Abstract — The use of submerged vanes has been experimentally validated as an effective method for controlling local scour and stabilizing riverine structures. This study evaluates the efficacy of submerged vanes in mitigating local erosion around a square bridge pier. Four experiments were conducted under controlled conditions in the sedimentation channel of the Laboratory of the Faculty of Civil and Environmental Engineering at the National Polytechnic School in Quito, Ecuador. Acrylic submerged vanes were installed upstream of the pier at a 15° attack angle relative to the flow direction, aiming to modify the velocity distribution and sediment transport dynamics. The experimental results showed that submerged vanes reduced the maximum scour depth by up to 60 % compared to tests without vanes, with an average reduction of approximately 58 %. This significant reduction was attributed to the generation of vortices that redistributed sediment, resulting in shallower and more stable scour holes. Furthermore, the average sediment transport downstream decreased by approximately 40 %, further validating the vanes' efficiency in controlling erosive processes. The vanes demonstrated consistent effectiveness across varying flow rates and sedimentation conditions, underscoring their practical adaptability. By modifying flow dynamics and reducing bed shear stress, the vanes provided reliable scour protection regardless of the hydraulic conditions tested. This study highlights the submerged vanes' potential as a viable, economical, and innovative solution for protecting riverine infrastructures, particularly bridge piers, against erosive forces. Their scalability and adaptability to different hydraulic conditions make them suitable for mitigating scour in river systems with high sediment transport activity and for retrofitting existing infrastructure to enhance its stability. This research contributes to the body of knowledge on local scour mitigation by presenting a replicable experimental methodology and emphasizing the practical applicability of submerged vanes. in hydraulic engineering. The findings suggest that submerged vanes are not only effective but also cost-efficient, making them a promising alternative to traditional scour protection methods such as riprap or aprons.

Resumen — El uso de paneles sumergidos ha sido validado experimentalmente como un método efectivo para controlar la erosión local y estabilizar estructuras fluviales. Este estudio evalúa la eficacia de los paneles sumergidos en la mitigación de la erosión local alrededor de una pila de puente cuadrada. Se realizaron cuatro experimentos bajo condiciones controladas en el canal de sedimentación del Laboratorio de la Facultad de Ingeniería Civil y Ambiental de la Escuela Politécnica Nacional en Quito, Ecuador. Los paneles sumergidos de acrílico se instalaron aguas arriba de la pila con un ángulo de ataque de 15° respecto a la dirección del flujo, con el objetivo de modificar la distribución de velocidades y la dinámica del transporte de sedimentos. Los resultados experimentales mostraron que los paneles sumergidos redujeron la profundidad máxima de socavación en hasta un 60 % en comparación con las pruebas sin paneles, con una reducción promedio de aproximadamente 58 %. Esta reducción significativa se atribuyó a la generación de vórtices que redistribuyeron el sedimento, resultando en cavidades de socavación más someras y estables. Además, el transporte promedio de sedimentos aguas abajo disminuyó aproximadamente un 40 %, lo que valida aún más la eficiencia de los paneles en el control de los procesos erosivos. Los paneles demostraron una efectividad consistente frente a diferentes caudales y condiciones de sedimentación, subrayando su adaptabilidad práctica. Al modificar la dinámica del flujo y reducir las tensiones cortantes del lecho, los paneles proporcionaron una protección confiable contra la socavación, independientemente de las condiciones hidráulicas evaluadas. Este estudio destaca el potencial de los paneles sumergidos como una solución viable, económica e innovadora para proteger infraestructuras fluviales, particularmente pilas de puentes, contra fuerzas erosivas. Su escalabilidad y adaptabilidad a diferentes condiciones hidráulicas los hacen adecuados para mitigar la socavación en sistemas fluviales con alta actividad de transporte de sedimentos y para reacondicionar infraestructuras existentes, mejorando su estabilidad. Esta investigación contribuye al cuerpo de conocimiento sobre la mitigación de la socavación local al presentar una metodología experimental replicable y resaltar la aplicabilidad práctica de los paneles sumergidos.

ABSTRACT: The success of endodontic treatments is related to the neutralization of bacteria and their toxins, inside and outside the root canal system of a tooth. Usually this is achieved, under ideal conditions, by means of a chemical-mechanical action (endodontic files and irrigation with appropriate solutions). Silver nanoparticles (AgNPs) are well-known for their antibacterial properties, and, for this reason, the aim of this work was to modify the surface of Nickel-Titanium (NiTi) endodontic files with AgNPs, to confer them antimicrobial ability and avoid infections. For this purpose, the preparation and characterization of stable colloids of AgNPs were carried out. Ten NiTi files for endodontics (brand K3 XF, Sybron-Endo Keer) were divided into 2 groups; 5 for group 1 (control, files as received) and 5 for group 2 (files previously coated with AgNPs). Both groups were subjected to biofilm formation using a culture composed of Candida albicans and Enterococcus faecalis, in an anaerobic environment. Endodontic files were successfully modified with silver nanoparticles, and, after exposure under anaerobic conditions to the selected microorganisms. Scanning electron microscopy revealed the proliferation of microorganisms on the surface of the control files. In contrast, the modified and coated files showed no biofilm formation, and the bacteria exhibited changes in cell wall morphology, likely associated with wall rupture and subsequent cell death. The coating of silver nanoparticles on the surface of the files shows to change the morphology of the bacterial wall, causing death and thus inhibition in formation of microbiological biofilms. Since reactive oxygen species (ROS) are unlikely to be present under the anaerobic conditions used, the microbicidal effect of the nanoparticles indicates that ROS-promoted oxidative stress is not an important mechanism of action, and inactivation of thiol-containing proteins could be a more important mechanism.

RESUMEN: El éxito de los tratamientos de endodoncia está relacionado con la neutralización de las bacterias y sus toxinas, dentro y fuera del sistema de conductos radiculares de un diente. Habitualmente esto se consigue, en condiciones ideales, mediante una acción químico-mecánica (limas endodónticas e irrigación con soluciones adecuadas). Las nanopartículas de plata (AgNPs) son conocidas por sus propiedades antibacterianas, por lo que el objetivo de este trabajo fue modificar la superficie de limas endodónticas de Níquel-Titanio (NiTi) con AgNPs, para conferirles capacidad antimicrobiana y evitar infecciones. Se realizó la preparación y caracterización de coloides estables de AgNPs. Diez limas NiTi para endodoncia (marca K3 XF, Sybron-Endo Keer) se dividieron en dos grupos; 5 para el grupo 1 (control, limas tal como se recibieron) y 5 para el grupo 2 (limas previamente recubiertas con AgNP). Ambos grupos fueron sometidos a la formación de biopelículas utilizando un cultivo compuesto por Candida albicans y Enterococcus faecalis, en un ambiente anaeróbico. Las limas endodónticas se modificaron exitosamente con nanopartículas de plata y, después de la exposición en condiciones anaeróbicas a los microorganismos seleccionados. El análisis mediante microscopía electrónica de barrido reveló proliferación de microorganismos en la superficie de las limas de control. En contraste, las limas modificadas y recubiertas no presentaron formación de biopelículas, y las bacterias evidenciaron cambios en la morfología de su pared celular, posiblemente asociados a la ruptura de esta y a la consecuente muerte celular. El recubrimiento de nanopartículas de plata en la superficie de las limas cambia la morfología de la pared bacteriana, provocando la muerte y por lo tanto la inhibición en la formación de biopelículas microbiológicas. Dado que es poco probable que estén presentes especies reactivas de oxígeno (ROS) en las condiciones anaeróbicas utilizadas, el efecto microbicida de las nanopartículas indica que el estrés oxidativo promovido por ROS no es un mecanismo de acción importante, y la inactivación de proteínas que contienen tioles podría ser un mecanismo más importante.

Resumo Objetivo: Descrever os parâmetros clínicos, radiológicos dos tumores malignos da coluna vertebral. Métodos: Esse é um estudo terapêutico do tipo estudo retrospectivo descritivo. A avaliação clínica incluiu idade, sexo, lesões tumorais, tratamentos e procedimentos cirúrgicos, além das complicações. A avaliação radiológica analisou exames radiográficos, tomografias computadorizadas e ressonâncias; focando em características morfopatológicas e os tratamentos empregados. Resultados: Entre os 236 pacientes avaliados, a maioria era do sexo feminino, com idades entre 6 e 91 anos. A principal queixa reportada foi a lombalgia. A abordagem cirúrgica mais utilizada foi a via de acesso posterior, incluindo fixação pelicular e descompressão do canal vertebral. A complicação mais prevalente observada foi a infecção. A maioria dos pacientes apresentava tumores primários de mama. O segmento mais frequentemente acometido da coluna vertebral foi o torácico. Ao analisar as porções da coluna vertebral afetadas, observou-se que a porção do arco posterior foi a mais comumente comprometida. Conclusão: A apresentação clínica e radiológica dos pacientes com lesões metastáticas na coluna vertebral em nossa amostra foi semelhante aos relatos da literatura. Resultados cirúrgicos alinharam-se às expectativas prévias. Nota-se a presença de sintomas iniciais, com variação nos intervalos entre sintomas, diagnóstico e tratamento. Nível de Evidência III; Estudo Retrospectivo Comparativo.

Abstract Objective: To describe the clinical and radiological parameters of spine malignant tumors. Methods: This is a therapeutic study of the descriptive retrospective type. Clinical evaluation included age, sex, tumor lesions, treatments, surgical procedures, and complications. The radiological evaluation analyzed radiographic exams, computed tomographies, and MRIs, focusing on morpho-pathological characteristics and the treatments employed. Results: Among the 236 patients evaluated, the majority were female, aged 6 to 91 years. The main complaint reported was low back pain. The most commonly used surgical approach was the posterior access, including pedicle fixation and decompression of the spinal canal. The most prevalent complication observed was infection. The majority of patients had primary breast tumors. The predominantly affected segment of the spine was the thoracic. Upon analyzing the portions of the spine affected, it was observed that the posterior arch portion was the most commonly affected. Conclusion: The clinical and radiological presentation of patients with metastatic lesions in the spine in our sample was similar to reports in the literature. Surgical outcomes aligned with previous expectations. Initial symptoms were noted, varying intervals between symptoms, diagnosis, and treatment. Level of Evidence III; Comparative Retrospective Study.

Abstract: Cone beam computed tomography (CBCT) is an imaging exam used increasingly in various fields of dentistry, and a greater number of endodontists are progressively gaining access to this technology. This study focused on applying an artifact suppression algorithm featured in CBCT software, and designed specifically to address artifacts related to root canal filling materials. Method The sample consisted of eighty-four mandibular molars, with mesial root canals endodontically treated by using the lateral condensation technique. Four root canal sealers were applied: G1 – Sealapex®, G2 – AH Plus®, G3 – Endofill®, and G4 – Bio-C Sealer. CBCT scans were taken using PreXion 3D Elite®. Initially, the diameter of the root canal filling (in the mesiodistal and buccolingual directions) was measured using a digital micrometer (control). Next, these diameters were reevaluated in the CBCT images using the blooming artifact reduction (BAR) tool of the e-Vol DX software. The Van der Waerden nonparametric analysis of variance was performed, followed by applying the Tukey test to the normalized data. The significance level was set at α = 5%. Results There were no statistically significant differences (p>0.05) in the measurement of original root canal filling materials obtained by the micrometer versus the e-Vol DX software in the mesiodistal and buccolingual directions. Conclusions The tested software algorithm effectively suppressed artifacts resulting from obturation materials.

RESUMEN Introducción: los desgarros del canal del parto son complicaciones indeseables que se presentan durante el parto vaginal y que dejan secuelas estéticas y funcional es en el periné o en el canal del parto en sí. Su prevalencia, lejos de ir disminuyendo con los conocimientos actuales de la medicina obstétrica, se ha ido incrementando paulatinamente en los últimos años. Objetivo: determinar las características obstétricas y perinatales en pacientes con desgarros del canal de los partos atendidos en el Centro Médico Nacional - Hospital Nacional en el periodo 2021-2022. Metodología: estudio observacional, descriptivo, de corte transversal y retrospectivo en el que se incluyeron mujeres con lesiones del canal del parto atendidas en el Centro Médico Nacional - Hospital Nacional en el periodo 2021-2022. Se utilizó la estadística descriptiva para el análisis de datos. Resultados: se identificaron 198 mujeres con lesiones del canal del parto. El rango etario de mayor frecuencia fue 19-29 años, provenientes del departamento Central. Presentaron más desgarros del canal del parto las nulíparas (47,5 %) sin antecedente de cesárea previa (92,9 %), la lesión más frecuente fue el desgarro de cuello uterino (64,1 %). La morbilidad más frecuente fue la atonía uterina (20,7 %). Con respecto a los datos perinatales, el peso normal y la edad gestacional de término fueron más frecuentes. Conclusión: Los desgarros de cuello uterino fueron la lesión del canal del parto más frecuente, en nulíparas sin cicatriz previa en un rango etario de 19-29 años provenientes del departamento Central.

ABSTRACT Introduction: birth canal tears are undesirable complications that occur during vaginal delivery, causing aesthetic and functional problems in the perineum or in the birth canal itself. Its prevalence, far from decreasing with current knowledge of obstetric medicine, has been gradually increasing in recent years. Objective: to determine the obstetric and perinatal characteristics in patients with birth canal tears treated at the Centro Médico Nacional- Hospital Nacional in the period of 2021-2022. Methodology: this was an observational, descriptive, cross-sectional, and retrospective study, including women with birth canal injuries treated at the Centro Médico Nacional- Hospital Nacional in the period 2021-2022.Descriptive statistics were used for the data analysis. Results: 198 women with birth canal injuries were identified. The most frequent age range was 19-29 years and most of them lived in the Central department. Most of the birth canal tears were observed innulliparous women (47.5 %) and without a previous cesarean section (92.9 %); the most frequent injury was the cervical tear (64.1 %). The most common morbidity was uterine atony (20.7 %). Regarding perinatal data, normal weight and term gestational age were more frequent. Conclusion: cervical tears were the most frequent birth canal injury in nulliparous women without previous cesarean section with an age range of 19-29 years and from the Central department.

ABSTRACT Objective: To evaluate the surface defects in Wave One Gold and Jizai rotary files after 1 and 3 uses. Material and Methods: Ninety-six resin blocks with stimulated canals and 12 files per system were used. The files were pre-examined under scanning electron microscopy (SEM) to exclude files with pre-existing cracks and craters. Instrumentation and SEM evaluation of the files were performed after 1 and 3 uses, respectively. Two independent operators analyzed the images, and scoring was carried out for each file's coronal, middle, and apical thirds. The surface defects at different thirds of the file systems were analyzed using the Chi-Square test and Kendel Tau’s test. Results: After one use, both the file systems did not produce any significant surface defects in the coronal, middle, and apical thirds. However, after three uses, there was minor plastic deformation in the coronal and middle thirds of the Wave One Gold file system. Jizai file system did not produce any surface defects in the coronal, middle, and apical thirds. Conclusion: After one use, no surface defects were created in Wave One gold and Jizai rotary files. Wave One Gold exhibited more significant surface defects after three uses in the coronal and middle thirds. Objective Methods Ninetysix Ninety six used preexamined pre examined (SEM preexisting existing craters respectively images s ChiSquare Chi Square Taus Tau Results use However Conclusion

ABSTRACT: This study obtained information about the external and internal morphology of the alimentary canal of the main pest of brassica, Plutella xylostella L. (Lepidoptera: Plutellidae), when it is exposed to a microencapsulated formulation of the seed extract of Annona muricata L. (Annonaceae). The toxicity of the microencapsulated formulation of the caterpillars fed for 12, 24, and 48 hours plus the control was evaluated to verify and evaluate external and internal morphological changes caused by the extract that may have killed the caterpillars. After the assays, the alimentary canal of the caterpillars was dissected, fixed, dehydrated, blocked, cut, and colored. Then, histological slides were produced and studied under light microscopy and scanning microscopy (SEM). The microencapsulated formulation of A. muricata caused irreversible damage to the alimentary canal of P. xylostella, with disorganization, cell stratification, and modifications in the morphology of the cells considered essential for survival. SEM verified that the peritrophic membrane and the muscular layer remained intact during all the assays. The effects were more severe with more hours of exposure. These results demonstrated that after contact by ingestion, the insect dies due to intoxication and cellular disorganization, inhibiting its ability to continue feeding. ABSTRACT brassica L Lepidoptera (Lepidoptera Plutellidae, Plutellidae , Plutellidae) Annonaceae. Annonaceae . (Annonaceae) 12 24 4 assays dissected fixed dehydrated blocked cut colored Then SEM. (SEM) A P disorganization stratification survival exposure ingestion feeding (Annonaceae 1 2 (SEM

RESUMO: O objetivo deste estudo foi obter informações sobre a morfologia externa e interna do canal alimentar da principal praga das brássicas, Plutella xylostella L. (Lepidoptera: Plutellidae), quando exposta a uma formulação microencapsulada do extrato da semente de Annona muricata L. (Annonaceae). A toxicidade da formulação microencapsulada das lagartas alimentadas por 12, 24 e 48 horas mais o controle foi avaliada para verificar alterações morfológicas externas e internas causadas pelo extrato que possam ter causado a morte das lagartas. Após os ensaios, o canal alimentar das lagartas foi dissecado, fixado, desidratado, bloqueado, cortado e colorido. Em seguida, lâminas histológicas foram produzidas e estudadas em microscopia óptica e microscopia de varredura (MEV). A formulação microencapsulada de A. muricata, causou danos irreversíveis ao canal alimentar de P. xylostella, com desorganização, estratificação celular e modificações na morfologia das células consideradas essenciais para a sobrevivência. Na análise por MEV, verificou-se que a membrana peritrófica e a camada muscular permaneceram intactas durante todos os ensaios. Os efeitos foram mais graves com mais horas de exposição. Esses resultados demonstraram que após contato por ingestão, o inseto morre por intoxicação e desorganização celular, inibindo sua capacidade de continuar se alimentando. RESUMO brássicas L Lepidoptera (Lepidoptera Plutellidae, Plutellidae , Plutellidae) Annonaceae. Annonaceae . (Annonaceae) 12 2 4 ensaios dissecado fixado desidratado bloqueado colorido seguida MEV. MEV (MEV) P sobrevivência verificouse verificou exposição ingestão alimentando (Annonaceae 1 (MEV

Abstract This article delves into the social, political and judicial processes that led Chile, a historically conservative country in terms of sexuality, gender and family, to approve a law recognizing marriage and parentage for same-sex couples in 2021. To this end, the empirical design combines 42 semi-structured interviews with activists, lawyers, judges, presidential advisor, and parents; 490 newspaper articles; 11 judicial records as well as the parliamentary discussions for 2 draft bills. Based on these data, we propose a genealogy of the Bill on Equal Marriage, which highlights both the political dynamics of the medium term the post-dictatorship period and of the short term the ‘Chilean October’ of 2019. We analyze the articulation of three spaces of mobilization: in the media, in Courts, and in Parliament. Indeed, gay and lesbian activism has been able to articulate strategies in order to overcome the inherent blockages in each space and broaden its support. As for the justice system, we show the connexions between the national, interand supranational levels. Notably, strategic litigation in lower courts has used the international framing of LGBT rights as human rights. Moreover, the article shows that legal mobilization, which is usually approached in common law systems has proven to be an effective channel for influencing policy makers in the Chilean civil law system as well.

Resumen Este artículo ahonda en los procesos sociales, políticos y judiciales que desembocaron en que Chile, un país históricamente conservador en materia de sexualidad, género y familia, llegara a aprobar en 2021 una ley que reconoce el matrimonio y la filiación para las parejas del mismo sexo. Para ello, la investigación se fundamenta en el análisis de 42 entrevistas semiestructuradas con activistas, abogados, jueces, asesor presidencial y progenitores; 490 artículos de prensa; 11 registros judiciales y las discusiones parlamentarias de dos proyectos de ley. En base a aquellas fuentes, proponemos una genealogía de la Ley de matrimonio igualitario que rescata tanto las dinámicas políticas de mediano - la post dictadura - y corto plazo - el “Octubre chileno” del 2019. Analizamos la articulación de tres espacios de movilización: el mediático, el judicial y el legislativo. De hecho, el activismo gay y lésbico ha sido capaz de articular varias estrategias, con el fin de superar los bloqueos inherentes a cada espacio y ampliar su apoyo. En cuanto al espacio judicial, mostramos la interconexión entre los niveles nacional (importancia de la litigación estratégica a nivel de primera instancia), inter y supranacional (framing de los derechos gays y lésbicos en referencia al derecho internacional de los DDHH). La movilización legal, que suele ser abordada en los sistemas de derecho común donde las decisiones judiciales constituyen un precedente vinculante, ha resultado ser un canal efectivo para influenciar a los decidores políticos en un sistema de derecho civil como es Chile.

Resumen Desde su surgimiento, WhatsApp ha extendido las posibilidades de las instituciones mediáticas para conectar con los públicos. La sistematización de la literatura revela que las experiencias internacionales apuestan principalmente por su utilización como herramienta para la distribución de informaciones (funcionalidad de “emisión”) y, en menor medida, como canal de retroalimentación continua con los públicos (funcionalidad de “recepción-emisión”). El objetivo central de este estudio fue caracterizar la dinámica de un grupo experimental de recepción-emisión creado por un programa radiofónico cubano para interactuar con su audiencia sobre problemáticas locales. Esta experiencia no solo puede ofrecer luces para acortar la disonancia entre los medios y sus públicos en Cuba, sino para cualquier medio que apueste por mayor participación de y vínculo con los públicos. El estudio se centró en la dinámica de las interacciones y la relación entre las agendas temáticas emergentes en el grupo. Para ello se acudió a la producción teórica sobre las interacciones en la plataforma WhatsApp y a la Teoría de la Agenda Setting. El diseño metodológico fue cuantitativo. Se aplicó análisis de contenido al 100 % de los mensajes que aparecieron en dicho grupo, y una encuesta on line autoseleccionada y autoadministrada, a la cual respondió una muestra probabilística de los miembros (34 personas de 60 participantes). Los resultados evidenciaron alta interacción medio-ciudadanos y ciudadanosciudadanos, lo que propició correlación significativa entre la agenda propuesta por el medio y los temas de interés para los públicos.

Abstract Since its inception, WhatsApp has expanded the possibilities for media institutions to connect with audiences. A review of the literature reveals that international experiences primarily utilize it as a tool for distributing information ("broadcasting" functionality) and, to a lesser extent, as a channel for continuous feedback with audiences ("reception-broadcasting" functionality). This study mainly intended to characterize the dynamics of an experimental reception-broadcasting group created by a Cuban radio program to interact with its audience on local issues. This experience can not only shed light on how to reduce dissonance between media and their audiences in Cuba, but it also can be beneficial for any media outlet seeking greater audience participation and engagement. The study focused on the dynamics of the interactions and the relationship between the emerging thematic agendas in the group. To do this, theoretical production on interactions on the WhatsApp platform and the Agenda Setting Theory were used. The methodological design was quantitative. Content analysis was applied to 100% of the messages that appeared in the group, and a self-selected and self-administered online survey was conducted, to which a probabilistic sample of the members responded (34 out of 60 participants). The results showed high interaction between the media and citizens, as well as between citizens themselves, which fostered a significant correlation between the agenda proposed by the media and the topics of interest to the audiences.

Resumo Desde a sua criação, o WhatsApp expandiu as possibilidades para as instituições de mídia se conectarem com o público. Uma revisão da literatura revela que as experiências internacionais o utilizam principalmente como uma ferramenta para distribuir informações (funcionalidade de "transmissão") e, em menor escala, como um canal de feedback contínuo com o público (funcionalidade de "recepção-transmissão"). O principal objetivo deste estudo foi caracterizar a dinâmica de um grupo experimental de recepção-transmissão criado por um programa de rádio cubano para interagir com seu público sobre questões locais. Essa experiência pode não apenas esclarecer a redução da dissonância entre a mídia e seu público em Cuba, mas também ser benéfica para qualquer meio de comunicação que busque maior participação e envolvimento do público. O estudo concentrou-se na dinâmica das interações e na relação entre as pautas temáticas emergentes no grupo. Para isso, foi utilizada a produção teórica sobre interações na plataforma do WhatsApp e a Teoria do Agenda Setting. O desenho metodológico foi quantitativo. A análise de conteúdo foi aplicada a 100% das mensagens que apareceram no grupo, e uma pesquisa on-line auto-selecionada e auto-administrada foi realizada, com respostas de uma amostra probabilística dos membros (34 de 60 participantes). Os resultados mostraram alta interação entre a mídia e os cidadãos, bem como entre os próprios cidadãos, o que promoveu uma correlação significativa entre a agenda proposta pela mídia e os tópicos de interesse do público.

Resumen Uno de los principales objetivos del tratamiento de conductos es la adecuada desinfección del sistema de conductos radiculares mediante la instrumentación mecánica en combinación con soluciones desinfectantes para eliminar las bacterias y prevenir la reinfección. La solución irrigante/ desinfectante endodóntica más utilizada es el hipoclorito de sodio, del cual se han reportado efectos adversos biológicos importantes y riesgos relacionados, por lo que es necesario proponer y evaluar alternativas para ser utilizadas como soluciones irrigantes/desinfectantes. La solución hiperosmótica a base de cloruro de sodio y sorbato de potasio ha demostrado tener un efecto antimicrobiano adecuado contra los microorganismos patógenos endodónticos, tanto en forma planctónica y en biopelícula. El presente estudio evaluó la genotoxicidad de una solución hiperosmótica empleada como solución de desinfección endodóntica. Se cultivaron células de fibroblastos humanos en placas de cultivo y se expusieron a la solución hiperosmótica (30% / 100%) y se compararon con NaClO (1%); después de la exposición a las soluciones se realizó una evaluación mediante ensayo Micronucleo, Tunel y Mitotracker. De acuerdo a los resultados, la solución hiperosmótica es una solución de irrigación endodóntica segura o un adyuvante para la desinfección del sistema de conductos radiculares.

Abstract One of the main aims of a root-canal treatment is to disinfect the root-canal system through mechanical instrumentation and cleaning by endodontic disinfection solutions. The most common endodontic disinfection solution used has been the sodium hypochlorite. However, it has been reported some important biological adverse effects and risks related to it, so it is necessary to propose and evaluate alternatives to be used as an endodontic disinfection solution. Hyperosmotic solution based on sodium chloride and potassium sorbate previously has been shown an adequate antimicrobial effect against endodontic microorganisms in planktonic and biofilm forms. This study evaluated the genotoxicity of a hyperosmotic solution proposed as an endodontic disinfection solution. Human fibroblast cells were seeded and incubated into well-culture plates and exposed to the hyperosmotic solution (30% and 100%) and compared to NaClO 1%, after cells were cultured, an evaluation was performed by Micronucleus, Tunel and Mitotracker assays. Based on results, the hyperosmotic solution is a safe potential endodontic disinfection solution or adjuvant for root canal system disinfection.

Resumen Este estudio evaluó la compatibilidad de la técnica de obturación de cono único mediante el uso de Micro-CT (microtomografía computarizada). Las muestras se dividieron en dos grupos según el sistema rotatorio utilizado. En ambos grupos, el conducto se obturó con compactación lateral y el otro con una técnica de cono único combinada con el cemento biocerámico BioRoot RCS. El porcentaje de espacios vacíos en el conducto se evaluó mediante micro-CT antes y después de la obturación. Independientemente de la cinemática utilizada, la técnica de cono único dejó significativamente menos espacios que la compactación lateral. El grupo conformado con el sistema recíproco y obturado con el sistema de cono único obtuvo los mejores resultados. El sistema recíproco con una técnica de obturación de gutapercha de cono único es más eficaz en términos de reducir los espacios vacíos en el conducto radicular.

Abstract This study is aimed to evaluate the compatibility of single-cone filling technique in reciprocal and rotationally formed canals in using Micro-CT (Micro-computed tomography). The samples were split into two groups according to the kinematics system used. In both groups, one canal of the shaped roots was filled with the lateral compaction and the other one with a matched single-cone technique with a bioceramic root canal sealer, BioRoot RCS. The percentage of voids in the canal were evaluated by micro-CT radiograph before and after obturation. Regardless of the kinematics used, the single-cone technique left significantly fewer voids than the lateral compaction. In the kinematics comparison, the group shaped with the reciprocal system and filled with the single-cone system had the best results. The reciprocal nickel-titanium (NiTi) system with a matching single-cone gutta percha filling technique was found to be more effective in terms of reducing voids in root canal filling.

Resumen El desafío más grande en el tratamiento de conductos es la eliminación de los microorganismos; por lo que se busca continuamente nuevas técnicas para alcanzar éxito en el tratamiento. Se determinó el efecto antibacteriano y antifúngico del aceite esencial ozonizado de sacha inchi, hidróxido de calcio en pasta y la combinación de ambas; se utilizó el método de difusión en agar, siendo el medio de cultivo para los Enterococcus faecalis infusión cerebro corazón y para la Candida albicans agar sabouraud, para determinar el efecto antibacteriano y antifúngico se midieron y se registraron los halos de inhibición que se formaron alrededor de los pocillos que contenían los medicamentos a las 24 horas y 48 horas. Obteniendo como resultado que el efecto antibacteriano y antifúngico del aceite ozonizado es mayor a las 6 horas proporcional a la mayor concentración de peróxido. El presente estudio mostró el efecto antibacterial del aceite ozonizado de sacha inchi que es superior frente al hidróxido de calcio y la combinación de ambas sustancias.

Abstract The biggest challenge in root canal treatment is the elimination of microorganisms; there- fore, new techniques are continually sought to achieve success. The agar diffusion method was used to determine the antibacterial and antifungal effect of ozonated Sacha Inchi essential oil, calcium hydroxide paste, and the combination of both. Brain heart infusion and sabouraud agar were the culture media for Enterococcus faecalis and Candida albicans respectively. The antibacterial and antifungal effects were determined using the inhibition halos that formed around the wells containing the drugs at 24 hours and 48 hours. From the study, the antibacterial and antifungal effects of the ozonized oil was greater after 6 hours, proportional to the higher concentration of peroxide. This study showed that the antibacterial effect of ozonated Sacha Inchi oil is superior to that of calcium hydroxide and the combination of both substances.

SUMMARY: The upper second primary molars play a crucial function in oral development and their conservation is of vital importance. Therefore, when necessary, endodontic treatment depends on the morphological variability of the roots and root canals of the tooth, information that has not been described in primary secondary molars in Chilean children. The objective of the present study was to describe the morphological characteristics of the maxillary second primary molars in a subpopulation of Chilean children using cone beam computed tomography. In the present study, tomographic images of the upper second primary molars were obtained, from which the number of roots (N), the number of root canals per molar (N) and the length of the root were determined. (mm). the root canal (mm) and the morphological classification of the root canal system for each root using the Vertucci classification. Of a total of 26 upper primary second molars, a higher frequency of 3 roots (96.2 %) and 4 root canals (46.2 %) per molar was observed. Regarding root morphology, it was shown that the most frequent classification in the three roots present in the population of Chilean children was type I (Mesiovestibular: 53.8 %; Distovestibular: 73.1 %; Palatal: 92.3 %). The morphological characteristics of the upper second primary molars in the population of Chilean children mainly present 3 roots with a singular root canal, information that can help endodontic treatments to preserve premature teeth in the oral cavity, reducing possible complications.

RESUMEN: Los segundos molares temporales maxilares desempeñan funciones cruciales en el desarrollo bucal y su conservación es de vital importancia. Para ello, cuando es necesario, el tratamiento endodóntico depende de la variabilidad morfológica de las raíces y de los conductos radiculares del diente, información que no ha sido descrita en los molares secundarios temporales en niños chilenos. El objetivo del presente estudio fue describir las características morfológicas de los segundos molares temporales maxilares en subpoblación de niños chilenos mediante el uso de Tomografía Computarizada de Haz Cónico. En el presente estudio se obtuvieron imágenes tomográficas de segundos molares temporales maxilares, a partir de las cuales se determinó el número de raíces (N), número de conductos radiculares por molar (N), longitud de la raíz (mm) y del conducto radicular (mm) y la clasificación morfológica del sistema de conductos radiculares para cada raíz mediante la clasificación de Vertucci. De un total de 26 segundos molares temporales maxilares se observó una mayor frecuencia de 3 raíces (96,2 %) y 4 conductos radiculares (46,2 %) por molar. Respecto a la morfología radicular, se demostró que la clasificación más frecuente en las tres raíces presente en la población de niños chilenos fue tipo I (Mesiovestibular: 53,8 %; Distovestibular: 73.1 %; Palatina: 92,3 %). Las características morfológicas de los segundos molares temporales maxilares de la población de niños chilenos presentan principalmente 3 raíces con un conducto radicular singular, información que puede ayudar a los tratamientos endodónticos en la conservación del diente prematuro en la cavidad oral, disminuyendo posibles complicaciones.

ABSTRACT: Complete removal of filling material is essential for proper endodontic retreatment. The aim of this study was to compare, through digital radiography, the effectiveness of the ProTaper Retreatment (PRO), WaveOne Gold (WOG), and Reciproc Blue (REC) systems in removing filling material. Sixty extracted human mandibular premolars were treated and subsequently retreated. Initial endodontic treatment was performed with ProTaper Next system. After obturation, the specimens were retreated using the following systems (n=20): WOG, REC, and PRO. Then, the specimens were analyzed in the mesio-distal (MD) and bucco-lingual (BL) directions using the ImageJ software, considering the residual material as a percentage of the total area of initial obturation. Statistical analysis was performed using ANOVA and Tukey's tests. Although the percentage of residual material in the BL direction was higher than in the MD direction in all groups, there was no differences among groups (p>0.05). So, none of the systems completely removed the filling material, showing similar effectiveness among them.

RESUMEN: La remoción completa del material de relleno es esencial para un retratamiento endodóntico adecuado. El objetivo de este estudio fue comparar, a través de radiografía digital, la efectividad de los sistemas ProTaper Retreatment (PRO), WaveOne Gold (WOG) y Reciproc Blue (REC) en la remoción de material de relleno. Se trataron y retrataron sesenta premolares mandibulares humanos extraídos. El tratamiento endodóntico inicial se realizó con el sistema ProTaper Next. Después de la obturación, las muestras fueron retratadas utilizando los siguientes sistemas (n = 20): WOG, REC y PRO. Luego, las muestras fueron analizadas en las direcciones mesio-distal (MD) y buco-lingual (BL) utilizando el software ImageJ, considerando el material residual como un porcentaje del área total de la obturación inicial. El análisis estadístico se realizó mediante ANOVA y pruebas de Tukey. Aunque el porcentaje de material residual en la dirección BL fue mayor que en la dirección MD en todos los grupos, no hubo diferencias entre los grupos (p>0,05). Se puede concluir que ninguno de los sistemas eliminó completamente el material de relleno, mostrando una efectividad similar entre ellos.

ABSTRACT: Endodontic treatments are among the dental procedures with the highest success rate. They are performed due to the evolution of a carious process or dental trauma, which leads the pulp to a state of irreversible inflammation or directly to pulp necrosis. The aim of the treatment is to eliminate the affected pulp tissue together with the microorganisms, keeping the root canal disinfected during and post-treatment. One of the factors described in the literature that leads to endodontic treatment failure is bacterial microleakage through the coronal filling, so the sealing capacity of provisional materials plays a fundamental role in the evolution and prognosis of the treatment. The aim of this review is to evaluate the coronal microleakage of temporary filling materials in endodontically treated teeth using the dye penetration technique. A systematic review was carried out by searching for publications in the PubMed, SciELO and Cochrane databases from the last 24 years, in English and Spanish. Only in vitro/ex vivo studies of endodontic teeth coronally filled with different provisional materials and subjected to dye penetration testing were included. From a total of 201 articles found, 23 were selected, analyzed and included in this review. The results of the selected studies were diverse. The most analyzed materials in the studies are Coltosol, Cavit and MRI. The microleakage found varied according to the material used, however, no material was able to avoid microleakage completely. Bioplic, a light-curing resinous material, is the only material which in one of the two studies where it was tested had no microleakage. Due to the heterogeneity in the measurement methodology of the studies analyzed, it is suggested to standardize when carrying out new research.

RESUMEN: Los tratamientos de endodoncia son de los procedimientos odontológicos con mayor tasa de éxito. Se realizan por la evolución de un proceso carioso o trauma dental, que llevan a la pulpa a un estado de inflamación de carácter irreversible o directamente a la necrosis pulpar. El objetivo del tratamiento es la eliminación del tejido pulpar afectado junto con los microorganismos, manteniendo el conducto radicular desinfectado durante y post-tratamiento. Uno de los factores descritos en la literatura que conlleva al fracaso del tratamiento endodóntico es la microfiltración bacteriana a través de la obturación coronal, por lo que la capacidad de sellado de los materiales provisorios cumple un rol fundamental en la evolución y pronóstico del tratamiento. El objetivo de esta revisión es evaluar la microfiltración coronal de los materiales de obturación provisoria en dientes tratados endodónticamente, mediante el uso de la técnica de penetración del tinte. Se realizó una revisión sistemática mediante la búsqueda de publicaciones en las bases de datos PubMed, SciELO y Cochrane, de los últimos 24 años, en idioma inglés y español. Se incluyeron solo estudio in vitro/ex vivo de dientes endodonciados, obturados coronalmente con diferentes materiales provisorios y sometidos a pruebas de penetración de tinte. De un total de 201 artículos encontrados, 23 fueron seleccionados, analizados y se incluyeron en esta revisión. Los resultados de los estudios seleccionados fueron diversos. Los materiales más analizados en los estudios son Coltosol, Cavit e IRM. La microfiltración encontrada fue variada según el material utilizado, sin embargo, ningún material logró evitar la microfiltración completamente. Bioplic, material resinoso fotopolimerizable, es el único material el cual en uno de los dos estudios donde se analizó no tuvo microfiltración. Debido a la heterogeneidad en la metodología de medición de los estudios analizados, se sugiere estandarizar al momento de realizar nuevas investigaciones.