Conventional 3D Printing Research Articles

PHASE SEPARATION AND PARTICULATE LEACHING INTEGRATED 3D PRINTING OF POROUS SCAFFOLDS FOR BONE TISSUE ENGINEERING APPLICATIONS

Conventional 3D printing by itself is incapable of creating pores on a micro scale within deposited filaments throughout 3D scaffolds. These pores and hence larger surface areas are needed for cells to be adhered, proliferated, and differentiated. The aim of this work was to fabricate 3D polycaprolactone (PCL) scaffolds with internal multiscale porosity by using two different 3D printing techniques (ink/pellet of polymer-salt composite in low/high temperature printing) combined with salt leaching to improve cell adhesion, and cell proliferation besides to change degradation rate of PCL scaffolds:1. Non-solvent phase separation integrated 3D printing of polymer-salt inks with various salt content (i.e., low temperature ink-based printing, LT).2. FDM printing of composite polymer-salt pellets which will be obtained by casting and evaporating of prepared ink (i.e., high temperature composite-pellet-based printing, HT).Further, the two approaches were followed by post salt leaching. Stem cells were able to attach on the surface and grow up to 14 days based on increasing cellular activities.

4D food printing technology: Structural changes to culinary art and beyond

AbstractThe evolution of food manufacturing through 3D printing has expanded with the development of 4D printing technology and opened new possibilities in culinary applications. Compared to conventional 3D printing, 4D printing incorporates time as a new dimension, allowing for dynamic modifications to food structures. Self‐assembly and reactions to external factors such as pH, moisture content, or temperature are examples of these alterations. The gastronomic design and nutritional possibilities have increased with the use of 4D printing in the food preparation process. Personalized nutrition is a significant use of 4D printing in the food industry. With the use of this technology, food products may be tailored to meet the dietary requirements of everyone, encouraging better eating practice and treating nutritional shortages. Furthermore, complex culinary designs that were previously difficult to accomplish are now possible by 4D printing. Intelligent materials that adapt their surroundings allow for self‐adjusting forms or packaging, which lowers waste and promotes sustainable food practices. Transportation and food storage could be revolutionized by 4D printing. Food deterioration and waste can be reduced, and food quality preserved throughout storage and transportation with the help of self‐adjusting packaging that adjusts to temperature fluctuations. Examining the most recent advancements in 4D food printing technology, this review highlights how this technology can revolutionize customized nutrition, sustainability, waste management, and culinary inventiveness.Practical ApplicationsUnderstanding the concept and advances in food printing technology is important to develop nutritionally enriched food products with desired shape. The factors involved in 4D food printing technologies and the structural and biochemical changes in products during processing are critically analyzed.

Towards Sustainable Additive Manufacturing: Exploring Ecofriendly Materials for Green 3D Printing

The area of additive manufacturing, usually referred to as 3D printing, has recently experienced major growth and advancement, leading to dramatic changes across different industries like as healthcare and aerospace. But the issue of environmental sustainability remains to be of extreme significance, considering the significant utilization of resources and production of waste that relates to conventional 3D printing materials and methods. The objective of this research study is to examine the potential and efficacy of environmentally friendly materials in the wider context of 3D printing. This study examines recent advances in sustainable materials, with a focus on analysing their environmental effects, efficacy, and feasibility comparative to conventional equivalent. The research also investigates the implementation of environmentally friendly techniques within the method of additive manufacturing, covering aspects such as obtaining of materials, energy usage, and management of waste. The results of our investigation indicate that making use of environmentally friendly materials, combined with green production techniques, has the potential to considerably decrease the ecological impact of 3D printing. This progress holds promise for furthering the sustainability of additive manufacturing and designing a more sustainable future.

Numerical Model of 3D Printed Joint of Wooden Frame

Regardless of the type of material, 3D printing seems to be an interesting alternative to conventional construction methods. Leaving aside the use of 3D printing systems for concrete or cement composites, the more conventional 3D printing of plastic, metal or other separated materials may also have its hypothetical benefits in the creation of structural joints. For truss structures, such as arch bridges, certain types of joints can be expected that do not always have the same angle between the single-plane load-bearing elements of the structure. In such a case, the use of 3D printing technology for joint fabrication is defensible. In the case of a standard scale and using experience from timber bridges, one would assume that an embedded plate and pin connection would be the appropriate connection form. In contrast, from the point of view of producing smaller physical models, mainly for a deeper understanding of the comparability issues of numerical modelling and experimental testing, it is advantageous to use so-called enveloping timber element connections. The present paper describes the basic process of numerical analysis of a detail of a wooden arch bridge connection made from 3D printed polycarbonate joints.

Review of the 3D bioprinting methods and materials applicable in 4D bioprinting

The advent of 4D bioprinting, a technique that integrates time dimensions into the conventional 3D method, substantially changed tissue engineering. By providing a time dimension to conventional 3D printing, the innovative process of 4D bioprinting is revolutionising tissue engineering. This development allows the creation of dynamic tissues, allowing structures to change and adapt over time to reflect the complexity of natural tissues. Specifically, shape memory polymers enable customised scaffold fabrication with improved mechanical strength and biomimicry for use in bone tissue engineering. An essential additional use for soft tissue regeneration is the development of injectable thermosensitive hydrogels that react to body temperature. Within asymmetrical defect regions, these hydrogels gel, offering a flexible cure for healing injured soft tissues. In addition to structural considerations, the potential applications of 4D bioprinting include organisms, vascularisation and dynamic disease models. Despite the advancements, issues like suitable biocompatibility and long-term stability still need to be resolved. However, by creating complex, adaptable and patient-specific designs in the realm of tissue engineering, 4D bioprinting has enormous potential to transform personalised medicine and regenerative therapies. This review provides a comprehensive investigation into the future of regenerative medicine by exploring the various uses and potentially revolutionary effects of 4D bioprinting in tissue engineering.

Modular photoorigami-based 4D manufacturing of vascular junction elements.

Four-dimensional (4D) printing, combining three-dimensional (3D) printing with time-dependent stimuli-responsive shape transformation, eliminates the limitations of the conventional 3D printing technique for the fabrication of complex hollow constructs. However, existing 4D printing techniques have limitations in terms of the shapes that can be created using a single shape-changing object. In this paper, we report an advanced 4D fabrication approach for vascular junctions, particularly T-junctions, using the 4D printing technique based on coordinated sequential folding of two or more specially designed shape-changing elements. In our approach, the T-junction is split into two components, and each component is 4D printed using different synthesized shape memory polyurethanes and their nanohybrids, which have been synthesized with varying hard segment contents and by incorporating different weight percentages of photo-responsive copper sulfide-polyvinyl pyrrolidone nanoparticles. The formation of a T-junction is demonstrated by assigning different shape memory behaviors to each component of the T-junction. A cell culture study with human umbilical vein endothelial cells reveals that the cells proliferate over time, and almost 90% of cells remain viable on day 7. Finally, the formation of the T-junction in the presence of near-infrared light has been demonstrated after seeding the endothelial cells on the programmed flat surface of the two components and fluorescence microscopy at day 3 and 7 reveals that the cells adhered well and continue to proliferate over time. Hence, the proposed alternative approach has huge potential and can be used to fabricate vascular junctions in the future.

Towards an Optimal Motor Mounting Bracket Using Topology Optimization Combined with Sustainability and Manufacturing Cost Analysis

The engine is the most important component of a vehicle. It attaches to the main frame via the engine mounting bracket which supports weight and operating loads. The engine mount therefore plays a crucial role in the durability and comfort of the vehicle. This article contributes to the search for the most optimal model from the point of view of resistance, environmental impact, and manufacturing cost. This involves, on the one hand, optimizing the support by reducing its initial mass by 30%, and on the other hand, seeking suitable material and manufacturing process with the least environmental impact. To this end, topology optimization will be combined with an environmental assessment and a manufacturing cost analysis. Four materials will be tested and evaluated. Finally, a cost analysis will present a comparison between a conventional process and 3D printing.

The impacts of post‐processing treatments done under reactive and non‐reactive atmospheres on the densification of binder jetting parts

AbstractAt the intersection between chemical and materials engineering, binder jetting is an additive manufacturing technique that foregoes many of the limitations of the conventional metal 3D printing technique. Binder composition and thermal post‐processing influence final part quality. Herein, three different atmospheres, ranging from reactive (air) to non‐reactive (vacuum, argon), are studied to determine their effect on the quality of binder jetting printed parts after thermal treatments, namely debinding and sintering. These parts were printed using SS316L powder. Samples debound in air were negatively affected as they presented high porosities and low densities, averaging 6.80 (±0.4) g/cm3, whereas samples debound and sintered under vacuum demonstrated the best outcome with low porosities and high densities, averaging 7.65 (±0.1) g/cm3. This study highlights how oxide formation during debinding causes ferrite phase formation during sintering and how it affects atomic diffusion in the samples during both thermal treatments. This research also demonstrates the respective effects of these on the densification and porosity of parts.

A continuous toolpath strategy from offset contours for robotic additive manufacturing

Toolpath planning is an essential component of robotic additive manufacturing. An efficient toolpath strategy allows parts to be made that are geometrically accurate, free of defects, have good mechanical properties and have low residual stress. Toolpaths for cold spray additive manufacturing have some technical constraints that need to be considered compared to their counterpart designed for conventional 3D printing machines. This study presents an automated toolpath planning method based on offset contours. The generated toolpath is globally continuous, layer-wise setting, making it suitable for robotic cold spray additive manufacturing. The toolpath algorithm was tested on a variety of geometries to demonstrate its robustness. One model was selected for printing using a commercial high-pressure cold spray system. The experimental results show that our method is applicable to cold spray robotic additive manufacturing for near-net shape construction. The method is particularly good for web-rib structures.

3D Printing of Individualized Microfluidic Chips with DLP-Based Printer

Microfluidic chips have shown their potential for applications in fields such as chemistry and biology, and 3D printing is increasingly utilized as the fabrication method for microfluidic chips. To address key issues such as the long printing time for conventional 3D printing of a single chip and the demand for rapid response in individualized microfluidic chip customization, we have optimized the use of DLP (digital light processing) technology, which offers faster printing speeds due to its surface exposure method. In this study, we specifically focused on developing a fast-manufacturing process for directly printing microfluidic chips, addressing the high cost of traditional microfabrication processes and the lengthy production times associated with other 3D printing methods for microfluidic chips. Based on the designed three-dimensional chip model, we utilized a DLP-based printer to directly print two-dimensional and three-dimensional microfluidic chips with photosensitive resin. To overcome the challenge of clogging in printing microchannels, we proposed a printing method that combined an open-channel design with transparent adhesive tape sealing. This method enables the rapid printing of microfluidic chips with complex and intricate microstructures. This research provides a crucial foundation for the development of microfluidic chips in biomedical research.

4D-Printable Photocrosslinkable Polyurethane-Based Inks for Tissue Scaffold and Actuator Applications.

4D printing recently emerges as an exciting evolution of conventional 3D printing, where a printed construct can quickly transform in response to a specific stimulus to switch between a temporary variable state and an original state. In this work, a photocrosslinkable polyethylene-glycol polyurethane ink is synthesized for light-assisted 4D printing of smart materials. The molecular weight distribution of the ink monomers is tunable by adjusting the copolymerization reaction time. Digital light processing (DLP) technique is used to program a differential swelling response in the printed constructs after humidity variation. Bioactive microparticles are embedded into the ink and the improvement of biocompatibility of the printed constructs is demonstrated for tissue engineering applications. Cell studies reveal above 90% viability in 1 week and ≈50% biodegradability after 4 weeks. Self-folding capillary scaffolds, dynamic grippers, and film actuators are made and activated in a humid environment. The approach offers a versatile platform for the fabrication of complex constructs. The ink can be used in tissue engineering and actuator applications, making the ink a promising avenue for future research.

Filament-Reinforced 3D Printing of Clay.

This research resulted in the development of a method that can be used for filament-reinforced 3D printing of clay. Currently, clay-based elements are mixed with randomly dispersed fibrous materials in order to increase their tensile strength. The advantages of taking this new approach to create filament-reinforced prints are the increased bridging ability while printing, the increased tensile strength of the dried elements, and the achievement of non-catastrophic failure behavior. The research methodology used involves the following steps: (1) evaluating properties of various filament materials with respect to multiple criteria, (2) designing a filament guiding nozzle for co-extrusion, and (3) conducting a comprehensive testing phase for the composite material. This phase involves comparisons of bridging ability, tensile strength evaluations for un-reinforced clay prints and filament-reinforced prints, as well as the successful production of an architectural brick prototype. (4) Finally, the gathered results are subjected to thorough analysis. Compared to conventional 3D printing of clay, the developed method enables a substantial increase in bridging distance during printing by a factor of 460%. This capability facilitates the design of objects characterized by reduced solidity and the attainment of a more open, lightweight, and net-like structure. Further, results show that the average tensile strength of the reinforced sample in a dry state exhibited an enhancement of approximately 15%. The combination of clay's ability to resist compression and the filament's capacity to withstand tension has led to the development of a structural concept in this composite material akin to that of reinforced concrete. This suggests its potential application within the construction industry. Producing the prototype presented in this research would not have been possible with existing 3D printing methods of clay.

Hybrid Multimaterial 3D Printing Using Photocuring-While-Dispensing.

Three-dimensional (3D) printing methods, such as vat photopolymerization (VPP) and direct-ink-writing (DIW) processes, are known for their high-resolution and multimaterial capabilities, respectively. Here a novel hybrid 3D printing technique that combines the strengths of VPP and DIW processes to achieve multimaterial and high-resolution printing of functional structures and devices, is presented. The method involves dispensing liquid-like materials via syringes into a photocurable matrix material and subsequently using a Galvano mirror-controlled laser beam to selectively photocure the dispensed material trace or the matrix material surrounding the trace. The laser beam scanning and syringe dispensing are synchronized with a set delay to control liquid diffusion and in situ fixture. The versatility of the method is demonstrated by fabricating intricate 3D ant and wheel prototypes using various materials available for VPP and DIW technologies. The proposed photocuring-while-dispensing strategy offers advantages over conventional multimaterial 3D printing methods, such as integrating materials regardless of photocurability and viscosity, and fabricating heterogeneous structures with complex geometries and high resolution. With its principle demonstrated, this multimaterial 3D printing process will open up a wide range of potential applications with diverse functionalities and materials.

Large-scale hollow-core 3D printing (HC3DP): A polymer 3D printing technology for large-scale ultralightweight components

Material extrusion (ME) has become a popular 3D printing method for large-scale applications such as in the automotive, naval, aerospace, and architecture sectors. It allows the production of complex, customized parts without the need of labour-intensive molds. The increasing need to produce larger and larger parts has been addressed with the introduction of large pellet extrusion systems to increase the extrusion rate. With these extruders the production time is not limited by the extrusion rate of the extruder (kg/h) but by the time the material needs to cool down before the next layer can be printed consecutively. Furthermore, larger bead dimensions result in increased material usage and, therefore, might affect the environmental impact of the printed element. In this study, a method for large extrusion 3D printing based on hollow beads is proposed, to address the limitations of speed, cooldown and maximize the extrusion rate of thermoplastic 3D printing. This paper introduces Hollow-Core 3D printing (HC3DP) and compares it to off-the shelf large-scale pellet extruders and their maximum achievable extrusion rate for a given geometry. A comparative analysis of cooldown characteristics between conventional thermoplastic extrusion 3D printing and HC3DP validates that the latter increases the maximum possible extrusion rate. Additionally, the successful 3D printing of large-scale beads with multiple polymer feedstocks is demonstrated. Then the data associated with printing speed and material usage is presented and discussed in comparison with thermoplastic and other large-scale 3D printing methods. The fabrication of large-scale hollow-core beads at a dimension of 24×20mm is showcased with an extrusion rate of 7250 mm3/s (1308 material, 5941 air). HC3DP for large-scale applications is validated through the production of 2-meter tall cylinders with a diameter of 400 mm in less than two hours. Furthermore, bespoke die geometries that subdivide the inside of hollow 3D-printed beads are presented. To successfully print those, the concept of differentiated internal air pressure per print point is introduced. Finally, 3PT bending tests are conducted to compare different die geometries. In conclusion, this study presents a printing method that highlights the benefits of hollow core 3D printing for large-scale applications, showcasing its positive impact on both the printing process and resulting part properties. By addressing the limitations of traditional approaches, HC3DP pushes polymer 3D printing into a scale relevant for architecture and construction, offering similar extrusion rates as concrete 3DP.

Temperature-Controlled 3D Cryoprinting Inks Made of Mixtures of Alginate and Agar.

Temperature-controlled 3D cryoprinting (TCC) is an emerging tissue engineering technology aimed at overcoming limitations of conventional 3D printing for large organs: (a) size constraints due to low print rigidity and (b) the preservation of living cells during printing and subsequent tissue storage. TCC addresses these challenges by freezing each printed voxel with controlled cooling rates during deposition. This generates a rigid structure upon printing and ensures cell cryopreservation as an integral part of the process. Previous studies used alginate-based ink, which has limitations: (a) low diffusivity of the CaCl2 crosslinker during TCC's crosslinking process and (b) typical loss of print fidelity with alginate ink. This study explores the use of an ink made of agar and alginate to overcome TCC protocol limitations. When an agar/alginate voxel is deposited, agar first gels at above-freezing temperatures, capturing the desired structure without compromising fidelity, while alginate remains uncrosslinked. During subsequent freezing, both frozen agar and alginate maintain the structure. However, agar gel loses its gel form and water-retaining ability. In TCC, alginate crosslinking occurs by immersing the frozen structure in a warm crosslinking bath. This enables CaCl2 diffusion into the crosslinked alginate congruent with the melting process. Melted agar domains, with reduced water-binding ability, enhance crosslinker diffusivity, reducing TCC procedure duration. Additionally, agar overcomes the typical fidelity loss associated with alginate ink printing.

Development of a cyber physical production system framework for 3D printing analytics

3D printing technology is considered one of the emerging areas to deal with global sustainability challenges and to facilitate the Industry 4.0 adoption. However, 3D printing technology is still immature due to several limitations and negative perceptions about its quality and performance. The goal of this paper is to propose a cyber physical production system (CPPS) framework for a 3D printer to (i) monitor the process, parameters, and carbon footprint, (ii) predict the nozzle’s remaining useful life (RUL), and (iii) prescribe optimum 3D printing parameters for minimizing carbon footprint and printing time, simultaneously at the targeted surface quality. Experiments were designed based on Taguchi L-27 orthogonal array to investigate the relationship between printing parameters and performance characteristics. The usefulness of the proposed framework has been demonstrated for a 3D printer to predict the remaining useful life of the printer nozzle (prognostic model), and to find an optimal combination of printing parameters for the simultaneous optimization of sustainability and productivity at the targeted surface quality (prescriptive model). Layer height was found to have a statically significant impact on the specific carbon footprint followed by scale and bed temperature. Layer height is the only statically significant contributor to the surface roughness of 3D printed parts. The scale and layer height followed by infill have significant effect on the printing time. The significance of the present work lies in enhancing the performance of a conventional 3D printer using low-cost smart sensors, devices, and open-source software. The usefulness of the proposed CPPS framework is demonstrated as a decision support tool for a 3D printer real-time monitoring, visualization, and control. The proposed CPPS framework and its application for prognostic and prescriptive analytics is generic in nature, and is transferable and applicable to other FDM 3D printers, irrespective of brand and size.

Design and Analysis of a Rotational Mixer to produce 3D Bioprinting Gyroid-Helical-Patterned Scaffolds for Tissue Engineering Applications.

Tissue engineering scaffolds require complex networks for nutrient diffusion and cell attachment. They must have specific surface area and curvature, and often need a multimaterial composition, demanding advanced micro-fabrication methods. 3D extrusion bioprinting offers versatility to manufacture different scaffold, and strategies for multimaterial printing have been introduced. We propose a method to fabricate scaffolds based on gyroid-helical-patterned microfibers, providing a platform to study the effect of the gyroid minimum curvature on cellular processes, since the geometry wont be layer-by-layer approximated. The pattern is obtained by mixing inks using a gyroid-helix shaped rotational mixer, modifying the extruder of a conventional 3D printer. The mixer was simulated using computational fluid dynamics tools, varying the volumetric flow to obtain different gyroid-thickness. Due to its surface area minimization, it shows lower energy requirements than state-of-art fluid mixers, with a pressure drop of 1.7%, a power number of 39, and a rotation-induced shear stress of ∼400 Pa, enabling the use of cell-embedded bioinks.

UV polymerization fabrication method for polymer composite based optical fiber sensors

Optical fiber (OF) sensors are critical optical devices with excellent sensing capabilities and the capacity to operate in remote and hostile environments. However, integrating functional materials and micro/nanostructures into the optical fiber systems for specific sensing applications has limitations of compatibility, readiness, poor control, robustness, and cost-effectiveness. Herein, we have demonstrated the fabrication and integration of stimuli-responsive optical fiber probe sensors using a novel, low-cost, and facile 3D printing process. Thermal stimulus–response of thermochromic pigment micro-powders was integrated with optical fibers by incorporating them into ultraviolet-sensitive transparent polymer resins and then printed via a single droplet 3D printing process. Hence, the thermally active polymer composite fibers were grown (additively manufactured) on top of the commercial optical fiber tips. Then, the thermal response was studied within the temperature range of (25–35 °C) and (25–31 °C) for unicolor and dual color pigment powders-based fiber-tip sensors, respectively. The unicolor (with color to colorless transition) and dual color (with color to color transition) powders-based sensors exhibited substantial variations in transmission and reflection spectra by reversibly increasing and decreasing temperatures. The sensitivities were calculated from the transmission spectra where average change in transmission spectra was recorded as 3.5% with every 1 °C for blue, 3% for red and 1% for orange-yellow thermochromic powders based optical fiber tip sensors. Our fabricated sensors are cost-effective, reusable, and flexible in terms of materials and process parameters. Thus, the fabrication process can potentially develop transparent and tunable thermochromic sensors for remote sensing with a much simpler manufacturing process compared to conventional and other 3D printing processes for optical fiber sensors. Moreover, this process can integrate micro/nanostructures as patterns on the optical fiber tips to increase sensitivity. The developed sensors may be employed as remote temperature sensors in biomedical and healthcare applications.

3D Printing‐Assisted Nanoimprint Lithography of Polymers

Fused filament fabrication, commonly referred to as 3D printing, is an additive manufacturing method finding plenty of applications nowadays. In contrast, polymer nanopatterning by nanolithographic techniques plays an important role in obtaining functional surfaces and coatings for applications in different fields including micro‐ and nanoelectronics. In spite of their relevance, additive manufacturing and polymer nanolithography have not found yet a common niche to be developed. Although both approaches are oriented to achieve different types of objects, it is shown that the confluence of both technologies can be desirable and potentially convenient. Herein, it is demonstrated that by employing conventional 3D printing, it is possible to fabricate nanostructured polymer surfaces in a relatively simple way by using similar approaches as those used in nanoimprint lithography but without the need for clean room conditions. To do that, a printed‐assisted nanoimprint lithography concept (3DPrANIL) has been tested for different types of polymer and silicon templates. It is demonstrated that a polymeric nanostructured hydrophilic template can be replicated accurately on another polymer rendering a nanostructured surface with enhanced hydrophobicity. The results support 3DPrANIL as novel method to obtain micro‐ and nanostructured surfaces with different functionalities like iridescence and hydrophobicity.

Experimental Study on Mechanical Properties of Different Resins Used in Oral Environments.

Background and Objectives: Acrylic resins remain the materials of choice for removable prosthesis due to their indisputable qualities. The continuous evolution in the field of dental materials offers practitioners today a multitude of therapeutic options. With the development of digital technologies, including both subtractive and additive methods, workflow has been considerably reduced and the precision of prosthetic devices has increased. The superiority of prostheses made by digital methods compared to conventional prostheses is much debated in the literature. Our study's objective was to compare the mechanical and surface properties of three types of resins used in conventional, subtractive, and additive technologies and to determine the optimal material and the most appropriate technology to obtain removable dentures with the highest mechanical longevity over time. Materials and Methods: For the mechanical tests, 90 samples were fabricated using the conventional method (heat curing), CAD/CAM milling, and 3D printing technology. The samples were analyzed for hardness, roughness, and tensile tests, and the data were statistically compared using Stata 16.1 software (StataCorp, College Station, TX, USA). A finite element method was used to show the behavior of the experimental samples in terms of the crack shape and its direction of propagation. For this assessment the materials had to be designed inside simulation software that has similar mechanical properties to those used for obtaining specimens for tensile tests. Results: The results of this study suggested that CAD/CAM milled samples showed superior surface characteristics and mechanical properties, comparable with conventional heat-cured resin samples. The propagation direction predicted by the finite element analysis (FEA) software was similar to that observed in a real-life specimen subjected to a tensile test. Conclusions: Removable dentures made from heat-cured resins remain a clinically acceptable option due to their surface quality, mechanical properties, and affordability. Three-dimensional printing technology can be successfully used as a provisional or emergency therapeutic solution. CAD/CAM milled resins exhibit the best mechanical properties with great surface finishes compared to the other two processing methods.