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El artículo se centra en la aplicación de tecnología CAD/CAM en la odontología, específicamente en la fabricación de prótesis dentales totales. Este avance ha transformado la forma en que se diseñan y producen estas prótesis, emergiendo la fabricación de ella mediante capas sucesivas a base de tecnologías de impresión 3D como la estereolitografía, el procesamiento digital de luz y la pantalla de cristal líquido. En la presente revisión se profundizó en aspectos clínicos y biomecánicos, evaluando la retención, adaptación de la base, resistencia a la flexión y límite elástico de las prótesis. Los resultados indican que las prótesis digitales ofrecen mejor retención y adaptación en comparación con los métodos convencionales, aunque no hay diferencias estadísticamente significativas en resistencia a la flexión. También se exploraron aspectos económicos, destacando la reducción de costos y ahorro de tiempo en el proceso clínico con el enfoque digital. Los pacientes experimentan mayor satisfacción con prótesis impresas en 3D en términos de comodidad y eficiencia. Sin embargo, existen limitaciones, como la dificultad en la evaluación estética de prótesis monocromáticas, además de la dependencia de técnicas convencionales para evaluar la funcionalidad del paciente. La tecnología CAD/CAM ha revolucionado la fabricación de prótesis dentales totales, ofreciendo ventajas y beneficios. Este avance tecnológico promete mantener su relevancia en la comunidad científica y odontológica.

The article focuses on the application of CAD/CAM technology in dentistry, specifically in the manufacturing of complete dentures. This advance has transformed the way these dentures are designed and produced, with the manufacturing of layers emerging through successive 3D printing technologies such as stereolithography, digital light processing and liquid crystal display. In the present review clinical and biomechanical aspects were delved into, evaluating retention, adaptation of the base, resistance to flexion and elastic limit of the prostheses. The results indicate that digital prostheses offer better retention and adaptation compared to conventional methods, although there are no statistically significant differences in bending resistance. Economic aspects were also explored, highlighting the cost reduction and time savings in the clinical process with the digital approach. Patients experience greater satisfaction with 3D printed dentures in terms of comfort and efficiency. However, there are limitations, such as the difficulty in the aesthetic evaluation of monochromatic dentures, in addition to the dependence on conventional techniques to evaluate the patient's functionality. CAD/CAM technology has revolutionized the manufacturing of total dental prostheses, offering advantages and benefits. These technological advance promises to maintain its relevance in the scientific and dental community.

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Objective To evaluate whether three-dimensional (3D) printing increases agreement in the classification of tibial pilon fractures. Methods Orthopedists and traumatologists reviewed radiographs, computed tomography scans with 3D reconstruction, and prototyping 3D printing, and classified the fractures based on the Rüedi-Allgöwer and Arbeitsgemeinschaft für Osteosynthesefragen (AO, Association for the Study of Internal Fixation) Foundation/Orthopedic Trauma Association (AO/OTA) classification systems. Next, data evaluation used Kappa agreement coefficients. Results The use of the 3D model did not improve agreement for tibial pilon fractures regarding the treatment proposed by the groups. Regarding the classification systems, the agreement only improved concerning the AO/OTA classification when the 3D model was used in the assessment by the foot and ankle specialists. Conclusion Although 3D printing is statistically relevant for surgeons specializing in foot and ankle, its values remain lower than optimal.

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Abstract Objective To evaluate whether three-dimensional (3D) printing increases agreement in the classification of tibial pilon fractures. Methods Orthopedists and traumatologists reviewed radiographs, computed tomography scans with 3D reconstruction, and prototyping 3D printing, and classified the fractures based on the Rüedi-Allgöwer and Arbeitsgemeinschaft für Osteosynthesefragen (AO, Association for the Study of Internal Fixation) Foundation/Orthopedic Trauma Association (AO/OTA) classification systems. Next, data evaluation used Kappa agreement coefficients. Results The use of the 3D model did not improve agreement for tibial pilon fractures regarding the treatment proposed by the groups. Regarding the classification systems, the agreement only improved concerning the AO/OTA classification when the 3D model was used in the assessment by the foot and ankle specialists. Conclusion Although 3D printing is statistically relevant for surgeons specializing in foot and ankle, its values remain lower than optimal.

Resumo Objetivo Avaliar se a impressão tridimensional (3D) aumenta a concordância na classificação de fraturas do pilão tibial. Métodos Foram selecionadas radiografias, tomografias com reconstrução 3D e impressão de prototipagem em impressora 3D. Os exames foram apresentados a profissionais da área de Ortopedia e Traumatologia que classificaram as fraturas com base nas classificações da Arbeitsgemeinschaft für Osteosynthesefragen (AO, Associação para o Estudo da Fixação Interna) Foundation/Orthopedic Trauma Association (AO/OTA) e de Rüedi-Allgöwer. Posteriormente, os dados foram avaliados pelos coeficientes de concordância de Kappa. Resultados O uso do modelo 3D não melhorou a concordância na fratura do pilão tibial quanto ao tratamento proposto pelos grupos. Em relação aos sistemas de classificação, somente a concordância na classificação AO/OTA melhorou quando foi utilizado o modelo 3D na avaliação pelos especialistas em pé e tornozelo. Conclusão Apesar de o uso da impressão 3D ter relevância estatística para os cirurgiões especialistas em pé e tornozelo, ainda apresenta valores menores do que os ideais.

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Rapid prototyping technology, known as three-dimensional (3D) printing, and its use in the medical field are advancing. Studies on severe bone deformity treatment with 3D printing showed benefits in postoperative outcomes thanks to this technology. Even so, preoperative planning guidance for surgeons is lacking. This technical note describes a practical step-by-step guide to help surgeons use this technology to optimize the therapeutic plan with free license software and an intuitive interface. This study aims to organize the 3D modeling process using a preoperative computed tomography (CT) scan. This technology allows a deeper understanding of the case and its particularities, such as the direction, planes, and dimensions of the deformity. Planning considering these topics may reduce the surgical time and result in better functional outcomes by understanding the deformity and how to correct it. Associating planning via software with 3D printing can further enhance this therapeutic method.

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ABSTRACT Introduction: 3-dimensional printing has enabled the development of unique and affordable additive manufacturing, including the prototyping and production of surgical forceps. Objective: demonstrate the development, 3D printing and mechanical-functional validation of a laparoscopic grasping forceps. Methods: the clamp was designed using a computer program and printed in 3 dimensions with polylactic acid (PLA) filament and added 5 screws for better leverage. Size and weight measurements were carried out, as well as mechanicalfunctional grip and rotation tests in the laboratory with a validated simulator. Results: Called "Easylap", the clamp weighed 48 grams, measured 43cm and was printed in 8 pieces, taking an average of 12 hours to produce. It allowed the simulation of the functional characteristics of laparoscopic pressure forceps, in addition to the rotation and rack locking mechanism. However, its strength is reduced due to the material used. Conclusion: It is possible to develop plastic laparoscopic grasping forceps through 3-dimensional printing.

RESUMO Introdução: a impressão em 3 dimensões permitiu o desenvolvimento de manufaturas aditivas únicas e acessíveis, inclusive na prototipagem e produção de pinças cirúrgicas. Objetivo: Demonstrar o desenvolvimento, a impressão em 3D e a validação mecânico-funcional de pinça laparoscópica do tipo apreensão. Métodos: a pinça foi desenhada em programa de computador e impressa em 3 dimensões com filamento de ácido poliláctico (PLA) e acrescida de 5 parafusos para melhor efeito de alavanca. Foram realizadas aferições de tamanho e peso, bem como testes mecânicos-funcionais de preensão e rotação em laboratório com simulador validado. Resultados: denominada "Easylap", a pinça pesou 48 gramas, mediu 43 cm e foi impressa em 8 peças, levando em média 12 horas para sua produção. Ela permitiu a simulação das características funcionais de pinça laparoscópicas de apreensão, além de mecanismo de rotação e travamento por cremalheira. Porém sua força é reduzida devido ao material utilizado. Conclusão: é possível desenvolver pinça laparoscópica plástica de apreensão através de impressão em 3 dimensões.

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Abstract Computer-aided manufacturing (CAM) technology allows the use of different manufacturing techniques. This in vitro study aimed to evaluate the marginal fit of temporary restorations manufactured using conventional chairside methods, milling, and three-dimensional printing. Fifteen 3-element temporary restorations specimens were produced and categorized into three groups: non-digital, obtained using the conventional chairside method (GC); milled (GM); and three-dimensionally printed (GP). Marginal fit was assessed using scanning electron microscopy (SEM) performed under two conditions: one with only the central screw tightened, and the other with all three screws tightened. Horizontal misfit values were categorized as over-, equal-, and under-extended and qualitatively analyzed. Statistical analysis was performed using the Tukey-Kramer test (α=0.05). In the vertical assessment, three-dimensionally printed restorations demonstrated greater misfit than restorations obtained by milling and the conventional chairside method (P<0.05). In the horizontal assessment, the misfit in the GP group was significantly higher than that in the GM and GC groups. Restorations obtained using the conventional chairside method and milled provisional restorations showed more favorable results than three-dimensionally printed restorations.

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ABSTRACT Purpose: To develop and assess three-dimensional models of physeal fractures in dog femurs (3D MPFDF) using radiographic imaging. Methods: The study was conducted in three phases: development of 3D MPFDF; radiographic examination of the 3D MPFDF; and comparative analysis of the anatomical and radiographic features of the 3D MPFDF. Results: The base model and the 3D MPFDF achieved high fidelity in replicating the bone structures, accurately maintaining the morphological characteristics and dimensions such as length, width, and thickness, closely resembling natural bone. The radiographs of the 3D MPFDF displayed distinct radiopaque and radiolucent areas, enabling clear visualization of the various anatomical structures of the femur. However, in these radiographs, it was challenging to distinguish between the cortical and medullary regions due to the use of 99% internal padding in the printing process. Despite this limitation, the radiographs successfully demonstrated the representation of the Salter-Harris classification. Conclusions: This paper presents a pioneering project focused on technological advancement aimed at developing a method for the rapid and cost-effective production of three-printed models and radiographs of physeal fractures in dogs.

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ABSTRACT Purpose: To evaluate the impact of simulators on the training of urology residents in retrograde intrarenal surgery (RIRS). Methods: The study involved training eight urology residents, using two artificial simulators; one developed by the Universidade Estadual do Pará, using three-dimensional printing technology, and the other one patented by the medical equipment manufacturer Boston Scientific The qualification of residents took place through a training course, consisting of an adaptation phase (S0), followed by three training sessions, with weekly breaks between them (S1, S2 and S3). Study members should carry out a RIRS in a standardized way, with step-by-step supervision by the evaluator using a checklist. The participants' individual performance was verified through a theoretical assessment, before and after training (pre- and post-training), as well as by the score achieved in each session on a scale called global psychomotor skill score. In S3, residents performed an analysis of the performance and quality of the simulation, by completing the scale of student satisfaction and self confidence in learning (SSSCL). Results: At the end of the course, everyone was able to perform the procedure in accordance with the standard. The training provided a learning gain and a considerable improvement in skills and competencies in RIRS, with p < 0.05. SSSCL demonstrated positive feedback, with an overall approval rating of 96%. Conclusions: Artificial simulators proved to be excellent auxiliary tools in the training of urology residents in RIRS.

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Abstract Rapid prototyping technology, known as three-dimensional (3D) printing, and its use in the medical field are advancing. Studies on severe bone deformity treatment with 3D printing showed benefits in postoperative outcomes thanks to this technology. Even so, preoperative planning guidance for surgeons is lacking. This technical note describes a practical step-by-step guide to help surgeons use this technology to optimize the therapeutic plan with free license software and an intuitive interface. This study aims to organize the 3D modeling process using a preoperative computed tomography (CT) scan. This technology allows a deeper understanding of the case and its particularities, such as the direction, planes, and dimensions of the deformity. Planning considering these topics may reduce the surgical time and result in better functional outcomes by understanding the deformity and how to correct it. Associating planning via software with 3D printing can further enhance this therapeutic method.

Resumo Observa-se o avanço da tecnologia de prototipagem rápida, conhecida como impressão tridimensional (3D) e seu uso na área médica. Existem estudos a respeito do tratamento de deformidades ósseas graves com impressão 3D, os quais mostram benefícios no resultado pós-operatório às custas do uso da tecnologia em questão. Ainda assim, nota-se a escassez quando o assunto é disponibilizar ao cirurgião orientações para planejamento pré-operatório. O objetivo desta nota técnica é descrever um passo-a-passo prático para auxiliar cirurgiões a utilizarem a tecnologia como ferramenta para otimizar o plano terapêutico, dispondo de um programa de licença gratuita e de interface intuitiva. Este é um estudo que visa a organização do processo de modelagem 3D, no qual foi utilizado um exame de tomografia computadorizada (TC) pré-operatória. Com esta tecnologia, é possível uma compreensão mais profunda do caso e suas particularidades como direção, planos e dimensões das deformidades. Acredita-se que um planejamento que leve em consideração tais tópicos gera redução do tempo cirúrgico e melhores resultados funcionais devido ao entendimento da deformidade e maneiras de correção. Associar o planejamento via software com a impressão 3D pode potencializar ainda mais na elaboração do método terapêutico.

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Objective The interest in using 3D printing in the healthcare field has grown over the years, given its advantages and potential in the rapid manufacturing of personalized devices and implants with complex geometries. Thus, the aim of the present study was to compare the mechanical fixation behavior of a 3D-printed interference screw, produced by fused deposition modeling of polylactic acid (PLA) filament, with that of a titanium interference screw. Methods Eight deep flexor porcine tendons, approximately 8 mm wide and 9 cm long, were used as graft and fixed to a 40 pounds-per-cubic-foot (PCF) polyurethane block at each of its extremities. One group was fixed only with titanium interference screws (group 1) and the other only with 3D-printed PLA screws (BR 20 2021 018283-6 U2) (group 2). The tests were conducted using an EMIC DL 10000 electromechanical universal testing machine in axial traction mode. Results Group 1 (titanium) obtained peak force of 200 ± 7 N, with mean graft deformation of 8 ± 2 mm, and group 2 (PLA) obtained peak force of 300 ± 30 N, and mean graft deformation of 7 ± 3 mm. Both the titanium and PLA screws provided good graft fixation in the polyurethane block, with no slippage or apparent deformation. In all the samples, the test culminated in graft rupture, with around 20 mm of deformation in relation to the initial length. Conclusion The 3D-printed PLA screw provided good fixation, similar to that of its titanium counterpart, producing satisfactory and promising results.

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Abstract Objective The interest in using 3D printing in the healthcare field has grown over the years, given its advantages and potential in the rapid manufacturing of personalized devices and implants with complex geometries. Thus, the aim of the present study was to compare the mechanical fixation behavior of a 3D-printed interference screw, produced by fused deposition modeling of polylactic acid (PLA) filament, with that of a titanium interference screw. Methods Eight deep flexor porcine tendons, approximately 8 mm wide and 9 cm long, were used as graft and fixed to a 40 pounds-per-cubic-foot (PCF) polyurethane block at each of its extremities. One group was fixed only with titanium interference screws (group 1) and the other only with 3D-printed PLA screws (BR 20 2021 018283-6 U2) (group 2). The tests were conducted using an EMIC DL 10000 electromechanical universal testing machine in axial traction mode. Results Group 1 (titanium) obtained peak force of 200 ± 7 N, with mean graft deformation of 8 ± 2 mm, and group 2 (PLA) obtained peak force of 300 ± 30 N, and mean graft deformation of 7 ± 3 mm. Both the titanium and PLA screws provided good graft fixation in the polyurethane block, with no slippage or apparent deformation. In all the samples, the test culminated in graft rupture, with around 20 mm of deformation in relation to the initial length. Conclusion The 3D-printed PLA screw provided good fixation, similar to that of its titanium counterpart, producing satisfactory and promising results.

Resumo Objetivo O interesse em utilizar a impressão 3D na área da saúde tem crescido ao longo dos anos, dadas as suas vantagens e o seu potencial na rápida fabricação de dispositivos e implantes personalizados com geometrias complexas. Assim, o objetivo do presente estudo foi comparar o comportamento de fixação mecânica de um parafuso de interferência impresso em 3D, produzido pela modelagem fundida de deposição do filamento de ácido polilático (PLA), com o de um parafuso de interferência de titânio. Métodos Oito tendões suínos flexores profundos, de aproximadamente 8 mm de largura e 9 cm de comprimento, foram utilizados como enxerto e fixados em um bloco de poliuretano de 40 PCF em cada uma de suas extremidades. Um grupo foi fixado apenas com parafusos de interferência de titânio (grupo 1) e o outro apenas com parafusos PLA impressos em 3D (BR 20 2021 018283-6 U2) (grupo 2). Os testes foram realizados utilizando uma máquina de teste universal eletromecânica EMIC DL 10.000 no modo de tração axial. Resultados O grupo 1 (titânio) obteve força máxima de 200 ± 7 N com deformação média do enxerto de 8 ± 2 mm, e a força máxima do grupo 2 (PLA) foi de 300 ± 30 N e deformação média do enxerto de 7 ± 3 mm. Ambos os parafusos de titânio e PLA forneceram boa fixação de enxerto no bloco de poliuretano, sem deslizamento ou deformação aparente. Em todas as amostras o teste culminou na ruptura do enxerto, com cerca de 20 mm de deformação em relação ao comprimento inicial. Conclusão O parafuso PLA impresso em 3D proporcionou boa fixação, semelhante à de sua contraparte de titânio, produzindo resultados satisfatórios e promissores.

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Objetivo: Discorrer sobre o tratamento cirúrgico de uma fratura idiopática de mandíbula atrófica. Relato de caso: Idosa compareceu à emergência de um hospital referência em traumas na Paraíba relatando dificuldade ao se alimentar, impossibilidade de uso da prótese dentaria, sintomatologia dolorosa em região mandibular direita com processo infeccioso ativo, sem histórico de trauma direto em face. Ao exame tomográfico constatou-se fratura em mandíbula atrófica com presença de dente incluso na região. Diante do quadro, optou-se por iniciar antibioticoterapia empírica e planejou-se tratamento cirúrgico de reconstrução mandibular com sistema load-sharing, tendo auxílio de biomodelo para conformação prévia da placa. Conclusão: O correto planejamento e escolha do sistema de fixação são fundamentais para o sucesso do tratamento. O uso de biomodelo com pré modelagem de placa mostrou-se positivo por otimizar o tempo cirúrgico, reduzindo os riscos inerentes ao procedimento nesta faixa etária e a utilização de sistema capaz de suportar a carga sofrida na estrutura óssea comprometida nestes casos é mandatório... (AU)

Objective: to discuss the surgical treatment of an idiopathic fracture of the atrophic mandible. Case report: elderly woman attended the emergency department of the Emergency and Trauma Hospital Dom Luiz Gonzaga Fernandes, in Campina Grande, Brazil. The patient reported pain on eating and inability to use her denture as painful symptoms in the right mandibular region with active fistula, without any records of facial trauma. Tomographic examination revealed an atrophic mandibular fracture with an impacted tooth in the region. The following procedures were performed: antibiotic therapy, surgical fixation using a 2.4mm pre-molded plate, shaped using a biomodel, and fistulectomy. Conclusion: Thus, to plan accordingly aiming to minimize the surgical time and its associate damage and the use of appropriate fixation systems capable of supporting the load on the compromised bone are essential to a successful treatment, specially with elderly patients due their general health condition and preexistent comorbities... (AU)

Objetivo: Discutir sobre el tratamiento quirúrgico de una fractura idiopática de la mandíbula atrófica. Caso clínico: Anciana compareció al servicio de urgencias del Hospital de Emergencia y Trauma de Campina Grande Dom Luiz Gonzaga Fernandes, PB, relatando dificultad para alimentarse, imposibilidad de uso de prótesis dental, sintomatología dolorosa en la región mandibular derecha con fístula activa, sin antecedentes de traumatismo directo en la cara. El examen tomográfico presentó una fractura mandibular atrófica con presencia de un diente incluido en la región. Como resultado se realizó antibioticoterapia, procedimiento de fijación quirúrgica con una placa de 2,4 mm premoldeada en biomodelo y fistulectomía. Conclusión: De esta forma, el correcto planeamiento para minimizar el tiempo quirúrgico y los daños asociados, principalmente en los ancianos por su estado general de salud y comorbilidades preexistentes, la utilización de sistemas de fijación adecuados capaces de soportar la carga sufrida en los huesos comprometidos, es fundamental para el éxito del tratamiento... (AU)

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Objective To evaluate a proposed three-dimensional (3D) printing process of a biomodel developed with the aid of fused deposition modeling (FDM) technology based on computed tomography (CT) scans of an individual with nonunion of a coronal femoral condyle fracture (Hoffa's fracture). Materials and Methods Thus, we used CT scans, which enable the evaluation of the 3D volumetric reconstruction of the anatomical model, as well as of the architecture and bone geometry of sites with complex anatomy, such as the joints. In addition, it enables the development of the virtual surgical planning (VSP) in a computer-aided design (CAD) software. This technology makes it possible to print full-scale anatomical models that can be used in surgical simulations for training and in the choice of the best placement of the implant according to the VSP. In the radiographic evaluation of the osteosynthesis of the Hoffa's fracture nonunion, we assessed the position of the implant in the 3D-printed anatomical model and in the patient's knee. Results The 3D-printed anatomical model showed geometric and morphological characteristics similar to those of the actual bone. The position of the implants in relation to the nonunion line and anatomical landmarks showed great accuracy in the comparison of the patient's knee with the 3D-printed anatomical model. Conclusion The use of the virtual anatomical model and the 3D-printed anatomical model with the additive manufacturing (AM) technology proved to be effective and useful in planning and performing the surgical treatment of Hoffa's fracture nonunion. Thus, it showed great accuracy in the reproducibility of the virtual surgical planning and the 3D-printed anatomical model.

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Objective Due to the popularity of 3D technology, surgeons can create specific surgical guides and sterilize them in their institutions. The aim of the present study is to compare the efficacy of the autoclave and ethylene oxide (EO) sterilization methods for objects produced by 3D printing with polylactic acid (PLA) material. Methods Forty cubic-shaped objects were printed with PLA material. Twenty were solid and 20 were hollow (printed with little internal filling). Twenty objects (10 solid and 10 hollow) were sterilized in autoclave, forming Group 1. The others (10 solid and 10 hollow) were sterilized in EO, composing Group 2. After sterilization, they were stored and referred to culture. Hollow objects of both groups were broken during sowing, communicating the dead space with the culture medium. The results obtained were statistically analyzed (Fisher exact test and residue analysis). Results In group 1 (autoclave), there was bacterial growth in 50% of solid objects and in 30% of hollow objects. In group 2 (EO), growth occurred in 20% of hollow objects, with no bacterial growth in solid objects (100% of negative samples). The bacteria isolated in the positive cases was non-coagulase-producing Staphylococcus Gram positive. Conclusions Sterilization by both autoclave and EO was not effective for hollow printed objects. Solid objects sterilized by autoclave did not demonstrate 100% of negative samples and were not safe in the present assay. Complete absence of contamination occurred only with solid objects sterilized by EO, which is the combination recommended by the authors.

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Na formação em Odontologia os acadêmicos realizam treinos pré-clínicos para aperfeiçoar suas técnicas. O objetivo deste estudo é relatar a experiência de produção de dentes decíduos artificiais por impressão tridimensional (3D), com baixo custo, para práticas laboratoriais acadêmicas em Odontopediatria. Partiu-se de uma pesquisa laboratorial e experimental, tendo sido realizada uma revisão bibliográfica para obtenção dos dados. A obtenção das imagens 3D se deu a partir da biblioteca gratuita de dentes permanentes Brenner e edição no programa Meshmixer para incorporação das características de dentes decíduos, seguida de impressão 3D utilizando estereolitografia. Posteriormente, foram preenchidos os condutos radiculares com cera 7 e poliacetato de vinila (PVA)vermelha. Foi realizada também a pintura do cemento e da coroa, com tinta de esmalte marrom e branca, respectivamente. As duas resinas exibiram fidelidade anatômica externa, entretanto, para viabilidade do uso na Endodontia, foi analisada a anatomia interna, imagem radiográfica, tempo de impressão, custo de produção e custo/benefício. A combinação de resina Anycubic para a representação dos tecidos mineralizados com cera 7 para simulação da polpa possibilitou a adequada reprodução da anatomia interna de dentes decíduos (AU).

En la formación en Odontología, los alumnos realizan una formación preclínica para mejorar sus técnicas. El objetivo de este estudio es relatar la experiencia de producción de dientes temporales artificiales por impresión tridimensional (3D), a bajo costo,para prácticas académicas de laboratorio en Odontopediatría. Se inició con una investigación de laboratorio y experimental, habiéndose realizado una revisión bibliográfica para la obtención de los datos. Las imágenes 3D se obtuvieran de la biblioteca gratuita de dientes permanentes de Brenner y se editó en el programa Meshmixer para incorporar las características de los dientes temporales, seguida de una impresión 3D mediante estereolitografía. Posteriormente se obturaron los conductos radiculares con cera7 y acetato de polivinilo rojo (PVA). El cemento y la corona también se pintaron con pintura de esmalte marrón y blanco, respectivamente. Las dos resinas exhibieron fidelidad anatómica externa, sin embargo, para la factibilidad de uso en Endodoncia se analizó la anatomía interna, imagen radiográfica, tiempo de impresión, costo de producción y costo/beneficio. La combinación de la resina Anycubic para la representación de tejidos mineralizados con la cera 7 para la simulación de la pulpa permitió reproduciradecuadamente la anatomía interna de los dientes temporales (AU).

During Dentistry training, students undertake pre-clinical training to improve their techniques. The objective of this study is to report the experience of producing artificial deciduous teeth using three-dimensional (3D) printing, at low cost, for academic laboratory practices in Pediatric Dentistry. The starting point was laboratory and experimental research, and a bibliographic review was carried out to obtain data. The 3D images were obtained from the free Brenner permanent teeth library and edited in the Meshmixer program to incorporate the characteristics of deciduous teeth, followed by 3D printing using stereolithography. Subsequently, the root canals were filled with wax 7 and red polyvinyl acetate (PVA). The cementum and crown were also painted with brown and white enamel paint, respectively. The two resins exhibited external anatomical fidelity, however, for feasibility of use in Endodontics, the internal anatomy, radiographic image, printing time, production cost and cost/benefit were analyzed. The combination of Anycubic resin to represent mineralized tissues with wax 7 to simulate the pulp made it possible to adequately reproduce the internal anatomy of deciduous teeth (AU).

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Abstract Objective To evaluate a proposed three-dimensional (3D) printing process of a biomodel developed with the aid of fused deposition modeling (FDM) technology based on computed tomography (CT) scans of an individual with nonunion of a coronal femoral condyle fracture (Hoffa's fracture). Materials and Methods Thus, we used CT scans, which enable the evaluation of the 3D volumetric reconstruction of the anatomical model, as well as of the architecture and bone geometry of sites with complex anatomy, such as the joints. In addition, it enables the development of the virtual surgical planning (VSP) in a computer-aided design (CAD) software. This technology makes it possible to print full-scale anatomical models that can be used in surgical simulations for training and in the choice of the best placement of the implant according to the VSP. In the radiographic evaluation of the osteosynthesis of the Hoffa's fracture nonunion, we assessed the position of the implant in the 3D-printed anatomical model and in the patient's knee. Results The 3D-printed anatomical model showed geometric and morphological characteristics similar to those of the actual bone. The position of the implants in relation to the nonunion line and anatomical landmarks showed great accuracy in the comparison of the patient's knee with the 3D-printed anatomical model. Conclusion The use of the virtual anatomical model and the 3D-printed anatomical model with the additive manufacturing (AM) technology proved to be effective and useful in planning and performing the surgical treatment of Hoffa's fracture nonunion. Thus, it showed great accuracy in the reproducibility of the virtual surgical planning and the 3D-printed anatomical model.

Resumo Objetivo Avaliar uma proposta de processo de impressão tridimensional (3D) de um biomodelo preparado com o auxílio da tecnologia de modelagem por deposição de material fundido (fused deposition modeling, FDM, em inglês) a partir de imagens de tomografia computadorizada (TC) de um indivíduo com pseudartrose de fratura coronal do côndilo femoral (fratura de Hoffa). Materiais e Métodos Para tanto, utilizamos imagens de TC, que permitem estudar a reconstrução volumétrica 3D do modelo anatômico, além da arquitetura e geometria óssea de sítios de anatomia complexa, como as articulações. Também permite o planejamento cirúrgico virtual (PCV) em um programa de desenho assistido por computador (computer-aided design, CAD, em inglês). Essa tecnologia possibilita a impressão de modelos anatômicos em escala real que podem ser utilizados em simulações cirúrgicas para o treinamento e a escolha do melhor posicionamento do implante de acordo com o PCV. Na avaliação radiográfica da osteossíntese da pseudartrose de Hoffa, verificou-se a posição do implante no modelo anatômico impresso em 3D e no joelho do paciente. Resultados O modelo anatômico impresso em 3D apresentou características geométricas e morfológicas semelhantes às do osso real. O posicionamento dos implantes em relação à linha de pseudartrose e pontos anatômicos foram bastante precisos na comparação do joelho do paciente com o modelo anatômico impresso em 3D. Conclusão A utilização do modelo anatômico virtual e do modelo anatômico impresso em 3D com a tecnologia de manufatura aditiva (MA) foi eficaz e auxiliou o planejamento e a realização do tratamento cirúrgico da pseudartrose da fratura de Hoffa. Desta forma, foi bastante preciso na reprodutibilidade do planejamento cirúrgico tanto virtual quanto no modelo anatômico impresso em 3D.

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Abstract Objective Due to the popularity of 3D technology, surgeons can create specific surgical guides and sterilize them in their institutions. The aim of the present study is to compare the efficacy of the autoclave and ethylene oxide (EO) sterilization methods for objects produced by 3D printing with polylactic acid (PLA) material. Methods Forty cubic-shaped objects were printed with PLA material. Twenty were solid and 20 were hollow (printed with little internal filling). Twenty objects (10 solid and 10 hollow) were sterilized in autoclave, forming Group 1. The others (10 solid and 10 hollow) were sterilized in EO, composing Group 2. After sterilization, they were stored and referred to culture. Hollow objects of both groups were broken during sowing, communicating the dead space with the culture medium. The results obtained were statistically analyzed (Fisher exact test and residue analysis). Results In group 1 (autoclave), there was bacterial growth in 50% of solid objects and in 30% of hollow objects. In group 2 (EO), growth occurred in 20% of hollow objects, with no bacterial growth in solid objects (100% of negative samples). The bacteria isolated in the positive cases was non-coagulase-producing Staphylococcus Gram positive. Conclusions Sterilization by both autoclave and EO was not effective for hollow printed objects. Solid objects sterilized by autoclave did not demonstrate 100% of negative samples and were not safe in the present assay. Complete absence of contamination occurred only with solid objects sterilized by EO, which is the combination recommended by the authors.

Resumo Objetivo Devido à popularidade da tecnologia 3D, cirurgiões podem criar guias cirúrgicos específicos e esterilizá-los nas suas instituições. O objetivo do presente estudo é comparar a eficácia dos métodos de esterilização por autoclave e óxido de etileno (OE) de objetos produzidos pela impressão 3D com material ácido polilático (PLA, na sigla em inglês). Métodos Quarenta objetos em formato cúbico foram impressos com material de PLA. Vinte eram sólidos e 20 eram ocos (impressos com pouco enchimento interno). Vinte objetos (10 sólidos e 10 ocos) foram esterilizados em autoclave, formando o Grupo 1. Os demais (10 sólidos e 10 ocos) foram esterilizados em OE, compondo o Grupo 2. Após a esterilização, os objetos foram armazenados e encaminhados para cultura. Objetos ocos de ambos os grupos foram quebrados durante a semeadura, comunicando o espaço morto com o meio de cultura. Os resultados obtidos foram analisados estatisticamente (teste exato de Fisher e análise de resíduo). Resultados No grupo 1 (autoclave) houve crescimento bacteriano em 50% dos objetos sólidos e em 30% dos objetos ocos. No grupo 2 (OE) o crescimento ocorreu em 20% dos objetos ocos, com ausência de crescimento bacteriano nos objetos sólidos (100% de amostras negativas). A bactéria isolada nos casos positivos foi Staphylococcus Gram positivo não produtor de coagulase. Conclusões A esterilização tanto em autoclave quanto pelo OE não foi eficaz para objetos impressos no formato oco. Objetos sólidos esterilizados em autoclave não demonstraram 100% de amostras negativas, não sendo seguro no presente ensaio. Ausência completa de contaminação ocorreu apenas com objetos sólidos esterilizados pelo OE, sendo a combinação recomendada pelos autores.

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Esta tese de doutorado investigou os espaços vazios em materiais restauradores bulk-fill, também conhecidos como poros, ou no inglês, voids, presentes no conteúdo resinoso não polimerizado nas seringas e nas restaurações realizadas. Visando o desenvolvimento de soluções inovadoras para pesquisas laboratoriais, almejou-se proporcionar precisão e reprodutibilidade das cavidades a serem preenchidas para os objetivos desta tese, e ao mesmo tempo diminuir o viés do operador na fabricação dos corpos de prova. Esta dissertação contemplou cinco estudos, sendo eles: (1) uma revisão bibliométrica sobre os compósitos restauradores bulk-fill (CBF); (2) um estudo laboratorial para avaliar os espaços presentes no interior do conteúdo de embalagens de resinas compostas (micro-híbrida (MH), nano-híbrida (NH), e duas bulk-fill: seringa (BFF) e compule (BFT) em diferentes marcas comerciais disponíveis no mercado nacional; (3) um estudo laboratorial para desenvolver protótipos de cavidades dentárias de forma digital, sendo impressos tridimensionalmente para a utilização em diferentes testes laboratoriais; (4) um estudo laboratorial que avaliou as características dos voids internos e a topografia superficial nos CBF, nas seringas e restaurações de diferentes viscosidades (alta (AV) e baixa (BV), em duas posições do longo eixo do protótipo na arcada (superior e inferior); (5) e uma produção técnica-didática de conteúdo digital por meio de e-book, para levar informações sobre as aplicações clínicas dos CBFs à alunos e dentistas que realizam procedimentos restauradores na área da Odontopediatria. (1) Evidenciou-se que os CBFs de AV foram os mais testados, sendo aplicados em molares permanentes e em restaurações de classe II. A integridade marginal e as novas lesões de cárie ao redor da restauração foram as propriedades mais investigadas. (2) Evidenciaram-se voids no conteúdo resinoso não polimerizado das marcas analisadas, que variou em relação ao tamanho e distribuição dentre as diferentes composições (NH, MH, BFF e BFT) e embalagens (seringa e compule). As amostras embaladas em tipo seringa apresentaram maiores quantidades de voids localizados nas regiões do meio e da tampa/topo, enquanto nas compules observaram-se na região entre a base e o meio da embalagem. (3) Desenvolveu-se um protótipo de cavidade 3D de formato paraboloide com base plana, impresso tridimensionalmente em material poliácido láctico (PLA). Sua conicidade proporcionou um ajuste preciso no alvéolo no manequim simulador de paciente, estabilizando o protótipo para a realização dos ensaios desta tese. Sendo assim, o protótipo demonstrou eficácia na realização de procedimentos restauradores que utilizam compósitos; não interferindo nos resultados das imagens radiográficas dos exames por micro-CT; apresentou base estável durante as oscilações de leitura da topografia de superfície, realizadas em perfilômetro óptico 3D de não contato; na condução dos procedimentos de acabamento e polimento utilizando discos de lixa finos específicos para resinas compostas. (4) Identificaram-se voids nos compósitos não polimerizados no interior das seringas, assim como nas restaurações realizadas com esses compósitos. Os voids nas cavidades restauradas com AV foram maiores do que nas BV (p<0,05), tanto em percentual como em quantidade. A maioria dos voids exibiu dimensões inferiores a 0,05 mm3; sendo os maiores de tamanho entre 1 e 2 mm3. As restaurações com CBF de BV exibiram uma menor quantidade de voids e poros superficiais, apresentando uma superfície mais lisa tanto antes como após a aplicação de acabamento e polimento. A ocorrência de voids internamente na restauração não implicou em um impacto equivalente em sua topografia superficial. Em relação ao posicionamento do protótipo nas arcadas, apesar de as restaurações inferiores apresentarem uma maior quantidade numérica de voids em comparação com as superiores (p=0,014), o volume total de voids não mostrou diferença. (5) O estudo foi realizado em três etapas: investigação de conteúdo e revisão da literatura; elaboração de modelo inicial e diagramação do e-book; e avaliação por especialistas. O material técnico-didático e institucional foi publicado junto ao repositório Pantheon desta universidade, no formato e-book, estando disponível digitalmente e de maneira gratuita. Concluiu-se que os voids estão presentes nos CBFs, tanto no interior das embalagens como nas restaurações, independentemente da posição dentária durante o atendimento clínico, da técnica de aplicação ou da viscosidade do material utilizado. Destaca-se, não só a eficácia do protótipo 3D confeccionado, como a importância da inovação tecnológica nos futuros estudos na área da Odontologia. Diante da evidência da presença de voids nos CBFs, torna-se necessário reavaliar os cuidados com este material. A solução criativa desenvolvida para uso em manequins odontológicos distinguiu-se pelo seu potencial em se adaptar às necessidades da pesquisa em Odontologia, devido à sua notável versatilidade e capacidade de personalização, o que permitiu sua integração com os objetivos das práticas laboratoriais (AU)

This doctoral thesis investigated void spaces in bulk-fill restorative materials, also known as pores, present in unpolymerized resin content in syringes and in the restorations performed. Aiming to develop innovative solutions for laboratory research, the goal was to provide precision and reproducibility of the cavities to be filled for the objectives of this thesis, while reducing operator bias in the production of test specimens. This dissertation comprised five studies: (1) a bibliometric review on bulk-fill composite restoratives (BFC); (2) a laboratory study to assess the voids present within the content of composite resin packages (micro-hybrid (MH), nano-hybrid (NH), and two bulk-fill: syringe (BFF) and compule (BFT) from different commercial brands available in the national market; (3) a laboratory study to develop prototypes of digital dental cavities, which were three-dimensionally printed for use in various laboratory tests; (4) a laboratory study that evaluated the characteristics of internal voids and surface topography in BFC, in syringes and restorations of different viscosities (high (HV) and low (LV), in two positions of the long axis of the prototype in the arch (upper and lower); (5) and a technical-didactic production of digital content through an ebook, to provide information on the clinical applications of BFC to students and dentists performing restorative procedures in the field of Pediatric Dentistry. (1) It was evidenced that HV BFCs were the most tested, being applied in permanent molars and in class II restorations. Marginal integrity and new caries lesions around the restoration were the most investigated properties. (2) Voids were evidenced in the unpolymerized resin content of the analyzed brands, which varied in terms of size and distribution among different compositions (NH, MH, BFF, and BFT) and packaging types (syringe and compule). Samples packaged in syringe type showed higher quantities of voids located in the middle and top regions, while in compules they were observed in the region between the base and the middle of the package. (3) A prototype of a 3D paraboloid-shaped cavity with a flat base was developed and three-dimensionally printed in polylactic acid (PLA) material. Its conical shape provided a precise fit in the alveolus in the patient simulator mannequin, stabilizing the prototype for the tests in this thesis. Thus, the prototype demonstrated effectiveness in performing restorative procedures using composites; not interfering with the results of radiographic images from micro-CT examinations; presenting a stable base during surface topography readings, performed with a non-contact 3D optical profilometer; and in conducting finishing and polishing procedures using specific fine abrasive discs for composite resins. (4) Voids were identified in the unpolymerized composites inside the syringes, as well as in the restorations made with these composites. The voids in cavities restored with AV were larger than those in BV (p<0.05), both in percentage and quantity. Most voids exhibited dimensions smaller than 0.05 mm3, with the largest ones ranging between 1 and 2 mm3. Restorations with CBF of BV showed a lower quantity of voids and superficial pores, presenting a smoother surface both before and after finishing and polishing. The occurrence of voids internally in the restoration did not imply an equivalent impact on its surface topography. Regarding the positioning of the prototype in the arches, although lower restorations showed a higher numerical quantity of voids compared to upper ones (p=0.014), the total volume of voids showed no difference. (5) The study was carried out in three stages: content investigation and literature review; initial model development and e-book layout; and evaluation by specialists. The technical-didactic and institutional material was published in the Pantheon repository of this university, in e-book format, being digitally available and free of charge. It was concluded that voids are present in BFCs, both inside the packaging and in the restorations, regardless of dental positioning during clinical care, application technique, or material viscosity. Not only does the effectiveness of the manufactured 3D prototype stand out, but also the importance of technological innovation in future studies in the field of Dentistry. Given the evidence of voids in BFCs, it becomes necessary to reassess care with this material. The creative solution developed for use in dental mannequins stood out for its potential to adapt to the needs of research in Dentistry, due to its remarkable versatility and customizability, enabling its integration with the objectives of laboratory practices (AU)

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Purpose: This study compared, through biomechanical evaluation under ventral flexion load, four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs. Methods: In total, 28 identical atlantoaxial joint models were created by digital printing from computed tomography images of a dog, and the specimens were divided into four groups of seven. In each group, a different technique for ventral stabilization of the atlantoaxial joint was performed: transarticular lag screws, polyaxial screws, multiple screws and bone cement (polymethylmethacrylate­PMMA), and atlantoaxial plate. After the stabilization technique, biomechanical evaluation was performed under ventral flexion load, both with a predefined constant load and with a gradually increasing load until stabilization failure. Results: All specimens, regardless of stabilization technique, were able to support the predefined load without failing. However, the PMMA method provided significant more rigidity (p ≤ 0.05) and also best resisted the gradual increase in load, supporting a significantly higher maximum force (p ≤ 0.05). There was no statistical difference in flexural strength between the transarticular lag screws and plate groups. The polyaxial screws method was significantly less resistant to loading (p ≤ 0.05) than the other groups. Conclusions: The PMMA technique had biomechanical advantages in ventral atlantoaxial stabilization over the other evaluated methods.

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Purpose: To evaluate the gain of microsurgical skills and competencies by urology residents, using low-fidelity experimental models. Methods: The study involved the use of training boards, together with a low-fidelity microsurgery simulator, developed using a 3D printer. The model consists in two silicone tubes, coated with a resin, measuring 10 cm in length and with internal and external diameters of 0.5 and 1.5 mm. The support for the ducts is composed by a small box, developed with polylactic acid. The evaluation of the gain of skills and competencies in microsurgery occurred throughout a training course consisting of five training sessions. The first sessions (S1-S4) took place at weekly intervals and the last session (S5) was performed three months after S4. During sessions, were analyzed: the speed of performing microsurgical sutures in the pre and post-training and the performance of each resident through the Objective Structure Assessment of Technical Skill (OSATS) and Student Satisfaction Self-Confidence tools in Learning (SSSCL). Results: There was a decrease in the time needed to perform the anastomosis (p=0.0019), as well as a progressive increase in the score in the OSATS over during sessions S1 to S4. At S5, there was a slightly decrease in performance (p<0.0001), however, remaining within the expected plateau for the gain of skills and competences. The SSSCL satisfaction scale showed an overall approval rating of 96.9%, with a Cronback alpha coefficient of 83%. Conclusions: The low-fidelity simulation was able to guarantee urology residents a solid gain in skills and competencies in microsurgery.

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