Root Canal Treatment of Mandibular First Premolar with 3 Canals: A Case Report

SUMMARY: The mandibular first premolar is commonly a single-rooted tooth with occasional presentation of radicular variations. This tooth usually has one root with only one canal (97.9 %). Presence of three canals is very rare. Anomalies may appear during odontogenesis which can lead to anatomical variations in teeth. Similarly, these variations may be associated with characteristics that can be attributed to specific population groups. Due to their low frequency, these additional canals can easily be missed. For this reason, a meticulous knowledge of tooth morphology and their possible anatomical variations are necessary, and the presence of extra roots and canals should be always considered before initiation of root canal treatment. Additionally, different radiographs and appropriated access cavity preparation is needed to ensure a success endodontic treatment. This article reports a diagnosis and endodontic treatment of a mandibular first premolar with three canals.

El primer premolar mandibular suele ser un diente unirradicular con presentación ocasional de variaciones radiculares. Este diente suele tener una raíz con un solo conducto (97,9 %). La presencia de tres canales es muy rara. Durante la odontogénesis pueden aparecer anomalías que pueden provocar variaciones anatómicas en los dientes. De manera similar, estas variaciones pueden estar asociadas con características que pueden atribuirse a grupos de población específicos. Debido a su baja frecuencia, estos canales adicionales pueden pasar desapercibidos fácilmente. Por esta razón, es necesario un conocimiento meticuloso de la morfología dental y sus posibles variaciones anatómicas, y siempre se debe considerar la presencia de raíces y conductos adicionales antes de iniciar el tratamiento de conducto. Además, se necesitan diferentes radiografías y una preparación adecuada de la cavidad de acceso para garantizar un tratamiento de endodoncia exitoso. Este artículo reporta un diagnóstico y tratamiento endodóntico de un primer premolar mandibular con tres canales.

Quality analysis of four filling techniques in ovoid root canals prepared with M® instruments

Aims: This study aimed to assess the quality of various filling techniques in ovoid root canals prepared using M® instruments. Materials and Methods: Sixty ovoid root canals underwent endodontic treatment with M® instruments and were subsequently divided randomly into four experimental groups, each employing a different obturation technique: TU - single cone; TL - active lateral condensation; TH - Tagger hybrid; TS - Schilder technique. Digital radiographs were taken in both mesiodistal and buccolingual directions to examine the filled teeth. The percentage of filling material and empty spaces was quantified using Photoshop® software. Data were subjected to statistical analysis using the one-way ANOVA test and T test (? = 0.05). Results: In the TL and TS groups, there was a significantly lower average percentage of unfilled spaces compared to the TU and TH groups (P<0.0001). When analyzing the radiographic directions, the mesiodistal view exhibited the highest mean percentage of unfilled spaces, with differences in filling quality observed only in the TU and TL groups. Conclusions: Active lateral condensation and Schilder techniques demonstrated superior performance in achieving effective filling of ovoid root canals.

Comparación de la microfiltración apical de cuatro tipos de cementos endodónticos: Endofill, mtaFillapex, Adseal y Roeko Seal / Comparison of the Apical Microleakage of Four Types Of Endodontic Cements: Endofill, mta Fillapex, Adseal and Roeko Seal / Comparação da microinfiltração apical de quatro tipos de cimentos endodônticos: Endofill, mta Fillapex, Adseal e Roeko seal

Introducción: La microfiltración apical es uno de los principales causantes de fracasos endodónticos donde hay invasión de bacterias y líquidos periapicales a la parte interna del conducto radicular y material de relleno. Materiales y Métodos: La muestra estuvo conformada por 60 dientes premolares unirradiculares que fueron seccionados en la unión amelocementaria, la instrumentación biomecánica se realizó con técnica rotatoria e irrigación con hipoclorito de sodio al 5.25% y EDTA 17%, se dividió aleatoriamente en 4 grupos (n=15) para cada tipo de cemento, la obturación se realizó con la técnica de condensación lateral, a nivel coronal se obturó con Ionómero vidrio base y resina, se colocaron en una incubadora a 37° sumergidos en NaCL 0.9% por 5 días hasta el fraguado de los cementos, para observar la microfiltración se utilizó el método filtración de tinta china y la diafanización con la técnica de Robertson. Las medidas de microfiltración apical se observaron utilizando el Estereomicroscopio. Resultados: El valor promedio fue menor para el cemento Adseal 0,33mm, seguido por los cementos Fillapex 0,87mm, Roeko seal 1,00mm y Endofill 1,30mm respectivamente. Hubo diferencias estadísticamente significativas en la microfiltración apical de los cuatro cementos endodónticos (p=0.00) Conclusiones: El cemento Adseal presentó menor microfiltración en comparación a los cementos Fillapex, Roeko seal y Endofill.

Introduction: Apical microleakage is one of the main causes of endodontic failure, either due to invasion of microorganisms or periapical fluids into the canal, and only the composition of the type of obturator cement favors its reduction. The objective of this research was to compare the apical microleakage of four types of endodontic cements Endofill, MTA Fillapex, Adseal and Roeko Seal. Materials and methods: The sample consisted of 60 single root premolar teeth that were sectioned at the cement- enamel junction, the biomechanical instrumentation was performed with a rotary technique and irrigation with sodium hypochlorite and edta, randomly divided into 4 groups (n = 15) for each type of cement, the obturation was performed with the lateral condensation technique, at the coronal level it was obturated with base glass ionomer and resin, they were placed in an incubator at 37° submerged in NaCL 0.9% for 5 days until setting. of the cements, to observe the microleakage the India ink filtration method was used and diaph-anization with the Robertson technique. Apical microleakage measurements were observed using the Stereomicroscope. Results: The average value was lower for the Adseal 0.33 mm cement, followed by the Fillapex 0.87 mm, Roeko Seal 1.00 mm and Endofill 1.30 mm cements respectively. There were sta-tistically significant differences in the apical microleakage of the four endodontic cements (p = 0.00) Conclusions: Adseal cement presented less microfiltration compared to Fillapex, Roeko Seal and Endofill cements

Introdução: a microinfiltração apical é uma das principais causas de falhas endodônticas onde há inva-são de microrganismos e líquidos periapicais ao interior do conducto e só a composição do tipo de cimento obturador favorece sua disminuição. O objetivo desta pesquisa foi comparar a microinfiltração apical de quatro tipos de cimentos endodônticos Endofill, MTA Fillapex, Adseal e Roeko Seal. Materiais e métodos: a amostra foi composta por 60 dentes pré-molares uniradiculares que foram seccionados na junção amelocementária. A instrumentação biomecânica foi realizada com técnica rotatória e irrigação com hipoclorito e edta, sendo dividida aleatoriamente em 4 grupos (n = 15) para cada tipo de cimento. A obturação foi realizada pela técnica de condensação lateral, no nível coronal foi obturado com base de ionômero de vidro e resina, foram colocados em incubadora a 37° submersos em NaCl 0,9% por 5 dias até a pega dos cimentos. Para observar a microfiltração utilizou-se o método de filtração em tinta nan-quim e diafanização pela técnica de Robertson. As medidas de microinfiltração apical foram observadas utilizando o estereomicroscópio. Resultados: o valor médio foi menor para o cimento Adseal (0,33 mm), seguido pelos cimentos Fillapex (0,87 mm), Roeko Seal (1,00 mm) e Endofill (1,30 mm), respectivamente. Houve diferenças estatisticamente significativas na microinfiltração apical dos quatro cimentos endo-dônticos (p = 0,00). Conclusões: o cimento Adseal apresentou menor microinfiltração comparado aos cimentos Fillapex, Roeko seal e Endofill.

Morphology of the Second Mesiobuccal Canal in the Maxillary Second Molar / Morfología del Segundo Canal Mesiovestibular en el Segundo Molar Maxilar

SUMMARY: Failure to locate a complete canal system affects the prognosis of root canal treatment. A missed root canal is one of the most common reasons for failed root canal treatment. The prevalence of the second mesiobuccal canal in the maxillary second molar is relatively high and has a variety of configurations. Therefore, knowledge of its morphology is required in clinical endodontics. This review presented the canal in terms of its prevalence, classification, anatomical features, and the method for locating the second mesiobuccal canal in the maxillary second molar. Root canal treatment requires knowledge of tooth morphology, appropriate access preparation, and a thorough examination of the tooth's interior. Thus, clinicians should carefully employ various methods for assessing the anatomy of the entire root canal system to prevent failure in locating the second mesiobuccal canal. This canal can be located by modifying the access cavity design and utilizing specific instruments to improve the second mesiobuccal canal system visualization.

La falta de localización de un sistema completo de canal afecta el pronóstico del tratamiento de éste. La omisión de un tratamiento de canal es uno de los motivos más frecuentes por las que el tratamiento de canal fracasa. La prevalencia del segundo canal mesiovestibular en el segundo molar superior es relativamente alta y tiene una variedad de configuraciones. Por tanto, el conocimiento de su morfología es necesario en endodoncia clínica. Esta revisión presentó el canal en términos de su prevalencia, clasificación, características anatómicas y el método para localizar el segundo canal mesiovestibular en el segundo molar superior. El tratamiento de canal requiere conocimiento de la morfología del diente, una preparación adecuada del acceso y un examen exhaustivo del interior del diente. Por lo tanto, los dentistas deben emplear cuidadosamente varios métodos para evaluar la anatomía de todo el sistema de canales radiculares para evitar fallas en la localización del segundo canal mesiovestibular. Este canal se puede localizar modificando el diseño de la cavidad de acceso y utilizando instrumentos específicos para mejorar la visualización del sistema del segundo canal mesiovestibular.

Descripción de la Morfología del Sistema de Canales Radiculares en Premolares Maxilares Mediante Tomografía Computarizada Cone Beam en una Población Chilena

El tratamiento endodóntico requiere detallados conocimientos sobre la morfología radicular. En premolares maxilares, se ha reportado variabilidad en el número de raíces y morfología del sistema de canales radiculares (SCR). La causa más frecuente de fracaso endodóntico son los conductos no tratados. Por lo tanto, una mejor compresión de la morfología del SCR y sus variaciones es crucial para el tratamiento endodóntico. El objetivo de esta investigación fue describir la frecuencia del número de raíces y morfología del SCR en premolares maxilares, mediante exámenes de tomografía computarizada Cone Beam (CBCT) en una población chilena. Se realizó un estudio observacional descriptivo de corte transversal donde se observó la morfología del sistema de canales radiculares de primeros y segundos premolares maxilares a través de exámenes CBCT, agrupándolos de acuerdo con la Clasificación de Vertucci. Se observaron 228 exámenes CBCT, donde se incluyeron 268 primeros premolares superiores y 233 segundos premolares maxilares. Se determinó que en primeros premolares maxilares un 56,3 % presentó una raíz, un 43,3 %, siendo más frecuente una morfología del SCR tipo IV. En los segundos premolares maxilares, se determinó la presencia de una raíz en el 95,7 % de los casos, siendo más frecuente una morfología del SCR tipo I. Estos resultados pueden ser de interés para endodoncistas, ya que conocer la morfología del SCR de premolares maxilares permite mejorar la planificación de la terapia endodóntica realizada en estos dientes.

Endodontic treatment requires detailed knowledge of root morphology. In maxillary premolars, variability in root number and root canal system (RCS) morphology has been reported. The most frequent cause of endodontic failure is non treated canals. Therefore, a better understanding of RCS morphology and its variations is crucial for endodontic treatment. The aim of this research was to describe the frequency of root number and SCR morphology in maxillary premolars, by means of Cone Beam Computed Tomography (CBCT) examinations in a Chilean population. A cross-sectional descriptive observational study was carried out in which the morphology of the root canal system of maxillary first and second premolars was observed through CBCT examinations, grouping them according to the Vertucci Classification. A total of 228 CBCT examinations were observed, which included 268 upper first premolars and 233 maxillary second premolars. It was determined that in maxillary first premolars 56.3 % presented one root, 43.3 %, being more frequent a SCR type IV morphology. In maxillary second premolars, the presence of one root was determined in 95.7 % of the cases, being more frequent a SCR type I morphology. These results may be of interest to endodontists, since knowing the morphology of the RCS of maxillary premolars allows improving the planning of endodontic therapy performed on these teeth.

Microcomputed-Tomographic Analysis of the Root Canal Morphology of the Mandibular First Molars in a Malaysian Subpopulation Using Two Classification Systems / Análisis por Tomografía Microcomputada de la Morfología del Conducto Radicular de los Primeros Molares Mandibulares en una Subpoblación de Malasia Utilizando dos Sistemas de Clasificación

SUMMARY: This work investigated the morphology of the root canal system of the mandibular first molar in a Malaysian subpopulation. Using micro-computed tomography with an isotropic resolution of 22 µm, 140 mandibular first molars were scanned. MIMICS software was used for segmentation, 3-D reconstruction and analysis of the acquired images. The canal configuration was described using Vertucci [supported by the supplementary configurations proposed by Sert & Bayirli (2004)] and Ahmed et al. (2027), coding systems. The chi-square test was used to assess the association between qualitative variables. By non-considering intercanal communications, Vertucci types IV (17.1%) and I (76.4%) were the most frequently reported configurations in the mesial and distal roots, respectively. Of the reported configurations, 24.3% and 4.3% were non-classifiable by Vertucci system in the mesial and distal roots, respectively. Up to 63.6% and 9.3% of the reported configurations were non- classifiable, and type I was the most frequent when considering intercanal communications (7.1% and 76.4% in the mesial and distal roots, respectively). According to Ahmed et al., system, almost half of the sample had more than four digits (47.9%), followed by the 3-digits category (20.71%). In both systems, a significant association was found between the canal configuration and the root type (p<0.001). The mandibular first molar of this Malaysian subpopulation demonstrated a wide range of root canal morphology. When compared to the Vertucci system, the system developed by Ahmed et al., successfully classified all molars configurations despite their level of complexity. The complex canal anatomy of mandibular first molars in this subpopulation warrants special attention during root canal treatment procedures.

En este trabajo se investigó la morfología del sistema de conductos radiculares del primer molar mandibular en una subpoblación de Malasia. Utilizando tomografía microcomputada con una resolución isotrópica de 22 µm, se escanearon 140 primeros molares mandibulares. Se utilizó el software MIMICS para segmentar (enmascarar), reconstruir en 3D, visualizar y analizar las imágenes adquiridas. La configuración del canal se describió utilizando Vertucci respaldado por las configuraciones complementarias propuestas por Sert & Bayirli (2004)] y Ahmed et al. (2017, 2020), sistemas de codificación. Se utilizó la prueba de chi-cuadrado para evaluar la asociación entre variables cualitativas. Sin considerar las comunicaciones intercanales, los tipos Vertucci IV (17,1%) y I (76,4%) fueron las configuraciones reportadas con mayor frecuencia en las raíces mesiales y distales, respectivamente. De las configuraciones reportadas, el 24,3 % y el 4,3 % fueron no clasificables por el sistema de Vertucci en las raíces mesial y distal, respectivamente. Hasta el 63,6 % y el 9,3 % de las configuraciones reportadas fueron no clasificables, siendo la tipo I la más frecuente al considerar las comunicaciones intercanales (7,1 % y 76,4 % en las raíces mesiales y distales, respectivamente). Según Ahmed et al. (2017, 2020) en el sistema, casi la mitad de la muestra tenía más de cuatro dígitos (47,9 %), seguido por la categoría de 3 dígitos (20,71 %). En ambos sistemas se encontró una asociación significativa entre la configuración del canal y el tipo de raíz (p<0,001). El primer molar mandibular de esta subpoblación de Malasia demostró una amplia gama morfológica del conducto radicular. En comparación con el sistema Vertucci, el sistema desarrollado por Ahmed et al. (2017, 2020) clasificaron con éxito todas las configuraciones de los molares a pesar de su nivel de complejidad. La compleja anatomía del canal de los primeros molares mandibulares en esta subpoblación merece una atención especial durante los procedimientos de tratamiento de conducto.

Micro-CT evaluation of the presence of voids in endodontic obturation / Evaluación microtomográfica de la presencia de vacíos en la obturación endodóntica

ABSTRACT Identifying the presence, size, type and location of voids in an endodontic obturation is of great clinical importance because it enables evaluation of the three-dimensionality of the sealing techniques, which can be related to the success of the endodontic treatment. Aim To analyze by micro-CT the presence of voids in lower single-rooted premolar root canal obturations prepared using the single cone and ultrasound vibration technique. Materials and methods Twenty extracted single-rooted lower premolars were selected, and the root canal prepared surgically and chemically. In GROUP 1 - Without Vibration, the canal was obturated with a single cone and bioceramic, without applying vibration. In GROUP 2 - With Vibration, the gutta-percha cone inside the root canal was held with a cotton plier to which ultrasound vibration was applied for 3 periods of 3 seconds each. A micro-CT scanner was used to acquire and reconstruct images for analysis. Results No significant difference was found between obturation techniques, though there were differences between thirds, with the cervical third having a higher percentage of voids than the middle and apical thirds. Conclusions The results suggest that the volume of closed, open and total voids does not differ between treatments with and without ultrasound vibration. In the cervical third, the highest volume of voids was related to oval geometry in the teeth evaluated.

RESUMEN La presencia de vacíos en la obturación endodóntica, su tamaño y el tipo y localización tiene gran importancia clínica ya que permite evaluar la tridimensionalidad de las técnicas de sellado y relacionarlas con el éxito del tratamiento endodóntico. Objetivo analizar mediante microtomografía la presencia de vacíos en la obturación del conducto radicular de premolares inferiores unirradiculares, utilizando la técnica de cono único y vibración con ultrasonido. Materiales y Método se seleccionaron 20 premolares inferiores unirradiculares a los que se les realizó la preparación quirúrgica y química del conducto radicular. Se realizó la obturación con cono único y biocerámico GRUPO 1- sin vibración. En el GRUPO 2 - con vibración se aplicó vibración por ultrasonido, se tomó del cono de gutapercha colocado en el interior del conducto con pinza de algodón que fue vibrada durante 3 períodos de 3 segundos cada uno. Las mismas fueron adquiridas y reconstruidas en un microtomógrafo para posterior análisis de las imágenes obtenidas. Resultados No se evidenciaron diferencias significativas entre ambas técnicas de obturación comparadas, pero si entre los tercios analizados, siendo el cervical el que mayor porcentaje de vacíos presenta en comparación a los cortes correspondientes al tercio medio y apical. Conclusiones Los resultados sugieren que el volumen de vacíos cerrados, abiertos y total no varía en los tratamientos donde se aplica vibración por ultrasonido. En el tercio cervical, el mayor volumen de vacíos se relaciona con la geometría oval que presentaron las piezas dentarias evaluadas en este estudio.

Efficacy of WaveOne Gold and ProDesign RT systems in removing filling material: a micro-CT analysis / Eficácia dos sistemas WaveOne Gold e ProDesign RT na remopáo material obturador: uma análise micro-CT

ABSTRACT The remaining filling material after retreatment can harbor bacteria and organic tissues that can influence the outcome of the therapy. Aim The aim of this study was to evalúate, by micro-CT, the amount of filling material remaining in the root canal after its removal using WaveOne Gold or ProDesign RT. Material and Method Forty human mandibular canines were instrumented with the ProTaper Next system up to the X2 instrument (25.06) and filled with gutta-percha cones and AHPlus. Teeth were divided into 2 groups (n=20): WaveOne Gold 25.07 (WOG) and ProDesign RT 25.08 (PRT) for filling removal, after which they were scanned in a micro-CT device to quantify the volume of remaining filling material. The data were subjected to log 10 transformation, Student 's t-test was performed to account for multiple observationsper sample, significance was set at 5%. Results Student 's t-test showed that there was no difference between the two systems regarding the volume of remaining filling material in the thirds: apical (p = 0.392), middle (p = 0.065), or cervical (p = 0.918). Conclusión Remaining filling material was present in all groups and both systems were similar in removing root filling material in mandibular canines.

RESUMO A permanencia de material obturador após o retratamento pode abrigar bactérias e tecidos orgánicos que podem influenciar o resultado da terapia. Objetivo O objetivo deste estudo foi avaliar, por micro-CT, a quantidade de material obturador remanescente no canal radicular após a desobturagdo com WaveOne Gold e ProDesign RT. Material e Método Quarenta caninos inferiores humanos foram instrumentados com o sistema ProTaper Next até o instrumento X2 (25.06) e obturados com cones de guta-percha e AHPlus. Os dentes foram divididos em dois grupos (n=20): WaveOne Gold 25.07 (WOG) e ProDesign RT 25.08 (PRT) e escaneados em micro-CT para quantificagdo do volume de material obturador remanescente. Os dados foram submetidos á transformando log10, o teste t de Student foi realizado para contabilizar múltiplas observagoes por amostra, a significáncia foi fixada em 5%. Resultados O teste t de Student mostrou que ndo houve diferenga no volume de material obturador remanescente entre os dois sistemas nos tergos: apical (p = 0,392), médio (p = 0,065) ou cervical (p = 0,918). Conclusao O material obturador remanescente estavapresente em todos os grupos e ambos os sistemas foram semelhantes na remogdo do material obturador radicular nos caninos inferiores.

Nivel de ansiedad y dolor dental en diferentes momentos en el tratamiento de conductos durante la pandemia por COVID-19 / Level of anxiety and dental pain at different times in root canal treatment during the COVID-19 pandemic / Nível de ansiedade e dor dentária em diferentes momentos do tratamento de canal durante a pandemia de COVID-19

RESUMEN Objetivo : Evaluar el nivel de ansiedad dental (AD) y dolor dental (DD) en diferentes momentos en el tratamiento de conductos durante la pandemia por COVID-19. Materiales y métodos : Estudio observacional, descriptivo y longitudinal. La muestra estuvo constituida por 68 participantes de la Clínica Estomatológica del Hospital Militar Central (HMC), que cumplieron con los criterios de inclusión y exclusión. El procedimiento consistió en el registro del nivel de AD y DD de los pacientes en distintos momentos del tratamiento de conductos mediante una escala visual analógica (EVA). Resultados : Antes del procedimiento, los participantes mostraron 3,66 ± 1,83 de AD y 4,54 ± 1,79 de DD; durante el procedimiento, obtuvieron valores de 3,13 ± 1,96 y 2,09 ± 1,39 de AD y 2,96 ± 1,57 y 1,82 ± 1,09 de DD; y al culminar el procedimiento, tuvieron 0,75 ± 0,74 de AD y 0,53 ± 0,72 de DD. Conclusiones : La AD y el DD estuvieron presentes antes de iniciar el tratamiento, pero, conforme se avanzaba con el procedimiento, sus niveles fueron disminuyendo.

ABSTRACT Objective : To evaluate the level of dental anxiety (DA) and dental pain (DD) at different times in root canal treatment during the COVID-19 pandemic. Materials and methods : Observational, descriptive, and longitudinal study. The sample consisted of 68 participants from the Stomatology Clinic of the Hospital Militar Central (HMC), who met the inclusion and exclusion criteria. The procedure consisted of recording the level of AD and DD of the patients at different times during root canal treatment using a visual analog scale (VAS). Results : Before the procedure, participants showed 3.66±1.83 of AD and 4.54±1.79 of DD; during the procedure, they obtained values of 3.13±1.96 and 2.09±1.39 of AD and 2.96±1.57 and 1.82±1.09 of DD; and at the end of the procedure, they had 0.75±0.74 of AD and 0.53±0.72 of DD. Conclusions : AD and DD were found to be present before starting treatment, but as the procedure progressed their levels decreased.

RESUMO Objetivo : avaliar o nível de ansiedade dentária (AD) e dor dentária (DD) em diferentes momentos do tratamento de canal durante a pandemia da COVID-19. Materiais e métodos : Estudo observacional, descritivo e longitudinal. A amostra foi composta por 68 participantes da Clínica de Estomatologia do Hospital Militar Central (HMC), que atenderam aos critérios de inclusão e exclusão. O procedimento consistiu em registar o nível de DA e DD dos pacientes em diferentes momentos durante o tratamento do canal radicular, utilizando uma escala visual analógica (EVA). Resultados : antes do procedimento, os participantes apresentavam 3,66±1,83 de DA e 4,54±1,79 de DD; durante o procedimento, obtiveram valores de 3,13±1,96 e 2,09±1,39 de DA e 2,96±1,57 e 1,82±1,09 de DD; e, no final do procedimento, apresentavam 0,75±0,74 de DA e 0,53±0,72 de DD. Conclusões : A DA e a DD estavam presentes antes do início do tratamento, mas à medida que o procedimento avançava, os seus níveis diminuíram.

Performance of calcium sulfate-based root canal sealers for deciduous teeth / 口腔疾病防治

Objective@#To investigate the physicochemical and biological properties of a new calcium sulfate-based root canal sealer for deciduous teeth containing calcium sulfate hemihydrate, barium sulfate, chlorhexidine acetate, and polyethylene glycol 400 (PEG 400).@*Methods@#This study was reviewed and approved by the Ethics Committee. The calcium sulfate hemihydrate and barium sulfate powders with different mass percentages were mixed with liquid PEG 400 at a powder-to-liquid ratio of 3∶1, and chlorhexidine acetate was added to a concentration of 0.2 mg/mL according to the volume of PEG 400. The above materials were mechanically ground at 250 r/min for 24 h to obtain a calcium sulfate-based root canal sealer for deciduous teeth. The sealer was classified into different groups according to mass percentages of components. The mass percentages of components were optimized by performing time, fluidity, and radiopacity experiments, and then the pH, mass loss in vitro, and microscopic morphology of the optimal sealer were evaluated. The antimicrobial properties of the sealer were evaluated by a bacterial-material cocultivation method. The cytocompatibility of the sealer was evaluated by a CCK-8 assay and cytomorphological staining, and its biocompatibility was evaluated by a subcutaneous tissue embedding assay.@*Results@#After optimization, mass percentage of calcium sulfate hemihydrate was 80 wt%, and the mass percentage of barium sulfate was 20 wt%. The flowability and radiopacity of the sealer were in accordance with international standards. The pH stabilized between 6-7. On the 7th and 14th days, the pH in the water group was significantly greater than that in the PBS group (P<0.001), although the pH in both groups gradually increased (P>0.05). In vitro degradation experiments, the mass loss of the sealer was approximately 15.17% during the preimmersion period, and rate of mass loss decreased after 3 weeks, reaching only approximately 8.33%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that the main component of the sealer after hydration was calcium sulfate dehydrate. In bacterial growth assays and cytological tests, the sealer showed significant inhibition of the growth of E. faecalis (P<0.001). After 1 and 4 days of culture, the cell viability in the 1∶10 and 1∶20 sealer extract dilution group was lower than that in the control group (P<0.05). On the 7th day, the 1∶20 sealer extract dilution had no significant effect on cell proliferation (P>0.05). Both the sealer group and the control group (Vitapex and zinc oxide eugenol) caused mild inflammatory reactions in tissue sections.@*Conclusion@#In this study, a new type of root canal sealer for deciduous teeth was designed based on calcium sulfate, which has good physicochemical properties and strong antibacterial properties and meets biocompatibility requirements. This study provides an idea for the development of a new type of root canal sealer for deciduous teeth.

Research progress on small biomolecule formulations for chemical disinfection of root canals / 口腔疾病防治

@#Successful treatment of endodontic and periapical diseases requires the elimination of bacteria and microbial biofilms from root canals. Currently, the most preferred irrigation method involves the delivery of sodium hypochlorite via the combination of a syringe and ultrasonic activation. Calcium hydroxide is the main choice for intracanal medicament between endodontic appointments and treatment. However, conventional chemical disinfection of root canals is controversial due to drug permeability and drug resistance. New small biomolecule formulations with high penetrability and bioremediatory capacity, including antimicrobial peptides such as M33D and LL-37, antisense RNA ASwalR/ASvicR and nanoparticles such as silver nanoparticles, mesoporous calcium-silicate nanoparticles and chitosan nanoparticles, have effective antibacterial and antibiofilm properties for use in root canal systems and dentinal tubules, thereby promoting the healing of apical lesions. However, the in vivo drug stability, biosafety, and clinical efficacy of small biomolecule formulations need further investigation. Future research will still focus on the improvement and combination of traditional drugs, as new small molecule formulations and ideal disinfectant drugs need to be developed. In the present paper, we reviewed the development of new antibacterial agents and application of small biomolecule formulations for chemical disinfection of infected root canals.

Comparative Analysis of Antimicrobial Efficacy of Electrolyzed Water with Sodium Hypochlorite Solution against Root Canal Pathogen: A Scoping Review

@#Electrolyzed water (EW) has been introduced as a surface disinfectant due to its antimicrobial properties without cytotoxic effects to oral tissues contrary to sodium hypochlorite (NaOCl), which is cytotoxic and can be detrimental if extruded beyond the root canal. This scoping review aimed to compare antimicrobial efficacy of EW with NaOCl on root canal pathogens and to assess effect of concentration and exposure time on antimicrobial efficacy. The review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews protocol guidelines. Electronic databases were searched for eligible articles published between 2011-2021 in PubMed, PLOS, Science Direct, and Google Scholar. Joanna Briggs Institute Critical Appraisal Tool was used for quality assessment. Of the 784 articles recovered, only 8 were eligible based on inclusion criteria. The included studies assessed several types of EW, which showed antimicrobial potential against E. faecalis in vitro in suspension and biofilm forms. EW demonstrated antimicrobial efficacy comparable with NaOCl in 5 of 8 studies. Only one study found that higher concentration and exposure time increased antimicrobial efficacy of EW; other studies showed otherwise. It can be concluded that EW can be a potential alternative solution for NaOCl as an endodontic irrigant.

Sealing effect of GuttaFlow2 in curved root canals / 北京大学学报(医学版)

Objective:To evaluate the sealing ability of GuttaFlow2 single cone obturation in curved root canals.Methods:(1)Slight,moderate and severe curved 3D printed root canals were made.After instrumentation,these samples were randomly divided into 2 groups(n=10)according to different root canal filling techniques:GuttaFlow2 single cone group(GF2)and AH-Plus warm vertical compation group(WVC).All the samples were sectioned at 2 mm to apex(the apical of the root),4 mm,6 mm to apex(the middle of the root)and 8 mm to apex(the coronal of the root).The filling void areas were ob-served by stereomicroscope,and the percentages of void areas in each section were calculated by ImageJ 1.52a.(2)Forty-eight roots of extracted adult molars were selected.After instrumentation,they were randomly divided into 2 groups(n=8):GF2 group and WVC group.Before root canal filling,the sea-lers were mixed with Rhodamine B dye for visualization under confocal laser scanning microscope.All samples were sectioned at 2 mm to apex(the apical of the root),5 mm to apex(the middle of the root)and 8 mm to apex(the coronal of the root).Then,the percentages of sealer penetration into dentinal tu-bules in each section were calculated.Results:At the apical of the root,there were no obvious voids in slight,moderate and severe curved canals in the GF2 group and the WVC group.There was no signifi-cant difference between the two groups(P＞0.05).At the middle of the root,there was no significant difference in the percentages of void areas between the two filling methods,but at the coronal of the root,there were more voids in the slight curved root canal in the GF2 group than in the WVC group,and the difference was significant(P=0.009).The percentages of sealer penetration into dentinal tubules of slight,moderate and severe curved root canals in the GF2 group were 36.10％,55.80％,65.08％,re-spectively.And they were all higher than those in the WVC group(15.78％,20.70％,15.61％),re-spectively,the difference between the two groups was significant(P=0.001).At the middle of the root,the percentages of sealer penetration into dentinal tubules of slight and moderate curved root canals in GF2 group were also significantly higher than those in the WVC group(P=0.001).At the coronal of the root,there was no significant difference between the two groups(P＞0.05).Conclusion:Gutta-Flow2 filling technique has the same sealing effect on the root canal at the apical and middle of the root as the warm vertical technique,but has a better sealing effect on the dentin tubules,especially for severe curved root canal.

Root canal therapy of maxillary molars with atypical canals:A report of three cases / 北京大学学报(医学版)

Maxillary molar with three roots and 3 to 4 canals is a common occurrence.However,in addition to common root canal anatomy,there may be significant differences in the number,distribution,and morphological structure of root canals.The success of root canal treatment is dependent on ensuring that all the intricate details associated with it are meticulously followed.Failure to locate all canals could have a negative effect on the treatment as it may lead to initiation or continuation of periapical pathology.Missed canals were the main reason for patients reporting back for nonsurgical root canal retreatment.Moreover,the bacteria residing in such canals could also result in persistence of symptoms.Root canal anatomy is complex,and the recognition of anatomic variations could be a challenge for clinicians.This article presents three cases of endodontic management of maxillary molars with atypical canal morphology.In the three cases of this study,the patients underwent cone beam computed tomographic(CBCT)examination before root canal treatment.The CBCT images revealed that the maxillary molars in case 1 and case 2 had 5 canals.Case 1:2 mesiobuccal(MB,MB2),two distobuccal(DB and DB2),and one palatal canal.Case 2:2 mesiobuccal(MB,MB2),one distobuccal(DB),and two palatal canals(MP and DP).In case 3,CBCT scan slices showed that the maxillary first molar presented as a C-shaped root canal with a rare tooth anomaly of taurodontism.Although C-shaped root canals were most frequently seen in the mandibular second molar,they might also appear in maxillary molars.A literature search revealed only a few case reports of C-shaped root canal systems in maxillary molars.Case 3 described the fusion between mesiobuccal and palatal roots of the maxillary first molar,forming a C-shaped mesiopalatal root canal.The above cases suggest that endodontists should always be aware of aberrancies in root canal sys-tem apart from the knowledge of normal root canal anatomy.CBCT as a means of diagnosis can be helpful for identifying and managing these complex root canal systems.This case series also highlights the impor-tance of magnification and illumination.Through using an endodontic microscope,clinicians can identify root canals that are difficult to locate or overlooked with normal vision.A correct access opening is a most important step to locate and negotiate the orifices of root canals.The use of ultrasonic tips can refine the access cavity and allow controlled and delicate removal of calcifications and other interferences to the ca-nal orifices,thereby helping to locate the extra orifices.

Inhibitory effects of allicin effective component DATS on Enterococcus faecalis bofilm:An in vitro Study / 实用口腔医学杂志

Objective:To investigate the antibacterial efficacy of allicin effective component,dially trisulfide(DATS),on the biofilms of Enterococcus faecalis(E.faecalis)in vitro.Methods:60 healthy single root canal permanent teeth were selected.After cleaning and autoclaving,15 teeth without infection were used in the negative control group,45 teeth were contaminated by E.faecalis and incubated for 28 days as the infection models and devided into 3 groups(n=15)as below:DATS group,Calcium hydroxide group and positive(without antibacteria treatment)control group.The minial inhibition concentration(MIC)and minial bactericidal concentrition(MBC)of DATS on E.feacalis were studied with doubling diluting method.At the day 1,2 and 7 of the exprement,the 4 mg of root canal in-ner dentin powder,5 specimens of each group were sespectively transfered into sterile bottle containing 2 mL BHI broth and cultured at 37 ℃ 5％CO2 for 72 h,the turbitity of the upper layer of liquid of the culture was measured.Results:MIC and MBC(μg/mL)of DATS to E.feacalis was 2 560 and 5 120 repsectively.At the first day,turbidity in the DATS group was the lowest(P＜0.05).At the third day,turbidity showed no difference between DATS group and negative control group(P=0.454).At the 7th day,between calcium hydroxide and the negative control group,P＜0.05.Conclusion:DATS may suppress E.faecalis in the biofilm in vitro.

Influence of NIC X-FILE and DENCO Pre-Shaper nickel-titanium instruments on the shaping of simulated curved canals / 中国组织工程研究

BACKGROUND:Root canal preparation is a key step in root canal therapy.In recent years,with the rapid development of new nickel-titanium instruments,the results of root canal shaping ability have been significantly improved.However,the shaping abilities of different nickel-titanium instruments are also different.At present,there are few reports about the influence of the shaping ability of R-phase heat treatment NIC X-FILE and DENCO Pre-Shaper in simulated curved canals. OBJECTIVE:To compare the shaping effect of NIC X-FILE and DENCO Pre-Shaper nickel-titanium instruments in preparation for simulated curved canals. METHODS:Fifty simulated resin-curved canals were selected and randomly divided into two groups(n=25).NIC X-FILE and DENCO Pre-Shaper nickel-titanium files were used for root canal preparation.The root canal preparation time was recorded.Images of pre-and post-root canal preparation were taken.Image processing and analysis software were used to measure the amount of resin removed from the inner and outer walls of the root canal at each observation point.Statistical software was used to compare the root canal preparation time and centering ability of two kinds of mechanical nickel-titanium files. RESULTS AND CONCLUSION:(1)The average root canal preparation time was(1.58±0.02)minutes in the DENCO Pre-Shaper group and(2.22±0.03)minutes in the NIC X-FILE group.There was a significant difference between the two groups(P<0.05).(2)The amount of resin removed from the inner walls of the root canal of the DENCO Pre-Shaper group at 4,5,7,8,9,and 10 mm from the apical foramen was higher than that of the NIC X-FILE group(P<0.05).The amount of resin removed from the outer walls of the root canal of the DENCO Pre-Shaper group at 3,5,6,7,and 8 mm from the apical foramen was lower than that of the NIC X-FILE group(P<0.05).(3)At 2,4,5,6,7,8,and 9 mm away from apical foramen,the centering ability of the NIC X-FILE group was better than that of the DENCO Pre-Shaper group(P<0.05),and the centering ability of the NIC X-FILE group was the best at 4 mm away from apical foramen.(4)The results show that DENCO Pre-Shaper has higher mechanical efficiency than NIC X-FILE nickel-titanium root canal files.However,the centering ability of DENCO Pre-Shaper is inferior to NIC X-FILE nickel-titanium root canal files.

Intentional replantation for the treatment of a double-rooted maxillary lateral incisor with periodontal-endodontic lesions: a case report and literature review / 口腔疾病防治

Objective@#To investigate the clinical characteristics, diagnosis and treatment of severe combined periodontal-endodontic lesions in a double-rooted maxillary lateral incisor with a palatal radicular groove and to provide a reference for clinical diagnosis and treatment.@*Methods@#A patient with a double-rooted left maxillary lateral incisor with a palatal radicular groove and severe combined periodontal-endodontic lesions underwent complete root canal therapy and intentional replantation, and a retrospective analysis of the management of this type of patient was performed based on the literature.@*Results@#The 3-year follow-up examination revealed no discomfort, good healing of the upper left lateral incisor, no pathological loosening, and a palatal gingival sulcus was found at a depth of approximately 1 mm. Review of the literature showed that the prognosis of the affected tooth and the choice of treatment plan were correlated with the length and depth of extension of the lingual groove toward the root, the periodontal condition and the pulpal status of the affected tooth. For minor PRGs or for affected teeth with no loss of pulpal viability, flap surgery and odontoplasty can be used to avoid endodontic treatment or retreatment. For deep or long lingual grooves that result in significant loss of periodontal tissue, endodontic treatment, odontoplasty, or closure of the grooves and guided tissue regeneration are needed. In the case of PRGs with double root formation, the affected tooth can be preserved via root canal therapy, removal of the small root and filling with apical restorative material, and intentional replantation.@*Conclusion@#In cases of severe combined periodontal-endodontic lesions due to palatal radicular grooves occurring in double-rooted maxillary lateral incisors, clinical presentation and imaging can prevent missed diagnoses, and appropriate treatment should be based on the length and depth of lingual grooves extending toward the roots, periodontal conditions, and pulpal status of the affected teeth.

Clinical efficacy of pulpotomy in elderly patients / 中华老年医学杂志

Objective:To evaluate the clinical efficacy of pulpotomy in elderly patients with caries-related exposed pulp.Methods:A randomized controlled study was conducted at the Department of General Dentistry, Peking University Stomatology Hospital from October 2019 to March 2022.The study included 46 elderly patients with carious exposure, who were randomly divided into two groups: an experimental group with 22 cases and a control group with 24 cases.The teeth in the experimental group underwent pulpotomy, while the teeth in the control group underwent root canal treatment.The patients in both groups were followed up at 1 week, 6 months, and 12 months after the operation.Self-perceived pain symptoms were assessed using a visual analogue scale(VAS)before and 1 week after treatment in the experimental group, and before, at the second visit(visit 1), at the third visit(visit 2), and 1 week after treatment in the control group.Results:The mean preoperative pain score of the patients, as measured by the VAS scale, was(1.09±1.19)in the experimental group.There was no statistically significant difference when compared to the control group(1.13±1.23)( t=-0.096, P=0.924). The postoperative pain score of the experimental group was(0.27±0.77). On the other hand, the average overall pain score of the control group after treatment(visit 1, visit 2, and 1 week postoperatively)was(1.19±1.82). The postoperative pain score of the experimental group was significantly lower than that of the control group( t=-3.416, P=0.001). The effective rates were 95.24%(20/21)(experimental group)and 100%(22/22)(control group)respectively.There was no significant difference between the cure rates of the two groups( χ2=1.458, P=0.488). Conclusions:The findings suggest that pulpotomy can be an effective method for managing elderly patients with exposed pulp due to caries.

Efficacy of oral midazolam solution for preoperative sedation in pediatric outpatients undergoing root canal treatment under general anesthesia / 中华麻醉学杂志

Objective:To evaluate the efficacy of oral midazolam solution for preoperative sedation in the pediatric outpatients undergoing root canal treatment under general anesthesia.Methods:One hundred and forty-seven pediatric patients of either sex, aged 2-7 yr, weighing 10-30 kg, of American Society of Anesthesiologists Physical Status classificationⅠ or Ⅱ, were divided into 3 groups ( n=49 each) using a random number table method: oral midazolam solution group (OM group), midazolam injection group (M group), and dexmedetomidine group (D group). In OM group, patients received oral midazolam solution at a dose of 0.5 mg/kg along with a placebo (an equivalent amount of normal saline based on body weight) administered via nasal drops. In M group, patients were given oral midazolam injection at a dose of 0.5 mg/kg along with a placebo via nasal drops. In D group, patients were administered a placebo orally along with dexmedetomidine at a dose of 2 μg/kg via nasal drops. The Induction Compliance Checklist (ICC) scores upon entering the operating room, sedation success rates (ICC score ≤ 3), drug acceptance scores, mask acceptance scores, and separation anxiety scores were recorded. The emergence time, time of stay in postanesthesia care unit (PACU), and occurrence of adverse events such as bradycardia, hypotension, hypoxemia, and laryngospasm during surgery and in PACU were recorded. Results:A total of 143 pediatric patients were finally included in the study, with 48 cases in OM group, 48 cases in M group and 47 cases in D group. Compared with M and D groups, the ICC scores upon entry to the operating room were significantly decreased, the sedation success rates were increased, drug acceptance scores were increased, separation anxiety scores were decreased, and mask acceptance scores were decreased in OM group ( P<0.05). Compared with D group, the ICC scores upon entry to the operating room were significantly decreased, the sedation success rates were increased, and mask acceptance scores were decreased in M group ( P<0.05). There were no statistically significant differences in the emergence time, time of stay in PACU, and incidence of adverse events during surgery and in PACU among the three groups ( P>0.05). Conclusions:Oral midazolam solution provides good effect with less adverse reactions when used for preoperative sedation in the pediatric outpatients undergoing root canal treatment under general anesthesia.

Influence of genetic polymorphisms on oral health-related quality of life after root canal treatment

Abstract To evaluate the impact of genetic polymorphisms in interleukins (IL1A rs17561, rs1304037; IL10 rs1800871; IL1RN rs9005), nitric oxide (NOS2 rs2779249, rs2897518) and suppressor of cytokine signaling (SOCS1 rs243327, rs33977706) on oral health-related quality of life (OHRQoL) of patients under-going root canal treatment (RCT). Methods: The sample consisted of 108 participants, presenting single-rooted teeth with asymptomatic periapical periodontitis. The impact of the OHRQoL was recorded using the Oral Health Impact Profile (OHIP-14) before, seven, and 30 days after RCT. Saliva samples were collected as a source of genomic DNA. Genetic polymorphisms were genotyped by Real-Time PCR using the Taqman method. Univariate and Multivariate analyses were used (p<0.05). Results: A significant difference was observed for the polymorphism rs2297518 in the NOS2 gene in functional limitation in the codominant (p=0.037) and recessive (p=0.001) models; in the physical pain (p<0.001 in both models); in psychological discomfort (p<0.001 in both models); in physical disability (p<0.001 in both models) and in psychological disability (p<0.001 in both models). Polymorphisms in the SOCS1 gene, in the recessive model, rs33977706 (p=0.045) and rs243327 (p=0.019), influenced the OHRQoL in the psychological discomfort domain. Conclusions: Polymorphisms in NOS2 and SOCS1 genes influenced the OHRQoL of patients undergoing RCT.

Resumo Avaliar o impacto de polimorfismos genéticos em interleucinas (IL1A rs17561, rs1304037; IL10 rs1800871; IL1RN rs9005), óxido nítrico (NOS2 rs2779249, rs2897518) e supressor da sinalização de citocinas (SOCS1 rs243327, rs33977706) na qualidade de vida relacionada à saúde bucal (QVRSB) de pacientes submetidos a tratamento endodôntico (TE). Métodos: A amostra foi composta por 108 participantes, que apresentavam dentes unirradiculares com lesão periapical assintomática. O impacto da QVRSB foi registrado usando o Oral Health Impact Profile (OHIP-14) antes, sete e 30 dias após o TE. Amostras de saliva foram coletadas como fonte de DNA genômico. Os polimorfismos genéticos foram genotipados por PCR em tempo real usando o método Taqman. Análises univariadas e multivariadas foram utilizadas (p<0,05). Resultados: Observou-se diferença significativa para o polimorfismo rs2297518 no gene NOS2 na limitação funcional nos modelos codominante (p=0,037) e recessivo (p=0,001); na dor física (p<0,001 em ambos os modelos); no desconforto psicológico (p<0,001 em ambos os modelos); na deficiência física (p<0,001 em ambos os modelos) e na deficiência psicológica (p<0,001 em ambos os modelos). Polimorfismos no gene SOCS1, no modelo recessivo, rs33977706 (p=0,045) e rs243327 (p=0,019), influenciaram a QVRSB no domínio desconforto psicológico. Conclusões: Polimorfismos nos genes NOS2 e SOCS1 influenciaram a QVRSB de pacientes submetidos a TE.