, CAC can be recommended with caution as an alternative access to TAC.

The aim of this study was to evaluate the root canal morphology of permanent maxillary molars by cone-beam computed tomography (CBCT) using the classifications of Weine et al. and Vertucci and to correlate the findings with sex, age, position in the dental arch, and prevalence of a second canal in the mesiobuccal root (MB2). A total of 414 scans were evaluated, corresponding to 1,000 teeth. The assessment consisted of coronal, axial, and sagittal reconstructions using i-CAT Workstation®. Type 0 was assigned when neither classification could be applied. The data were entered into an Excel spreadsheet and analyzed using SPSS. The chi-squared test or Fisher's exact test was used to compare the distribution of root canal morphology classified using the two systems. Analysis of the distribution of Weine types showed a predominance of type III in mesiobuccal roots, while type 0 predominated in distobuccal and palatal roots. Vertucci type IV predominated in mesiobuccal and distobuccal roots and type VII in palatal roots. There was no difference in the distribution of morphological canal types in permanent maxillary molars evaluated by CBCT according to sex, age group, or position in the dental arch of the patients. MB2 canals were identified in 68.4% of the teeth evaluated.

The study aimed to investigate the influence of various factors on the localization of the second mesiobuccal (MB2) canal in maxillary molars, a commonly missed canal during endodontic treatment. A comprehensive assessment of maxillary molars treated over three years with a dental operative microscope was conducted. Factors such as patient gender, age, tooth type, pulp status, pre-operative cone-beam computed tomography (CBCT), and treatment modality were examined. Statistical analyses included chi-square and multiple logistic regression. Among 333 treated maxillary molars, the MB2 canal was identified in 60.1%. The prevalence of MB2 canals was significantly higher in the first molars (72.3%) compared to the second molars (40.2%; P=0.001). Multiple logistic regression models showed that gender, tooth type, and treatment modality emerged as significant determinants of MB2 canal localization: males [odds ratio 3.01(CI 95%:1.71-5.32), P<0.001], first molar tooth [odds ratio 4.26 (CI 95%:2.53-7.18), P<0.001] and secondary endodontic treatment [odds ratio 0.06 (CI 95%: 0.004-0.890), P<0.04]. Patient gender, tooth type, and treatment modality play pivotal roles in the identification of the MB2 canal. Additionally, the availability of pre-operative CBCT imaging was associated with a heightened ability to locate the MB2 canal.

Objective: To evaluate the accuracy of cone-beam computed tomography (CBCT) in detecting second mesiobuccal (MB2) canals in maxillary first molars. Methods: A systematic review was conducted in accordance with PRISMA 2020 and registered in PROSPERO (CRD420251067699). Searches were performed in MEDLINE (via PubMed), BVS, LILACS, Cochrane Library, and Google Scholar for studies published between 2013 and 2025. Eligible studies included clinical trials, observational studies, systematic reviews, and meta-analyses evaluating CBCT for MB2 detection in maxillary first molars. Exclusion criteria were case reports, animal studies, and experimental models. Data extraction covered study design, population characteristics, imaging protocols, and MB2 prevalence. The certainty of evidence was assessed with the GRADE approach. Results: From 2,502 records, seven studies met the inclusion criteria. CBCT showed higher diagnostic accuracy than conventional radiographs, with MB2 prevalence ranging from 69.6% to 92%. No significant differences were found between right and left maxillary molars. Findings regarding sex and age were inconsistent, while ethnicity, Vertucci classifications, and inter-orifice distances were reported as influencing factors. Certainty of Evidence ranged from moderate to high. Final considerations: CBCT is a reliable and accurate tool for detecting MB2 canals in maxillary first molars, improving diagnostic capacity, treatment planning, and endodontic outcomes.

Background: In endodontics, glide path creation has been extensively considered a mandatory clinical step to improve the safety and efficiency of rotary nickel–titanium instruments. The high anatomic variations in the mesiobuccal (MB) root of the maxillary molars are observed in the form of canal configuration, number, and position. The aim of this study was to evaluate the negotiability of MB canals in maxillary molars using different pathfiling systems (ProGlider, R-pilot, HyFlex electrical discharge machining [EDM], WaveOne Gold Glider, and C-Pilot). Materials and Methods: This in vitro study included 125 maxillary first molars with closed apex. Before preparation, all teeth were scanned by periapical radiograph for review of the presence of second MB (MB2) canals, without any resorption or calcification, and moderate curve of MB root canal. Subsequently, the access cavity was prepared with a Diamond Fissure Bur. Then, the samples were divided into five groups (ProGlider, R-pilot, HyFlex EDM, WaveOne Gold Glider, and C-Pilot). Certain relevant indices were recorded for analysis, such as the negotiability of the glide path file in the MB canals, file fracture rate, and negotiation speed. The level of significance P value was set at 0.05. Results: In this study, HyFlex EDM was the only path file that could not reach the full working length (WL) in some cases. The highest frequency of file fracture in the MB2 was observed with HyFlex EDM (24%); nevertheless, R-Pilot presented an intermediate fracture rate (16%), and both ProGlider and WaveOne Gold Glider were the safest files (4%) in this regard. However, there were no significant differences between the groups (P = 0.065). The lowest and the highest average time of reaching full WL was observed with WaveOne Gold Glider and HyFlex EDM; nonetheless, there was no significant difference between the four rotary groups. The average number of pecks in HyFlex EDM was significantly higher in comparison to those reported for WaveOne Gold Glider and ProGlider. Conclusion: Path files used for glide path preparation in the MB2 canals of maxillary molars should be flexible with low taper. The use of HyFlex EDM in the MB2 canals is not recommended due to its high taper.

Objectives:The success of endodontic treatment is based on cleaning and shaping of the root canals. The root canals have complex morphology and wide individual variations. The objective of this study was to analyze root canals morphology and existence of extra canals in maxillary molars in Saudi subpopulation.Methods:Freshly extracted maxillary first molars (n=100) were included in this study. All teeth were examined for morphology of roots, root canals and apical foramen by Cone Beam Computed Tomography (CBCT). The root canals configuration was classified using Vertucci’s classification.Results:The majority of maxillary first molars (94%) were having three distinctly separated roots and 6% had four roots. Palatal and distobuccal roots were observed to contain one root canal (100%) and Vertucci’s type I configuration. The mesiobuccal root had one (29.4%; type I) or two canals (70.6%; type II, III or IV).Conclusions:The occurrence of second canal in the mesiobuccal root of upper first molar is very much likely (>70%). The mesiobuccal roots are more likely to have Vertucci’s type I or II configuration (>76%). The palatal and distobuccal roots always have a Vertucci’s type I canal configuration.

Purpose: The aim of this retrospective study was to investigate the prevalence rate and types of C-shaped roots and C-shaped canal in maxillary molars by analyzing cone-beam computed tomography (CBCT) in a Korean population. Materials and Methods: Total of 357 CBCT images of maxillary molars (186 first molar, 171 second molar) were evaluated by two Endodontic specialists. Results: Eight types of C-shaped roots and 5 types of C-shaped canals were founded, the prevalence rate of C-shaped roots and canals were 21.0% and 5.3% respectively. Conclusion: These anatomical variations were more frequent in second molars than the first molars. Clinicians should have anatomical knowledge about various types of C-shaped root and root canal for successful root canal therapy.