3D Rapid Prototyping Research Articles

Application of 3D Scanning Techniques, CAD/CAE Modeling and 3D Printing, in the Development of Customized Ankle and Foot Orthoses

Objective: To develop a prototype of a custom ankle and foot orthosis using 3D scanning, CAD/CAE systems and rapid prototyping, evaluating ABS and PLA materials under specific loads. Theoretical Framework: Innovation in custom orthoses is based on advances in 3D scanning, virtual model processing, and 3D printing, to obtain ergonomic and durable devices. Method: Using a digital model by 3D scanning, a solid model was built using a CAD/CAE system, which allowed comparing its response in terms of strength and deformation for ABS and PLA materials, under loads of patients of different weights. Results and Discussion: Both materials showed good response: PLA offered rigidity and stability, ideal for immobility; ABS, flexibility and impact resistance, suitable for fluctuating loads. Research Implications: This study suggests that both materials are viable for custom orthoses. In addition, it proposes evaluating composite materials that combine the qualities of ABS and PLA. Originality/Value: This research is original in exploring alternative materials for orthoses through additive manufacturing and offers value to the rehabilitation sector by proposing personalized orthoses according to the characteristics of the patient, improving the effectiveness and durability in mobility treatments.

Dosage by design – 3D printing individualized cabozantinib tablets with immediate release

Production of patient-specific dosage forms is important to improve patient adherence and effectiveness while reducing the prevalence and severity of adverse effects. Due to its possibility of rapid prototyping 3D printing can be used to produce individual dosages while utilizing techniques such as hot melt extrusion to increase the bioavailability of poorly soluble drugs. In this work, Parteck MXP and Kollicoat IR were used as water-soluble polymer bases for formulation development for 3D printing of various dosages incorporating cabozantinib while enabling immediate release. The effect of tablet design and the excipients sorbitol, croscarmellose sodium, and sodium starch glycolate was investigated for this goal. A way to calculate the size of tablets for predetermined dosages is proposed to enable the printing of individual strengths from one formulation. Rheological data were collected to deepen the understanding of the role of melt viscosity in 3D printing and hot melt extrusion processes. The production of immediate-release cabozantinib tablets containing every therapeutically relevant dosage in a single unit produced by two-step 3D printing was realized.

Clinical and Radiographic Evaluation of Soft Tissue and Bone Status in Immediate Loaded Implants Placed Following Their Extraction in the Maxillary Anterior Region.

In the maxillary anterior region, teeth extraction leads to significant soft and hard tissue changes. Immediate implant placement following extraction aims to reduce bone loss and overall treatment time. However, it may result in adverse soft tissue changes impacting esthetics. This study evaluates the clinical and radiographic outcomes of immediately loaded implants in the maxillary anterior region, focusing on soft tissue preservation and bone status. This study, conducted from April 2022 to August 2024 at the Department of Oral and Maxillofacial Surgery, Ragas Dental College and Hospital, included 10 immediately loaded implants in seven patients. Following atraumatic extraction, implants were placed and loaded with functional provisional crowns fabricated using three-dimensional (3D) rapid prototyping models. Parameters such as crestal bone loss, buccal and palatal bone width, and interdental papilla thickness were evaluated preoperatively and postoperatively using radiographsand clinical assessments. The study found significant crestal bone loss at both mesial and distal sites over time, with the greatest loss observed at the three-month follow-up. Buccal and palatal bone width showed no significant differences preoperatively and postoperatively. Interdental papilla thickness and overall pink esthetic scores also showed no significant differences between preoperative and postoperative evaluations. Immediate implant placement in the maxillary anterior region, using 3D rapid prototyping for custom splint fabrication, demonstrated effective preservation of soft tissue profile and bone architecture. This approach provides functional and esthetic benefits, although careful monitoring of crestal bone loss is necessary.

Mucus, airway and plume temperature effects on pMDI-drug delivery in a mouth-throat airway: Experimental and numerical studies

Effective pulmonary drug delivery through pressurized-metered dose inhalers (pMDIs) depends on accurately targeting pharmaceutical aerosols to specific lung areas. Achieving this necessitates a comprehensive understanding of airflow dynamics in the airway and particle transport mechanisms.In this study, a replica of the realistic geometry of the VCU medium-sized mouth-throat (MT) airway was fabricated by rapid prototyping (3D printing) to connect to a next-generation impactor (NGI) setup. The drug concentration deposited in the replica was measured at a constant flow rate of 30 L/min and room temperature using a high-performance liquid chromatography (HPLC) assay. This measurement validated our computational fluid dynamics (CFD) model for simulating particle transport under the same conditions. Large eddy simulation (LES) and discrete phase model (DPM) were employed to model the MT's airflow and particle transport. Using our CFD modeling, we focused on the effects of the temperature distribution of aerosol injection (plume), the influence of inlet air temperature, and the presence of the mucus layer on particle transport and deposition.Our findings revealed that decreasing the plume temperature from 10 °C to −54 °C reduced deposition by approximately 15%, although increasing the average deposited particle sizes within the MT by about 34.5%. The airflow pattern, affected by different plume temperatures, was the prevalent parameter in particle MT deposition. In contrast, the effect of different air inlet temperatures on deposition was negligible. Additionally, incorporating mucus layer features in CFD modelling could further modify the inhaler's efficiency by up to 11%, depending on the specific conditions like diverse plume temperature (−54 °C–10 °C) and airflow temperature conditions (−15 °C–45 °C).

A Review on 3D Printing Processes in Pharmaceutical Engineering and Tissue Engineering: Applications, Trends and Challenges

AbstractAs a 3D rapid prototyping technology, 3D printing (3DP) technology has been widely applied in medical research, fabricating various medical devices or implants. With the development of biomaterials and cell‐related technologies, 3DP, especially bioprinting technology, is quietly bringing great changes and opportunities in the medical industry. Beyond surgical models, medical devices, and implants, traditional 3DP, cell‐based 3D bioprinting, and emerging 4D printing (4DP) have significantly aided in the advancement and manufacture of pharmaceuticals and biological alternatives for tissue engineering. It is envisioned that future healthcare systems, based on evolving 3DP technology and precision medicine, will deliver customized solutions that cater to the unique differences and needs of each patient. In this review work, several mainstream 3D bioprinting technologies are presented, with a focus on recent advances in 3DP for pharmaceutical engineering and important tissue engineering, including vascular and bone tissue engineering. Challenges and future prospects of 3DP for drug discovery, drug delivery systems, artificial blood vessels, vascular and bone tissue engineering scaffolds, and practical applications are also covered. Finally, the differences between 3DP and 4DP, as well as the advantages and disadvantages of different stimulus response mechanisms in 4DP and their potential applications are summarized.

3D-printed porous zinc scaffold combined with bioactive serum exosomes promotes bone defect repair in rabbit radius.

Currently, the repair of large bone defects still faces numerous challenges, with the most crucial being the lack of large bone grafts with good osteogenic properties. In this study, a novel bone repair implant (degradable porous zinc scaffold/BF Exo composite implant) was developed by utilizing laser melting rapid prototyping 3D printing technology to fabricate a porous zinc scaffold, combining it under vacuum conditions with highly bioactive serum exosomes (BF EXO) and Poloxamer 407 thermosensitive hydrogel. The electron microscope revealed the presence of tea saucer-shaped exosomes with a double-layered membrane structure, ranging in diameter from 30-150 nm, with an average size of 86.3 nm and a concentration of 3.28E+09 particles/mL. In vitro experiments demonstrated that the zinc scaffold displayed no significant cytotoxicity, and loading exosomes enhanced the zinc scaffold's ability to promote osteogenic cell activity while inhibiting osteoclast activity. In vivo experiments on rabbits indicated that the hepatic and renal toxicity of the zinc scaffold decreased over time, and the loading of exosomes alleviated the hepatic and renal toxic effects of the zinc scaffold. Throughout various stages of repairing radial bone defects in rabbits, loading exosomes reinforced the zinc scaffold's capacity to enhance osteogenic cell activity, suppress osteoclast activity, and promote angiogenesis. This effect may be attributed to BF Exo's regulation of p38/STAT1 signaling. This study signifies that the combined treatment of degradable porous zinc scaffolds and BF Exo is an effective and biocompatible strategy for bone defect repair therapy.

An In Vivo Study to Compare the Clinical Effectiveness of Clear Retainer Made on a Conventional and a Digitally Fabricated Model Over a Six-Month Period After Debonding.

Background With the advent of 3D printing, many more possibilities have arisen for treatment planning. 3D rapid prototyping has enabled us to see a whole other dimension that has helped us to give the best possible care for our patients. With more and more advancements being made in this subject, it becomes necessary to check the reliability of the equipment and its effectiveness in the management of the problem at hand. This original study was conducted with the aim of checking the accuracy, dimensional stability, and reliability of orthodontic retainers made on a conventional and digitally fabricated model over a six-month period after debonding. Material and methods The patients were selected from those who have completed fixed orthodontic mechanotherapy from the Department of Orthodontics and Dentofacial Orthopaedics, Sri Guru Ram Das Institute of Dental Sciences and Research, Sri Amritsar. Fifty patients received a clear retainer, which was fabricated for the upper and lower arch after removing the brackets. Patients were included in this study irrespective of their age groups.The manual method used a vacuum-forming machine to fabricate six retainers on stone models. In the digital method, new impressions were taken after three months, and digital models were obtained through 3D scanning and printing, followed by clear retainer fabrication. The data were gathered through a systematic process involving manual and digital methods for clear retainer fabrication and subsequent evaluation. The data obtained was computed for statistical evaluation and comparison. Results Mean and standard deviations of conventional (manual) and digital variables in the two groups were calculated. An ANOVA test was used to evaluate statistically significant differences for mesiodistal widthand buccolingual width, and a post hoc Tuckey test was applied for multiple comparisons. The results indicated that most mesiodistal and buccolingual width measurements showed non-significant variations and exhibited a good correlation. Extraction space opening, assessed through an independent t-test for both the maxilla and mandible, also yielded non-significant and comparable results. Additionally, intra-operator and inter-operator measurements using a digital caliper demonstrated high agreement. Intra-class correlation (ICC) values exceeded 0.75, and inter-operator ICC results reflected a high level of agreement ranging from 0.8 to 0.99. Conclusion The primary objective of this study was to establish a correlation between the accuracy, dependability, and clinical efficacy of orthodontic retainers produced using both conventional and digitally created models. This investigation spanned a duration of six months following the removal of orthodontic brackets. The results showed that most of the statistically significant values were due to the inherent potential of the 3D printer for polymerization shrinkage, which, being a stereolithographic 3D printer, had a potential for a slight dimensional shift in the transverse dimension. However, the mean difference between all the models printed was slight and clinically insignificant.

Continuously released Zn2+ in 3D-printed PLGA/β-TCP/Zn scaffolds for bone defect repair by improving osteoinductive and anti-inflammatory properties.

Long-term nonunion of bone defects has always been a major problem in orthopedic treatment. Artificial bone graft materials such as Poly (lactic-co-glycolic acid)/β-tricalcium phosphate (PLGA/β-TCP) scaffolds are expected to solve this problem due to their suitable degradation rate and good osteoconductivity. However, insufficient mechanical properties, lack of osteoinductivity and infections after implanted limit its large-scale clinical application. Hence, we proposed a novel bone repair bioscaffold by adding zinc submicron particles to PLGA/β-TCP using low temperature rapid prototyping 3D printing technology. We first screened the scaffolds with 1wt% Zn that had good biocompatibility and could stably release a safe dose of zinc ions within 16 weeks to ensure long-term non-toxicity. As designed, the scaffold had a multi-level porous structure of biomimetic cancellous bone, and the Young's modulus (63.41±1.89MPa) and compressive strength (2.887±0.025MPa) of the scaffold were close to those of cancellous bone. In addition, after a series of in vitro and in vivo experiments, the scaffolds proved to have no adverse effects on the viability of BMSCs and promoted their adhesion and osteogenic differentiation, as well as exhibiting higher osteogenic and anti-inflammatory properties than PLGA/β-TCP scaffold without zinc particles. We also found that this osteogenic and anti-inflammatory effect might be related to Wnt/β-catenin, P38 MAPK and NFkB pathways. This study lay a foundation for the follow-up study of bone regeneration mechanism of Zn-containing biomaterials. We envision that this scaffold may become a new strategy for clinical treatment of bone defects.

Design and optimization of the construction of a mobile disinfection chamber for small communication devices and small objects

Abstract This manuscript aims to familiarise readers with the development of a device for the construction of a mobile disinfection chamber for small communication devices and small objects. The conceptual design and the material of the new device play essential roles in the design process of a new device. The manuscript presents concepts based primarily on previous experience and different perspectives. The concept design is created in the 3D modelling program CREO Parametric 8.0. A multi-criteria team evaluation determined the most suitable version of the idea. For dimensioning and shape adaptation of the device was used EinScan SP device (3D scanning method). The article's aim was also to establish a suitable way of producing a prototype using tribological research in available production methods and materials within rapid prototyping. Using the ALICONA Infinite Focus G5 device, experimentally investigated the parameters characterising the surface of the parts. The end of the manuscript focused on the mechanical structure and subjecting them to FEM analysis in the program ANSYS Workbench. The design of the concept disinfection device was also for extreme cases of use. Within this issue was optimising shapes, wall thicknesses, reinforcement design and other necessary modifications using the FEM analysis. From the results, the most suitable material to produce a more significant number of parts may not be the most suitable material to create prototype devices. Tools such as 3D scanning, rapid prototyping, and FEM analysis can "significantly" help reduce mistakes before testing the device.

3D scanning and 3D printing to develop internally helically ribbed tubes

We developed 3D scanning and rapid prototyping-based approach for an easier design of high precision, single pass tube drawing technology dedicated to the manufacturing of high-quality internally helically ribbed tubes. The major difficulty in the currently used process design is the identification of floating plug stability criterion allowing manufacturing of high precision helical ribs. The novelty of the proposed approach is therefore to use a combination of 3D scanning and rapid prototyping processes to design a complex floating plug geometry based on minimizing membrane energy. It was combined with computer-aided design of drawing die geometry and process parameters of the optimal tube drawing.

Streamline Effect Improvement of Additive Manufactured Airfoil Utilizing Dynamic Stream Control Procedure

In the era of fast transport, to create inventive stream flow management solutions that are capable of diminishing the aerodynamic drag of the vehicles, there is a need to modify the flow characteristics over the vehicle by deferring or expelling the position of the flow partition. The objective of this study involves the parameterized design of an airfoil utilizing the Bezier curve technique with the assistance of the simulation program. For flow regulations, synthetic jet modules are ingrained at different percentages of the chord to manage the stall characteristics. The parametrization system, combined with the stream control method, can give a much better insight into flow re-energization and pave some way for the reduction of the wake. Digital fabrication technique (3d printing or Rapid Prototyping method) is used to fabricate the end product for aerodynamic testing. The comparative outcome showed a reduction in drag at certain angles of attack due to the surface finish obtained. By comparing the results, the aerodynamic efficiency showed a significant rise of 13.05% at lower angles of attack when compressed gas was used in the synthetic jet closer to the frontier edge of the airfoil. Near the stall angle of attack, the coefficient of lift (Cl) and coefficient of drag (Cd) values showed no progress.

A Method for 3D Printing and Rapid Prototyping of Fieldable Untethered Soft Robots.

Because they are made of elastically deformable and compliant materials, soft robots can passively change shape and conform to their environment, providing potential advantages over traditional robotics approaches. However, existing manufacturing workflows are often labor intensive and limited in their ability to create highly integrated three-dimensional (3D) heterogeneous material systems. In this study, we address this with a streamlined workflow to produce field-deployable soft robots based on 3D printing with digital light processing (DLP) of silicone-like soft materials. DLP-based 3D printing is used to create soft actuators (2.2 g) capable of exerting up to 0.5 Newtons of force that are integrated into a bioinspired untethered soft robot. The robot walks underwater at speeds comparable with its biological analog, the brittle star. Using a model-free planning algorithm and feedback, the robot follows remote commands to move to desired positions. Moreover, we show that the robot is able to perform untethered locomotion outside of a laboratory and in a natural aquatic environment. Our results represent progress in soft robot manufacturing autonomy for a 3D printed untethered soft robot.

Development of a Hot-Melt-Extrusion-Based Spinning Process to Produce Pharmaceutical Fibers and Yarns.

Fibers and yarns are part of everyday life. So far, fibers that are also used pharmaceutically have mainly been produced by electrospinning. The common use of spinning oils and the excipients they contain, in connection with production by melt extrusion, poses a regulatory challenge for pharmaceutically usable fibers. In this publication, a newly developed small-scale direct-spinning melt extrusion system is described, and the pharmaceutically useful polyvinyl filaments produced with it are characterized. The major parts of the system were newly developed or extensively modified and manufactured cost-effectively within a short time using rapid prototyping (3D printing) from various materials. For example, a stainless-steel spinneret was developed in a splice design for a table-top melt extrusion system that can be used in the pharmaceutical industry. The direct processing of the extruded fibers was made possible by a spinning system developed called Spinning-Rosi, which operates continuously and directly in the extrusion process and eliminates the need for spinning oils. In order to prevent instabilities in the product, further modifications were also made to the process, such as a the moisture encapsulation of the melt extrusion line at certain points, which resulted in a bubble-free extrudate with high tensile strength, even in a melt extrusion line without built-in venting.

Compatibility of Popular Three-Dimensional Printed Microfluidics Materials with In Vitro Enzymatic Reactions.

3D printed microfluidics offer several advantages over conventional planar microfabrication techniques including fabrication of 3D microstructures, rapid prototyping, and inertness. While 3D printed materials have been studied for their biocompatibility in cell and tissue culture applications, their compatibility for in vitro biochemistry and molecular biology has not been systematically investigated. Here, we evaluate the compatibility of several common enzymatic reactions in the context of 3D-printed microfluidics: (1) polymerase chain reaction (PCR), (2) T7 in vitro transcription, (3) mammalian in vitro translation, and (4) reverse transcription. Surprisingly, all the materials tested significantly inhibit one or more of these in vitro enzymatic reactions. Inclusion of BSA mitigates only some of these inhibitory effects. Overall, inhibition appears to be due to a combination of the surface properties of the resins as well as soluble components (leachate) originating in the matrix.

3D-printed stators & drive caps for magic-angle spinning NMR

3D printing has evolved into an invaluable tool for rapid and cost-effective production of intricate parts. In this paper we describe 3D printing and other rapid prototyping methods to fabricate 3.2 mm stators and drive caps for use in magic angle spinning (MAS) NMR experiments. These components can be fabricated with the assistance of computer-aided design (CAD) software and at a fraction of the cost of commercial parts. Additionally, we show that the performance of these 3D printed stators and drive caps is comparable to commercially available systems and that they have significant advantages over their machined counterparts.

PLGA/β-TCP composite scaffold incorporating cucurbitacin B promotes bone regeneration by inducing angiogenesis.

ObjectivesVascularization is an essential step in successful bone tissue engineering. The induction of angiogenesis in bone tissue engineering can be enhanced through the delivery of therapeutic agents that stimulate vessel and bone formation. In this study, we show that cucurbitacin B (CuB), a tetracyclic terpene derived from Cucurbitaceae family plants, facilitates the induction of angiogenesis in vitro.MethodsWe incorporated CuB into a biodegradable poly (lactide-co-glycolide) (PLGA) and β-tricalcium phosphate (β-TCP) biomaterial scaffold (PT/CuB) Using 3D low-temperature rapid prototyping (LT-RP) technology. A rat skull defect model was used to verify whether the drug-incorporated scaffold has the effects of angiogenesis and osteogenesis in vivo for the regeneration of bone defect. Cytotoxicity assay was performed to determine the safe dose range of the CuB. Tube formation assay and western blot assay were used to analyze the angiogenesis effect of CuB.ResultsPT/CuB scaffold possessed well-designed bio-mimic structure and improved mechanical properties. CuB was linear release from the composite scaffold without affecting pH value. The results demonstrated that the PT/CuB scaffold significantly enhanced neovascularization and bone regeneration in a rat critical size calvarial defect model compared to the scaffold implants without CuB. Furthermore, CuB stimulated angiogenic signaling via up-regulating VEGFR2 and VEGFR-related signaling pathways.ConclusionCuB can serve as promising candidate compound for promoting neovascularization and osteogenesis, especially in tissue engineering for repair of bone defects.The translational potential of this articleThis study highlights the potential use of CuB as a therapeutic agent and strongly support its adoption as a component of composite scaffolds for tissue-engineering of bone repair.

Sacrificial 3D Printing of Highly Porous, Soft Pressure Sensors

AbstractAdditive manufacturing (AM) technologies offer the possibilities of rapid prototyping, novel and innovative geometrical freeform 3D designs. Recent progress in AM has proved its potential to facilitate the fabrication of multi‐material innovative sensing devices for wearable soft electronics. Extrusion based 3D printing such as fused deposition modeling FDM is gaining popularity in academic research due to availability, affordability, the ability to be modified, simultaneous multi‐material fabrication, ease of material adaption, and development. Herein, a method of fabricating soft compressible multi‐layered pressure sensors via FDM 3D multi‐material printing is presented. Highly sensitive and tunable pressure sensors are realized with enhanced compressibility and wide sensing range. The electromechanical properties of the 3D printed sensors are investigated throughout this paper. The 3D printed pressure sensors demonstrate high tactile sensitivity reaching 0.7145 kPa−1 at 0.5 kPa. Cyclic testing of the multi‐layered sensor shows linear and reproducible response with wide range sensitivity that suggests their great potential in wearable and robotic applications.

Study on the Application Value of CT Thin-Layer Scan Data Assisted 3D Printing Technology in Hip and Knee Replacement.

To better study hip and knee replacement, 50 eligible hip and knee patients from March 2020 to April 2021 were selected. A 1 : 1 scale solid model was printed with CT thin-layer scanning data assisted by 3D printing technology to evaluate the ankle function of patients six months after surgery. The results showed that the 3D rapid prototyping time of the 1 : 1 fracture model in 50 patients was 3-4 hours. The operation time was 70–90 min, and the average operation time was 80 min. The actual application in operation was consistent with that in the simulation of the 3D printing model, after surgery, and there was no infection of incision soft tissue or loss of reduction in all 50 patients. CT thin-layer scan data aided 3D printing technology can help clinical hip and knee replacement simulation and planning, improving surgery's accuracy and safety.

Optimization Of Process Parameters In 3d Printing-Fused Deposition Modeling Using Taguchi Method

3D printing or Rapid Prototyping (RP) or Additive Manufacturing (AM) is an innovative manufacturingmethod that is mostly used for prototypes in various Industries such as Aerospace, Defense, Medical, Automotive, etc. One of the worthy and widely used 3 D printing techniques is Fused Deposition Modeling (FDM), which involves adding melted material layer by layer. FDM has several benefits over other manufacturing methods. While setting the 3 D printing options, we have to take several parameters into account, such as speed, layer thickness and infill density, etc. The present experimental work illustrates the performance of ABS built parts fabricated by AION 500 make FDM machine. The quality of parts produced by FDM process mainly depends on the selection of process parameters. The present research work consists of process parameters such as layer thickness, infill density and speed of deposition, etc. This study aims to find effects of process parameters on different performance parameters i.e., mechanical considerations (impact strength), build time, surface roughness in a systematic manner with less number of experimental runs. Taguchi design of experiment (DOE) approach has been used to save cost and time of experimentation. Statistical significance of process parameters is analyzed using analysis of variance (ANOVA). The significant parameters for optimum results and optimal parameter setting has been suggested using S/N ratio.

Retention in maxillofacial prosthetics: A review

The facial region defects caused by trauma, accident, tumour or congenital defects are treated with maxillofacial prostheses. A part from esthetics, the most common problem encountered with these prostheses is the retention of prostheses. Recent techniques along with newer materials, treatment options, and its application are described. The success of maxillofacial prostheses in meeting the expectations of patients and prosthodontists is on rise with the development of adhesive material science, the emergence of technical knowledge, and the development of implant technology. Increase in retention provides ease of use and psychological acceptance by the patient thereby improving the long-term prognosis of the prosthesis. In the present article review, the methods used for the retention of prostheses from past to present along with the advantages of adhesives and implants, implementation of 3D technology and rapid prototyping were critically appraised.