Designing and making an open source, 3D-printed, punctal plug with drug delivery system

With the advancement in the study of keratoconjunctivitis sicca and the scope of its treatment, punctal plugs are being widely used for the therapeutic management of dry eye disease. With the emergence of 3D printing in medicine, 3D printing of punctal plugs that have an inbuilt drug delivery system and also that can be personalized from patient to patient according to their punctum size can be a great therapeutic option. Another benefit of the device is that its printing takes a short period of time and is cost-effective. This study aimed at making an open source design and 3D printing an efficient model of a punctal plug with an inbuilt drug delivery system that can be eventually used for the treatment of various ocular diseases that require frequent drug instillation or blockage of the nasolacrimal pathway. The 3D design for the punctal plug was made using the open source application, FreeCAD, and slicing was done using the application ChituBox. After that, the plugs were printed using the LCD printer Crealty LD-002R. The material used was resin that was compatible with the Crealty LD-002R. Punctal plugs with satisfactory results were printed using the LCD printer. The punctal plugs showed suitable structure and were also easily reproduced in the 3D printer without any complications or setbacks.

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)

Usage of printing equipment in college teachers' offices and influencing factors of released particulate matter / 环境与职业医学

Background Printing and copying equipment is likely to release a large amount of particulate matter, thereby endangering human health. However, there is insufficient research on the level of particulate matter released by printers in offices and its influencing factors. Objective This study is designed to investigate the usage of printing equipment in college teachers' offices and the level of indoor particulate matter during printing, and to explore the influence of printer location and indoor ventilation on the particulate matter pollution level released during printer operation. Methods From 9:00 to 16:00 on January 4 to 6, 2021, 20 faculty offices in a university in Beijing were selected by convenient sampling to measure the indoor particulate matter level during printing, and to investigate the printing equipment usage of 31 users in the offices. Besides, experiments were designed to explore the influence of position and distance from a printer, ventilation, and the distance between a printer and a nearby window during ventilation on the number concentration of particulate matter released by the printers. Results Except one printer being placed on the ground, the other 30 printers were placed on office desks (0.71±0.16) m above the ground. Among them, 65% of the printers (n=20) were less than 1 m away from the users horizontally, and 74% of the users (n=23) accessed the printers 1-5 times a week, printing (7.03±4.07) pages per time. The peak mass concentrations in users' offices during printing of PM10, PM2.5, and PM1 were (21.96±12.96), (7.92±5.54), and (5.77±5.00) μg·m−3, respectively, and the peak number concentration of PM0.25−0.28 was (40941±36926) P·L−1. The experiments showed that when the particle sizer was located in the front, side, and back of the printers, the peak values of PM0.25−0.28 number concentration during printing were (24257±551), (12588±1354), and (11192±249) P·L−1, respectively, and the difference among them was statistically significant (F=214.9, P<0.01); when the particle sizer was placed 0.1, 0.2, and 0.3 m away from the printers, the peak values of PM0.25−0.28 number concentration during printing were (24257±551), (19847±1426), and (16480±878) P·L−1, respectively, and the difference among them was statistically significant (F=44.66, P<0.01); when the experiment room was ventilated or not, the peak values of PM0.25−0.28 number concentration during printing were (18595±488) and (24257±551) P·L−1, respectively, and the difference between them was statistically significant (F=192.6, P<0.01); when the distance between the printer and the window was 1, 2, 3 m, the peak values of PM0.25-0.28 number concentration during printing were (16780±823), (18347±348), and (18595±488) P·L−1, respectively, and the difference among them was statistically significant (F=8.407, P<0.05). Conclusion The overall printer workload is small and the concentration of particulate matter in the faculty offices is low when the printers are working. Printer position, distance, ventilation, and the distance from a nearby window under ventilation conditions are factors affecting the concentration of particulate matter released by the printers.

Accuracy evaluation of cardiac models of cases with complex congenital heart disease printed by domestic 3D printers / 中华胸心血管外科杂志

Objective To evaluate the accuracy of 3D models of patients with complex congenital heart disease(CHD) printed by domestic 3D priuters based on cardiac CT data.Methods From April 2018 to June 2018,our hospital used domestic 3D printers to print the hearts of 50 patients with complex CHD.The median age of the patients was 24 months(1 month to 61 years),and the diseases included pulmonary atresia,right ventricular double outlet and transposition of aorta.3 measurement sites(150 in total) were selected for each patient.Pearson correlation coefficient calculation,paired t test and Bland-Altman analysis were performed.Results Pearson correlation coefficient is 0.997.The difference of the measured value of CT-model was tested for normality.P was 0.2 of the D test.The Q-Q graph showed that the data point and the theoretical line were highly overlapped.The mean difference was (-0.07 ± 0.67) mm,P =0.196.In Bland-Altman analysis,the consistency boundary value interval of the difference was(-1.29 mm,1.16 mm) between which there were 143/150(95.33％) points.Conclusion 3D models of patients with complex CHD printed by domestic 3D printers based on cardiac CT data have good accuracy.

Analysis of characteristics and influencing factors of fine particulate matters and submicron particulate matters in printing shop / 中华预防医学杂志

Objective@#To analyze the physical characteristics of fine particulate matters (PM2.5) and submicron particulate matters (PM1), and investigate the factors influencing the emission peak of printer particles.@*Methods@#A 12-hour particle concentration monitoring for PM2.5 and PM1 was conducted in a printing shop on January 5th, 2018. PM2.5 in the air was analyzed after the monitoring process to figure out morphological characteristics and element composition of printer particles. Besides, experiments were carried out in an enclosed space to detect the number concentration peaks of PM1 during every printing process. Influencing factors investigated in this study were printer types, toner coverages and interval time between different printing processes.@*Results@#The 12-hour particles concentration monitoring showed that the number concentration of PM1 and the mass concentration of PM2.5 were 7.510×104 pt/cm3 and 96.85 μg/m3. The diameter of most PM2.5 was less than 100 nm, with a fractal dimension of 2.591. Most PM2.5 appeared as regular spheres with typical agglomeration phenomenon, while some were in rhabditiform or irregular shapes. Element analysis showed that PM2.5 was mainly composed of C, O, Si, Ca, with less metallic element. The PM1 emission peak values of three printers were 3.60×104, 3.43×104, 0.31×104 pt/cm3, respectively and the difference was not statistically significant (χ2=5.42, P>0.05). When the page coverage rate was 0%, 2.5%, 5%, 10%, 20% and 50%, the PM1 emission peak value of printer A was 6.74×104, 4.62×104, 3.82×104, 2.82×104, 1.00×104 and 1.08×104 pt/cm3, and the difference was also not statistically significant (χ2=7.01, P>0.05). The natural logarithm of PM1 emission peak value in printing work was associated with the resting time before printing and the change value of heating roller temperature (r value was 0.83 and 0.89, respectively, all P values<0.05).@*Conclusion@#PM2.5 and PM1 in the printing shop stayed at a high level. Particles appeared as various shapes and element compositions were complex. The temperature change of heating roller was one of most important factors that lead to the increased number concentration peak of PM1.

Effect of accelerated aging on long-term accuracy of full arches manufactured using various 3-dimensional printers / 대한치과재료학회지

Full arch models play an important role in clear aligner orthodontic therapy and the preparation of prosthodontic appliances. Three dimensional (3D) printed full arches are very popular with the benefit of easy production and good mechanical properties for fabricating clear aligner. However, the accuracy of 3D printed full arches after long storage have not been proved yet. The objective of this study was to estimate the long-term accuracy of 3D full arches produced by the four types of 3D printers (stereo-lithography apparatus (SLA), digital light projector (DLP), Polyjet™ (POL), and fused deposition modeling (FDM)) following an accelerated aging treatment. The highest accuracy was produced by POL (before treatment) and SLA (after treatment) group, respectively. Comparisons between absolute mean trueness for the 3D printed full arches before and after treatment indicated that the deviation of the trueness values of FDM group were significantly higher than those of other experimental groups (p<0.05). In addition, all trueness relative errors for FDM group were greater than 0.04 after treatment, which was high compared to those of other experimental groups. Therefore, the long-term storage of full arches fabricated by FDM type 3D printer is not recommended and the 3D printed full arches should be used immediately whenever possible.

All-on-4 implant restoration with full-digital system preserving existing occlusion: A case report / 대한치과보철학회지

In edentulous patients, implant - supported fixed prosthesis treatment has been proved to be useful, but involves complex treatment process. On the other hand, in the modern dentistry, digital technology has been developed day by day and it has expanded its range to the implant restoration of edentulous patients. In this case, a digital system was used for all stages of diagnosis, surgery, design and fabrication of provisional implants fixed prosthesis restoration in 66-year-old mandibular edentulous patients. In the preoperative diagnosis stage, a provisional restoration was designed based on the mucosal scan using the intraoral scanner and the stable occlusion of prefabricated complete denture of the patient. After flapless implant surgery using the surgical guide, the prefabricated interim restoration was connected to the implant and used as immediate provisional restoration. The final restoration was designed and fabricated by transferring the vertical dimension and the centric relation of the provisional restoration with stable occlusion using digital technology. We report a simple protocol of implant treatment in edentulous patients by using digital techniques to preserve the patient's vertical dimension and occlusion.

Editando el otoño 2017

El trabajo editorial, aunque omnipresente, es ampliamente desconocido. Recuerdo con nostalgia mis años de niñez, cuando leía caricaturas en las que, de vez en cuando, aparecían autorretratos de los editores y caricaturistas. Pepo aparecía con rostro alterado por el sueño; y Themo Lobos prefería retratarse rodeado de tazas de café y echado sobre una enorme hoja en blanco. Chiqui de la Fuente, en sus orígenes en la argentina revista "Cocodrilo", era caracterizado como un genio loco que realizaba las más variadas labores. Incluso Félix Rodríguez de la Fuente, el entrañable colega, zoólogo y naturalista español, hacía referencia a las noches en las que, rodeado de leones en el Masai Mara, dedicaba algo de tiempo para redactar sus editoriales a la luz de una linterna "sorda". Los cómics de súper héroes de los Estados Unidos inmortalizaron a John Jonah Jameson, Editor del Daily Bugle en El Hombre Araña; y a Perry White, del Daily Planet, en las historias de Súperman. Y otro médico, el Dr. Watson, compilaba y editaba de algún modo, desde su libreta de anotaciones, las aventuras de Sherlock Holmes. Y es que el trabajo editorial ha sido, es y seguirá siendo un interesantísimo camino de colaboración codo a codo con el conocimiento, requiriendo de quienes lo siguen un variado arsenal de actitudes, conocimientos, habilidades (en resumen, de "competencias") muy integrales. Con todo, extremadamente silencioso. Lejos del humor cascarrabias de los editores de los diarios de Marvel y DC comics, lo cierto es que los editores y miembros de los comités editoriales son personas que prefieren hablar a través de la consecución de estilos, incluso más que de un muy escaso número de textos escritos personalmente. Desde la invención de la imprenta por los chinos en el siglo VI hasta la constitución de la primera imprenta en Europa diez siglos más tarde, y hasta nuestros días, los editores buscaron la trascendencia de los escritos publicados a través de estilos característicos: Redacción, tipografía, formas literarias, encuadernaciones, imágenes, tipo de papel, etc. Todo ello, amalgamado en una obra en particular o en una colección de obras. ¿El espíritu en común? Hacer perdurar el contenido a partir de un continente que facilite su traslado y motive su conocimiento y comprensión más allá de las generaciones. La primera imprenta occidental ya tenía muy marcadamente adquiridas estas características. Aldo Manuzio, el iniciador de la imprenta Aldina ("imprenta de Aldo"), en la Venecia de 1494, dedicó su esfuerzo a comercializar la literatura griega y romana clásica, evitando que cayera en el olvido. Inventó la tipografía itálica, optimizó enormemente la fabricación y utilización de tipos, utilizando tintas de primerísima calidad, y fue el creador de los primeros libros "de bolsillo" (...)

Flexural strength of various kinds of the resin bridges fabricated with 3D printing

PURPOSE: Manufacturing with AM (Additive manufacturing) technique has many advantages; but, due to insufficient study in the area, it is not being widely used in the general clinic. In this study, differences of flexural strength among various materials of 3 unit fixed dental prosthesis were analyzed. MATERIALS AND METHODS: A metal jig for specimens that had a 3-unit-fixed dental prosthesis figure were fabricated. The jigs were made appropriately to the specifications of the specimens. Three different kinds of materials of specimens which were NC (mathacrylic esther based), DP-1 (Bisphenol A epoxy acrylate type oligomer based), and DT-1 (urethane acrylate based) were printed with DLP machine. Five specimens for each kind of material were printed with an angle of 30° from the horizontal surface. The specimens were placed on the jig and the flexural strength was measured and recorded using Universal testing machine. The recorded data was analyzed in SPSS using One-way ANOVA and Tukey HSD to determine the significance of the differences of flexural strength among the groups. RESULTS: The flexural strengths of each group were the followings: NC, 1119 ± 305 N; DP-1, 619 ± 150 N; DT-1, 413 ± 65 N. Using One-way ANOVA and Tukey Honestly Significant Difference test, significant difference was found between NC and the other groups (P 0.05). CONCLUSION: Higher flexural strength was shown in 3-unit-fixed dental prosthesis that were 3D printed using a DLP machine with NC material.

3D-Printed Nose-to-Larynx Airway Model, Preliminary Study / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Flexible fiberscopy is essential in the examination of the nose to larynx airway. However, the instrument is sensitive to manipulation and can sometimes be damaged when excessive external force is applied. In addition, patients can be injured during fiberscopic examination. In this regard, a airway model mimicking the human airway passage was developed for the education of fiberscopy to minimize the danger to both patient and fiberscope. MATERIALS AND METHOD: Neck CT data was used to 3D-print the airway model. Using the 3D doctor software, the outlines of the air-filled cavities were extracted. The outline data was modified to make the inside of the outline empty and the outside filled with 3D ink resin. The airway data was used to 3D-print the replica in three pieces, which were then assembled into one. Flexible laryngoscopic examination of nose to larynx was performed using the nose-to-larynx airway model, and for a male patient enrolled in the study. Virtual endoscopy was performed using the same CT data. The examination data were then compared frame by frame with regards to the shapes and positions of nasal inlet, inferior turbinate, torus tubarius, hypopharynx, epiglottis and vocal cord. RESULTS: The airway model was very similar in shape and position of the anatomic landmarks compared with real human airway examined by the fiberscope. CONCLUSION: The results of 3D-printed airway model showed similar shapes as the real human airway, and real time endoscopy could be done using the model. This technique can be extended to make models of tubed organs such as the intestine or the bronchial tree.

Three-Dimensional Bio-Printing Equipment Technologies for Tissue Engineering and Regenerative Medicine

Three-Dimensional (3D) printing technologies have been widely used in the medical sector for the production of medical assistance equipment and surgical guides, particularly 3D bio-printing that combines 3D printing technology with biocompatible materials and cells in field of tissue engineering and regenerative medicine. These additive manufacturing technologies can make patient-made production from medical image data. Thus, the application of 3D bio-printers with biocompatible materials has been increasing. Currently, 3D bio-printing technology is in the early stages of research and development but it has great potential in the fields of tissue and organ regeneration. The present paper discusses the history and types of 3D printers, the classification of 3D bio-printers, and the technology used to manufacture artificial tissues and organs.

Clinical Application of Solid Model Based on Trabecular Tibia Bone CT Images Created by 3D Printer / 대한의료정보학회지

OBJECTIVES: The aim of this work is to use a 3D solid model to predict the mechanical loads of human bone fracture risk associated with bone disease conditions according to biomechanical engineering parameters. METHODS: We used special image processing tools for image segmentation and three-dimensional (3D) reconstruction to generate meshes, which are necessary for the production of a solid model with a 3D printer from computed tomography (CT) images of the human tibia's trabecular and cortical bones. We examined the defects of the mechanism for the tibia's trabecular bones. RESULTS: Image processing tools and segmentation techniques were used to analyze bone structures and produce a solid model with a 3D printer. CONCLUSIONS: These days, bio-imaging (CT and magnetic resonance imaging) devices are able to display and reconstruct 3D anatomical details, and diagnostics are becoming increasingly vital to the quality of patient treatment planning and clinical treatment. Furthermore, radiographic images are being used to study biomechanical systems with several aims, namely, to describe and simulate the mechanical behavior of certain anatomical systems, to analyze pathological bone conditions, to study tissues structure and properties, and to create a solid model using a 3D printer to support surgical planning and reduce experimental costs. These days, research using image processing tools and segmentation techniques to analyze bone structures to produce a solid model with a 3D printer is rapidly becoming very important.

Different printers in the detection of cerebral lacunae infarction:a comparison analysis / 军事医学科学院院刊

Objective:To compare the diagnostic accuracy of cerebral lacunae infarction by a dry laser printer and by a paper printer. Methods:The films of a dry laser printer(Konica Drypro 752) and a paper printer (Locus) on 100 patients were interpreted by three radiologists(with five years and above experience).The time interval was two weeks .Results:There was no significant difference between the dry laser printer and paper printer for cerebral lacunae infarction.Concusion:For cerebral lacunae infarction, images obtained from a dry laser printer are similar to those from a paper printer.Thus, the former printer can be used for cerebral lacunae infarction.

Study and application of ECG fast printing / 医疗卫生装备

Thermal printer is ideal for micro-EGG for its excellences such as high speed, low volume and low noise. Single-lead printing and 6-lead printing are usually adopted. This paper, taking the newly-developed fully automatic ECG based on AduC812 MCU as an example, introduces the realization of different printing manners of ECG and emphasizes the solution of 12-lead fast synchronous printing.