Congruencia entre modelos dentales impresos 3D y el archivo digital de origen: estudio in vitro comparativo de 5 impresoras 3D / Congruence between 3D printed dental models and the original digital file: comparative in vitro study of 5 3D printers

Este trabajo tuvo como objetivo conocer la fiabilidad de la impresora 3D (i3D) aditiva por Matriz de Proceso Digital de Luz (MDLP) Hellbot modelo Apolo®, a través de verificar la congruencia dimensional entre las mallas de modelos impresos (MMi) y su correspondiente archivo digital de origen (MMo), obtenido del software de planificación ortodontica Orchestrate 3D® (O3D). Para determinar su uso en odontología y sus posibilidades clínicas, fue comparada entre cinco i3D de manufactura aditiva, dos DLP, dos por estereolitografía (SLA) y una por Depósito de Material Fundido (FDM). La elección de las cinco i3D se fundamentó en su valor de mercado, intentando abarcar la mayor diversidad argentina disponible. Veinte modelos fueron impresos con cada i3D y escaneados con Escáner Intraoral (IOS) Carestream modelo 3600® (Cs3600). Las 120 MMi fueron importadas dentro del programa de ingeniería inversa Geomagic® Control X® (Cx) para su análisis 3D, consistiendo en la superposición de MMo con cada una de las MMi. Luego, una evaluación cualitativa de la desviación entre la MMi y MMo fue realizada. Un análisis estadístico cuidadoso fue realizado obteniendo como resultado comparaciones en 3d y 2d. Las coincidencias metrológicas en la superposición tridimensional permitieron un análisis exhaustivo y fácilmente reconocible a través de mapas colorimétricos. En el análisis bidimensional se plantearon planos referenciados dentariamente desde la MMo, para hacer coincidir las mediciones desde el mismo punto de partida dentaria. Los resultados fueron satisfactorios y muy alentadores. Las probabilidades de obtener rangos de variabilidad equivalentes a +/- 50µm fueron de un 40,35 % y de +/- 100µm un 71,04 %. Por lo tanto, te- niendo en cuenta las exigencias de congruencia dimensional clínicas de precisión y exactitud a las cuales es sometida nuestra profesión odontológica, se evitan problemas clínicos arrastrados por los errores dimensionales en la manufactura (Cam) (AU)

The objective of this study was to determine the reliability of the Hellbot Apollo® model additive 3D printer (i3D) by Matrix Digital Light Processing (MDLP) by verifying the dimensional congruence between the printed model meshes (MMi) and their corresponding digital source file (MMo), obtained from the Orchestrate 3D® (O3D) orthodontic planning software. A comparison was made between five i3D of additive manufacturing, two DLP, two by stereolithography (SLA), and one by Fused Material Deposition (FDM), to determine its use in dentistry and its clinical possibilities. The choice of the five i3D was based on their market value, trying to cover most of the Argentinean diversity available. Twenty models were printed with each i3D and scanned with Carestream Intraoral Scanner (IOS) model 3600® (Cs3600). The 120 MMi were imported into the reverse engineering program Geomagic® Control X® (Cx) for 3D analysis, consisting of overlaying MMo with each MMi. Then, a qualitative evaluation of the deviation between MMi and MMo. Also, a careful statistical analysis was performed, resulting in 3d and 2d comparisons. Metrological coincidences in three-dimensional overlay allowed a comprehensive and easily recognizable analysis through colorimetric maps. In the two-dimensional analysis, dentally referenced planes were proposed from the MMo, to match the measurements from the same dental starting point. The results were satisfactory and very encouraging. The probabilities of obtaining ranges of variability equivalent to +/- 50µm were 40.35 % and +/- 100µm 71.04 %. Therefore, considering the demands of clinical dimensional congruence, precision, and accuracy to which our dental profession it is subjected, clinical problems caused by dimensional errors in manufacturing (Cam) are avoided (AU)

Aplicações da manufatura aditiva em oftalmologia / Applications of additive manufacturing in ophthalmology

RESUMO A manufatura aditiva, mais popularmente conhecida como impressão tridimensional, baseia-se no desenvolvimento de um objeto com a ajuda de um software de desenho assistido por computador seguido de sua impressão por meio da deposição de uma matéria-prima, camada por camada, para a construção do produto desejado. Existem vários tipos de técnicas de impressão tridimensional, e o tipo de processo de impressão escolhido depende da aplicação específica do objeto a ser desenvolvido, dos materiais a serem utilizados e da resolução necessária à impressão do produto final. A impressão tridimensional abriu perspectivas na pesquisa e revolucionou o campo das ciências da saúde, com a possibilidade de criação e de desenvolvimento de produtos personalizados de maneira rápida, econômica e de forma mais centralizada do que no processo de manufatura tradicional. As tecnologias de manufatura aditiva remodelaram os diagnósticos médicos; as medidas preventivas e pré-operatórias; o tratamento e a reabilitação, assim como os processos de engenharia de tecidos nos últimos anos. Na oftalmologia, as aplicações da impressão tridimensional são extensas. Modelos anatômicos para aplicação na área da educação e planejamentos cirúrgicos, desenvolvimento de implantes, lentes, equipamentos para diagnósticos, novas aplicações terapêuticas e desenvolvimento de tecidos oculares já estão em desenvolvimento. Por possuir um campo amplo e ser alvo de pesquisa constante, a área oftalmológica permite que a manufatura aditiva ainda seja amplamente utilizada a favor dos médicos e dos pacientes.

ABSTRACT Additive manufacturing, more popularly known as three-dimensional (3D) printing, is based on the development of an object with the help of computer-aided design software followed by its printing through the deposition of a material, layer by layer, to create the desired product. There are several types of 3D printing techniques and the type of printing process chosen depends on the specific application of the object to be developed, the materials to be used, and the resolution required to print the final product. 3D printing has brought new perspectives to research and revolutionized the field of health sciences, with the possibility of creating and developing customized products in a faster, more economical, and more centralized way than in the traditional manufacturing process. Additive manufacturing technologies have reformulated medical diagnostics, preventive, preoperative, treatment, and rehabilitation, as well as tissue engineering processes in recent years. In ophthalmology, the applications of 3D printing are extensive. Anatomical models for application in education and surgical planning, development of implants, lenses, diagnostic equipment, new therapeutic applications, and development of ocular tissues (3D bioprinting) are already under development. As it has a wide field and is the subject of constant research, the ophthalmic area allows additive manufacturing to still be widely used in favor of doctors and patients.

Una nueva alternativa para la localización y la recuperación de agujas fracturadas durante la anestesia odontológica. Presentación de técnica y caso clínico / A new alternative for locating and removing a needle fractured during dental anesthesia. Technique and case report

Objetivo: Describir en un caso clínico una nueva técni- ca para la localización y la remoción de agujas fracturadas du- rante la anestesia odontológica mediante planificación virtual. Caso clínico: Una paciente de género femenino de 52 años de edad concurre a la Cátedra de Cirugía y Traumatolo- gía Bucomaxilofacial I de la Facultad de Odontología de la Universidad de Buenos Aires y relata que dos meses atrás, durante la atención odontológica, se produjo la fractura de la aguja durante la anestesia troncular mandibular. Se realiza diagnóstico y planificación virtual para conocer la ubicación exacta de la aguja y se confecciona un modelo estereolito- gráfico y una guía quirúrgica individualizada para removerla. El uso de una guía quirúrgica individualizada y confeccio- nada mediante planificación virtual permitió ubicar la aguja tridimensionalmente y con mayor precisión en espacios pro- fundos y disminuir tiempos operatorios (AU)

Aim: To describe in a clinical case a new virtual plan- ning technique for locating and removing a fractured dental anesthetic needle. Clinical case: A 52-year-old patient visited the De- partment of Oral and Maxillofacial Surgery I (School of Dentistry, University of Buenos Aires) with a retained den- tal needle in the pterygomandibular space. The needle had fractured during inferior alveolar nerve block two months previously. Virtual diagnosis and planning were performed to locate the needle and a stereolithographic model and a customized surgical guide were prepared. The use of cus- tomized surgical guides prepared by virtual planning ena- bled precise location of the dental needle in deep spaces and reduced operating times (AU)

Impresión 3D de modelos estereolitográficos con protocolo abierto / 3D Printing of Stereolithographic Models with Open Protocol

RESUMEN: Se realizó un estudio descriptivo y exploratorio con el objetivo de proponer y validar un protocolo abierto para hacer impresiones 3D de modelos estereolitográficos, que esté a disposición de profesionales en el área de la Odontología. Se capacitó mediante sesiones teórico prácticas, a nueve personas operadoras (estudiantes de último año de la carrera de Odontología), sin previa experiencia en el uso de software y hardware para impresión 3D, divididos en dos grupos; el A trabajó con tres tomografías helicoidales (TAC) y el B con tres Tomografías Computarizadas de Haz Cónico (CBCT), todas en formato DICOM, convertidas en archivos STL. En total se aplicó el protocolo en 99 estructuras óseas correspondientes a 33 mandíbulas, 33 axis y 33 macizos faciales-bases de cráneo, y se imprimieron un total de 33 mandíbulas en filamento PLA (ácido poliláctico). Al finalizar el estudio, no se encontró diferencia estadísticamente significativa en la implementación del protocolo propuesto entre los operadores, las mediciones de las piezas impresas por cada uno de ellos, el patrón de oro, la TAC y el CBCT, con lo cual no solo se validó el protocolo, sino que se logró determinar los recursos necesarios para realizar este tipo de impresiones 3D.

ABSTRACT: A descriptive and exploratory study was carried out with the aim of proposing and validating an open protocol for making 3D impressions of stereolithographic models, which is available to professionals in the area of Dentistry. Nine operators (senior students of the Dentistry degree), without previous experience in the use of software and hardware for 3D printing, divided into two groups were trained through theoretical and practical sessions. The A worked with three helical tomographies (TAC) and the B with three cone beam computed tomography (CBCT), all in DICOM format, converted to STL files. In total, 99 bone structures corresponding to 33 jaws, 33 axis and 33 facial masses-skull bases were analyzed, and a total of 33 jaws were printed in PLA (polylactic acid filament). At the end of the study, no statistically significant difference was found in the implementation of the proposed protocol between the operators, the measurements of the pieces printed by each of them, the gold standard, the TAC and the CBCT, with which not only validated the protocol, but it was possible to determine the resources necessary to carry out this type of 3D printing.

ULTRA Tomografia Computadorizada Multidetectores com ultra baixa dose de radiação e impressão 3D como auxiliares para cirurgia guiada em implantodontia / Ultra-low dose Multidetector CT and 3D printing as aids to guided implant surgery

Objetivo: relatar um caso clínico de reabilitação com implante dentário imediato realizado utilizando Tomografia Computadorizada Multidetectores (TCMD) com ultra baixa dose de radiação, software de código aberto para manipulação das imagens e impressão 3D de baixo custo do guia cirúrgico. Relato de caso: paciente, sexo masculino, 50 anos de idade, foi avaliado clinicamente relatando dor na região do dente 45, com suspeita de fratura radicular. Como complemento ao exame clínico, o paciente realizou TCMD com ultra baixa dose de radiação para avaliar a condição dentária e do tecido ósseo adjacente. Tendo sido diagnosticada fratura radicular vertical, procedeu-se ao planejamento virtual do implante e à confecção do guia cirúrgico. As imagens em formato DICOM da TCMD foram convertidas para formato STL (Stereolithography) para manipulação e confecção do guia cirúrgico virtual. Esse guia foi impresso em PLA (poliácido láctico) utilizando impressora 3D pelo método FDM (Fusão e Deposição de Material). Após a exodontia atraumática, o guia cirúrgico foi posicionado nos dentes adjacentes e o implante foi inserido. Clinicamente, o paciente encontra-se assintomático, o implante sem sinais clínicos de inflamação e a prótese em função. Uma segunda tomografia do paciente permitiu comparar de forma tridimensional a posição final do implante e o planejamento virtual, que se mostraram equivalentes. Considerações finais: a impressão 3D em PLA mostrou-se uma solução com custo acessível para a produção de guias cirúrgicos, fornecendo previsibilidade e segurança ao implantodontista.(AU)

Objective: to report a clinical case of rehabilitation with dental implant performed using ultra- -low dose Multidetector Computed Tomography (MDCT), open source software for image manipulation, and low cost 3D printing of the surgical guide. Case report: a 50-year-old male patient was clinically evaluated complaining of pain in the tooth 45, and a root fracture was suspected. As a complement to the clinical examination, the patient performed an ultra-low dose MDCT to assess the dental condition and the adjacent bone tissue. A vertical root fracture was diagnosed, and then the virtual planning of the implant and preparation of the surgical guide were performed. The DICOM images from the MDCT were converted into STL (Stereolithography) format for manipulation and confection of the virtual surgical guide. The surgical guide was printed on PLA using a 3D printer by the FDM (Fused Deposition Modeling) method. After atraumatic extraction, the surgical guide was placed in the adjacent teeth and the implant was inserted. Clinically, the patient is asymptomatic, the implant has no clinical signs of inflammation, and the prosthesis is in function. A second ultra- -low dose MDCT of the patient allowed a three-dimensional comparison of the final position of the implant and the virtual planning, which were shown to be equivalent. Final considerations: 3D PLA printing has proved to be an affordable solution for the production of surgical guides, providing predictability and safety for the implantologist.(AU)

Dimensional Accuracy of 3D-printed Models of the Right First Metacarpal Bones of Cadavers

Background@#The use of 3D printing in medical education, prosthetics, and preoperative planning requires dimensional accuracy of the models compared to the replicated tissues or organs. Objective. To determine the dimensional accuracy of 3D-printed models replicated from metacarpal bones from cadavers. @*Methods@#Fifty-two models were 3D-printed using fused deposition modeling (FDM), stereolithography (SLA), digital light processing (DLP), and binder jetting method from 13 right first metacarpal bones of cadavers from the College of Medicine, University of the Philippines Manila. Six dimensional parameters of the 3D-printed models and their control bones were measured using 0.01 mm calipers — length, midshaft diameter, base width, base height, head width, and head height. Mean measurements were compared using non-inferiority testing and multidimensional scaling.@*Results@#Mean measurements of the 3D-printed models were slightly larger than their control bones (standard deviation range: 1.219-4.264; standard error range, 0.338-1.183). All models were found to be at least 90% accurate and statistically non-inferior compared to control bones. DLP-printed models were the most accurate (base width, 99.62 %) and most similar to their control bone (–0.05, 90% CI –0.34, 0.24). Through multidimensional scaling, DLP-printed models (coordinate = 0.437) were the most similar to the control bone (coordinate = 0.899).@*Conclusion@#The 3D-printed models are dimensionally accurate when compared to bones.

Comparación estadística entre modelo de yeso, digitalizado e impreso en 3D / Statistic comparison of digitalized plaster models and printed in 3D

Se realizaron mediciones en los ejes x, y, z sobre modelos dentales de yeso, digitalizados e impresos con impresoras 3D, con fines comparativos, estadísticos y evaluativos, cuyo objetivo fue estimar el grado de coincidencia significativa entre los modelos, realizados por dos profesionales, en dos momentos diferentes. Los resultados arrojaron datos de gran precisión en forma y tamaño en los tres estudios, con mínima distorsión (no significativa, p =0,05), lo que determinó la importancia de implementación en forma institucional o privado el estudio digital de los mismos, para realizar comparaciones, mediciones, diagnósticos y acopio de modelos virtuales en un ordenador, siendo estos más precisos y de menor tiempo de trabajo (AU)

Measurements were made in the x, y, z axes on gypsum dental models, digitized and printed with 3D printers, for comparative, statistical and evaluative purposes, whose objective was estimate the degree of significant coincidence between models, that were made by two professionals, at two different times.The results were the achieve of data with a great shape´s and size´s precisionat the three studies, with minimal distortion (not significant, p = 0.05), which determined the importance of the institutional or private way of an implementation of the model´s digital studies, with the aim of doing comparisons, measurements, diagnostics, and collection of virtual models in a computer, to being more precise and with less work time (AU)

Técnica de template customizável para remoção de enxerto ósseo de crista ilíaca para reconstruções de defeitos mandibulares / Customizable template technique to harvest iliac crest bone graft for reconstructions of mandibular defects

RESUMO A remoção de enxerto da crista ilíaca anterior é uma boa opção para a reconstrução de defeitos mandibulares após ressecções por trauma ou outras doenças. Para obtenção de resultados clínicos de excelência em cirurgias reconstrutivas com enxertos ósseos, um planejamento pré-operatório preciso e uma refinada técnica cirúrgica são essenciais. Portanto, este artigo descreve o uso de um template customizável, que é indicado para obter bloco de osso ilíaco livre para reconstruções mandibulares imediatas ou tardias após defeitos marginais ou segmentares. O template é baseado em um fragmento de metal maleável obtido de uma lata de bebida de alumínio. Ele é utilizado no transoperatório para demarcar o sítio doador do enxerto ósseo e é especialmente útil devido ao acesso limitado à cortical interna da crista ilíaca. O template customizável tem se mostrado uma ferramenta de fácil aplicação para determinar o tamanho do bloco de enxerto a ser coletado da região ilíaca, otimizando o tempo cirúrgico e evitando a remoção insuficiente de enxerto ósseo.

ABSTRACT Bone graft harvesting from the anterior iliac crest is a good option for reconstructing mandibular defects after trauma or other diseases. In order to achieve optimal clinical results in reconstructive surgeries with bone grafts, accurate preoperative planning and prestigious surgical technique are paramount. Therefore, this paper describes the use of a customizable template that is indicated for obtaining free iliac bone block for immediate or late mandibular reconstructions following marginal or segmental defects. The template is based on a piece of malleable metal obtained from an aluminum beverage can. It is used transoperatively to demarcate the bone graft donor site, being especially useful because of the limited access to the inner table of the anterior ilium. The described customizable template has been shown as a useful tool to easily determine the size of the bone block to be harvested from the iliac region, improving surgical time and preventing removal of insufficient bone graft.

The need for DICOM encapsulation of 3D scanning STL data

No abstract available.

Maxillary Reconstruction Using rhBMP-2 and Titanium Mesh: Technical Note About the Use of Stereolithographic Model / Reconstrucción Maxilar Utilizando rhBMP-2 y Malla de Titanio: Nota Técnica sobre el Uso de Modelo Estereolitográfico

Maxillary reconstruction is a common procedure in maxillofacial surgery; for this purpose is used autogenous bone, alloplastic bone or another one with different results. In all of them, traditionally the use of computed tomography is used to make the surgical plan, however, 3D models are not used frequently. This report show a new application of the stereolithography to anticipate the surgical treatment of maxillary reconstruction, using a titanium mesh and rhBMP-2 to obtain a predictable surgical result with diminished surgical time.

La reconstrucción maxilar es un procedimiento común en cirugía maxilofacial; para este propósito es utilizado hueso autógeno, hueso aloplástico u otro tipo de hueso con diferentes resultados. En todos ellos, tradicionalmente el uso de tomografía computadorizada se emplea para elaborar el plan quirúrgico, sin embargo, los modelos 3D no son utilizados con frecuencia. Este reporte presenta una nueva aplicación de la estereolitografia para anticipar el tratamiento quirúrgico de la reconstrucción maxilar, usando una malla de titanio y rhBMP-2 para obtener un resultado quirúrgico predecible con disminución del tiempo quirúrgico.