C-shaped Canal System in Maxillary Molars Evaluated by Cone- Beam Computed Tomography in an Argentine subpopulation / Conductos en C en molares superiores evaluados mediante tomografía cone-beam en una sub-población Argentina

ABSTRACT The aim of the present study was to evaluate the presence of maxillary first and second molars with a C-shaped canal system in an Argentine subpopulation, and to classify them. Materials and Method: Of the 332 CBCTs initially evaluated, 120 met the selection criteria. Once the presence of a C-shaped canal system had been established, the teeth were classified following Martins et al. Data were expressed as absolute frequencies, percentages with of 95% confidence intervals, according to the score test. Comparisons were analyzed by Chi-square test and Fisher' exact test, with 5% significance level. Results: It was found that 5 out of 120 first molars (4%) and 17 out of 152 second molars (11%) had a C-shaped canal system. Regarding the classification applied, of 5 C-shaped first molars, 2 corresponded to type E2 (40%), 2 corresponded to type C (40%), and 1 corresponded to type B1 (20%). Of 17 C-shaped second molars, 4 resembled a type A (24%), 7 resembled a type B1 (41%), 5 resembled a type B2 (29%), and 1 resembled a type C (6%). UC1 and UC2 configurations were the most common at all levels except apical level. Conclusion: The prevalence of C-shaped canal system pattern in maxillary first and second molars was estimated for the first time in an Argentine subpopulation, in vivo. Knowledge of these data should help clinicians during endodontic treatment.

RESUMEN El objetivo del presente estudio fue evaluar la presencia de conductos en C en primeros y segundos molares superiores, en una subpoblación de Argentina. Materiales y Método: Se observaron 332 CBCTs, de las cuales 120 cumplieron los criterios de selección. Una vez determinada la presencia de conducto en C se clasificaron según Martins et al. Los datos fueron descriptos mediante frecuencias absolutas y porcentajes, con intervalos de confianza al 95% (IC95), según método score. Las comparaciones fueron analizadas mediante la prueba de Chi-cuadrado o exacta de Fisher con un nivel de significación del 5%. Resultados: De 120 primeros molares, 5 presentaron conductos en C, es decir un 4% y de 152 segundos molares, 17 presentaron conductos en C, es decir un 11%. Según la clasificación aplicada, de 5 primeros molares en C, 2 correspondieron al tipo E2 (40%), 2 al tipo C (40%) y 1 al tipo B1 (20%). De 17 segundos molares en C, 4 pertenecieron al tipo A (24%), 7 al tipo B1 (41%), 5 al tipo B2 (29%) y 1 al tipo C (6%). Las clasificaciones UC1 y UC2 fueron las más representativas en todos los niveles, excluyendo el tercio apical. Conclusión: La prevalencia de conductos en C en primeros y segundos molares superiores, fue estimada por primera vez en una subpoblación Argentina, in vivo. Los datos obtenidos en el presente estudio, resultan de interés para el abordaje de los tratamientos endodónticos.

Prevalence and C-shaped root canal configuration in lower molars in the metropolitan region, Chile / Prevalencia y configuración de conductos en C en molares inferiores de la región metropolitana, Chile

Objetive: The aim of this study was to determine the prevalence, demographics, and root configuration of C-shaped canals of mandibular molars by means of cone beam computed tomography in the population of the Metropolitan Region, Chile. Material and Methods: 912 molars (456 first and 456 second molars) resulting from the analysis of 228 mandibular CT scans were evaluated. The root configuration was established by means of a panoramic reconstruction and axial tomographic sections, classifying the presence and type of canals through the analysis of five sections or cuts along the root. Data were statistically analyzed using a 5% confidence interval. Results: Of the 912 molars analyzed, 70 were classified as C-shaped canals (7.68%), corresponding to 58.33% of those molars that presented fused roots. 95.7% of this root canal configuration was observed in lower second molars, occurring more frequently in females (n=45, 64.29%). 45.65% of the cases that presented C-shaped canals were bilateral and the most frequent configuration was C3 (n=401, 66.63%) according to the Melton classification.Conclusion: The C-shaped canals of the mandibular molars in the studied population were observed mainly in second molars, showing a clear prevalence among females and a high percentage of bilaterality. The presence of fused roots significantly increases the possibility of finding this type of root configuration.

Objetivo: El objetivo del presente estudio fue determinar, por medio de tomografía computarizada de haz cónico, la prevalencia, demografía y configuración radicular de los conductos en forma de C de molares inferiores en la población de la Región Metropolitana, Chile. Material y Métodos: 912 molares (456 primeros y 456 segundos molares) resultantes del análisis de 228 tomografías mandibulares fueron evaluados. Mediante una reconstrucción panorámica y cortes tomográficos axiales se estableció la configuración radicular, clasificando la presencia y tipo de conducto por medio del análisis de 5 cortes a lo largo de la raíz. Los datos fueron analizados estadísticamente con un intervalo de confianza del 5%. Resultados: De los 912 molares analizados, 70 fueron clasificados como conductos en forma de C (7.68%), correspondiendo al 58.33% de aquellos molares que presentaron raíces fusionadas. El 95.7% de esta configuración de conductos fue observada en segundos molares inferiores, presentándose con mayor frecuencia en mujeres (n=45, 64.29%). El 45.65% de los casos que presentaron conductos en C se manifestaron bilateralmente y la configuración más frecuente observada fue la C3 (n=401, 66.63%) según la clasificación de Melton. Conclusión: Los conductos en forma de C de los molares mandibulares en la población estudiada fueron observados principalmente en segundos molares, marcando una clara predilección por el sexo femenino y un alto porcentaje de bilateralidad. La presencia de raíces fusionadas aumenta significativamente la posibilidad de encontrar este tipo de configuración radicular.

Relationship between root canal merging and presence of C-shaped canal in fused rooted maxillary molar teeth / Relação entre a fusão do canal radicular e a presença de canal em forma de C em dentes molares maxilares fundidos e enraizados

Objective: This study aimed to evaluate the prevalence of root fusion and the incidence of C-shaped canals in maxillary 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, incidence and number of C-shaped canals were ascertained according to the type of fusion, location, position, and level of canal merging in teeth with fused roots. Six types were established according to the C-shape configurations observed. Presence of root fusion and the C-shaped canal according to gender, age, and tooth position were evaluated by chi-square test. Values with p< 0.05 were considered significant in statistical tests. Results: The incidence 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< 0.05), the C shaped morphology was not affected by sex (p> 0.05). Individuals over the age of 50 years had a lower incidence of C-shaped canals (p< 0.05). Conclusion: C-shaped canal morphology was more commonly associated with complex types of root fusion involving three roots; 16.83% of MSMs with fused roots had C-shaped canals (AU).

Objetivo: o objetivo deste estudo foi avaliar a prevalência de fusão radicular e a incidência de canais em C nos dentes do primeiro molar superior (MFM) e do segundo molar superior (MSM) por meio da tomografia computadorizada de feixe cônico. Material e Métodos: Neste estudo, um total de 1233 MFMs e 1406 MSMs de 802 pacientes foram analisados. Primeiro, o número de dentes com raízes fundidas e o tipo de fusão radicular foram determinados. Posteriormente, a incidência e o número de canais em forma de C foram verificados de acordo com o tipo de fusão, localização, posição e nível de fusão do canal nos dentes com raízes fundidas. Seis tipos foram estabelecidos de acordo com as configurações em forma de C observadas. A presença de fusão radicular e do canal em C de acordo com sexo, idade e posição dentária foram avaliadas pelo teste do qui-quadrado. Valores com p <0,05 foram considerados significativos nos testes estatísticos. Resultados: A incidência de fusão nos dentes MFM e MSM foi de 6,16% e 22,40%, respectivamente. Apenas três MFMs (0,24%) e 3,77% dos MSMs tinham canais em forma de C. Enquanto a incidência de fusão foi maior em mulheres (p <0,05), a morfologia em forma de C não foi afetada pelo sexo (p> 0,05). Indivíduos com mais de 50 anos apresentaram menor incidência de canais em C (p <0,05). Conclusão: a morfologia do canal em forma de C foi mais comumente associada a tipos complexos de fusão radicular envolvendo três raízes; 16,83% dos HSH com raízes fundidas tinham canais em forma de C (AU).

Bilaterality and symmetry of c-shaped mandibular second molars in a Mexican Maya and non-Maya population: a CBCT in vivo study / Bilateralidad y simetría de los segundos molares mandibulares en forma de c en una población mexicana Maya y no Maya: estudio in vivo mediante CBCT

SUMMARY: The objective of this study was to evaluate the bilaterality and symmetry in C-shaped mandibular second molars in Mexican Maya and non-Maya populations using cone-beam computed tomography (CBCT). Five-hundred-twenty-five CBCT scans of patients with left and right mandibular second molars were analyzed to determine the prevalence and bilaterality. The teeth were assessed for the presence of C-shaped root canals, according to Fan et al. (2004) criteria. The sample was subdivided by ethnicity, sex, unilateral/bilateral presence, side of the longitudinal groove, and the C-shaped root canal configuration and symmetry, at the cervical, middle, and apical cross- sections of the root. C-shaped mandibular second molars were present in 24.95% of the individuals. Most (60.30%) of those showing this trait had it bilaterally. When comparing by ethnicity, sex, and side, we detected no significant differences. The vast majority (97.33%) presented the groove along the lingual side. The C3 was the most prevalent configuration in the overall sample, while in the Maya group, the C1 was the most common configuration. When analyzed by sex and ethnic group, the non-Maya females tended to deviate from the other groups in terms of bilaterality. Overall, 55.70% of bilateral C-shaped mandibular second molars were also symmetric in the three radicular thirds. The prevalence of C-shaped mandibular second molars was similar to that reported for northernAsian populations, which is consistent with the evolutionary origins of Native American populations. Most of the sample showed bilaterality and half were symmetric. Clinicians must be aware of the ethnic background of their patients and consider the possible variations to do more predictable root canal treatments.

RESUMEN: El objetivo de este estudio fue evaluar la bilateralidad y simetría de los segundos molares mandibulares en forma de C en una población Mexicana Maya y no-Maya mediante tomografía computarizada de haz cónico (CBCT). Material and Métodos: Se analizaron quinientos veinticinco tomografías de pacientes con segundos molares mandibularesderecho e izquierdo para determinar la prevalencia y bilateralidad. Los dientes fueron evaluados según la presencia de conductos en forma de C de acuerdo a los criterios de Fan et al. La muestra fue subdividida por etnicidad, sexo, presencia bilateral/unilateral, lado del surco y configuración y simetría de los conductos en los cortes transversales cervical, medio y apical. Los segundos molares mandibulares en forma de C estuvieron presentes en el 24.95 % de los individuos. La mayoría (60.30%) de los que mostraron este rasgo lo hicieron de forma bilateral. El comparar por etnicidad, sexo y lado, no se encontraron diferencias estadísticamente significativas. La gran mayoría (97.33%) presentó el surco por lingual. C3 fue la configuración más prevalente en la muestra general, mientras que en el grupo Maya el C1 fue la más común. El análisis por sexo y grupo étnico arrojó que las mujeres no Mayas tendieron a desviarse de los otros grupos en términos de bilateralidad. El 55.70% de los segundos molares mandibulares bilaterales fueron simétricos en sus tres tercios radiculares. La prevalencia de los segundos molars mandibulares en forma de C fue similar a la reportada para las poblaciones del norte de Asia, lo cual es consistente con los orígenes evolutivos de las poblaciones nativas americanas. La mayor parte de la muestra presentó el rasgo de forma bilateral y la mitad de éstos fueron simétricos. Los odontólogos deben tomar en cuenta el origen étnico de sus pacientes y considerar las posibles variaciones para realizar tratamientos endodónticos más predecibles.

CBCT study of the root and root canal morphology of mandibular second molars in a population in western Guangxi / 口腔疾病防治

Objective@#To observe the root and root canal morphology of mandibular second molars in Western Guangxi by CBCT, to provide a reference for clinical diagnosis and treatment.@*Methods@#In total, 564 patients′ 1 128 mandibular second molars that satisfy the inclusion criteria were analyzed with a planmecaromexis CBCT machine and its own image analysis software. The patients′ gender, age and ethnic differences in the root and canal morphology and the symmetry of the bilateral root and canal were statistically analyzed. @*Results@# Among the 1 128 mandibular second molars, 662 were the Zhuang ethnic group and 384 were the Han ethnic group, and 82 were other ethnic groups; the double root type and C-shaped root type accounted for a relatively high proportion: 73.94% and 24.47%, respectively. The detection rates of the double root type were higher in males than in females (P < 0.05); the detection rates of the C-shaped root type were higher in females than in males (P <0.05); the root type of the teeth was mainly double-rooted in the Zhuang ethnic group (P<0.01). The incidence of type IV in the mesial root of the double root type mandibular second molar was the highest (P < 0.01), and the incidence of type I in the distal root was the highest (P < 0.01). The C-shaped root canal is more continuous at the mouth of the root canal, more downward corresponds to a worse continuity: in three different levels of root canal orifice, root middle and root apex, the root canal orifice is dominated by the C1 type, and both root middle and root apex are mainly C3-type (P < 0.01). The difference in symmetry of bilateral roots and root canals was statistically significant among different gender groups, age groups, and ethnic groups (P < 0.05): there were more males than females, the results in the 18-35-year-old group and the Zhuang ethnic group were higher.@*Conclusion@# The root and root canal morphology of mandibular second molars in western Guangxi people are complex and changeable. The roots are mainly double root type in the Han ethnic group and the Zhuang ethnic group. C-shaped roots are also common. The detection rate of C-shaped roots in the Zhuang ethnic group was higher, and the symmetry rate of bilateral roots and that of bilateral root canals was higher in the Zhuang ethnic group than in the Han ethnic group.

A Cone-Beam Computed Tomography Study on the Morphometry of the Mandibular Molars and Their Relative Root Lengths to the Mandibular Height

@#The first, second and third mandibular molars (M1, M2, M3) show variations in the number of cusps and some distinction in size, occlusal design, and the relative lengths and number of roots. However, there are also genetic and racial related variations within them. This study determined the tooth length and related root-to-crown ratio (RCR), and root morphology variations in M1 and M2. We also determined the root length relative to the mandibular height of these teeth. Sixty-one conebeam computed tomography (CBCT) images of patients who had a good set of lower teeth with no sign of mandibular pathology or defect were included. Relevant measurements were made along the axes of the mesial and distal roots of these mandibular molars. The measurements obtained were used to calculate RCR and root-to-mandible (R/M) ratio. The crowns of 226 teeth and 465 roots were reviewed in 61 CBCTs of Malay patients. M1 and M2 were 19.41 mm and 18.15 mm long. The respective anatomical RCR and clinical RCR were 1.90 and 1.59 for M1, and 1.86 and 1.60 for M2. Thirteen molars (5.8%) presented with three roots, with twice the number affecting M1 than M2. More M1 (4.3%) had C-shaped morphology than M2 (1.8%). The R/M ratio at M1 was 42.32% and, at M2 this was 43.94 %. In summary, the morphometric measurements of M1 and M2 in Malay were established. These teeth did not have a high prevalence of supernumerary roots, but there is a high prevalence of C-shaped morphology in M1.

Cone-beam computed tomography study of C-shaped root canal of mandibular premolars / 口腔疾病防治

Objective@#To investigate the incidence and morphology of C-shaped root canals in mandibular premolars by cone-beam computed tomography (CBCT) imaging, which provides a reference for clinical diagnosis and treatment.@*Methods @#The CBCT scanning data of 964 mandibular first premolars and 907 mandibular second premolars in 508 cases were collected, and the root canal morphology, incidence of C-shaped root canals, bilateral symmetry and location of radicular grooves were analyzed.@*Results@#The incidence of C-shaped root canals in mandibular first premolars was 4.1% and that in mandibular second premolars was 0.6%. The incidence of C-shaped root canals of mandibular first premolars was significantly higher than that of mandibular second premolars (χ2=25.775, P < 0.001). The symmetrical ratio of C-shaped root canals in the mandibular first premolars was 29%. There were no symmetrical C-shaped root canals in the mandibular second premolars. There were significant differences in the distribution of the C-shaped root canal configuration in the root canal (P < 0.001). The C-shaped configuration mainly existed in the middle axial and apical level of the mandibular premolars. The C2 type was more common. No C-shape was found in the coronal level of the mandibular premolars. Vertucci I single tube type was the most common type of root canal for the mandibular premolars included in this study; the incidences were 81.7% and 98.3% for the mandibular first and second premolars, respectively, and the difference was statistically significant (χ2=140.544, P < 0.001). The other root canal types of mandibular first premolars were more than those of mandibular second premolars. The incidences of Vertucci Ⅱ, Ⅲ, Ⅳ, and Ⅴ and C-shaped root canals in mandibular first premolars were significantly higher than those in mandibular second premolars. C-shaped root canal mandibular premolars had radicular grooves, and most of them were located at the mesiolingual side.@*Conclusion@# The morphology of the C-shaped root canal in mandibular premolars was complicated. CBCT can provide direct and accurate imaging evidence for clinical diagnosis and treatment.

Prevalencia del Molar en C: estudio Transversal / Prevalence of C-Shaped Molar: cross-sectional Study

El objetivo fue evaluar mediante tomografía computarizada de haz cónico (CBCT), la prevalencia y tipología de conductos en C en molares inferiores. Se analizaron 422 CBCT y 1105 molares inferiores de pacientes de ambos géneros, mayores de 10 años, obtenidas en 2018. Variables registradas: género, número de pieza, y tipología, según clasificación anatómica de Fan, en los tres tercios. Se observaron cortes coronario, medio y apical. Se compararon frecuencias observadas con frecuencias esperadas bajo suposición de independencia, se utilizó prueba de bondad de ajuste de Chi-cuadrado. La comparación de pares de porcentajes se realizó con prueba de diferencia de proporciones de Pearson Chi-cuadrado con p-valores simulados por prueba de Monte Carlo. Según los resultados, el molar en C no se distribuyó homogéneamente en las tomografías analizadas. Chi-cuadrado (X2=264.13 p-valor <2,2) (p-valor dos colas <0.001), tampoco se distribuyó homogéneamente en el total de piezas dentarias Chi-cuadrado (X2=1011,1, p-valor <2.2e-16) (p-valor dos colas <0.001). Las variables género y presencia de molar en C no se distribuyeron independientemente, Chi-cuadrado (X2=4.7367, p-valor =0,042) (p-valor<0,05). Las variables tipología y piezas dentarias no se distribuyeron independientemente, Pearson Chi-cuadrado (p-valor<0.001), al igual que las variables tipología y tercios, Pearson Chi-cuadrado (p-valor<0.001). En conclusión, la CBCT es valiosa para identificar estas anatomías. Haber encontrado mayor prevalencia de tipología I confirma lo establecido en la literatura. Tienen alta prevalencia en las poblaciones asiáticas pero en caucásica son poco frecuentes (3%) (AU)

Anatomical morphology of the root and root canal system of the second permanent molar in the Uygur people / 口腔疾病防治

Objective @#To study the anatomical characteristics of the root and root canal system of the mandibular second permanent molar in the Uygur people and provide a reference for clinical practice.@*Methods @#A total of 125 mandibular second permanent molars were extracted from Uygur patients in hospitals in the Xinjiang Uygur Autonomous Region. Three-dimensional reconstruction was performed after micro-CT scanning. The number of root canals, the root canal type (Weine classification and Fan′s C-shaped canal classification) and the occurrence of lateral accessory canals were observed.@*Results @#A sex difference was not detected in the root number or root form (χ2 = 1.277, P = 0.259). The incidence of 2-rooted molars was 70.4% (n = 88); type 2-1 canals were most common in the mesial root, with an incidence of 29.5%, followed by type 1-1 and 2-2 canals (each with an incidence of 26.1%), and the distal root mostly had a type 1-1 canal (96.6%). The incidence of single-rooted molars was 28.8%, and the frequency of C-shaped (n = 28) and non-C-shaped (n = 8) single-rooted molars was 22.4% and 6.4%, respectively. A three-rooted molar was detected in one case. The incidence of accessory canals was 65.2%.@*Conclusion @# Uygur mandibular second molars are mainly composed of two roots, and the incidence of a single root and root canal fusion is low (including C-shaped canals). Two-rooted molars frequently have two mesial canals and one distal canal.

Root canal morphology of the mandibular first premolars in a Yucatecan population using cone beam computed tomography: an in vitro study / Morfología del conducto radicular de primeros premolares mandibulares en una población yucateca usando tomografía computarizada: estudio in vitro

A successful endodontic treatment requires knowledge of the internal configuration of dental root canals. Most of the people who live in Yucatan are of Maya origin, characterized by a Mongoloid dental pattern. Because of their ethnicity, variations are expected. The purpose of this investigation is to assess the morphological characteristics and variability of this population. One hundred and five extracted first mandibular premolars of Mexican Maya population were analyzed; the sample was obtained from the Oral Surgery Clinic in the School of Dentistry at the Autonomous University of Yucatan with written informed consent. Analyses were performed by means of Cone Beam Computed Tomography. Vertucci´s Type I was the most prevalent configuration with 51.4 %, but 41 cases (39.1 %) presented a radicular groove and a C-shaped canal configuration. Overall, we documented 1, 2, 3, and 4 root canals. Mandibular first premolars are very variable in the Yucatecan population. The variability and frequency of C-shape is similar to mandibular second molars confirming the importance of the ethnic background for the endodontic treatments.

El éxito en el tratamiento endodóntico requiere el conocimiento profundo de la configuración interna del sistema de conductos radiculares. La mayoría de las personas que viven en Yucatán son de origen Maya y poseen el patron dental Mongoloide; por lo tanto, se esperan variaciones debido a su etnicidad. El propósito de esta investigación fue evaluar las características morfológicas y la variabilidad del conducto radicular en la población yucateca. Se analizaron ciento cinco primeros premolars mandibulares extraídos de pacientes provenientes de una muestra Maya mexicana; la muestra fue obtenida de la Clínica de Cirugía Oral de la Facultad de Odontología de la Universidad Autónoma de Yucatán. Con consentimiendo informado escrito. Se utilizaron Tomografías Computarizadas para el análisis de la muestra. La configuración más prevalente fue la Tipo I de Vertucci con 51,4 %. Sin embargo, 41 de 105 casos (39,1 %) presentaron un surco radicular y la configuración en forma de "C". Se documentaron casos con 1, 2, 3 y 4 conductos radiculares. Los primeros premolares mandibulares de la población Yucateca son muy variables. La variabilidad y frecuencia de conductos en forma de "C" concuerda con estudios realizados en segundos molars mandibulares en esta zona confirmando la importancia del origen étnico de las poblaciones para los tratamientos endodónticos.

Mandibular first molar with C-shaped root canal system: a two-case report / 华西口腔医学杂志

The root and canal anatomy of the mandibular first molar is highly complicated. A mandibular first molar with a C-shaped root canal system is rare. This article describes two different cases of this system. Case 1 has a complete C-shaped fused root. The root canal is characterized by a mesial lingual root canal and a C-shaped fused root canal. Case 2 has a C-shaped fused root in the buccal region and a distal lingual root. The root canal is characterized by a type Ⅱ-Ⅰroot canal in the buccal region and a distal lingual root canal.

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

OBJECTIVES: The purpose of this study was to investigate the C-shaped root canal anatomy of mandibular second molars in a Korean population. MATERIALS AND METHODS: A 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. RESULTS: Of 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. CONCLUSIONS: There 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.

Diagnóstico de conducto radicular en C en segundos molares mandibulares mediante la evidencia del ángulo obtenido: estudio piloto de validación / Diagnosis of C-shaped root canals in mandibular second molars through the evidence of the obtained angle: a pilot validation study

Antecedentes: El estándar dorado para diagnosticar segundos molarescon conducto radicular en C antes del inicio de un tratamiento endodóntico restaurador es la tomografía cone beam. La difi cultad para accedera los servicios tomográfi cos y su baja distribución en los consultorios odontológicos nos han llevado a diseñar una técnica alternativa enradiografías panorámicas nombrada «evidencia del ángulo obtenido¼(EAO). Objetivo: El objetivo de este trabajo fue crear un punto de cortey estimar la precisión diagnóstica del mismo mediante un estudio pilotocuyo resultado será utilizado en una futura investigación de validación de pruebas diagnósticas...

Background: The gold standard to diagnose second molars withC-shaped root canals prior to beginning an endodontic and restorative treatment is cone-beam tomography. Tomographic services are hard to access and have a low distribution in dental clinics this has led usto design an alternative technique in panoramic radiographs named«evidence of the obtained angle¼ (EAO). Objective: The aim of thisstudy was to create a breakpoint and estimate its diagnostic accuracy through a pilot study; its results will be used in a future investigation of validation of diagnostic tests...

Clinical observation of the effects of CAD/CAM glass-ceramic onlay in the restoration of mandibular second molar / 实用口腔医学杂志

Objective:To evaluate the clinical effects of CAD/CAM glass-ceramic onlays in the restoration of mandibular second molar with distal caries.Methods:56 endodontically treated molars were restored with CAD/CAM glass-ceramic onlays after one-visit root canal treatment.The effects were evaluated by one experienced clinicians in accordanced with the modified USPHS-Criteria at baseline and after 6,12 18 and 24 months.Results:All teeth were completed 2-year-follow-up.Satisfactory effects were observed in retention,marginal adaptation,color match,the secondary caries and adjacency relation.Failure in 3 cases were noted.2 onlays were extracted and 1 fractured.Conclusion:CAD/CAM glass-ceramic onlays is an effective treatment in the restoration of permanent molars with serious caries.

Construction of C-shaped cartilage with electrospun gelatin/polycaprolactone nanofibrous membranes and 3D printed supporter / 上海交通大学学报（医学版）

Objective·To construct C-shaped cartilage rings by rabbit auricular cartilage-derived chondrocytes combing with both electrospun gelatin/ polycaprolactone(GT/PCL) nanofibrous membranes and 3D printed supporters for repairing tracheal cartilage defects.Methods·Primary chondrocytes were isolated from rabbit auricular cartilage with methods of trypsin enzyme digestion and collagenase enzyme digestion.After proliferation in vitro,the chondrocytes of passage 2 were harvested for further experiments.Ultrafine composite fibers of GT/PCL were fabricated via electrospinning.The electrospun GT/PCL membranes were tailored into rectangle shape,the length of which is 12 cm and the width is 2.5 cm.Chondrocytes were seeded on membrane at a density of 1 × 108 cells/mL.Then the membrane were rolled onto a 3D printed supporter of poly(DL-lactide-ε-caprolactone) (PLCL) material to construct a C-shaped cartilage-like complex.After 8 weeks of subcutaneous incubation in vivo,gross inspection and paraffin section staining were applied for evaluation.Results·After 8 weeks of culture in vivo,mature cartilage-like tissue were formed with open-cylindrical bellow appearance and pecific mechanical property.C-shaped rings arranged at regular intervals on the inner surface of tissue,which were similar to the normal structure of tracheal cartilages.Histological and immunohistological staining showed a large number of typical lacunar structures and extracellular matrix secretions.Conclusion·It is feasible to construct tissue engineered C-shaped cartilage tissue by combing chondrocytes with GT/PCL membrane and 3D printed PLCL supporter for tracheal cartilage repair.

Endodontic Management of Variants of C-Shaped Canal: Case Series

A thorough knowledge of the root canal morphology is required for successful endodontic therapy. One of the most important anatomic variations is the C-shaped configuration of the root canal system. The presence of high incidence of transverse anastomoses, lateral canals, and apical deltas makes it difficult to clean and seal the root canal system in these teeth and may complicate endodontic interventions. Meticulous mechanical and chemical debridement of the canal space with additional efforts is essential for complete elimination of pulpal pathology in the anatomical irregularities. Obturation of the canal space also requires special attention as obtaining a three dimensional fill of a C-shaped canal may prove to be a problem due to the various intricacies present within the root canal system. Hence, this case series presents various types of C-shaped canal morphologies of mandibular second molars and their management.

Healing outcomes of root canal treatment for C-shaped mandibular second molars: a retrospective analysis

OBJECTIVES: This study aimed to evaluate the healing rate of non-surgical endodontic treatment between C-shaped and non-C-shaped mandibular second molars. MATERIALS AND METHODS: Clinical records and radiological images of patients who had undergone endodontic treatment on mandibular second molars between 2007 and 2014 were screened. The periapical index scoring system was applied to compare healing outcomes. Information about preoperative and postoperative factors as well as the demographic data of the patients was acquired and evaluated using chi-square and multinomial logistic regression tests. RESULTS: The total healing rate was 68.4%. Healing rates for the mandibular second molar were 70.9% in C-shaped canals (n = 79) and 66.6% in non-C-shaped ones (n = 117). The difference was not statistically significant. CONCLUSIONS: The presence of a C-shaped canal in the mandibular second molar did not have a significantly negative effect on healing after treatment. Instead, proper pulpal diagnosis and final restoration were indicated as having significantly greater influence on the healing outcomes of C-shaped and non-C-shaped canals, respectively.

Endodontic treatment of a C-shaped mandibular second premolar with four root canals and three apical foramina: a case report

This case report describes a unique C-shaped mandibular second premolar with four canals and three apical foramina and its endodontic management with the aid of cone-beam computer tomography (CBCT). C-shaped root canal morphology with four canals was identified under a dental operating microscope. A CBCT scan was taken to evaluate the aberrant root canal anatomy and devise a better instrumentation strategy based on the anatomy. All canals were instrumented to have a 0.05 taper using 1.0 mm step-back filing with appropriate apical sizes determined from the CBCT scan images and filled using a warm vertical compaction technique. A C-shaped mandibular second premolar with multiple canals is an anatomically rare case for clinicians, yet its endodontic treatment may require a careful instrumentation strategy due to the difficulty in disinfecting the canals in the thin root area without compromising the root structure.

Analysis of C-shaped root canal configuration in maxillary molars in a Korean population using cone-beam computed tomography

OBJECTIVES: The 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 METHODS: Digitized 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. RESULTS: Root 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). CONCLUSIONS: In 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.

Analysis of C-shaped root canal configuration in maxillary molars in a Korean population using cone-beam computed tomography

OBJECTIVES: The 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 METHODS: Digitized 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. RESULTS: Root 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). CONCLUSIONS: In 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.