C-shaped Root Canal Research Articles

Cone-beam computed tomography evaluation of C-shape canals and longitudinal grooves of mandibular first and second molar teeth

Aim: This study aims to evaluate the anatomical features and prevalence of C-shaped roots and longitudinal grooves in mandibular first and second permanent teeth using cone-beam computed tomography (CBCT).Material and Methods: CBCT records of first and second mandibular teeth from 839 patients who applied to the Department of Oral and Maxillofacial Radiology between 2011 and 2018 were used. The CBCT examination was performed at five different axial levels and the mandibular molars were classified as types of longitudinal groove and C-shape according to the Fan criteria. Differences between genders, age groups, left and right side and type of tooth were determined.Result: A total of 2903 teeth (1321 first molars and 1582 second molar) from 839 patients were included in the study. C-shaped canals were found in mandibular first molar teeth with a prevalence of 0.15%, while 4.1% in mandibular second molar teeth. Only two mandibular first molars exhibited C-shaped canal. Female patients had a higher prevalence than males. Longitudinal grooves were most commonly found lingual surface. Conclusions: The occurence of C-shaped canals in mandibular first and second molars among Turkish population was generally less than in other populations. CBCT is a valuable tool to evaluate the C-shaped root canal configuration in vivo. Keywords: Cone-beam computed tomography; C-shaped canal; mandibular molar

Evaluation of Root and Root Canal Morphology of Mandibular First and Second Molars in a Greek Population: A CBCT Study.

Objective:Τo study the number of roots, canal configurations, and frequency of morphological variations in mandibular first and second molars in a Greek population.Methods:This study examined 478 mandibular first molars and 524 mandibular second molars using a high-resolution cone-beam computed tomography (CBCT). The number of roots was recorded and the root canal configuration was categorized based on the classification by Vertucci. The presence and configuration of C-shaped root canals were recorded and they were classified according to the Fan classification. The symmetry between the right and the left side was also evaluated.Results:Among the mandibular first molars, 0.2% teeth were single-rooted, 96.4% were two-rooted, and 3.3% were three-rooted. In the mandibular second molars, 12.2%, 82.8%, and 4.9% were single-rooted, two-rooted, and three-rooted, respectively. In two-rooted mandibular first and second molars, the most frequent root canal pattern observed was Vertucci’s type II in the mesial root (69.8% and 64.1%, respectively) and Vertucci’s type I in the distal root (81.7% and 97.7%, respectively). Three-rooted molars showed one oval-shaped mesial root and two distal roots (56.2% in first molars, 65.4% in second molars), where each distal root contained a single root canal (type I), and the mesial root presented either type II (53.3%), IV (26.6%), I (13.3%), or V (6.6%) canal configurations. C-shaped canals were only detected in mandibular second molars (5.3% of teeth, 10.8% of individuals), and bilateral occurrence was observed in 24.5% patients. The most frequent root canal pattern was Fan’s C1 type at the orifice, followed by C3a and C3b in the coronal and middle third, which joined into a single canal (C4) apically.Conclusion:The characteristics of the root and root canal anatomy of the mandibular first and second molars of Greek individuals were similar to those observed in Caucasians. However, the higher incidence of third roots in mandibular molars in Greek individuals compared to Caucasians requires absolute clinical awareness.

Autotransplantation of Impacted Third Molar Using 3D Printing Technology: A Case Report

Here, we describe a case of autotransplantation of a mandibular horizontally impacted third molar using a 3-dimensional (3D) model based on limited cone-beam computed tomography (CBCT) images for diagnosis, 3D morphological evaluation, preoperative treatment planning, and surgical simulation. A 27-year-old woman visited this hospital for conservative treatment of the mandibular left second molar. Intraoral radiography and CBCT images revealed a C-shaped root canal in the mesial root, and compressive resorption of the distal root due to impingement of the crown of the horizontally impacted lower left third molar. Extraction was therefore planned. Multiple tooth-jaw bone 3D models for preoperative diagnosis were fabricated using a low-cost desktop 3D printer and surgical simulation of autotransplantation performed. The autotransplantation was then performed accordingly. Cone-beam computed tomography images and 3D models were extremely useful in obtaining a stereoscopic understanding of the morphology of the transplanted tooth and its surrounding anatomical structures. At the one-year postoperative recall, the patient was able chew with the transplanted tooth without pain, and no significant abnormalities were detected on intraoral radiographs, indicating a successful postoperative clinical course. Our experience of using 3D models fabricated based on CBCT images using a desktop 3D printer for preoperative diagnosis and surgical simulation suggests that this technique is useful in tooth autotransplantation.

Analysis of Cause of Endodontic Failure of C-Shaped Root Canals.

The purpose of this study was to analyze various characteristics and classification of C-shaped root canals and evaluate the causes of endodontic failure of C-shaped root canals by examining the resected root surface with an endodontic microscope and a scanning electron microscope (SEM). Forty-two teeth with C-shaped root canals were included in this study and had undergone intentional replantation surgery. Before surgery, periapical radiography and cone-beam computed tomography were taken. The root canal configuration was analyzed and classified according to Melton's classification at coronal and apical level. After injection of 1 : 100,000 epinephrine with 2% lidocaine, the tooth was carefully extracted. After the root-end resection, the resected root surface was examined using an operating microscope and SEM. Mandibular second molars were most frequently involved teeth (90.4%). The most frequently observed root canal configurations were C1 at the coronal level (45.2%) and C3 at the apical 3 mm level (45.2%). The most common cause of failure for a C-shaped root canal treatment was a leaky canal (45.2%), followed by an isthmus (23.8%), missing canal, overfilling, and iatrogenic problems. In conclusion, C-shaped root canals were most frequently found in mandibular second molars. The most common cause of failure was a leaky canal and isthmus.

Endodontic treatment of a hypertaurodontic mandibular left second molar in a patient with many taurodonts combined with multiple pulp stones

Taurodontism is a rare embryologic anomaly of teeth, defined by an apical displacement of the furcation of roots and enlarged pulp chambers. Taurodontism has been classified as hypo-, meso- or hypertaurodontism according to the severity of the anomaly. The aim of this case report was to illustrate a clinical case with multiple bilateral taurodonts and to describe the endodontic management of the hypertaurodontic mandibular left second molar with a C-shaped canal and extensive dental pulp calcifications. A healthy 20-year-old male patient was referred for the endodontic treatment of his lower left second molar. Cone beam computed tomography revealed a C-shaped root canal configuration and several dental pulp calcifications in this tooth. The endodontic treatment was performed in two appointments under an operating dental microscope. A panoramic radiograph, made during the 18months follow-up appointment, revealed nine other taurodontic molars, most of them associated with dental pulp calcifications.

Prevalence of C-shaped canal system in mandibular first and second molars in a Saudi population assessed via cone beam computed tomography: a retrospective study.

The purpose of this study was to determine the prevalence of the C-shaped root canal configuration, location of the longitudinal groove, sex differences, and unilateral/bilateral presence in mandibular first and second molars in a Saudi population using cone beam computed tomography (CBCT). CBCT images for the mandibular first and second molars of 487 patients (a total of 529 first molars and 681s molars) were evaluated. The teeth were assessed for the presence of C-shaped root canals according to Fan criteria. Subdivisions were also made according to sex, direction of the longitudinal groove, and unilateral/bilateral presence. Only one C-shaped mandibular first molar was observed (0.19%), whereas 62 second molars (9.1%) exhibited C-shaped anatomy. Unilateral presence of the C-shaped root canal system was more common (53.85%). Female patients had a higher prevalence than males. Longitudinal grooves were most commonly found on the root lingual surface (58.1%). The prevalence of the C-shaped canal configuration in a Saudi Arabian population was 0.19% in the mandibular first molar and 9.1% in the mandibular second molar. Longitudinal groove prevalence was highest on the lingual surface. Women had a significantly higher prevalence of the C-shaped canal configuration than men. Patients with unilateral presence of the C-shaped canal configuration were more common than those with bilateral presence. Tooth type, patient sex, and ethnicity can help clinicians predict the prevalence of the C-shaped canal system in mandibular molars.

根管治療が施された下顎樋状根歯のX線的, マイクロCTおよび組織学的観察 ―27年長期症例―

根管治療が施された下顎樋状根歯のX線的, マイクロCTおよび組織学的観察 ―27年長期症例―

Evaluation of four instruments with different working motion using artificial plastic model with C-shaped single canal

The purpose of this study was to evaluate four instruments with different working motion for preparation of a C-shaped single canal wall using the same artificial plastic models reproduced from a human tooth. One tooth with root canal morphology C1 (the shape is an uninterrupted “C” with no separation or division) was selected among three-dimensional micro-computed tomography (micro-CT) imaging data of extracted human teeth. Imaging data were then converted into STL form data, and twenty-four C-shaped root canal model blocks were manufactured using this STL form data. These blocks were randomly divided into four groups of six blocks each and instrumented as follows: stainless steel K-files (SSK), Self-Adjusting File (SAF), ProTaper NEXT (PTN) and RECIPROC (REC). Micro-CT images taken before and after canal preparation were superimposed, and instrumented canal area, percentage of instrumented canal area, part of instrumented canal area, volume of instrumented canal and time taken for instrumentation were evaluated for each group. The greatest instrumented canal area, percentage of instrumented canal area and volume of instrumented canal were as follows (in decreasing order): SSK > SAF > PTN > REC (P < 0.05). The longest time taken for instrumentation was as follows (in decreasing order): SAF > SSK > PTN > REC (P < 0.05). The conscious shaping of SSK and the lattice structure of SAF were instrumented all root canal walls equally. PTN and REC required less time taken for instrumentation, but showed unequal instrumentation.

A cone-beam computed tomography study of C-shaped root canal systems in mandibular second premolars in a Taiwan Chinese subpopulation.

The purpose of this study is to investigate the prevalence and the morphologic characteristics of the radicular groove and root canal system in human mandibular second premolars with C-shaped root in a Taiwan Chinese subpopulation using cone-beam computed tomographic (CBCT) imaging. CBCT images of 580 mandibular second premolars were collected from 317 patients. All of the mandibular second premolars were examined in serial axial sections to identify the presence of any C-shaped root and C-shaped canal systems. The morphologic characteristics of mandibular second premolars with C-shaped roots were studied by performing measurements of serial axial sections. The prevalence rate of mandibular second premolars with a C-shaped root was 3.45% (20/580 teeth) and the rate of those with a C-shaped canal system was 2.24% (13/580 teeth). It was found that 69% of the radicular grooves were located on the lingual half of the root (9/13 teeth) in mandibular second premolars with a C-shaped canal system. In those teeth with a lingual radicular groove, the main canal was toward the buccal side. Frequently, the first C-shaped canal image was found at the mid-root level. The deepest part of the radicular groove was located at about 2.5 mm apical to the first C-shaped canal image. There was a 2-3% morphologic variation of the mandibular second premolar with a C-shaped root canal system among the Taiwan Chinese subpopulation investigated in this study. Detailed knowledge of the morphological characteristics of teeth may be valuable when choosing clinical treatments.

C-shaped root canals of mandibular second molars in a Korean population: a CBCT analysis.

ObjectivesThe purpose of this study was to investigate the C-shaped root canal anatomy of mandibular second molars in a Korean population.Materials and MethodsA total of 542 teeth were evaluated using cone-beam computed tomography (CBCT). The canal shapes were classified according to a modified version of Melton's method at the level where the pulp chamber floor became discernible.ResultsOf the 542 mandibular second molars, 215 (39.8%) had C-shaped canals, 330 (53%) had 3 canals, 17 (3.3%) had 2 canals, 12 (2.2%) had 4 canals, and 8 (1.7%) had 1 canal. The prevalence of C-shaped canals was 47.8% in females and 28.4% in males. Seventy-seven percent of the C-shaped canals showed a bilateral appearance. The prevalence of C-shaped canals showed no difference according to age or tooth position. Most teeth with a C-shaped canal system presented Melton's type II (45.6%) and type III (32.1%) configurations.ConclusionsThere was a high prevalence of C-shaped canals in the mandibular second molars of the Korean population studied. CBCT is expected to be useful for endodontic diagnosis and treatment planning of mandibular second molars.

Biometric Analysis of C-shaped Root Canals in Mandibular Second Molars Using Cone-Beam Computed Tomography.

The configuration of C-shaped root canals, root canal wall thickness and orientation of the thinnest area using CBCT in mandibular second molars were assessed. Seventy five CBCT scans were evaluated. Axial sections were evaluated to determine the configuration of C-shaped canals in the coronal, middle and apical regions. The root canal path from the orifice to the apex, the thinnest root canal wall and its orientation were all determined. Data were analyzed using one-way ANOVA and post hoc Tukey's test. The most common configurations were Melton's type I in the coronal and middle and types I and IV in the apical region. The mean thicknesses of the thinnest root canal wall were 1.94±0.43, 1.42±0.57 and 1.10±0.52 mm in the coronal, middle and apical regions, respectively. The lingual wall was the thinnest wall in the coronal, middle and apical regions and it was thinner in the apical than in the middle and coronal regions. The lingual wall was thinner in the middle third of the mesial root compared to the distal root (P<0.05). The lingual wall was the thinnest in C-shaped root canals of mandibular second molars of an Iranian population. Type, number and pathway of canals may vary from the orifice to the apex.

Anatomic Features of C-shaped Mandibular Second Molars in a Selected Iranian Population Using CBCT.

Introduction:The aim of this retrospective study was to analyze the frequency of C-shaped root canal configuration and characterize mandibular root canal morphology using cone-beam computed tomography (CBCT) with 3D images in an Iranian population. Methods and Materials:This study consisted of retrospective evaluation of CBCT images from 231 adult patients (153 with bilateral second mandibular molars). Two endodontists examined 384 mandibular second molars of a population in Tabriz, Iran to determine the presence of C-shaped canals and their anatomical characteristics. Root canal configurations were categorized at three different levels. Bilateral or unilateral occurrence of C-shaped canals and their relationship to gender, age and tooth position were examined and statistically analyzed using chi squared test and Fisher’s exact test in SPSS 17. The significance level was set at 0.05. Results:Of 384 mandibular second molars examined, 82 (21.4%) molars from 58 patients had a C-shaped root canal configuration. The prevalence of bilateral C-shaped canals was 15.6% amongst 153 patients with bilateral mandibular second molars. There were no significant differences in the distribution of C-shaped canals with respect to gender or age (P=0.06 and P=0.86, respectively). Only 4 teeth (4.9%) had the same root canal configuration from the orifice to the apex. In the remainder of the teeth, the cross-sectional root canal configuration changed at different levels of the root. Conclusion:There were significant variations in the number of roots and canal morphology in mandibular second molars, which should be considered during debridement and obturation of the root canal system.

Study of internal morphology of root-canal treated single-rooted mandibular second molars in a Greek population

Background/Aim: To determine the prevalence of single-rooted mandibular second molars in a Greek population and examine their internal morphology with the aid of intraoral periapical radiography. Material and Methods: Clinical records of 531 root-canal treated permanent single-rooted mandibular second molars were collected from the Postgraduate Clinic of the Department of Endodontology, Dental School, Aristotle University of Thessaloniki, Greece and from private dental clinics in the same city. The clinical records, along with the radiographic examination, were evaluated to determine the overall frequency of single-rooted mandibular second molars together with the number of root canals and their course. The root canals were categorized using Vertucci's classification with the addition of 3 further types where appropriate. Results: Out of 531 mandibular second molars; 102 (19.2%) presented a single root; 427 (80.4%) presented two roots; 2 (0.4%) presented three roots. In a total of 102 single-rooted mandibular second molars 31 (30.3%) presented with Type I, 18 (17.6%) with Type II, 14 (13.7%) with Type IV, 7 (7%) with 3 additional root canal types and 32 (31.4%) with a C-shaped root canal system. Conclusions: One out five mandibular second molars was single-rooted in a Greek population. The internal morphology of these teeth can be very complex with regard to the numbers and courses of root canals.

Rare occurrence of c-shaped root canal configuration in mandibular first molar

The occurrence of C-shaped root canal configuration in mandibular first molar is rare. The present case has an unusual C-shaped root canal configuration for both the appearances of the canal orifices and the configuration along the roots. Use of cone-beam computed tomography, rotary and hand instrumentation assisted with sonic and ultrasonic activation of irrigation solution is very important for effective management of this anomalous canal configuration. Modifications in the obturation techniques will ensure a three-dimensional fill of the canal system. Clinician should expect to encounter unusual features when performing endodontic treatment.

Worldwide Prevalence of Mandibular Second Molar C-Shaped Morphologies Evaluated by Cone-Beam Computed Tomography

IntroductionThe aim of this study was to evaluate and compare the C-shaped mandibular second molar prevalence in different regions around the world with the aid of cone-beam computed tomography technology. MethodsNine field observers from 9 different geographic regions were calibrated. A total of 400 samples were collected in each region. The prevalence of C-shaped anatomy was calculated. The number of roots and the configuration of the C-shaped canals at 3 different axial levels were also evaluated. The z-test was used to analyze the difference between the means of each independent group. Intrarater reliability was also tested. ResultsA total of 3600 teeth from 2735 patients were included in this research; 499 teeth presented C-shaped root canal configuration, representing a global prevalence of 13.9%. China had a prevalence of 44.0%, which was significantly higher than any other region. The C-shape prevalence in women was 16.5%, which was significantly higher than the 10.4% prevalence found in men. No difference between sides (37 or 47) was evident in the global sample. ConclusionsCone-beam computed tomography is a valuable tool to evaluate the C-shaped root canal configuration in vivo. In the present study, China presented the highest prevalence of C-shaped mandibular second molars when compared with other regions. Women exhibited a higher prevalence than men.

3-Rooted Maxillary First Premolars: An Ex Vivo Study of External and Internal Morphologies

IntroductionThis study aimed to analyze the external and internal morphologies of 3-rooted maxillary first premolars using cone-beam computed tomographic (CBCT) imaging. MethodsFifty-six three-rooted maxillary first premolars were imaged by CBCT imaging and classified into 4 groups on the basis of external root morphology. Internal morphologic features, including the shapes of the buccal and palatal orifices and distances of bifurcation of the buccal-palatal and mesiobuccal-distobuccal root canals from the cementoenamel junction (CEJ), were measured. ResultsThe teeth were classified into 4 groups on the basis of external morphology: group A, separation of the buccal and palatal roots with bifurcation of the former into the mesiobuccal and distobuccal roots (n = 22); group B, fusion of 2 buccal roots with the palatal root being separate (n = 19); group C, complete or partial fusion of the distobuccal and palatal roots (n = 9); and group D, fusion of all 3 roots (n = 6). The buccal orifice was mainly triangular/heart shaped. The distance of bifurcation of the buccal-palatal root canals from the CEJ in group A differed significantly from those in groups B and C (P < .05). There were significant differences in the distance of bifurcation of the mesiobuccal-distobuccal root canals from the CEJ among groups A, B, and C (P < .05). Four teeth exhibited C-shaped root canal systems of different configurations. ConclusionsThe external and internal morphologies of 3-rooted maxillary first premolars vary considerably.

Morphological evaluation of maxillary second molars with fused roots: a micro-CT study.

To evaluate the internal and external morphologies of fused-rooted maxillary second molars by means of micro-computed tomography (micro-CT) analysis. A total of 100 fused-rooted maxillary second molars from a Brazilian subpopulation were divided into six groups according to the root morphology. The samples were scanned at a resolution of 19.6μm and evaluated with regard to the external morphology of the roots, the root canal configuration, the percentage frequency of C-shaped canals and isthmuses, as well as the morphology of the root canal system at 1, 2 and 3mm from the anatomical apex of the fused roots. The most prevalent root canal fusions were type 1, mesiobuccal root fused with distobuccal root (32%), followed by type 3, DB root fused with P root (27%), and type 4, MB root fused with DB root, and P root fused with MB or DB roots (21%). The prevalence of C-shaped root canal systems were 22%. Depending on the type of root fusion, the percentage frequency of isthmuses in the apical level varied from 9.3% to 42.8%, whilst the presence of apical deltas ranged from 18.5% to 57.1% of teeth. The root canal system of maxillary second molars with fused roots may have a high incidence of merging canals, isthmuses, apical deltas and C-shaped configurations.

Root canal morphology and variations in mandibular second molar teeth of an Indian population: an in vivo cone-beam computed tomography analysis.

This study aims to investigate the root canal morphology of permanent mandibular second molars of an Indian population in vivo using cone-beam computed tomography (CBCT) images. CBCT images (n=983; males=489, females=494) of untreated, completely developed permanent mandibular second molar teeth were examined. CBCT scans were acquired as part of diagnosis and treatment planning for treatments unrelated to the present study. The number of roots and root canals were recorded. Canal configuration was classified based on Vertucci's and Fan's classifications. The most common configuration was two-root (79.35%) and three-root canals (53.50%). The incidence of three-rooted molars was 7.53%, whereas 13.12% of the studied teeth studied have fused roots with C-shaped canals. The predominant canal morphology in the mesial roots was Vertucci's type IV (45.17%), followed by type II (32.55%), type I (7.23%), type V (1.02%), and type III (0.91%). The distal root in contrast showed type I (61.14%) as the predominant canal configuration, followed by type II (18.21%) and type IV (7.53%). The incidence of three-rooted molars was higher in males (n=55; 5.59%) than in females (n=19; 1.94%) (p<0.01). The canals in the extra roots exhibited type I (100%) root canal morphology. In teeth with C-shaped root canal (13.12%), the variations in the coronal, middle, and apical third ranged from C1 to C4. Root canal systems of the mesial roots of mandibular second molars of the study population demonstrated a high degree of variability. While three roots were rare, there was a sexual predisposition. Fused roots with C-shaped canals were rare and demonstrated significant variations from the coronal to apical third. Root canal morphology can demonstrate variations based on race and sex of patients. Clinicians must always consider the possible variations to ensure successful endodontic treatment.

Case report. Endodontic treatment of lower molar in a patient with paraesthesia of inferior alveolar nerve – A Case Report

Summary Root canal (endodontic) treatment is demanding and complex procedure. A variety of difficulties can occur in different phases of endodontic procedure. Complex anatomorphological tooth structure, curved canals, close proximity of lower molars and premolars to inferior alveolar nerve make endodontic treatment even more challenging. During endodontic treatment, an inferior alveolar nerve may become traumatized and symptoms may vary from mild neurosensory dysfunction to a complete loss of sensation in the innervation area of damaged nerve. The aim of this paper is to present a clinical case of endodontic treatment of lower second molar with C-shaped root canal in a patient with paraesthesia of inferior alveolar nerve due to endodontic origin.

Retrospective Assessment of Healing Outcome of Endodontic Treatment for Mandibular Molars with C-shaped Root Canal.

A thorough knowledge of the anatomic morphology of the root canal system is necessary for the long-term success of the root canal therapy. The occurrence of C-shaped root canal configuration is one such variation. Achievement of favorable prognosis after commencing root canal therapy in such teeth is one of the challenges imposed on the endodontist. Hence, we evaluated the healing occurring after endodontic therapy in patients with C-shaped root canals in mandibular molars. The present study was conducted in the Department of Conservative Dentistry of the institution and included assessment of all the patients who underwent root canal treatment of the mandibular first and second molars. Endodontic therapy was performed in all the cases by experienced endodontist. Final postoperative radiographs were taken. Recording of the data of the personal and clinical details of a total of 250 patients was done. All the clinical and radiographic details of the patients, such as tooth location in the jaw, presence or absence of C-shaped canals, status of the pulp tissue, presence or absence of the fractures, and other details of the patients were recorded. Radiographic and clinical examination of the tooth of the patients was done during the baseline visit and further during the follow-up visits. The presence of C-shaped root canals was confirmed using the radiographs. Periapical index (PI) scoring system was used. Categories defined for enlisting the healing after the root canal treatment with the assessment of the PI score. All the results were analyzed by Statistical Package for the Social Sciences software. Vital pulp tissue was encountered in majority of the cases. C-shaped root canal configuration was observed in 40% of the cases included in the present study. After completion of the endodontic therapy, complete crown placement was done in only 22% of the cases. In cases of vital teeth with C-shaped root canals configuration, most of the teeth showed complete healing. Significant results were obtained while comparing the complete coverage crown parameter in relation to the healing process in teeth with C-shaped root canals. In the present study, no significant effect of the C-shaped root canal configuration was found on the healing rate of the endodontic therapy in mandibular molars. Meticulous endodontic therapy with special techniques should be done while preparing teeth with C-shaped root canals.