Dentin permeability after pretreatment with titanium tetrafluoride and self-etching or universal adhesive systems

Aim: To evaluate dentin permeability after pretreatment with 2.5% aqueous solution of titanium tetrafluoride (TiF4), followed by a self-etching universal adhesive system. Methods: Forty dentin discs (1.5 mm thick) were randomly divided into groups according to the application or non-application of a pretreatment, and the type of adhesive system to be tested (two-step self-etching/ Clearfil SE Bond/ Kuraray Medical, or universal adhesive system/ Single Bond Universal/ 3M ESPE). Both sides of the discs were conditioned with 37% phosphoric acid to remove the smear layer. The first hydraulic conductivity measurement (L1) was performed in a permeability machine, under 5 PSI pressure. The samples were sanded again to form a standardized smear layer. The teeth designated for pre-treatment with TiF4 received the TiF4 solutions applied actively for 60 seconds, and the adhesive systems were applied according to the manufacturer's instructions. Then, a new hydraulic conductivity measurement (L2) was performed for the purpose of calculating the hydraulic conductance at a later time, considering the water viscosity and the thickness of the specimen. The percentage (L) of dentin permeability after application of the adhesive system was obtained (L (%) = [(L1-L2) x100] / L1). The Mann-Whitney non-parametric test was applied. Results: There was no difference between the two adhesive systems, or between the groups with or without pretreatment, as regards dentin permeability (p>0.05). Conclusion: Pretreatment with 2.5% TiF4 did not influence dentin permeability, irrespective of the adhesive system used

Fatigue failure of NiTi endodontic files: scoping review / Falla por fatiga de limas NiTi para endodoncia: revisión exploratoria de cobertura temática

Abstract Introduction: Nickel-Titanium (NiTi) endodontic files are made of hyperelastic material with shape memory. However, these files suffer a sudden fracture during the endodontic treatment, which is considered an unfavorable prognosis. Many studies have been conducted to establish fatigue resistance focused on file brands and determine which is better. Although the most common failure mechanisms have been established for motorized endodontic files, the information is scattered, making it difficult to develop clear research trends. Methods: a scoping review was carried out using Scopus, Dimensions.ai, Web of Science, and Science Direct databases to answer screening questions related to the predominant fracture mechanism in NiTi files, test types, and equipment used for experimentation and to identify the most active authors. Results: using the general search terms, 432 research papers were found, of which 75 were finally selected after eliminating duplicates and applying exclusion criteria. Conclusions: typical failure mechanisms for rotatory and reciprocating files were identified based on the panoramic review and bibliometric indicators. Also, the standard mechanical tests for endodontic files and the characteristics of their assemblies were summarized. The most active authors in the area and their nationality were tagged. Finally, gaps for future research are proposed to generate a comprehensive knowledge of NiTi file failure.

Resumen Introducción: las limas de Níquel-Titanio (NiTi) utilizadas en endodoncia están hechas de un material hiperelástico con memoria de forma. Sin embargo, estas limas sufren fractura repentina durante el tratamiento, lo cual se considera un pronóstico desfavorable. Se han realizado diversos estudios para establecer la resistencia a la fatiga de limas, y determinar cuál marca es mejor. Aunque se han establecido los mecanismos de falla más comunes para las limas de endodoncia motorizadas, la información se encuentra dispersa, dificultando la definición de tendencias claras de investigación. Métodos: se realizó una revisión de cobertura temática utilizando las bases de datos Scopus, Dimensions.ai, Web of Science y Science Direct, para responder a preguntas orientadoras relacionadas con el mecanismo de fractura predominante en las limas NiTi, tipos de pruebas y equipos utilizados para la experimentación e identificar los autores más activos en el área. Resultados: utilizando términos generales de búsqueda, se encontraron 435 trabajos de investigación. Finalmente se seleccionaron 75, tras eliminar duplicados y aplicar criterios de exclusión. Conclusiones: a partir de la revisión panorámica de literatura y empleando algunos indicadores bibliométricos, se identificaron los mecanismos de falla más comunes para las limas rotatorias y reciprocantes. Se obtuvo información sobre ensayos mecánicos y los montajes más utilizados para las limas de endodoncia. Se identificaron los autores más activos en el área y su nacionalidad. Por último, se sugieren oportunidades de investigación para generar un conocimiento exhaustivo sobre la falla de las limas NiTi.

Retiro de elementos de osteosíntesis en trauma maxilofacial / Osteosynthesis elements removal in maxillofacial trauma

Resumen Objetivo: Analizar la prevalencia y los factores en la remoción de elementos de osteosíntesis (OTS) de pacientes tratados quirúrgicamente debido a fracturas maxilofaciales. Materiales y Método: Estudio retrospectivo descriptivo, donde fueron incluidos todos los pacientes con diagnóstico de fractura maxilofacial y tratados mediante reducción abierta y fijación interna rígida en un intervalo de 10 años, en el Servicio de Cirugía Oral y Maxilofacial en el Hospital Clínico Mutual de Seguridad (HCMS). Resultados: En un total de 807 pacientes intervenidos, con un rango etario entre 22-66 años, fueron utilizados 2.421 OTS. Entre ellos, 58 pacientes (7,2%) fueron sometidos a un segundo procedimiento quirúrgico, retirándose un total de 129 OTS (5,3%). La principal causa de retiro fue infección (41,1%), comúnmente de carácter tardío. El tercio inferior facial fue el más afectado, específicamente, la zona parasinfisiaria. El 39% fue retirado antes de los 12 meses de posicionados. Conclusiones: El retiro de OTS, posterior a trauma maxilofacial tiene una baja prevalencia. El sitio más afectado es el hueso mandibular y la mayoría se retira dentro de los primeros 12-24 meses. La etiología es variable, sin embargo, la infección se mantiene como una de las principales. Los hallazgos sugieren que no sería recomendable realizar este procedimiento de forma universal para todos los pacientes.

Aim: To analyse the prevalence and factors regarding to osteosynthesis elements (OTS) removal from patients surgically treated due to maxillofacial fractures. Materials and Method: Retrospective study in which all patients with diagnosis of maxillofacial fractures and treated with open reduction and internal rigid fixation were included, in an interval of 10 years, in the Maxillofacial Surgery Service of HCMS. Results: In 807 surgically treated patients, with an age between 22-66 years, 2.421 OTS were used. Among them, 58 patients (7.2%) underwent a second surgical procedure, with a total of 129 OTS removed (5.3%). The main cause of removal was infection (41.1%), commonly of a chronic nature. The lower third of the face was the most affected, specifically, the parasymphysis region. 39% of OTS were withdrawn before 12 months. Conclusions: OTS removal after maxillofacial trauma has a low prevalence, the most affected site is the mandibular bone, within the first 12-24 months. The aetiology is variable, however, infection remains one of the main. The findings suggest that it would not be advisable to perform this procedure universally for all patients.

Avaliação da formação de biofilme bacteriano em diferentes ligas metálicas ortopédicas / Evaluation of the formation of bacterial biofilm in different orthopedic metallic alloys

Objetivo: Esse trabalho objetiva identificar e caracterizar o desenvolvimento da bactéria Pseudomonas aeruginosa forte produtora de biofilme nos seguintes materiais ortopédicos: hastes de titânio e de cromo-cobalto. Método: A quantidade de biofilme formada nas amostras foi avaliada com base na quantidade de Pseudomonas aeruginosa, compondo o biofilme das amostras. Resultado: A formação de biofilme nas ligas de titânio foi significativamente maior do que o observado nas ligas cromo-cobalto, tanto no período de 17 horas quanto em uma semana. O cromo-cobalto possibilitou a formação de maior número de biofilme em uma semana, enquanto o titânio viabilizou maior geração de biofilme no período de 17 horas. Além disso, observou-se que um período de maior permanência do biomaterial em contato com a bactéria não pode ser considerado como um fator de proteção no processo de formação de biofilme. Desse modo, evidenciamos a necessidade de investimento em pesquisas relacionadas à prevalência e desenvolvimento de biofilme em ligas metálicas largamente utilizadas nos implantes cirúrgicos. Conclusão: O tempo influenciou apenas na formação de bactéria no cromo-cobalto, sendo quanto maior tempo de contato com a bactéria, maior quantidade de biofilme. Entre as ligas metálicas titânio e cromo-cobalto, o cromo-cobalto produziu menor quantidade de biofilme.

Objective: This work aims to identify and characterize the development of the bacterium Pseudomonas aeruginosa forte that produces biofilm in the following orthopedic materials: titanium and chromium-cobalt rods. Method: The amount of biofilm formed in the samples was evaluated based on the amount of Pseudomonas aeruginosa composing the biofilm of the samples. Result: The biofilm formation in titanium alloys was significantly higher than that observed in chromium-cobalt alloys both in 17 hours and in a week. Chromium-cobalt enabled the formation of a greater number of biofilms in one week, while titanium enabled greater generation of biofilms in 17 hours. In addition, it was observed that a period of greater permanence of the biomaterial in contact with the bacteria cannot be considered as a protective factor in the biofilm formation process. Thus, we highlight the need for investment in research related to the prevalence and development of biofilm in metal alloys widely used in surgical implants. Conclusion: Time influenced only the formation of bacteria in chromium-cobalt, the longer the contact with the bacteria, the greater the amount of biofilm. Among the titanium and chromium-cobalt metal alloys, chromium-cobalt produced less biofilm.

The influence of haematogenous bone marrow on the early osseointegration of a titanium implant which penetrates the endosteum / La influencia de la médula ósea hematógena en la osteointegración temprana de un implante de titanio que penetra en el endostio

SUMMARY: The utility of metallic bio-medical implants in osseous or dental affections is irrefutable. The paper aims to test the tolerance of the bone marrow to titanium implants. Titanium implants were inserted in the femur of 11-months old rabbits. The implants penetrated the endosteum, half of their length getting into the haematogenous bone marrow. Seven days after the insertion we collected bone fragments containing the implant. The CT exam revealed a significant decrease in the density of the bone at the interface with the implant and a more discrete one aloof from the insertion area. The histologic exam after 7 days revealed osseous reparatory processes only in the endosteal area from where it expanded on the surface of the implant which was inside the marrow. The presence and intensity of the osseous reparatory processes after only seven days post-implant demonstrates that the marrow actively participates in bone regeneration and implants osseointegration.

RESUMEN: La utilidad de los implantes biomédicos metálicos en afecciones óseas o dentales es irrefutable. El documento tiene como objetivo probar la tolerancia de la médula ósea a los implantes de titanio. Se insertaron implantes de titanio en el fémur de conejos de 11 meses. Los implantes penetraron en el endostio y la mitad de su longitud penetró en la médula ósea hematógena. Siete días después de la inserción, recolectamos fragmentos de hueso que contenían el implante. El examen de TC reveló una disminución significativa en la densidad del hueso en la interfaz con el implante y una más discreta alejada del área de inserción. El examen histológico a los 7 días reveló procesos de reparación ósea solo en el área endóstica desde donde se expandió en la superficie del implante que estaba dentro de la médula. La presencia e intensidad de los procesos de reparación ósea después de solo siete días del implante demuestra que la médula ósea participa activamente en la regeneración ósea y en la osteointegración de los implantes.

Influência do hipoclorito de sódio na resistência à fadiga cíclica em instrumentos rotatórios endodônticos de memória controlada de NiTi: uma avaliação experimental / Influence of sodium hypochlorite on cyclic fatigue resistance in niti controlled memory endodontics rotary instruments: an experimental evaluation

Introdução: É importante saber se o hipoclorito de sódio (NaOCl) influencia a resistência à fadiga cíclica das limas de níquel-titânio (NiTi). Objetivo: Avaliar a influência de NaOCl 2,5% na resistência à fadiga cíclica de dois sistemas de NiTi. Material e método: 40 instrumentos rotatórios - 20 TruNatomy® (TRU, Dentsply Sirona, Maillefer, Ballaigues, Suíça) e 20 Prodesing Logic2® (PDL2, Bassi, Belo Horizonte, Minas Gerais, Brasil) - foram aleatoriamente distribuídos em 4 grupos experimentais (n = 10) imersos em água destilada (H2O) e NaOCl 2,5% em temperatura a 37°C. Foram submetidos a testes de fadiga cíclica mensurando o número de ciclos para fratura (NCF) e análise dessas superfícies pós-teste em microscópio eletrônico por varredura. Para a análise estatística entre os grupos, foi aplicada a análise de variância (ANOVA), complementada com o pós-teste de Tukey. Resultado: Houve diferença estatística em todos os grupos (P<0.05). Os instrumentos PDL2 obtiveram maior resistência à fratura nas condições em H2O e em NaOCl 2,5% comparados aos instrumentos TRU. Na análise de grupos de instrumentos nas soluções de NaOCl e H2O, foi observado que o NaOCl 2,5% diminuiu o NCF. Conclusão: A resistência à fadiga cíclica dos instrumentos TRU e PDL2 diminuiu com NaOCl 2,5%. Os instrumentos PDL2 foram mais resistentes à fratura em relação aos instrumentos TRU.

Introduction: It is important to know whether sodium hypochlorite (NaOCl) influences the cyclic fatigue resistance of nickel-titanium (NiTi) files. Objective: To evaluate the influence of NaOCl 2.5% on the cyclic fatigue resistance of two NiTi systems. Material and method: Forty rotary instruments - 20 TruNatomy® (TRU, Dentsply Sirona, Maillefer, Ballaigues, Switzerland) and 20 Prodesign Logic2® (PDL2, Bassi, Belo Horizonte, Minas Gerais, Brazil) - were distributed randomly across four experimental groups (n=10) and submerged in distilled water (H2O) or 2.5% NaOCl at 37°C according to allocation. Cyclic fatigue testing was then performed, measuring the number of cycles to fracture (NCF), and post-test surfaces were analysed by scanning electron microscopy (SEM). Statistical Analysis: Analysis of variance (ANOVA) was applied for between-group analysis, followed by Tukey's post-hoc test. Result: A significant difference was observed in all groups (P<0.05). PDL2 instruments showed higher fracture resistance under H2O and 2.5% NaOCl conditions compared to TRU. Analysis of all instrument groups showed that exposure to 2.5% NaOCl decreased the NCF compared to H2O. Conclusion: Cyclic fatigue resistance of the TRU and PDL2 instruments was decreased by exposure to 2.5% NaOCl. PDL2 instruments were more resistant to fracture than TRU instruments.

Cyclic Fatigue Resistance and Surface Roughness of Rotary NiTi Instruments after Simulated Clinical Use in Curved Root Canals - An Atomic Force Microscopy Study

Abstract Objective: To examine the cyclic fatigue resistance and surface topography of TruNatomy and ProTaper Gold nickel-titanium rotary files and evaluate the presence of alterations to surface topography following instrumentation in simulated curved canals. Material and Methods: Twenty-four nickel-titanium instruments, twelve each of TN and PTG file systems, were evaluated for cyclic fatigue resistance. The rotary files were rotated in a simulated root canal with standardized diameter, angle of curvature, and radius of curvature in a custom-made cyclic fatigue testing device until the instrument fracture occurred. The time to fracture for each instrument was recorded with a stopwatch; in seconds in each group. Fractured instruments were subjected to atomic force microscopy analysis measuring the average roughness and the root mean square values to investigate surface features of endodontic files. Mean values and standard deviation were calculated. Data were analyzed using the Mann-Whitney U test. Results: Time to fracture was marginally higher in PTG instruments than in the TN file systems. PTG files exhibited higher surface roughness when compared with TN files (p<0.05). Conclusion: TN file system had a higher cyclic fatigue resistance than PTG. Cyclic fatigue causing file breakage did affect the surface topography of the files. PTG files showed a higher surface porosity value than the TN files (AU).

Influence of titanium nanotubular surfaces, produced by anodization, on the behavior of osteogenic cells: in vitro evaluation / Influência da superfície nanotubular do titânio, produzido por anodização, no comportamento de células osteogênicas: avaliação in vitro

Objective: The objective of this study was to evaluate in vitro the influence of the anodized surface of Ti35Nb7Zr alloy on the behavior of osteogenic cells, for future application in biomedical implants. Material and Methods: For the development of this research, samples of commercially pure titanium (TiCp) and samples of Ti35Nb7Zr alloy were anodized, both were characterized by scanning electron microscopy (SEM) and were plated afterwards with human osteoblast-like cells (MG63 line) (2 x 104). Cell adhesion, cytotoxicity test, formation of mineralization nodules and a comet assay were also performed in different periods. The bottom of the plate was used as a control, without a sample. Results: SEM analysis showed that the topography of both samples presented surfaces covered by nanotubes. Cellular morphology exhibited spreading in both samples proposing an intimate cell- material liaison. After 3 days, the Ti35Nb7Zr group exhibited greater cell viability than the TiCp group (p<0.01). Regarding calcium content, there was no statistical difference between the anodized groups, but there was a difference between the experimental groups and the control group (p<0.01). In the comet assay, the percentage of DNA in the comet tail did not exhibit any significant difference (p>0.05) among the groups in the evaluated periods. Conclusion: It was concluded that this process of anodization was efficient to form nanotubes, as well as promote a positive influence on the behavior of osteogenic cells without promoting cell damage. (AU)

Objetivo: O objetivo deste estudo foi avaliar in vitro a influência da superfície anodizada da liga Ti35Nb7Zr no comportamento de células osteogênicas, para futura aplicação em implantes biomédicos. Material e Métodos: Para o desenvolvimento desta pesquisa, amostras de titânio comercialmente puro (TiCp) e amostras da liga Ti35Nb7Zr foram anodizadas, ambas foram caracterizadas por microscopia eletrônica de varredura (MEV) e posteriormente plaqueadas com células semelhantes a osteoblastos humanos (linha MG63) (2 x 104). Foram realizados em diferentes períodos a adesão celular, teste de citotoxicidade, formação de nódulos de mineralização e ensaio do cometa. O fundo da placa foi usado como controle, sem amostra. Resultados: A análise em MEV mostrou que a topografia de ambas as amostras apresentava superfícies cobertas por nanotubos. A morfologia celular exibiu espalhamento em ambas as amostras, propondo uma ligação íntima célula-material. Após 3 dias, o grupo Ti35Nb7Zr exibiu maior viabilidade celular do que o grupo TiCp (p<0.01). Em relação ao teor de cálcio, não houve diferença estatística entre os grupos anodizados, mas houve diferença entre os grupos experimentais e o grupo controle (p<0.01). No ensaio do cometa, a porcentagem de DNA na cauda do cometa não apresentou diferença significativa (p> 0.05) entre os grupos nos períodos avaliados. Conclusão:Concluiu-se que esse processo de anodização foi eficiente para formar nanotubos, além de promover uma influência positiva no comportamento das células osteogênicas sem promover dano celular. (AU)

Postoperative anterior uveitis in a patient submitted to combined treatment with cataract surgery and iStent inject®. How to manage? / Uveíte anterior no pós-operatório de facectomia combinada com implante de iStent inject®. Como manejar?

ABSTRACT Minimally invasive glaucoma surgeries are surgical treatment alternatives for glaucoma aimed at reducing intraocular pressure with a better safety profile compared to traditional trabeculectomy. However, in spite of less invasive techniques, complications may develop in any surgical procedure. To the best of our knowledge, this is the first case report of anterior uveitis following combined treatment with cataract surgery and iStent inject® which addresses the management of postoperative inflammation.

RESUMO As cirurgias minimamente invasivas para glaucoma consistem em uma opção de tratamento cirúrgico para glaucoma, a qual promove redução da pressão intraocular com melhor perfil de segurança do que a trabeculectomia. Todavia, complicações são inerentes à realização de procedimentos cirúrgicos, apesar do uso de técnicas menos invasivas. Este é o primeiro relato que apresenta um caso de uveíte anterior após cirurgia combinada de catarata e iStent inject®, além de orientações quanto ao manejo do quadro inflamatório.

Defectos óseos segmentarios: uso de implantes de titanio trabecular diseñados a medida / Segmental bone defects: use of custom-designed trabecular titanium implants

Introducción: Se dispone de una amplia variedad de opciones terapéuticas para la reconstrucción de defectos óseos segmentarios causados por fracturas, tumores o infecciones, pero aún es un desafío en la cirugía ortopédica. materiales y métodos:Se presentan seis casos de pacientes con pérdida ósea masiva tratados mediante lo que denominamos "combinación sinérgica" de una membrana inducida para aportar beneficios biológicos, más un andamiaje (scaffold) de titanio trabecular desarrollado especialmente, según cada paciente, para el aporte de estabilidad y estructura. Resultados: Cinco hombres y una mujer (edad promedio 30 años) fueron operados con esta técnica. El seguimiento promedio fue de 24 meses. En el posoperatorio inmediato, se logró el restablecimiento del eje, la longitud y la estabilidad mecánica suficiente para iniciar la carga parcial. La carga total, según las condiciones del paciente (dolor, fuerza muscular), demandó un promedio de 25 a 30 días. Conclusiones: Proponemos una opción de tratamiento poco frecuente en nuestro medio que brinda estabilidad biomecánica suficiente para tolerar la carga precoz recuperando la longitud total del defecto en un solo acto, con excelentes resultados funcionales, entendiendo estas como ventajas frente a las opciones terapéuticas de uso tradicional, como transporte o técnica de Masquelet. Nivel de Evidencia: IV

Introduction: There is a wide variety of therapeutic options for the reconstruction of segmental bone defects caused by fractures, tumors, or infections, but it continues to be a challenge in orthopedic surgery. materials and methods: The present work presents six (6) cases of patients with massive bone loss treated by means of what we call a "synergistic combina-tion" of an induced membrane, to provide biological benefits, plus a trabecular titanium scaffold designed for each patient to provide stability and structure. Results: Five men and one woman with an average age of 30 years were operated on by this technique. The average follow-up was 24 months. In the immediate postoperative period, the axis, length, and sufficient mechanical stability to initiate partial weight-bearing were reestablished. Full weight-bearing according to the patients' conditions (pain, muscle strength) required an average of 25 to 30 days. Conclusion: We propose a rare treatment option in our field with sufficient biomechanical stability to tolerate early weight-bearing, recovering the entire length of the defect in a single stage with excellent functional outcomes, understanding these as an advantage over traditional therapeutic options such as bone transport or the Masquelet technique. Level of Evidence: IV

TiO2 nanoparticles and salinity stress in relation to artemisinin production and ADS and DBR2 expression in Artemisia absinthium L / Nanopartículas de TiO2 e estresse de salinidade em relação à produção de artemisinina e expressão de ADS e DBR2 em Artemisia absinthium L

Abstract Artemisia absinthium L. is an important herb that is widely cultivated in different parts of the world for its medicinal properties. The present study evaluated the effects of four concentrations of nanoparticles treatment (0, 10, 20 and 30 mg L-1) and NaCl salinity stress (0, 50, 100 and 150 mM NaCl) and their interactions with respect to the expression of two key genes, i.e. DBR2 and ADS, in the biosynthesis pathway of artemisinin in A. absinthium. Total RNA was extracted and a relative gene expression analysis was carried out using Real-Time PCR. The amount of artemisinin was also determined by HPLC. All the experiments were performed as factorial in a completely randomized design in three replications. The results revealed that salinity stress and nanoparticles treatment and their interaction affected the expressions of these genes significantly. The highest levels of ADS gene expression were observed in the 30 mg L-1 nanoparticles-treated plants in the presence of 150 mM salinity stress and the lowest levels in the 10 mg L-1 nanoparticles-treated plants under 50 mM salinity stress. The maximum DBR2 gene expression was recorded in the 10 mg L-1 nanoparticles-treated plants in the absence of salinity stress and the minimum expression in the 100 mM salinity-stressed plants in the absence of nanoparticles treatment. Moreover, the smallest amounts of artemisinin were observed in the 150 mM salinity-stressed plants in the absence of nanoparticles and the highest amounts in the 30 mg L-1 nanoparticles-treated plants. The maximum amounts of artemisinin and ADS gene expression were reported from the plants in the same nanoparticles treatment and salinity stress conditions. In this regard, the amount of artemisinin was decreased by half in the plants containing the highest DBR2 gene expression. Meanwhile, no significant correlation was observed between these gene expressions and the artemisinin amount in the other nanoparticles-treated plants under different levels of salinity stress. The biosynthetic pathway of secondary metabolites appears to be very complex and dose not directly dependent on these gene expressions.

Resumo Artemisia absinthium L. é uma erva importante que é amplamente cultivada em diferentes partes do mundo por suas propriedades medicinais. O presente estudo avaliou os efeitos de quatro concentrações de tratamento com nanopartículas (0, 10, 20 e 30 mg L-1) e estresse de salinidade com NaCl (0, 50, 100 e 150 mM NaCl) e suas interações com relação à expressão de dois genes-chave, isto é, DBR2 e ADS, na via de biossíntese da artemisinina em A. absinthium. O RNA total foi extraído, e uma análise de expressão gênica relativa foi realizada usando PCR em tempo real. A quantidade de artemisinina também foi determinada por HPLC. Todos os experimentos foram realizados como fatorial, em delineamento inteiramente casualizado, em três repetições. Os resultados revelaram que o estresse por salinidade e o tratamento com nanopartículas e sua interação afetaram significativamente as expressões desses genes. Os níveis mais altos de expressão do gene ADS foram observados nas plantas tratadas com nanopartículas de 30 mg L-1 na presença de estresse de salinidade de 150 mM, e os níveis mais baixos, nas plantas tratadas com nanopartículas de 10 mg L-1 com estresse de salinidade de 50 mM. A expressão máxima do gene DBR2 foi registrada nas plantas tratadas com nanopartículas de 10 mg L-1 na ausência de estresse de salinidade, e a expressão mínima, nas plantas estressadas com salinidade de 100 mM na ausência de tratamento com nanopartículas. Além disso, as menores quantidades de artemisinina foram observadas nas plantas com estresse de salinidade de 150 mM na ausência de nanopartículas, e as maiores quantidades, nas plantas tratadas com nanopartículas de 30 mg L-1. As quantidades máximas de expressão de genes de artemisinina e ADS foram relatadas a partir das plantas no mesmo tratamento com nanopartículas e condições de estresse de salinidade. A esse respeito, a quantidade de artemisinina diminuiu pela metade nas plantas que contêm a expressão gênica DBR2 mais alta. Enquanto isso, nenhuma correlação significativa foi observada entre essas expressões gênicas e a quantidade de artemisinina nas outras plantas tratadas com nanopartículas sob diferentes níveis de estresse de salinidade. A via biossintética dos metabólitos secundários parece ser muito complexa e não depende diretamente dessas expressões gênicas.

Photocatalytic activity, water absorption capacity, and thermal stability of white cement-based mortars with polysiloxane silicone and different doses of titanium dioxide nanoparticles / Actividad fotocatalítica, absorción de agua y estabilidad térmica de morteros a base de cemento blanco con silicona de polisiloxano y diferentes dosis de nanopartículas de dióxido de titanio

White cement-based mortars in urban areas are usually discolored and altered their esthetic properties due to air pollutants. The addition of nanoparticles in these mortars can provide photocatalytic properties that can decompose pollution agents. Likewise, other hydrophobic agents have been individually studied to improve outdoor building constructions. Therefore, this study presented the photocatalytic and hydrophobic effect of adding nano-TiO2and silicone hydrophobic powder (DOWSILTM) in a white cement matrix. The nano-TiO2 were characterized by X-Ray Diffraction (XRD); afterwards, the mortar was mixed with additions of nano-TiO2 (0.0, 0.5, 1.0, 3.0%) and DOWSILTM (0.0, 0.5%). The mortar's photocatalytic performance was evaluated using a modification of the standard Italian test Ente Nazionale Italiano di Unificazione 11259:2016 based on Rhodamine B (RhB) degradation on the sample exposed to UV irradiation. Therefore, mortar samples were subjected to UV irradiation to degrade the organic dye rhodamine B, monitoring their color variation using a C I E L* a* b* spectrophotometer. Moreover, the water permeability and the contact angle were evaluated. This research demonstrates that the white cement-based mortar samples added with nano-TiO2/DOWSILTM possess photocatalytic activity. The samples with the addition of 1.0%/0.5% and 3.0%/0.5% nano-TiO2/DOWSILTM showed a higher RhB degradation for R4 and R26. Therefore, these two materials can be employed in these proportions to improve the quality of the white cement-based mortars in urban constructions.

Los morteros a base de cemento blanco generalmente se decoloran y alteran sus propiedades estéticas debido a los contaminantes del aire en las áreas urbanas. Nanopartículas añadidas a estos morteros pueden proporcionar propiedades fotocatalíticas que descomponen estos contaminantes. Asimismo, otros agentes hidrofóbicos se han estu-diado individualmente para mejorar las construcciones a la intemperie. Por lo tanto, se presenta el efecto fotocatalítico e hidrofóbico al incorporar nano-TiO2 y silicona hidrofóbica de polisiloxano (DOWSILTM) en una matriz de cemento blanco. El nano-TiO2 se caracterizó por medio de Difracción de Rayos X (DRX); luego, el mortero se mezcló con adiciones de nano-TiO2 (0.0, 0.5, 1.0, 3.0%) y DOWSILTM (0.0, 0.5%). Los morteros se sometieron a irradiación UV, para degradar el colorante orgánico rodamina B, monitoreando su variación de color usando un espectrofotómetro C I E L* a* b*. La eficiencia fotocatalítica del mortero se evaluó utilizando una modificación de la norma italiana Ente Nazionale Italiano di Unificazione 11259:2016 basada en la degradación de la rodamina B (RhB) en el mortero expuesto a la radiación UV. Además, se evaluó la permeabilidad al agua y el ángulo de contacto. Esta investigación demostró que el mortero de cemento con nano-TiO2/ DOWSILTM posee actividad fotocatalítica. Las muestras con 1.0%/0.5% y 3.0%/0.5% nano-TiO2/DOWSILTM mostraron una mayor eficiencia de degradación de RhB para R4 y R26. Por lo tanto, estos materiales tienen potencial para mejorar la calidad de los morteros en construcciones urbanas.

Correção da deficiência transversal maxilar utilizando o expansor de níquel-titânio LEAF Expander® com o protocolo para expansão lenta: relato de caso clínico / Correction of maxillary transverse deficiency using the LEAF Expander® nickel-titanium expander with the protocol for slow expansion: a case report

Este trabalho teve como objetivo o relato do caso clínico de uma paciente que compareceu à Faculdade de Odontologia de Araçatuba com características de classe I de Angle e deficiência maxilar transversal, no tratamento foi utilizado o expansor de níquel-titânio LEAF Expander®, fabricado pela Leone, na Itália. Trata-se aparelho que possui inúmeras vantagens por aumentar a adesão do paciente ao tratamento já que não necessita da ativação em domicílio, facilitar o andamento clínico, tendo em vista que o tratamento é menos doloroso e mais fácil que os outros expansores, aumentar a previsibilidade do tratamento, pois as forças contidas nas molas são constantes e pré-determinadas em laboratório (450g de força). Mediante a análise de modelos, documentações fotográficas e do estudo do caso clínico, concluiu-se que o tratamento realizado utilizando o protocolo padrão de expansão lenta da maxila apresentou-se como uma ferramenta inovadora e eficiente no tratamento da deficiência maxilar transversal(AU)

This study aimed to report the clinical case of a patient who attended the Faculty of Dentistry of Araçatuba with Angle class I characteristics and transverse maxillary deficiency. Leon, Italy. It is a device that has numerous advantages for increasing patient adherence to treatment since it does not require activation at home, facilitating clinical progress, given that the treatment is less painful and easier than other expanders, increasing predictability treatment, as the forces contained in the springs are constant and predetermined in the laboratory (450g of force). Through the analysis of models, photographic documentation and the study of the clinical case, it was concluded that the treatment performed using the standard protocol of slow maxillary expansion presented itself as an innovative and efficient tool in the treatment of transverse maxillary deficiency(AU)

Evolution and development: engine-driven endodontic rotary nickel-titanium instruments / 国际口腔科学杂志·英文版

Various engine-driven NiTi endodontic files have been indispensable and efficient tools in cleaning and shaping of root canals for practitioners. In this review, we introduce the relative terms and conceptions of NiTi file, including crystal phase composition, the design of the cutting part, types of separation. This review also analysis the main improvement and evolution of different generations of engine-driven nickel-titanium instruments in the past 20 years in the geometric design, manufacturing surface treatment such as electropolishing, thermal treatment, metallurgy. And the variety of motion modes of NiTi files to improve resistance to torsional failure were also discussed. Continuous advancements by the designers, provide better balance between shaping efficiency and resistance to of NiTi systems. In clinical practice an appropriate system should be selected based on the anatomy of the root canal, instrument characteristics, and operators' experience.

Relationship between prognosis and different surgical treatments of zygomatic defects: A retrospective study / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effect and summarize the characteristics of different treatment methods in repairing zygomatic defect.@*METHODS@#A total of 37 patients with zygomatic defect were reviewed in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from August 2012 to August 2019. According to the anatomical scope of defect, the zygomatic defects were divided into four categories: Class 0, the defect did not involve changes in zygomatic structure or continuity, only deficiency in thickness or projection; Class Ⅰ, defect was located in the zygomatic body or involved only one process; Class Ⅱ, a single defect involved two processes; Class Ⅲa, referred to a single defect involving three processes and above; Class Ⅲb, referred to zygomatic defects associated with large maxillary defects. The etiology, defect time, defect size and characteristics of zygomatic defects, the repair and reconstruction methods, and postoperative complications were collected and analyzed. Postoperative computed tomography (CT) data were collected to evaluate the outcome of zygomatic protrusion. Chromatographic analysis was used to assess the postoperative stability.@*RESULTS@#Among the causes of defects, 25 cases (67.57%) were caused by trauma, and 11 cases (29.73%) were of surgical defects following tumor resection. We performed autologous bone grafts in 19 cases, 6 cases underwent vascularized tissue flap, 5 cases underwent external implants alone, and 7 cases underwent vascularized tissue flap combined with external implants. After the recovery of the affected side, the average difference of the zygomatic projection between the navigation group and the non-navigation group was 0.45 mm (0.20-2.50 mm) and 1.60 mm (0.10-2.90 mm), with a significant difference (P=0.045). Two patients repaired with titanium mesh combined with anterolateral thigh flap had obvious deformation or fracture of titanium mesh; 2 patients with customized casting prosthesis had infection after surgery and fetched out the prosthesis finally.@*CONCLUSION@#Autologous free grafts or alloplastic materials may be used in cases without significant structural changes. Pedicle skull flap or vascularized bone tissue flap is recommended for zygomatic bone defects with bone pillar destruction, chronic inflammation, oral and nasal communication or significant soft tissue insufficiency. Titanium mesh can be used to repair a large defect of zygomatic bone, and it is suggested to combine with vascularized bone flap transplantation.

Finite element analyses of retention of removable partial denture circumferential clasps manufactured by selective laser melting / 北京大学学报(医学版)

OBJECTIVE@#To compare the retentions of different designs of cobalt-chromium (Co-Cr), pure titanium (CP Ti), and titanium alloy (Ti-6Al-4V) removable partial denture (RPD) circumferential clasps manufactured by selective laser melting (SLM) and to analyze the stress distribution of these clasps during the removal from abutment teeth.@*METHODS@#Clasps with clasp arm size A (1.9 mm width/1.1 mm thickness at the body and 0.8-taper) or B (1.2 times A) and 0.25 mm or 0.50 mm undercut engagement were modeled on a prepared first premolar die, named as designs A1, A2, A3, and A4, respectively. The density and elastic modulus of SLM-built Co-Cr, CP Ti, and Ti-6Al-4V were measured and given to different groups of clasps. The density, elastic modulus, and Poisson ' s ratio of enamel were given to the die. The control group was the cast Co-Cr clasp with design A1, to which the density and elastic modulus of cast Co-Cr alloy were given. The Poisson's ratio of all metals was 0.33. The initial 5 N dislodging force was applied, and the maximum displacement of the clasp along the insertion path was computed. The load was reapplied with an increment of 5 N than in the last simulation until the clasp was completely dislodged. The retentive force range of different groups of clasps was obtained. The retentive forces of the SLM-built Co-Cr, CP Ti, and Ti-6Al-4V clasps with equivalent computed retentive force range to the control group were validated through the insertion/removal experiment. The von Mises stress distributions of these three groups of SLM-built clasps under 15 N loads were analyzed.@*RESULTS@#SLM-built Co-Cr, CP Ti, and Ti-6Al-4V clasps with designs B1 or B2, and Co-Cr clasps with design A2 had higher retentive forces than those of the control group. SLM-built CP Ti and Ti-6Al-4V clasps with design A1 had lower retentive forces than those of the control group. SLM-built Co-Cr clasp with design A1 and SLM-built CP Ti and Ti-6Al-4V clasps with design A2 had equivalent retentive forces to those of the control group. The insertion/removal experiment showed that the measured retentive forces of these three groups of SLM-built clasps were (21.57±5.41) N, (19.75±4.47) N, and (19.32±2.04) N, respectively. No statistically significant measured retentive force difference was found among these three groups of SLM-built clasps (P>0.05). The maximum von Mises stress of these three groups of SLM-built clasps exceeded their responding yield strength except for the Ti-6Al-4V one.@*CONCLUSION@#SLM-built Co-Cr circumferential clasps had higher retention than CP Ti and Ti-6Al-4V ones with the same clasp arm size and undercut engagement. The retention of SLM-built circumferential clasps could be adjusted by changing the undercut engagement and clasp arm size. If SLM-built circumferential clasps are used in clinical practice, the Ti-6Al-4V clasp with clasp arm size A and 0.50 mm undercut engagement is recommended considering the long-term use of RPD in the patient's mouth.

Clinical application of three-dimensional printed preformed titanium mesh combined with free latissimus dorsi muscle flap in the treatment of squamous cell carcinoma with skull defect in the vertex / 中华烧伤杂志

Objective: To explore the clinical effects of three-dimensional printed preformed titanium mesh combined with latissimus dorsi muscle flap free transplantation in the treatment of wounds with skull defect after radical surgery of squamous cell carcinoma in the vertex. Methods: A retrospective observational study was conducted. From January 2010 to December 2019, 5 patients with squamous cell carcinoma in the vertex accompanied with skull invasion who met the inclusion criteria were admitted to the Department of Burns and Plastic Surgery of the Second Affiliated Hospital of Air Force Medical University, including four males and one female, aged 50 to 65 years. The original lesion areas ranged from 5 cm×4 cm to 15 cm×8 cm. The titanium mesh was prefabricated via three-dimensional technic based on the result the scope of skull resection predicted with computerized tomography three-dimensional reconstruction before surgery. During the first stage, the soft tissue defect area of scalp (8 cm×7 cm to 18 cm×11 cm) after tumor enlargement resection was repaired with the preformed titanium mesh, and the titanium mesh was covered with latissimus dorsi muscle flap, with area of 10 cm×9 cm to 20 cm×13 cm. The thoracodorsal artery/vein was anastomosed with the superficial temporal artery/vein on one side. The muscle ends in the donor site were sutured together or performed with transfixion, and then the skin on the back were covered back to the donor site. On the 10th day after the first-stage surgery, the second-stage surgery was performed. The thin intermediate thickness skin graft was taken from the anterolateral thigh to cover the latissimus dorsi muscle flap. The duration and intraoperative blood loss of first-stage surgery were recorded. The postoperative muscle flap survival after the first-stage surgery and skin graft survival after the second-stage surgery was observed. The occurrence of complications, head appearance, and recurrence of tumor were followed up. Results: The average first-stage surgery duration of patients was 12.1 h, and the intraoperative blood loss was not more than 1 200 mL. The muscle flaps in the first-stage surgery and the skin grafts in the second-stage surgery all survived well. During the follow-up of 6-18 months, no complications such as exposure of titanium mesh or infection occurred, with good shape in the recipient sites in the vertex, and no recurrence of tumor. Conclusions: Three-dimensional printed preformed titanium mesh combined with latissimus dorsi muscle flap free transplantation and intermediate thickness skin graft cover is an effective and reliable method for repairing the wound with skull defect after extended resection of squamous cell carcinoma in the vertex. This method can cover the wound effectively as well as promote both recipient and donor sites to obtain good function and appearance.

Effects of nano titanium dioxide on gut microbiota based on human digestive tract microecology simulation system in vitro / 北京大学学报(医学版)

OBJECTIVE@#To explore the effects of oral exposure to titanium dioxide nanoparticles (TiO2 NPs) on the composition and structure of human gut microbiota.@*METHODS@#The particle size, shape, crystal shape and degree of agglomeration in ultrapure water of TiO2 NPs were characterized. The in vitro human digestive tract microecological simulation system was established by simulating the fluid environment and physical conditions of stomach, small intestine and colon, and the stability of the simulation system was evaluated. The bacterial communities were extracted from human feces and cultured stably in the simulated system. They were exposed to 0, 20, 100 and 500 mg/L TiO2 NPs, respectively, and the bacterial fluids were collected after 24 h of exposure. The effect of TiO2 NPs on the composition and structure of human gut microbiota was analyzed by 16S rRNA sequencing technology. Linear discriminant analysis effect size (LEfSe) was used to screen differential bacteria, and the Kyoto encyclopedia of genes and genomes (KEGG) database for functional prediction.@*RESULTS@#The spherical and anatase TiO2 NPs were (25.12±5.64) nm in particle size, while in ultra-pure water hydrated particle size was (609.43±60.35) nm and Zeta potential was (-8.33±0.22) mV. The in vitro digestive tract microecology simulation system reached a relatively stable state after 24 hours, and the counts of Enterococci, Enterobacte-rium, and Lactobacillus reached (1.6±0.85)×107, (5.6±0.82)×107 and (2.7±1.32)×107, respectively. 16S rRNA sequencing results showed that compared with the control group, the number and evenness of gut microbiota were not significantly affected at phylum, class, order, family and genus levels in TiO2 NPs groups (20, 100 and 500 mg/L). The relative abundance of some species was significantly changed, and a total of 42 different bacteria were screened between the TiO2 NPs groups (20, 100 and 500 mg/L) and the control group [linear discriminant analysis(LDA) score>3], represented by Enterobacter, Bacteroidaceae, Lactobacillaceae, Bifidobacteriaceae and Clostridium. Further predictive analysis of gut microbiota function showed that TiO2 NPs might affect oxidative phosphorylation, energy meta-bolism, phosphonate and phosphonate metabolism, and methane metabolism (P < 0.05).@*CONCLUSION@#In human digestive tract microecological simulation system, TiO2 NPs could significantly change the composition and structure of human gut microbiota, represented by Enterobacter and probiotics, and may further affect a variety of metabolism and function of the body.

Introduction of nickel titanium rotary instruments to undergraduate students: afour-yearclinical experience / Introdução de instrumentos rotários de níquel titânio para alunos de graduação: quatro anos de experiência clínica

Many studies address the quality of root canal treatments, but few refer to endodontics usingrotatory techniques performed by noviceoperators. This study evaluatedthe performance of undergraduates in their first contact with rotary root canal instrumentation concerningthe findings of the final periapical radiograph, and thepostendodontic treatment pain.A longitudinal observational studywas performed on periapical radiographs of 491teethfrom 450 patientssubmitted toroot canal treatmentby undergraduate students from 2015 to 2018. The analysis of the length of root canal filling followed the criteria: (i) acceptable, ifperiapical radiograph presentsroot filling ending 0 -1 mm short of radiographic apex; (ii) over, if periapical radiograph presentsroot filling ending beyond the radiographic apex; and (iii) under, ifperiapical radiograph presentsroot filling ending > 1 mm short of radiographic apex. Evaluation of postendodontic treatment painwas categorized into either absence or presenceof pain. Adequate length root canal filling was observed in 65.9% of the cases (324 teeth). Periapical lesions presenceand dimensions did not interfere to the obturation quality.Statistical relation was found between the pulp condition and postendodontic treatment pain. Thepresence of pain was observed in 4.7% of the vital teeth and 0.3% of non-vital teeth. The presence of periapical lesion did not influence postoperative pain.AdequatelengthrootcanalfillingwasobservedinmostcasesandNitTi rotary instrumentation hadapplicability in undergraduate programs, even with novice operators. Besides that, pulp condition had an effect on post endodontic pain (AU).

Muitos estudos abordam a qualidade dos tratamentos de canal radicular, mas poucos se referem à endodontia por meio de técnicas rotatórias realizada por operadores novatos. Este estudo avaliou o desempenho de graduandos no primeiro contato com a instrumentação endodôntica em relação aos achados da radiografia periapical final e à dor pós-tratamento endodôntico. Um estudo observacional longitudinal foi realizado em radiografias periapicais de 491 dentes de 450pacientes submetidos a tratamento endodôntico por estudantes de graduação no período de 2015 a 2018. A análise do comprimento da obturação de canais radiculares obedeceu aos critérios: (i) aceitável, se a radiografia periapical apresentasse término de obturação 0 -1 mm aquém do ápice radiográfico; (ii) acima, se a radiografia periapical apresentasse obturação que termina além do ápice radiográfico; e (iii) abaixo, se a radiografia periapicalapresentasse obturação, terminando > 1 mm aquém do ápice radiográfico. A avaliação da dor pós-operatória foi categorizada em ausência ou presença de dor. A obturação de canais radiculares de comprimento adequado foi observada em 65,9% dos casos (324 dentes). A presença e as dimensões das lesões periapicais não interferiram na qualidade da obturação. Foi encontrada relação estatística entre a condição pulpar e a dor pós-tratamento endodôntico. Presença de dor foi observada em 4,7% dos dentes vitais e 0,3% dos não vitais. A presença de lesão periapical não influenciou na dor pós-operatória. O comprimento de trabalho adequado foi observado na maioria dos casos e a instrumentação rotatória NitTi teve aplicabilidade em programas de graduação, mesmo com operadores iniciantes. Além disso, a condição pulpar afetou a dor pós-operatória (AU).

Tratamiento de la anquilosis temporomandibular en niños con materiales aloplásticos / Treatment of temporomandibular ankilosis in children with alloplastic materials

La anquilosis de la articulación temporomandibular en niños continúa siendo una patología presente a pesar de los avances médicos y sociales. El tratamiento de esta patología en niños tiene como objetivos restablecer la apertura bucal y mejorar la estética facial cuando se presentan hipoplasias o micrognatias asociadas. El uso de materiales aloplásticos para el tratamiento de la anquilosis temporomandibular en niños es evitar la reanquilosis y disminuir riesgos, molestias y costos que ocasionan la toma y aplicación de injertos, siendo utilizados con buenos resultados en niños en otras especialidades como la Traumatología y Ortopedia. Estos procedimientos pueden llevarse a cabo de manera segura y predecible. En este artículo se reportan dos casos de anquilosis temporomandibular en niños, tratados con materiales aloplásticos, llevados a cabo en la Unidad Médica de Alta Especialidad No. 71 del Instituto Mexicano del Seguro Social, Torreón, Coahuila, México, con un seguimiento de 11 y 16 años de postoperatorio, demostrando que se trata de una buena opción de tratamiento sin presentar alteraciones al crecimiento y desarrollo de los pacientes (AU)

Temporomandibular ankilosis in children is pathology still present despite the medical and social advances. The treatment of this pathology in children aims to restore mouth opening and improve facial aesthetics when hypoplasia or micrognatia are present. The use of alloplastic materials to treat temporomandibular ankilosis in children is to prevent the re ankilosis and reduce discomfort, risks, and cost causing by the take and application of graft, alloplastic materials being used with good results in children in other specialties such as Traumatology and Orthopedics. These procedures can be made safely and predictably. This article describes two cases of temporomandibular ankilosis in children, treated with alloplastic materials, carried out in the Medical Unit of High Specialty, number 71, of the Mexican Institute Social Security, Torreon, Coahuila, Mexico, with follow up of cases 11 and 16 years of postoperative, prove that is a good option of treatment, without presenting any alterations in growth and development of patients (AU)