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Objective To describe the morphological aspects of middle mesial canals (MMC) in mandibular first molars using micro-CT. Design Mandibular first molars collected from the Brazilian ( n = 136) and Turkish ( n = 122) populations were scanned (voxel size: 9.9 μm) and mesial roots with MMC ( n = 48) evaluated regarding several morphological aspects. The incidence of MMC in each population was statistically compared using Chi-square test ( α = 0.05). Results Overall, the incidence of MMC was 18.6% (48 out of 258 molars) and was significantly higher in the Brazilian ( n = 30; 22.1%) than in the Turkish ( n = 18; 14.8%) population ( p < 0.05). In both populations, confluent configuration of the MMC was the most frequent anatomy. Most of the specimens with MMC had 3 independent orifices ( n = 26; 54.2%) and 3 apical foramina ( n = 21; 43.8%). The mean minor diameter of the MMC orifice (0.16 mm) was 3 times less than the other orifices (∼0.50 mm). In mesial roots with independent configuration ( n = 3; 6.3%), the mean volumes (mm 3 ) of the MMC, mesiobuccal (MBC) and mesiolingual (MLC) canals were 0.20 ± 0.10, 0.75 ± 0.28, and 0.88 ± 0.19, respectively. In the specimens with canal confluence ( n = 26; 54.2%), MMC merged to the MBC ( n = 8; 16.7%), MLC ( n = 4; 8.3%), or to both MBC and MLC ( n = 14; 29.2%). Double mesial canal was observed in only 1 specimen. MMC with an independent foramen was observed mostly in Brazilian specimens. Conclusions Incidence of MMC was higher in the Brazilian molars. Confluent configuration was the most prevalent anatomic variation, while independent and fin configurations, as well as, double MMC, were found only in a few specimens. [ABSTRACT FROM AUTHOR]

Introduction This study evaluated the frequency of root canal isthmi (RCIs) in human permanent teeth by using cone-beam computed tomography. Methods A sample of 1400 teeth of 618 patients (394 women; mean age, 43.4 years) was selected. RCIs were detected longitudinally on 0.1-mm/0.1-mm axial slices of cone-beam computed tomography images of roots scanned from the pulp orifice to the apex, and findings were classified into 7 categories according to RCIs beginning and end: (1) both in the cervical third, (2) begin in the cervical third and end in the middle third, (3) begin in the cervical third and end in the apical third, (4) both in the middle third, (5) begin in the middle third and end in the apical third, (6) both in the apical third, or (7) no isthmus. A χ 2 test with Yates correction or the Fisher exact test was used to analyze categorical variables, described as frequencies (%). The Student t test was used to compare quantitative variables. Results RCI is a common anatomic structure in human permanent teeth, except in maxillary anterior teeth. Conclusions The higher frequencies of RCIs (87.9%) were found in mandibular first molars. The frequencies of RCIs according to mean age and tooth group were not significantly different ( P > .05), except in mandibular central incisors. RCIs were less frequent among older patients. [ABSTRACT FROM AUTHOR]

Dens invaginatus (DI) is associated with complex internal anatomy. This article represents a maxillary lateral incisor with 5 root canals including DI. The treatment was planned and performed using cone-beam computed tomographic (CBCT) imaging. After clinical and radiographic evaluations, tooth #7 was diagnosed with DI and pulp necrosis with symptomatic apical periodontitis. Periapical radiographs of the tooth showed 2 roots and complex internal anatomy. CBCT evaluation revealed tooth #7 had 5 separate canals (4 root canals and 1 DI canal extending through the root to the periodontal ligament), communication between DI and the root canal system, and severe and multiple curvatures of the palatal canals. Root canal treatment was completed in 2 visits. Modified access openings were required to safely treat the dilacerated palatal canals. At the 6-month re-evaluation, the patient reported he had remained asymptomatic and his tooth had remained functional since the treatment was completed. Clinical examination showed tooth #7 had no sensitivity to percussion or palpation, probe depths within normal limits (≤3 mm), and no mobility. Radiographic assessment of the tooth showed significant osseous healing of the preoperative lesion. Three-dimensional imaging is a valuable tool for endodontic management of teeth with complex internal anatomy. Three-dimensional imaging is recommended for evaluating and treatment planning cases with DI. [ABSTRACT FROM AUTHOR]

Introduction The aim of this study was to evaluate the morphologic aspects of the root canal anatomy of the distal root of a mandibular first molar using micro–computed tomographic analysis. Methods One-hundred distal roots of mandibular first molars were scanned using a micro–computed tomographic device at an isotropic resolution of 19.6 μm. The percentage frequency distribution of the morphologic configuration of the root canal was performed according to the Vertucci classification system. Two-dimensional parameters (area, perimeter, roundness, aspect ratio, and major and minor diameters) and the cross-sectional shape of the root canal were analyzed in the apical third at every 1-mm interval from the main apical foramen in roots presenting Vertucci types I and II configurations ( n = 79). Data were statistically compared using the Kruskal-Wallis and Dunn tests with a significance level set at 5%. Results Seventy-six percent of the distal roots had a single root canal. Two, three, and four canals were found in 13%, 8%, and 3% of the sample, respectively. In 13 specimens, the configuration of the root canal did not fit into Vertucci's classification. Overall, 2-dimensional parameter values significantly increased at the 3-mm level ( P < .05). The prevalence of oval canals was higher at the 1-mm level and decreased at the 5-mm level in which long oval and flattened canals were more prevalent. Conclusions The distal roots of the mandibular first molars showed a high prevalence of single root canals. The prevalence of long oval and flattened canals increased in the coronal direction. In 13% of the samples, canal configurations that were not included in Vertucci's configuration system were found. [ABSTRACT FROM AUTHOR]

This case report presents the categorization and management of two cases of C-shaped canals in need of root canal treatment, based on the available classification systems. The prediction of C-shaped root canal morphology using radiography and clinical picture is possible through the application of the classification schemes proposed in literature. A modified cold lateral compaction technique is described for obturation of C-shaped canals partly united by a narrow isthmus. [ABSTRACT FROM AUTHOR]

Successful endodontic therapy depends on adequate mechanical and chemical debridement of the canal which requires knowledge of the canal morphology. Conventional radiography has been used to evaluate the canal type; however, direct digital radiography has recently been practiced for this purpose due to the shortcomings of conventional radiography. The aim of the present study was to compare the accuracy of digital and conventional radiography taken at 0° and 30° angles in the diagnosis of the canal type of extracted maxillary premolars.This diagnostic study was performed on 90 extracted maxillary premolars. Conventional and digital radiographies were taken of all teeth at 0° and 30° horizontal angles. The images were assessed by an oral and maxillofacial radiologist. The clearing technique was used as the gold standard. The canal type was determined using Weine classification. The agreement between each one of the 4 radiographic modalities and gold standard was determined by kappa statistics.The kappa values for the agreement of parallel conventional, 30° conventional, parallel digital and 30° digital modalities with the clearing technique were 0.059, 0.215, 0.043 and 0.391, respectively. Parallel modalities were unable to determine the tooth canal type. Radiographic images taken at 30° significantly determined the canal type, although only a poor level of agreement was noted between the two modalities and the clearing technique.All modalities had limited value to determine the root canal type in maxillary premolars. However, direct digital imaging taken at 30° angle showed the highest accuracy for canal type assessment.

Introduction Although the internal anatomy of mandibular molars has been extensively studied, information about middle mesial (MM) canals is limited. The primary aim of this retrospective study was to evaluate the incidence of MM canals in mandibular first and second molars. The secondary aim was to correlate the incidence of MM canals with variables of molar type, sex, age, ethnicity, and presence of a second distal canal. Methods All mature permanent first and second mandibular molars treated from August 2012 to May 2014 were included in the analysis. After completion of root canal instrumentation in all main canals, the clinician inspected the isthmus area of the mesial root using the dental operating microscope. If there was a catch point in this area with a file or explorer, the operator spent more time attempting to negotiate an MM canal. Results Seventy-five mandibular first and second molars were treated during the specified period. Fifteen (20%) teeth had negotiable MM canals. The incidence of MM canals was 32.1% in patients ≤20 years old, 23.8% in patients 21–40 years old, and 3.8% in patients >40 years. Analysis of data revealed a significant difference in the distribution of MM canals among different age groups ( P < .05). The differences in the distribution of MM canals based on sex, ethnicity, molar type, and presence of a second distal canal were not significant. Conclusions The incidence of negotiable MM canals overall and their frequency of identification in younger patients were higher than in previous reports. [ABSTRACT FROM AUTHOR]

Nonsurgical endodontic therapy of a right maxillary first molar with three roots and seven root canals. This unusual morphology was diagnosed using a dental operating microscope (DOM) and confirmed with the help of cone-beam computed tomography (CBCT) images. CBCT axial images showed that both the palatal and distobuccal root have a Vertucci type II canal pattern, whereas the mesiobuccal root showed a Sert and Bayirli type XVIII canal configuration. The use of a DOM and CBCT imaging in endodontically challenging cases can facilitate a better understanding of the complex root canal anatomy, which ultimately enables the clinician to explore the root canal system and clean, shape, and obturate it more efficiently. [ABSTRACT FROM AUTHOR]

Aim. The aim of this study was to evaluate the root canal number and configuration of maxillary and mandibular premolar teeth by gender, intervals for decades, tooth position and unilateral or bilateral occurrence in a Turkish population using Cone Beam Computed Tomography(CBCT) scanning. Methodology. CBCT images of 5496 maxillary and mandibular premolars from 849 patients were evaluated. The following was evaluated in all the images: numbers of roots and root canals, the morphology of the root canal configuration according to the Vertucci classification, male-female differences in the tooth position and male-female differences in unilateral or bilateral occurrence. The reliability data were analyzed with a chi-square test. Results. The most prevalent root canal frequency was the two canals (86.2%) and type IV (76.9%) configuration for maxillary first premolar, one canal (59.7%) and type I (54.5%) canal configuration for second premolar. The incidence of one canal was higher in females and the occurrence of two or three canals was more common in males. The incidence of one canal was higher on the left side of maxillary premolars and the incidence of two canals was higher on the right side. Most mandibular first (93.5%) and second (98.5%) premolars had one canal. In general, females had one root canal of the mandibular premolar, whereas males had two or three canals. The type I configuration was most common and the incidence was higher on the right side. There were some differences found in the frequency distribution of the number of root canals and configuration of maxillary and mandibular premolar teeth according to intervals for decades. Conclusion. CBCT scanning provides comprehensive information about the root canal morphology of maxillary and mandibular premolar teeth. These data may help clinicians in root canal treatment of premolar teeth. [ABSTRACT FROM AUTHOR]

Introduction The morphology of the supernumerary third root (radix) in mandibular first molars was examined by micro–computed tomography (μCT) scanning. Methods Nineteen permanent mandibular first molars with radix were scanned in a μCT device to evaluate their morphology with respect to root length, root curvature direction, location of radix, apical foramen, accessory canals and apical deltas, and distance between canal orifices as well as 2- and 3-dimensional parameters of the canals (number, area, roundness, major/minor diameter, volume, surface area, and structure model index). Quantitative data were analyzed by 1-way analysis of variance and the Tukey test (α = 0.05). Results The mean length of the mesial, distal, and radix roots was 20.36 ± 1.73 mm, 20.0 ± 1.83 mm, and 18.09 ± 1.68 mm, respectively. The radix was located distolingually ( n = 16), mesiolingually ( n = 1), and distobuccally ( n = 2). In a proximal view, most radix roots had a severe curvature with buccal orientation and a buccally displaced apical foramen. The spatial configuration of the canal orifices on the pulp chamber floor was mostly in a trapezoidal shape. The radix root canal orifice was usually covered by a dentinal projection. The radix differed significantly from the mesial and distal roots for all evaluated 3-dimensional parameters ( P < .05). The radix canal had a more circular shape in the apical third, and the mean size of the minor diameter 1 mm short of the foramen was 0.25 ± 0.10 mm. Conclusions The radix root is an important and challenging anatomic variation of mandibular first molars, which usually has a severe curvature with a predominantly distolingual location, and a narrow root canal with difficult access. [ABSTRACT FROM AUTHOR]

Complete cleaning and shaping is the key to successful endodontic treatment. A thorough understanding of the internal anatomy and morphology of the root canal system is an important consideration when performing cleaning and shaping procedures. Mandibular premolars are one of the most difficult teeth to treat endodontically because of aberrant root canal anatomy. This article describes case series of mandibular premolars with variations in root canal anatomy treated successfully by conventional endodontic treatment. [ABSTRACT FROM AUTHOR]

Aims and Objective: To investigate the root canal configuration of permanent maxillary first molar in Khasi population of Meghalaya. Material and Methods: Sixty (60) permanent maxillary first molars collected from patients of Khasi population of Meghalaya were studied using canal staining and clearing technique. Observations of the number of roots, root canal configuration, lateral canal, apical delta, and presence of the additional type of canals were made. Results: Based on Vertucci's classification the different types of canal identified are: Mesiobuccal root, Type I (28.3%), Type II (28.3%), Type IV (30.0%), Type V (5.0%), Type VI (6.7%), and an additional type of canal (2-1-2-1-2; 1.7%) were observed. The distobuccal root displayed Type I (95%), Type II (1.7%), Type V (3.3%). The most prevalent canal configuration in the palatal roots is Type I (98.3%), Type II (1.7%). Conclusion: In Khasi population of Meghalaya, the most prevalent root canal configuration in the mesiobuccal root is Type IV followed by Type I and Type II. MB2 canals are present in more than 65% cases. In palatal and distobuccal roots, Type I configuration is present in most cases. Racial divergence may be responsible for such variations. [ABSTRACT FROM AUTHOR]

Although the possibility of three canals in maxillary second premolars is quite small, it must be taken into consideration in clinical and radiographic evaluations during endodontic treatment. This case report describes an unusual morphology of the three canals and two separated roots in maxillary second premolar in a Brazilian patient. A thirty-two year old male patient was referred to our clinic complaining of sensitivity to cold and pain at night in the second right upper premolar. The clinical examination revealed extensive distal caries. Percussion and cold tests were positive. The radiographic examination showed the presence of two roots. The diagnosis was an irreversible pulpitis. Root inspection revealed the existence of a third vestibular-palatal canal. The endodontic treatment was completed in a single session using manually serial instrumentation technique under sodium hypochlorite irrigation. Canals were obturated with thermoplasticized gutta-percha and sealed with zinc oxide and eugenol by lateral condensation technique. The presence of extra roots as a possible feature in maxillary second premolar should be considered during endodontic treatment. The instrumentation presented in this case report and the diagnosis methods were effective in successful three rooted second premolar treatment. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: This study aimed to describe the anatomy of mandibular central and lateral incisors using micro–computed tomographic imaging. Methods: One hundred mandibular incisors were scanned in a micro–computed tomographic device using an isotropic resolution of 22.9 μm. The anatomy of each tooth (length of the roots, presence and location of accessory canals and apical deltas, and number of canals) as well as the 2- and 3-dimensional morphologic aspects of the canal (area, roundness, diameter, volume, surface area, and structure model index) were evaluated. Data were statistically compared using the Student t test (alpha = 0.05). Results: The mean lengths of the mandibular central and lateral incisors were 20.71 and 21.56 mm, respectively. Most of the central (60%) and lateral (74%) incisors had no accessory canals. An apical delta was observed in only 1 specimen. The cross-section analysis of the apical third showed the presence of 1, 2, or 3 canal orifices. No statistical difference was observed in the comparison of the 2- and 3-dimensional morphologic parameters between central and lateral incisors (P < .05). The qualitative analyses of the 3-dimensional models of the root canal systems of the central and lateral incisor teeth confirm that the most prevalent configurations were Vertucci's types I (50% and 62%, respectively) and III (28%). Conclusions: Overall, mandibular central and lateral incisors were similar in terms of the 2- and 3-dimensional analyzed parameters. Vertucci's types I and III were the most prevalent canal configurations of the mandibular incisors; however, 8 new types have also been described. [Copyright &y& Elsevier]

Abstract: Introduction: The complexity of the root canal system of maxillary molars presents a constant challenge in the diagnosis and treatment of these teeth. This case report describes the importance of a surgical operating microscope and cone-beam computed tomographic (CBCT) imaging. Methods: Root canal treatment of a left maxillary first molar with 3 roots and 7 canals was successfully performed. Seven canals were identified with the help of a surgical operating microscope and CBCT imaging. CBCT images also confirmed the 3 roots and 7 canals in the right maxillary first molar. Results: CBCT images confirmed a type IV canal pattern in the distal and palatal root, whereas the mesial root had a type VIII canal pattern. Conclusions: The use of a surgical operating microscope and CBCT imaging helps the clinician to diagnose unusual anatomy of a tooth and facilitate successful endodontic treatment. [Copyright &y& Elsevier]

Abstract: Introduction: This study aimed to characterize the dimensions of a selection of 3-rooted maxillary premolars through high-resolution computed tomographic analysis considering measures of clinical interest for root canal treatment, such as root wall thickness, canal diameters, and distances between 2 canals in fused roots and between the root apex and foramen. Methods: Fifteen 3-rooted human maxillary premolars extracted for therapeutic reasons were individually scanned using a high-resolution desktop high-resolution computed tomographic system. Starting from the apical foramen, the selected cross-sectional images corresponding to each millimeter of the roots were evaluated. Measures of clinical interest were determined using Image J software (version 1.41; National Institutes of Health, Bethesda, MD). Results: Root wall thickness as thin as 0.4 and 0.6 mm was detected in the apical portion of buccal and palatal roots, respectively. In the cervical portion, buccal roots had narrower root walls (0.817–1.670 mm) compared with palatal roots (1.361–2.720 mm). In all thirds, the palatal canal was wider compared with the mesiobuccal and distobuccal canals. In the buccopalatal direction, all roots had thicker root walls toward the furcation, whereas in the mesiodistal direction the mesiobuccal and distobuccal roots had the thinnest walls along their distal and mesial aspects, respectively. Both buccal canals revealed dentin apposition 2 mm from the canal orifice, resulting in cervical constriction. Generally, the distance between the root apex and the foramen was greater in distobuccal roots in comparison with the others with a tendency for foramina to be eccentric. Conclusions: Three-rooted premolars are a clinical challenge not just because of their low frequency and difficulties regarding diagnosis and root canals access but also because of their fragile roots. These phenomena are critical in terms of the amount of dentin removed during the preparation of root canals and during post space preparation. [Copyright &y& Elsevier]

Aim To investigate the anatomy of single-rooted mandibular canine teeth using microcomputed tomography (μ CT). Methodology One hundred straight single-rooted human mandibular canines were selected from a pool of extracted teeth and evaluated using μ CT. The anatomy of each tooth (length of the roots, presence of accessory canals and apical deltas, position and major diameter of the apical foramen and distance between anatomical landmarks) as well as the two- and three-dimensional morphological aspects of the canal (area, perimeter, form factor, roundness, major and minor diameter, volume, surface area and structure model index) were evaluated. The results of the morphological analysis in each canal third were compared statistically using Friedman's test (α = 0.05). Results The length of the roots ranged from 12.53 to 18.08 mm. Thirty-one specimens had no accessory canals. The location of the apical foramen varied considerably. The mean distance from the root apex to the major apical foramen was 0.27 ± 0.25 mm, and the major diameter of the major apical foramen ranged from 0.16 to 0.72 mm. Mean major and minor diameters of the canal 1 mm short of the foramen were 0.43 and 0.31 mm, respectively. Overall, the mean area, perimeter, form factor, roundness, major and minor diameters, volume, surface area and structure model index ( SMI) were 0.85 ± 0.31 mm2, 3.69 ± 0.88 mm, 0.70 ± 0.09, 0.59 ± 0.11, 1.36 ± 0.36 mm and 0.72 ± 0.14 mm, 13.33 ± 4.98 mm3, 63.5 ± 16.4 mm2 and 3.35 ± 0.64, respectively, with significant statistical difference between thirds ( P < 0.05). Conclusions The anatomy and morphology of the root canal of single-rooted canines varied widely in different levels of the root. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to analyze the variations in canal and root cross-sectional area in three-rooted maxillary premolars between high-resolution computed tomography (μCT) and cone beam computed tomography (CBCT). Materials and methods: Sixteen extracted maxillary premolars with three distinct roots and fully formed apices were scanned using μCT and CBCT. Photoshop CS software was used to measure root and canal cross-sectional areas at the most cervical and the most apical points of each root third in images obtained using the two tomographic computed (CT) techniques, and at 30 root sections equidistant from both root ends using μCT images. Canal and root areas were compared between each method using the Student t test for paired samples and 95 % confidence intervals. Results: Images using μCT were sharper than those obtained using CBCT. There were statistically significant differences in mean area measurements of roots and canals between the μCT and CBCT techniques ( P < 0.05). Root and canal areas had similar variations in cross-sectional μCT images and became proportionally smaller in a cervical to apical direction as the cementodentinal junction was approached, from where the area then increased apically. Conclusion: Although variation was similar in the roots and canals under study, CBCT produced poorer image details than μCT. Clinical relevance: Although CBCT is a strong diagnosis tool, it still needs improvement to provide accuracy in details of the root canal system, especially in cases with anatomical variations, such as the three-rooted maxillary premolars. [ABSTRACT FROM AUTHOR]

Aim To assess the impact of cross-sectional root canal shape ( CSRCS) on the canal volume that can be filled and the root filling material that remains following a subsequent retreatment procedure. Methodology A total of 15 extracted two-rooted human maxillary premolars and 15 mandibular first molars were used. Both root canals in the premolars ( N = 30) and the distal root canal in the molars ( N = 15) were prepared using Pro File instruments and filled by lateral compaction using gutta-percha and AH Plus sealer. Canals were later retreated using the last Pro File used for instrumentation followed by two Pro Files of increasing size. Teeth were viewed in a μ CT scanner before and after each treatment step. Defined and validated threshold levels were used to differentiate empty root canal volumes, root dentine and root filling materials from each other. CSRCS was defined as the averaged ratio between bucco-lingual and mesio-distal canal diameter (round ≤ 1, oval 1-2, long oval 2-4 and flattened ≥ 4), determined for each 1 mm over the total root length. Data were averaged between the two canals in premolars, only the distal canals were assessed in molars. Parametric and non-parametric tests were used to statistically compare the data, alpha = 0.01. Results Canals in premolars had a round CSRCS after preparation (1.0 ± 0.0), whereas distal counterparts in molars were oval (1.6 ± 0.5). Significantly ( P < 0.01) more canal volume could be filled, and significantly less filling material remained after retreatment in premolars compared with mandibular molar distal canals. There was a high correlation between CSRCS, filled canal volume and remaining filling material. Conclusions The endodontic procedures under investigation were significantly influenced by the cross-sectional root canal shape. [ABSTRACT FROM AUTHOR]

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.)

Objective: Successful endodontic therapy depends on adequate mechanical and chemical debridement of the canal which requires knowledge of the canal morphology. Conventional radiography has been used to evaluate the canal type; however, direct digital radiography has recently been practiced for this purpose due to the shortcomings of conventional radiography. The aim of the present study was to compare the accuracy of digital and conventional radiography taken at 0° and 30° angles in the diagnosis of the canal type of extracted maxillary premolars. Materials and Methods: This diagnostic study was performed on 90 extracted maxillary premolars. Conventional and digital radiographies were taken of all teeth at 0° and 30° horizontal angles. The images were assessed by an oral and maxillofacial radiologist. The clearing technique was used as the gold standard. The canal type was determined using Weine classification. The agreement between each one of the 4 radiographic modalities and gold standard was determined by kappa statistics. Results: The kappa values for the agreement of parallel conventional, 30° conventional, parallel digital and 30° digital modalities with the clearing technique were 0.059, 0.215, 0.043 and 0.391, respectively. Parallel modalities were unable to determine the tooth canal type. Radiographic images taken at 30° significantly determined the canal type, although only a poor level of agreement was noted between the two modalities and the clearing technique. Conclusion: All modalities had limited value to determine the root canal type in maxillary premolars. However, direct digital imaging taken at 30° angle showed the highest accuracy for canal type assessment. [ABSTRACT FROM AUTHOR]

The primary objective of endodontic therapy is to achieve a three-dimensional obturation of the root canal space after adequate preparation of the canal space to remove the tissue debris, microorganisms, and their byproducts. Anatomical variations have frequently been encountered in endodontic practice and have to be adequately managed by the clinician. Missed roots and canals are a major reason for failure of therapy. Technological advances have given the clinician ample opportunity to identify and treat these aberrations successfully. The present report describes a left mandibular second permanent molar requiring root canal treatment, found to have three separate canals in the mesial root. This case demonstrates a rare anatomical configuration and emphasizes the need for the clinician to be aware of and look out for such variations and use adequate diagnostic methodologies prior to and during therapy to detect such variations. The possibility of additional canals, whenever in doubt, should be explored with the assistance of technologies such as those of magnification and illumination and various diagnostic aids. Operator experience has also shown to be a key factor in negotiation and management of these aberrant canal configurations. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: This study examined the anatomy of 4-rooted maxillary second molars by using micro–computed tomography. Methods: Twenty-five 4-rooted maxillary second molars were scanned to evaluate the size and curvature of the roots; the distance and spatial configuration between some anatomical landmarks; the number of root canals and the position of apical foramina; the occurrence of fusion of roots and enamel pearls; the configuration of the canal at the apical third; the cross-sectional appearance, the volume, and surface area of the root canals. Data were compared by using analysis of variance post hoc Tukey test (α = 0.05). Results: The specimens were classified as types I (n = 16), II (n = 7), and III (n = 2). The size of the roots was similar (P > .05), and most of them presented straight with 1 canal, except the mesiobuccal that showed 2 canals in 24% of the samples. The configuration of the pulp chamber was mostly irregular quadrilateral-shaped. The lowest mean distance of the orifices was observed between the buccal roots (P < .05). Accessory canals were present mostly in the apical third. Location of the apical foramina varied considerably. Fusion of roots and enamel pearls occurred in 44% and 8% of the samples, respectively. Mean distance from the pulp chamber floor to the furcation was 2.15 ± 0.57 mm. No statistical differences were found in the bi-dimensional and 3-dimensional analyses (P > .05). Conclusions: All analyzed parameters showed differences between roots, except for the length of the roots, the configuration of the canals at the apical third, cross-sectional appearance, volume, and surface area of the canals. [Copyright &y& Elsevier]

Kottoor J, Murugesan R, Albuquerque DV. A maxillary lateral incisor with four root canals. International Endodontic Journal, 45, 393-397, 2012. Abstract Aim To describe the successful non-surgical endodontic management of a permanent maxillary lateral incisor tooth with four root canals. Summary Aberrant morphology of root canals can occur in any tooth, including maxillary lateral incisors. In the presented case, clinical examination and radiographs clearly depicted the presence of four root canals in a right maxillary lateral incisor. The differential diagnosis included fusion, gemination, dens invaginatus or a combination of these. The report emphasises the need for attention during root canal treatment of maxillary lateral incisors. Key learning points [ABSTRACT FROM AUTHOR]