Análise de forças de movimentação e características físico-químicas em alinhadores ortodônticos: avanços tecnológicos e considerações críticas / Analysis of motion forces and physicochemical characteristics in orthodontic aligners: technological advances and critical considerations

O avanço tecnológico revolucionou a prática odontológica, com os alinhadores ortodônticos emergindo como uma escolha altamente popular entre pacientes que buscam tratamentos estéticos e confortáveis. No entanto, apesar de sua crescente demanda, permanecem questões cruciais relacionadas à eficácia e análise dimensional desses dispositivos. Este artigo oferece uma análise abrangente das características químicas, físicas e mecânicas dos alinhadores ortodônticos, iluminando a influência vital do processo de termoformação e da espessura nas propriedades desses materiais. Compreender profundamente essas características é essencial para aprimorar a eficácia e a durabilidade dos alinhadores ortodônticos, contribuindo, assim, para o sucesso e a evolução dos tratamentos ortodônticos modernos. Neste estudo, exploraremos: 1) as propriedades químicas dos materiais e como elas afetam a biocompatibilidade e a resistência à degradação; 2) as características físicas, incluindo textura de superfície, transparência e sua influência na adaptação bucal e no conforto do paciente; 3) as propriedades mecânicas, como flexibilidade e rigidez, e como essas características afetam a distribuição de forças de movimentação dentária; 4) a influência do processo de termoformação na precisão e reprodutibilidade dos alinhadores, bem como sua relação com a qualidade do tratamento; 5) a análise crítica da espessura dos alinhadores e seu papel na capacidade de aplicar forças adequadas para a movimentação dentária. Ao abordar esses aspectos, este artigo visa oferecer uma visão holística das complexidades envolvidas na fabricação e uso de alinhadores ortodônticos. Esperamos que esta revisão contribua para uma compreensão mais profunda desses dispositivos e promova avanços significativos na ortodontia, beneficiando tanto os profissionais quanto os pacientes.

Technological advancement has revolutionized dental practice, with orthodontic aligners emerging as a trendy choice among patients seeking aesthetic and comfortable treatments. However, despite their growing demand, crucial questions remain regarding these devices' effectiveness and dimensional analysis. This article offers a comprehensive analysis of the chemical, physical, and mechanical characteristics of orthodontic aligners, illuminating the vital influence of the thermoforming process and thickness on the properties of these materials. Understanding these characteristics in depth is essential to improving the effectiveness and durability of orthodontic aligners, thus contributing to the success and evolution of modern orthodontic treatments. In this study, we will explore 1) the chemical properties of materials and how these properties affect biocompatibility and resistance to degradation; 2) the physical characteristics, including surface texture, transparency and their influence on oral adaptation and patient comfort; 3) mechanical properties, such as flexibility and stiffness, and how these characteristics affect the distribution of tooth movement forces; 4) the influence of the thermoforming process on the precision and reproducibility of the aligners, as well as its relationship with the quality of the treatment; 5) critical analysis of aligner thickness and its role in the ability to apply adequate forces for tooth movement. By addressing these aspects, this article aims to offer a holistic view of the complexities involved in manufacturing and using orthodontic aligners. We hope this review will contribute to a deeper understanding of these devices and promote significant advances in orthodontics, benefiting professionals and patients.

Restauração transcirúrgica: passo a passo / Transsurgical restoration: step by step

Sabe-se que para uma restauração ser considerada um sucesso clínico é preciso que haja uma concomitância saudável entre a estrutura dentária, o material restaurador e as estruturas biológicas periodontais. As restaurações transcirúrgicas caracterizam-se como procedimentos alternativos para possibilitar a restauração de dentes com cárie dentária extensa, restaurações subgengivais desadaptadas e fraturas. O presente estudo teve como objetivo realizar um relato de caso de um procedimento cirúrgico-restaurador, através de uma técnica de restauração transcirúrgica. Este estudo tem como justificativa relatar um caso clínico, colaborando com maiores informações sobre a escolha da técnica a ser empregada, mostrando em quais situações devemos escolher uma restauração transcirúrgica e quais seus benefícios. Também, salientar se devemos fazer a recuperação do espaço biológico do periodonto ou não(AU)

It is known that for a restoration to be considered a clinical success, there must be a healthy concomitance between the tooth structure, the restorative material and the periodontal biological structures. Transsurgical restorations are characterized as alternative procedures to enable the restoration of teeth with extensive dental caries, maladapted subgingival restorations and fractures. The present study aims to carry out a case report of a surgical-restorative procedure, using a transsurgical restoration technique. This study is justified by reporting a clinical case, providing more information on the choice of technique to be used, showing in which situations we should choose a transsurgical restoration and what its benefits are. Also, highlight whether we should recover the biological space of the periodontium or not(AU)

Desenredando los nudos en cirugía: creando maestría con un simulador práctico en casa / Untangling the knots in surgery: Creating mastery with a practical at-home simulator

Introducción. Anudar es una de las habilidades quirúrgicas esenciales y de su correcta ejecución dependen procesos de vital importancia. La adquisición de estas competencias requiere trabajo motor, entornos amigables y realistas. Una estrategia para facilitar el aprendizaje de la técnica de anudado es generar instrumentos de simulación accesibles. Métodos. Se presenta un simulador de nudos quirúrgicos, construido con materiales de bajo costo y asequibles para la población en general, con un presupuesto de aproximadamente $5.000 COP (US$ 1,23). Resultados. Se desarrolló un simulador de nudos quirúrgicos que, al fijarse a la extremidad inferior desde una posición sentada, proporciona una superficie estable para llevar a cabo la práctica de anudado de manera efectiva. Conclusión. La cirugía moderna considera la seguridad del paciente como la principal prioridad, por lo que ya no es apropiado adoptar un método de formación de "ver uno, hacer uno, enseñar uno". Es la práctica constante mediante simuladores, el método más adecuado. Este trabajo presenta una alternativa de aprendizaje ininterrumpido de las técnicas quirúrgicas relacionadas con los nudos.

Introduction. Knotting is one of the essential surgical skills and vitally important processes that depends on its correct execution. The acquisition of these skills requires motor work, friendly and realistic environments. A strategy to facilitate learning the knotting technique is to generate accessible simulation instruments. Methods. A surgical knot simulator is presented, built with low-budget materials and affordable for the general population, with a budget of approximately $5,000 COP (US$ 1.23). Results. A surgical knot simulator has been developed in a way that, when attached to the thigh of a lower extremity from a seated position, provides a stable surface to effectively perform knot tying practice. Conclusion. Modern surgery considers patient safety as the top priority, so it is no longer appropriate to adopt a "see one, do one, teach one" training method. Constant practice using simulators is the most appropriate method. This work presents an alternative for uninterrupted learning of surgical techniques related to knots.

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

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

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

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

Integrity and functionality of surgical instruments in a public university hospital: prospective study / Integridad y funcionalidad de instrumentos quirúrgicos en un hospital público universitario: estudio prospectivo / Integridade e funcionalidade dos instrumentais cirúrgicos de um hospital público universitário: estudo prospectivo

Objective: To characterize the integrity and functionality of surgical instruments in a public university hospital. Method: This is an explora-tory, cross-sectional research, carried out in a large university hospital in the Northeast of Brazil, from May to July 2022. 384 instruments were evaluated regarding their integrity and functionality, divided into twelve classes, each containing 32 items. The inspection mechanisms used followed national and international standards. Results: Approximately half of the equipment evaluated showed non-compliance in at least one integrity and one functionality test. Conclusion: There was a high rate of non-compliance of instruments representing the hospital's layette. The data reflects the pressing need for the institution to invest in screening, periodic evaluation, and maintenance of instruments. (AU)

Objetivo: Caracterizar la integridad y funcionalidad del instrumental quirúrgico en un hospital público universitario. Método: Se trata de una investigación exploratoria, transversal, realizada en un gran hospital universitario del Nordeste de Brasil entre los meses de mayo y julio de 2022. Se evalua-ron 384 instrumentos, divididos en doce clases de 32 instrumentos cada una, según las normas nacionales y internacionales para evaluar integridad y funcionalidad. Resultados: Aproximadamente la mitad de los instrumentos evaluados no cumplieron al menos una prueba de integridad y una de fun-cionalidad. Conclusión: Hubo un alto índice de incumplimiento entre los instrumentos que representan la canastilla del hospital. Los datos reflejan la urgente necesidad de la institución de invertir en el área de screening, evaluación periódica y mantenimiento de instrumentos. (AU)

Objetivo: Caracterizar a integridade e a funcionalidade dos instrumentais cirúrgicos de um hospital público universitário. Método: Trata-se de uma pesquisa exploratória, transversal, realizada num hospital universitário de grande porte do Nordeste do Brasil, de maio a julho de 2022. Foram avalia-dos 384 instrumentais quanto à sua integridade e funcionalidade, divididos em doze classes, cada uma contendo 32 itens. Os mecanismos de inspeção uti-lizados seguiram normas nacionais e internacionais. Resultados: Aproximadamente metade dos equipamentos avaliados apresentaram não conformidade em pelo menos um teste de integridade e um de funcionalidade. Conclusão: Houve alto índice de não conformidade dos instrumentais representativos do enxoval do hospital. Os dados refletem a necessidade premente de a instituição investir em rastreio, avaliação periódica e manutenção de instrumentais. (AU)

Impresiones digitales dentales con escáneres intraorales: una revisión de la literatura / Dental digital impressions with intraoral scanners: a review of the literature / Impressões digitais dentárias com scanners intraorais: uma revisão da literatura

RESUMEN El diseño asistido por computadora y la fabricación asistida por ordenador (CAD-CAM, por sus siglas en inglés) se ha aplicado en odontología para la confección y el análisis de diversos tratamientos dentales. Inicia con la captura de imágenes a través de escáneres intraorales, contando con diversos tipos de softwares y sistemas de exportación de imágenes y tecnología. Las ventajas de este flujo de trabajo digital son el mejor ajuste, el empleo de menor tiempo clínico y la celeridad en tratamientos dentales, además de que brinda una mayor practicidad en el uso de los cirujanos dentistas. La precisión que brinda es clínicamente aceptable en comparación con los métodos convencionales, por lo cual existe suficiente evidencia para su validez; sin embargo, se debe tener en cuenta que diversos factores pueden alterar el resultado, como la experiencia del operador, el tipo de escáner, el tipo de software, la actualización del software, el principio de escaneo del escáner, el ambiente, la secuencia de escaneo y las estructuras bucales. El presente artículo de revisión tiene como objetivo analizar la literatura sobre las diferentes características y propiedades que presentan los escáneres intraorales en la actualidad, así como la evidencia de los posibles beneficios y la precisión de las técnicas de impresión digital frente a las técnicas de impresión convencionales.

ABSTRACT Computer-aided design and computer-aided manufacturing (CAD-CAM) has been applied in dentistry for the preparation and analysis of various dental treatments. It starts with capturing images through intraoral scanners, having different types of software and image export systems and technology. The advantages of this digital workflow are the following: better adjustment, shorter clinical time, and speed in dental treatments, in addition to providing greater practicality for dental surgeons. The accuracy he provide is clinically acceptable in comparison with conventional methods, so there is sufficient evidence for their validity; however, it should be taken into account that several factors can alter the result, such as the operator's experience, the type of scanner, the type of software, the software update, the scanning principle of the scanner, the environment, the scanning sequence, and the oral structures. The present review article aims to analyze the literature on the different characteristics and properties that intraoral scanners present today and the evidence of the potential benefits and accuracy of digital impression techniques versus conventional impression techniques.

RESUMO O desenho assistido por computador e o fabrico assistido por computador (CAD-CAM) têm sido aplicados na medicina dentária para a preparação e análise de vários tratamentos dentários. Começa com a captura de imagens através de scanners intraorais, com vários tipos de software e sistemas e tecnologia de exportação de imagens. As vantagens deste fluxo de trabalho digital são as seguintes: melhor ajuste, menor tempo clínico, rapidez nos tratamentos dentários, além de proporcionar maior praticidade no uso dos cirurgiões-dentistas. A precisão que proporcionam é clinicamente aceitável quando comparada com os métodos convencionais, pelo que existem evidências suficientes para a sua validade; no entanto, deve ter-se em conta que vários fatores podem alterar o resultado, tais como a experiência do operador, o tipo de scanner, o tipo de software, a atualização do software, o princípio de digitalização do scanner, o ambiente, a sequência de digitalização e as estruturas orais. Este artigo de revisão tem como objetivo analisar a literatura sobre as diferentes características e propriedades dos scanners intraorais atuais, bem como a evidência dos potenciais benefícios e precisão das técnicas de moldagem digital em comparação com as técnicas de moldagem convencionais.

Quality Improvement Pathway of Cultivated Chinese Medicinal Materials Based on Physiological Ecology of Plants Under Adversity / 中国实验方剂学杂志

The quality of Chinese medicinal materials is related to the environment， with an optimal quality under adversity. The origin of Chinese medicinal materials has converted from wild collection to cultivation， and a better cultivation environment leads to a decline in their quality. At present， there are few effective methods to improve the quality of Chinese medicinal materials. Plants are bound to produce a large amount of reactive oxygen species （ROS） under adversity， and the quality improvement of Chinese medicinal materials under adversity may be achieved through ROS. This paper described the relationship between plant adversity-ROS-secondary metabolism： ROS can alter the structure of proteins （including enzymes） and regulate enzyme activities， thus affecting secondary metabolism to improve the adaptive capacity of plants. Therefore， ROS is the essential cause of adversity changing secondary metabolism. The cells of plants are omnipotent， and the medicinal parts of plants can independently complete the whole process of secondary metabolism， so regulation of secondary metabolism during the processing of fresh Chinese medicinal materials can significantly improve the quality of Chinese medicinal materials. Exogenous ROS can be used as inducible factors to stimulate medicinal parts， inducing a physiological state of fresh medicinal parts similar to that under adversity， thus enhancing secondary metabolism， and improving the contents of active ingredients in Chinese medicinal materials. In addition， the content and ratio of each ingredient in Chinese medicinal materials are closer to those of wild Chinese medicinal materials. The mechanism of plant adaptation to adversity is the mechanism of the quality formation of Chinese medicinal materials， and the application of ROS as inducible factors can provide a new pathway for the production of high-quality Chinese medicinal materials.

Bionic design,preparation and clinical translation of oral hard tissue restorative materials / 北京大学学报(医学版)

Oral diseases concern almost every individual and are a serious health risk to the popula-tion.The restorative treatment of tooth and jaw defects is an important means to achieve oral function and support the appearance of the contour.Based on the principle of"learning from the nature",Deng Xu-liang's group of Peking University School and Hospital of Stomatology has proposed a new concept of"microstructural biomimetic design and tissue adaptation of tooth/jaw materials"to address the worldwide problems of difficulty in treating dentine hypersensitivity,poor prognosis of restoration of tooth defects,and vertical bone augmentation of alveolar bone after tooth loss.The group has broken through the bottle-neck of multi-stage biomimetic technology from the design of microscopic features to the enhancement of macroscopic effects,and invented key technologies such as crystalline/amorphous multi-level assembly,ion-transportation blocking,and multi-physical properties of the micro-environment reconstruction,etc.The group also pioneered the cationic-hydrogel desensitizer,digital stump and core integrated restora-tions,and developed new crown and bridge restorative materials,gradient functionalisation guided tissue regeneration membrane,and electrically responsive alveolar bone augmentation restorative membranes,etc.These products have established new clinical strategies for tooth/jaw defect repair and achieved inno-vative results.In conclusion,the research results of our group have strongly supported the theoretical im-provement of stomatology,developed the technical system of oral hard tissue restoration,innovated the clinical treatment strategy,and led the progress of the stomatology industry.

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

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

Advances in Biochemical Sensor Devices Based on Two-dimensional Material Field Effect Transistors / 分析化学

Field effect transistor(FET)biochemical sensors show great potential in the fields of environmental monitoring,food safety,disease diagnosis and clinical treatment due to their low noise,low power consumption,label-free,easy integration and miniaturization characteristics.Two-dimensional(2D)materials,as a new generation of channel materials for FET biochemical sensors,have atomic-level thickness,high carrier mobility,high specific surface area and tunable bandgap,which can further improve the performance of FET biochemical sensors,extend their application areas,and promote the rapid development of FET biochemical sensors.This review focused on the development and latest progress of 2D material-based FET biochemical sensors,along with the challenges and prospects of 2D material-based FET biochemical sensors,which aimed to provide new device design conceptions and promote the further development of biochemical sensing technology.

Recognition of Tibetan Medicinal Material Slices Based on Multi-Feature Fusion Combined with Deep Learning Model / 世界科学技术-中医药现代化

Objective The objective of this study is to improve the accuracy of automatic identification in complex background herbal slice images.The goal is to achieve accurate recognition of herbal slice images in the presence of complex backgrounds.Methods The experiment was conducted on a collected and organized dataset of Tibetan herbal slice images.The RGB,HOG,and LBP features of the slices were analyzed.An improved HOG algorithm was used to fuse multiple features,and a deep learning network was utilized for image recognition.Results The proposed method of multi-feature fusion combined with deep learning achieved an identification accuracy of 91.68%on 3610 Tibetan herbal slice images with complex backgrounds.Furthermore,the average identification accuracy for 20 common traditional Chinese medicine slices,such as Chuan Beimu,Hawthorn,and Pinellia,reached 98.00%.This method outperformed existing methods for identifying herbal slices in complex backgrounds,indicating its feasibility and wide applicability for the identification of other traditional Chinese herbal medicines.Conclusion The fusion of multiple features effectively captures distinguishing characteristics of herbal slices in complex backgrounds.It exhibits high recognition rates for Tibetan herbal slices with complex and heavily occluded backgrounds,and can be successfully applied to the recognition of natural scene-based traditional Chinese herbal medicines and herbal slices.This approach shows promising prospects for practical applications.

Properties of polyetheretherketone and its application in prosthodontics / 实用口腔医学杂志

Polyetheretherketone(PEEK),as a new biomaterial,has been reported to have more performance studies and clinical application in the field of prosthetics in recent years.This paper reviewes the material research of PEEK from 4 aspects of its mechani-cal properties,processing properties,adhesive properties,and aesthetic properties,and then introduces the current status of its clini-cal application of removable and fixed PEEK oral restorations,respectively.

Advances of the application of 3D printing technology in dental teaching models / 实用口腔医学杂志

With the development of digital technology,computer-aided design and manufacturing(CAD/CAM)combined with 3D printing technology is increasingly used in clinical and teaching applications in dentistry.In clinical dentistry,3D printing technology has been widely used in oral and maxillofacial surgery,orthodontics and implantation.Traditional oral laboratory teaching usually uses extracted teeth,resin teeth or various dental models,while 3D printing of oral models can achieve standardized,mass-produced and close-to-real clinical application,which better meets the needs of clinical pre-practice teaching.This article reviews the latest educa-tional applications of 3D printing of dental models in teaching of oral restoration,dental pulp-cavity,oral and maxillofacial surgery,and summarizes the selection of different printing processes and printing materials,aiming to apply the research strategy of 3D printing technology in pre-clinical teaching in dentistry.Finally,the article explores the trends and urgent problems that need to be solved in the development of 3D printed dental models.

Preparation and performance of gelatin modified by methacrylic anhydride/treated dentin matrix bioactive scaffolds / 中国组织工程研究

BACKGROUND:Pulp regeneration has been a hot and difficult research topic in recent years,and the construction of composite bio-scaffolding materials provides new ideas and methods for pulp regeneration. OBJECTIVE:To observe the effect of freeze-dried gelatin modified by methacrylic anhydride/treated dentin matrix bioactive scaffolds on proliferation,migration,and osteogenic differentiation of human dental pulp stem cells. METHODS:The mass ratios of gelatin modified by methacrylic anhydride and treated dentin matrix at 2:1,1:1 and 1:2 were obtained by dispersing different masses of treated dentin matrix into gelatin modified by methacrylic anhydride solution.The gelatin modified by methacrylic anhydride/treated dentin matrix bioactive scaffolds were prepared by vacuum freeze-drying.The microstructure,water absorption,and mechanical properties of the scaffolds were measured.Human dental pulp stem cells were cultured with different mass ratios of scaffold extract and DMEM(control group)to detect cell proliferation and migration.Human dental pulp stem cells were cultured with different mass ratios of scaffold extract + osteogenic induction solution and DMEM + osteogenic induction solution(control group),and their osteogenic ability was analyzed by alkaline phosphatase staining. RESULTS AND CONCLUSION:(1)Under scanning electron microscopy,the scaffolds of the three groups all had porous structures.The porosity of the scaffolds increased with the increase of treated dentin matrix quality,and there was significant difference between the two groups(P＜0.05).The water absorption of scaffolds increased with the increase of treated dentin matrix mass,and there was significant difference between groups(P＜0.05).The compressive strength and shear strength of the scaffold increased with the increase of the mass of treated dentin matrix.(2)CCK-8 assay showed that after 3,5,and 7 days of culture,the cell proliferation absorbance values in the 2:1,1:1,and 1:2 scaffold groups were higher than those in the control group(P＜0.05).The cell proliferation absorbance values increased with the increase of treated dentin matrix mass in the scaffold(P＜0.05).The cell scratch test showed that the cell migration rate in the 2:1,1:1,and 1:2 scaffold groups was higher than that in the control group(P＜0.05),and the cell migration rate increased with the increase of treated dentin matrix mass in the scaffold(P＜0.05).(3)Alkaline phosphatase staining showed that the osteogenic differentiation ability of cells in the 2:1,1:1,and 1:2 scaffold groups was stronger than that in the control group,and the osteogenic ability of cells was enhanced with the increase of treated dentin matrix mass in the scaffold.(4)The results showed that the scaffold with a mass ratio of 1:2 between gelatin modified by methacrylic anhydride and treated dentin matrix was the most suitable for the proliferation and differentiation of dental pulp stem cells.

Research progress on dental materials for preventing root caries / 口腔疾病防治

@#The high incidence and untreated rate of root caries, a common and frequently occurring oral disease with challenging treatment in elderly individuals, is the main cause of tooth loss among elderly people, as rapid development results in pulpitis and periapical periodontitis or residual crown and root, which has been regarded as one of the common chronic oral diseases seriously affecting the quality of life of elderly people. Thus, early intervention and prevention are important. Traditional dental materials for preventing root caries have been widely used in clinical practice; however, they have the disadvantages of tooth coloring, remineralization and low sterilization efficiency. A series of new dental materials for preventing root caries have gradually become a research hotspot recently, which have the advantages of promoting the mineralization of deep dental tissue, prolonging the action time and enhancing adhesion. Future caries prevention materials should be designed according to the characteristics of root surface caries and the application population and should be developed toward simplicity, high efficiency and low toxicity. This review describes current research regarding anti-caries prevention material application, serving as a theoretical underpinning for the research of root caries prevention materials, which is important for both promotion in the effective prevention of root caries and improvement in the status of oral health and the quality of life among old people.

Methods for Identifying Seeds of Chinese Medicinal Materials： A Review / 中国实验方剂学杂志

Seeds are the source for the production of Chinese medicinal materials. The seed authenticity and quality of directly affect the effectiveness and safety of Chinese medicinal materials. The seed quality is faced with the problems such as mixed sources， existence of adulterants and seeds stocked for years， low maturity， and low purity. To ensure the high-quality and sustainable development of the Chinese medicinal material industry， it is urgent to standardize the seed market and identify and evaluate the quality of the seeds circulating in the market. Seed identification methods include visual inspection， microscopic observation， micro-character identification， chemical fingerprinting， molecular identification， electronic nose， X-ray diffraction， electrochemical fingerprinting， spectral imaging， and artificial intelligence. These methods have different application scopes and unique advantages and disadvantages. According to the different species of Chinese herbal medicines and different requirements of testing sites， suitable methods can be selected to achieve rapid and accurate identification with low costs. In the future， the seed identification methods should be developed based on emerging technologies with interdisciplinary knowledge， and intelligent， nondestructive， and single-grain detection methods are needed for the modern Chinese medicinal material industry. This paper introduces the seed identification technologies currently applied in research and production， compares the principles， applicability， advantages， and disadvantages of different technologies， and provides an outlook on the future development of seed identification technologies， aiming to provide a reference for the identification and quality evaluation of seeds of Chinese medicinal material.

Culture of rabbit corneal stromal cells on thermo-sensitive materials by the radiation polymerization / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To explore the synthesis of thermo-sensitive poly N-isopropylacry-lamide(PNIPAAm)and the petri dish grafted with PNIPAAm hydrogels by the electron accelerator, as well as the growth conditions and the biological characteristics of rabbit corneal stromal cells on thermo-sensitive PNIPAAm hydrogels, and the cell sheets obtained from the PNIPAAm hydrogels.METHODS: NIPAAm monomer was dissolved in 2-propanol at concentrations of 55% with 0.5% N,N'-Methylenebisacry-lamide(MBA). Solution(70 μL)was added and spread uniformly over 35 mm petri dish. These dishes were immediately subjected to irradiation. After follow-up treatment, rabbit corneal stromal cells were cultured on thermo-sensitive petri dish in vitro.RESULTS: According to the monomer formula and radiation synthesis scheme in this experiment, PNIPAAm can be synthesized on the surface of the petri dish. Rabbit corneal stromal cells grew well in the thermo- sensitive surface and can be separated into sheets.CONCLUSION: The single and multilayer carrier-free cell sheets can be obtained from the use of thermo-sensitive petri dish.

Research Progress in Comprehensive Utilization of Solid By-products in the Process of Industrialization of Chinese Materia Medica / 中国中医药信息杂志

With the rapid development and expansion of the scale of the industry of Chinese materia medica,a large number of by-products in the process industrialization of Chinese materia medica have been produced,among which,the solid by-products of Chinese materia medica have been favoured by researchers due to the fact that they are rich in a large number of proteins,cellulose,hemicellulose,lignin,etc.,which can be used in the preparation of high value-added products.Therefore,the authors elaborated on the research on biochemical conversion,thermochemical conversion,resource oriented chemical components,preparation of biomass fuel,new composite materials and high-efficiency adsorbent of solid by-products in the process of industrialization of Chinese materia medica in recent years,aiming to provide theoretical basis for the comprehensive and high-value utilization of the solid by-products of Chinese materia medica and extension of the industrial chain.

Visualization Analysis on Research Hotspots and Trends of Animal Medicinal Materials from 2000 to 2003 / 中国中医药信息杂志

Objective To understand the research status,hotspots and trends of animal medicinal materials;To provide reference for future research.Methods The literature related to animal medicinal materials was retrieved from CNKI,VIP,Wanfang Data and CBM from January 1,2000 to April 30,2023.NoteExpress 3.6 was used to merge and deduplicate,and the author,institution and keywords were mapped and interpreted by CiteSpace 6.1.R6 software.Results A total of 1 169 articles were included,and the overall publication quantity in this field showed a stable fluctuation trend;the top journals were Lishizhen Medicine and Materia Medica Research,China Journal of Chinese Materia Medica and Modern Chinese Medicine;the main research institutions were China Academy of Chinese Medical Sciences,Changchun University of Chinese Medicine and Chinese Academy of Medical Sciences;a total of 676 authors were involved,and the authors with more publications included Zhang Hui(22),Liu Rui(15),Lin Zhe and Ma Shuangcheng(14);high-frequency keywords included"identification","TCM resources","clinical application"and so on.Conclusion Resource survey of animal medicinal materials,standardized breeding of medicinal animals,development of alternatives to rare medicinal animal resources,and construction of quality standard system for animal medicinal materials are the research hotspots in this field.The basic research of pharmacodynamic substances of animal medicinal materials based on the integrated analysis strategies of proteomics,peptideomics and transcriptomics,and the revelation of the signaling pathways and targets of animal medicinal materials from the molecular biology level are the research trends in this field.

Investigation on polyurethane grouting waterproof material-induced occupational acute 1,2-dichloroethane poisoning in the construction industry / 中国职业医学

ObjectiveTo analyze the causes of occupational acute 1,2-dichloroethane (1,2-DCE) poisoning accident during the use of polyurethane grouting materials for waterproof plugging operation in the construction industry. Methods By combining the clinical symptoms of the patient, worksite survey of occupational health and workplace occupational hazards monitoring method, the cause of an occupational acute 1,2-DCE poisoning accident was investigated at a construction site during the use of polyurethane grouting material for waterproofing and plugging operations. Results The patient was engaged in waterproof grouting work using polyurethane grouting material. The main volatile organic components in the raw materials were 1,2-DCE, with traces of dichloromethane, methyl acetate and others. The result of post-incident on-site investigation showed that the short-term exposure concentration of 1,2-DCE in the workplace air was 578.70 mg/m3, which was more than 30 times higher than the national occupational health standard limit. The mass concentration of 1,2-DCE in the patient's blood was 230 μg/L. Combined with the patient's occupational hazard exposure history, clinical manifestations, worksite survey of occupational health, and laboratory test results, according to GBZ 39-2016 Diagnosis of Occupational Acute 1,2-Dichloroethane Poisoning, this incident was diagnosed as a severe occupational acute 1,2-DCE poisoning event caused by the use of inferior polyurethane grouting material. Conclusion The excessive concentration of 1,2-DCE in the workplace air is the main cause of this poisoning accident. Construction sites with confined space operations should improve various occupational health management systems, occupational health engineering protective facilities, and personal protective equipment must be provided for workers.