CAD Software Research Articles

Effect of the scanner type on the marginal gap and internal fit of two monolithic CAD/CAM esthetic crown materials: An in vitro study.

The durability of indirect restorations is significantly influenced by marginal adaptation and internal fit. The use of computer-aided design/computer-aided manufacturing (CAD/CAM) with digital impressions has reduced dental prosthesis fabrication errors, improving the long-term survivability of the restorations. The present study assessed the impact of intraoral and extraoral scanning methods on the marginal adaptation and internal fit of 2 different types of monolithic crowns manufactured using CAD/CAM. A total of 40 three-dimensional (3D) resin-printed dies were randomly assigned to 2 groups based on the type of crown material (n = 20 per group). Each group was divided into 2 subgroups (n = 10 per group) according to the die-scanning technique: subgroup A, scanned using the intraoral scanner (IOS) Primescan; and subgroup B, scanned using the extraoral scanner (EOS) inEos X5. The digitized photos were converted into a 3D virtual crown design using CAD software. The internal discrepancy values, and the marginal gap between the 3D resin-printed die and the crown were assessed using a ×50 digital microscope. The data was checked for normality with the Kolmogorov-Smirnov test, and the Mann-Whitney U test was used to compare the tested groups. The collected data was analyzed at a significance level set at p < 0.05. The different scanning techniques used had a statistically significant effect on the vertical marginal gap and the internal fit [μm] (p < 0.05). As far as the crown materials are concerned, BRILLIANT Crios showed a significantly higher marginal gap as compared to Tetric CAD when scanned with inEos X5 (p = 0.004), whereas the differences were insignificant with regard to the internal fit (p > 0.05).The crown parameters tested with both scanning systems were within the clinically acceptable ranges. Scanning methods and crown materials had an impact on the internal fit and vertical marginal gap of monolithic crowns.

The central neck in 3 dimensions: a digital model derived from radiology, peer-reviewed literature, and medical illustration

This project aims to create a 3-dimensional (3D) digital model of central neck anatomy, including muscles, neurovasculature, and viscera. The neck was segmented from a CT angiogram of a healthy 29-year-old female, and then transferred into 3D illustration software after removing imaging artifact. To enhance anatomical accuracy, details not captured by imaging or unclear from the study were added and refined with relevant peer-reviewed literature. These structures were later incorporated into the head and neck model. Following segmentation, the 3D models was refined in 3D CAD software. Structures not identified by segmentation were designed by a medical illustrator and all structures were refined from peer-reviewed anatomic literature. Where discrepancies were found in the literature, the size, source, and methodology of the studies were considered to determine the most common variants of each structure. Finally, the 3D model was uploaded to MedReality for online viewing. Technological progress in illustration software, patient specific anatomic modeling, and precise 3D CAD modeling has allowed the most accurate 3D surgical anatomy model to be created when combined with existing literature. The associated 3D model and manuscript will serve as a helpful tool for medical professionals regardless of academic level. To our knowledge, this literature-based model of the central neck combined with 3D anatomic modeling from real patient data is unprecedented and should aid in surgical anatomy education.

The lateral neck in 3 dimensions: A digital model derived from radiology, peer-reviewed literature, and medical illustration

ObjectivesTo develop an anatomically accurate 3-dimensional (3D) digital model of the lateral neck anatomy, including musculature, neurovasculature, and other associated structures such as lymphatics Materials and MethodsLateral neck anatomy, emphasizing level 1-4 structures, were segmented from a CT angiogram of a healthy 29-year-old female which was later transferred into a 3D illustration software after removal of imaging artifacts. To enhance anatomical accuracy, details not captured by imaging or unclear from the study were refined with relevant peer-reviewed literature. These structures were incorporated into the head and neck model. ResultsFollowing segmentation, the 3D models was refined in 3D CAD software. Structures not identified by segmentation, including vagus and phrenic nerves and lymphatics beyond the scan resolution, were designed by a medical illustrator and all structures were refined from peer-reviewed anatomic literature. Where discrepancies were found in the literature, the sample size, source, and methodology of the studies were considered to determine the most common variant of each structure. Finally, the 3D model was uploaded to MedReality® for online viewing. ConclusionThis study demonstrates the critical anatomic structures, landmarks, and surgical relationships relevant to the lateral neck. The associated 3D model and manuscript will serve as a helpful tool for a broad range of clinicians and trainees in search of a detailed 3D anatomic description of the lateral neck. This literature-based model of the central neck combined with 3D anatomic modeling from real patient data should aid in surgical anatomy education.

CLAMPING DIES DESIGN TO MINIMIZE AUTOMOTIVE COMPONENT DIES SETUP TIME AT PT GANDING TOOLSINDO

PT Ganding Toolsindo was faced with the problem of high automotive component die setup times. The main cause of the high setup time is the process of tightening and releasing the bolts which is done manually. The aim of this research is to design a tool for clamping dies which functions to help speed up the bolt installation process, so that the setup time for automotive component dies is reduced. The method used in this research is field observation followed by the die clamping design process. Design planning begins by drawing the object using CAD software based on the results of load calculations and determining the dimensions of the dies themselves and the press machine as well as selecting the dies material. Furthermore, proof was carried out that this die clamping design could reduce dies setup time using movement analysis with a pre-determined time study Measurement Time Method (MTM) method, where the results showed a time saving of 92.4%.

Implementation of experiential learning method in mechanical drawing course to enhance student understanding through real projects

This research explores the implementation of experiential learning to improve students' understanding and skills in mechanical drawing using CAD software. We used this approach to identify challenges in learning mechanical engineering, including lack of time to learn CAD, suboptimal mechanical drawing skills, and limitations in producing details of mechanical components. Through a quasi-experiment with experimental and control classes, we measured the impact of the experiential learning method on improving conceptual understanding and practical skills in mechanical drawing. The results show that this approach is effective in improving students' understanding of detailed drawings and practical skills. The implementation of Experiential Learning also improved students' cognitive learning outcomes and psychomotor skills in mechanical drawing. The findings highlight the importance of adaptive and technological approaches to engineering education that are aligned with modern industry needs.

Automated optimization of gating system through numerical simulation

Casting is a process for the production of complex shapes. Defects are unavoidable in any casting process. An efficient method of eliminating such defects can improve the process capability of the casting system. Computer simulation can save time, resources, and money in foundry trials, but it necessitates more human effort in terms of preparing the inputs and appropriately interpreting the results. In this work, a new method for evaluating and optimizing gating system design utilizing a simulation tool is proposed. It is possible to automatically modify the gating design with the help of CAD and casting simulation software from a given initial design and boundary conditions, and to check whether the design is effective to eliminate defects. Further this takes less human effort, making it more useful for industrial applications. The suggested methodology is demonstrated by autonomously optimizing the gating system for two industrial components and validated by producing actual castings made in sand molds.

An interdisciplinary treatment to reshape upper anterior displaced teeth by using dynamic occlusal recording with an intraoral scanner.

This article describes an interdisciplinary treatment that helped a patient with displaced upper anterior teeth. A gingivectomy, root canal therapies, digital smile design, digital wax-up, and guided tooth preparations were applied. A patient with pathologically migrated teeth asked for treatment without orthodontic involvement due to a primary failed orthodontic treatment history. A smile photo was taken and superimposed with the dentition in a CAD software to accomplish a digital smile design. The jaw movements were recorded with two different methods, a mechanical articulator and an intraoral scanner with Patient-Specific-Motion function. The occlusal contacts during protrusive and lateral movements were compared and the digital wax-up was designed according to the later occlusal data. An aesthetic crown lengthening and pre-op root canal treatment were carried out in advance accordingly. After guided tooth preparation with a silicone index, the final fixed restorations were manufactured and cemented. A 2-year follow-up showed that our prosthesis functions well. This clinical report revealed that an intraoral scanner with Patient-Specific-Motion function can effectively record individual dynamic occlusal patterns and these data can be integrated into the CAD/CAM process to enhance the fulfillment of clinical requirements. This clinical procedure with a 2-year follow-up demonstrated that a prosthodontic-based interdisciplinary treatment of pathologically migrated teeth using dynamic occlusal recording with an intraoral scanner could achieve satisfactory esthetics in a relatively short treatment period. The Patient Specific Motion module may be used to record a personalized functional movement and the data can be integrated into the design process of the final restorations.

Open-source Internet of Things (IoT)-based air pollution monitoring system with protective case for tropical environments

In recent years, the escalation of industrial activities has significantly increased natural resource pollution, with air pollution becoming a major cause of diseases affecting living organisms. To address this critical environmental challenge, this study proposes a comprehensive air pollution monitoring system utilizing advanced technological instruments based on the Internet of Things (IoT). The system’s primary objective is to provide precise, rapid, and efficient measurements, enabling detailed examinations of pollutant behaviors and facilitating data dissemination. The system includes a monitoring station equipped with sensors to measure ambient temperature, relative humidity, and concentrations of pollutants such as carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), suspended particles (PM2.5, PM10), and ozone (O3). Additionally, it captures meteorological variables like wind speed, wind direction, and precipitation, allowing a nuanced analysis of their correlation with air pollutants. The collected data are transmitted via the Internet and visualized on a user-friendly platform accessible from any internet-enabled device. A protective case, designed with SolidWorks CAD software and fabricated using 3D printing, was validated through simulations for extreme conditions to ensures the system’s robustness in tropical climates. The cost-effective, low-energy system offers a scalable solution for monitoring air pollution, advancing understanding of pollutant behaviors, and supporting environmental management.

The Effect of 3D-Printed Custom Insoles on Plantar Pressure for Obese Individual

ABSTRACT Introduction There are many types of insoles made for obese individuals. However, there is a need for studies on insoles produced with 3D printers using flexible materials and comparing and examining the effect of these on plantar pressure. Materials and Methods An obese individual with a body mass index (BMI) &gt; 35 recommended by physicians to use insoles was included in this study. The individual’s foot was scanned using a 3D scanner, and insoles were designed using CAD software. The insoles were produced with TPU-75A flexible filament on a 3D printer at different fill rates (5%, 10%, and 15%). The effects of the insoles on underfoot pressures were clinically compared. Results Custom insoles with different filling ratios were made for an obese individual using flexible filament in 3D printers. The most appropriate insole print filling ratio for minimum foot pain experienced by the obese patient during their daily activities has been determined. The results reveal that 3D-printed insoles distribute the plantar pressure more effectively with significantly reduced pressure in certain foot locations (i.e., heel, under the first metatarsal) as compared with the existing insoles. Conclusions Manufactured by additive manufacturing, these insoles are produced using a fully digitized scanning process that creates virtually no material wastage. The thermoplastic polyurethane was preferred due to its favorable properties. By changing the pressure structure and internal filling system, it allows producing personalized insoles in the desired contact areas of hard and soft. Clinical Relevance This study provides evidence that insoles produced in 3D printers with flexible materials are as effective as insoles produced with traditional methods in reducing plantar pressure. Therefore, it is an alternative to traditional methods due to less labor.

Numerical Simulation and Design of a Mechanical Structure of an Ankle Exoskeleton for Elderly People

This article presents the numerical simulation and design of an ankle exoskeleton oriented to elderly users. For the design, anatomical measurements were taken from a user of this age group to obtain an ergonomic, resistant, and exceptionally reliable mechanical structure. In addition, the design was validated to support a “weight range” of users between 50 and 80 kg in order to evaluate the reaction of the mechanism within the range of loads generated in relation to the first principal stress, the safety coefficient, the Von Mises stress, and principal deformations, for which the 3D CAD software Autodesk Inventor and theoretical correlations were used to calculate the displacement and rotation angles of the ankle in the structure. Likewise, two types of materials were evaluated: ABS (acrylonitrile butadiene styrene) and a polymer reinforced with carbon fiber. Finally, the designed pieces were assembled with the guarantee that the mobility of the system had been validated through the numerical simulation environment, highlighting that by being generated through 3D printing, manufacturing costs are reduced, allowing them to be accessible and ensuring that more people can benefit from this ankle exoskeleton.

Design and Optimization of Centrifugal Pump Impeller Blade

Centrifugal pumps exploit the transformation of rotating kinetic energy into hydrodynamic energy to move fluid. They are a subclass of dynamic axisymmetric work-absorbing turbo machines. In order to aid in pump design, this project uses computational fluid dynamics software to explore intricate internal flows in centrifugal pump impellers. Three distinct kinds of pump impellers were taken in this instance. Pump specs under consideration include speed and discharge. These parameters have been adjusted in order to conduct a comparison analysis of these pump impellers. The plane between blades is modeled in CFD software is used to perform the flow analysis in addition to CAD software. As a consequence, the pressure and velocity distributions were the basis for the valid results, and the computational results were used to compare the pumps' respective performances.

Thermal analysis of cooling plate motor jacket and radiator for managing an electric bike energy storage system

The performance of electric bikes has increased with their increased use commercially and it has led to a corresponding increase in the charge and discharge rates for the batteries, and associated battery temperatures. Unfortunately, the cooling mechanisms for these electric bikes have not been able to keep up, with most organizations not implementing any cooling aside from passive ambient air cooling. This has led to a general decrease in battery life and charge capacity for these electric bikes. The proposed research has focused on the development of a novel electric bike cooling system under the practical industrial and environmental framework. It is cheap, effective, and simple to manufacture. Contemporary papers related to the topic have been studied, and the most feasible have been shortlisted to 4 distinct cooling plate designs, 3 Radiator Designs and 5 motor cooling jacket designs, which have been modeled in CAD software and then analyzed through use of CFD software. For the cooling plate design 1 had the lowest cooling capability, design 2 showed a 53.3% increase in total heat transfer from plate to coolant, design 3 showed a 107.52% increase, and design 4 showed a 183.03% increase relative to design 1. For the radiator, design number 2 has been recommended due to optimal cooling and temperature drop of coolant, within the dimensional and space constraints on the electric bike. For the motor cooling jacket, design number 5 was deemed to be the most feasible due to the high heat extraction from motor and good temperature uniformity of contact surface. Their respective advantages and disadvantages are discussed, and the most effective one of them all has been proposed for use. Further potential improvements to its design have also been recommended along with Thermoelectric Generator (TEG) integration for harvesting waste heat to produce energy.

On the correlation between pre-processing workflow and dimensional accuracy of 3D printed parts in high-precision Material Jetting

Material Jetting (MJ) is distinguished in the additive manufacturing field for its ability to create accurate multi-material functional objects with features in the range of few micrometers. Analyzing the impact of each step in MJ from virtual design to 3D printed object on the process response is essential for optimizing the technology’s capabilities. The current state-of-the-art reveals a gap in MJ regarding the fundamental understanding of the correlation between the pre-processing workflow and the geometrical and dimensional accuracy. This study aims to bridge this gap by examining factors such as utilization of different CAD software with diverse working principles, part-based versus assembly-based design, alternative 3D model formats (STL, OBJ, 3MF, AMF, STP), and slicing approaches (using open-source slicers). Two test specimens, each containing ten elements (either cylinders or hemispheres) with diameters ranging from 254 µm to 12.7 mm are examined. The results demonstrate the significant influence of the aforementioned factors on geometrical and dimensional accuracy, except for 3D model formats. Specifically, for large elements, the achievable accuracy depends on the tessellation approach of the CAD system, while for very small elements, the rasterization process is defining, and designing in assembly mode can further enhance accuracy. The handling of the 3D model by the slicer particularly affects geometrical accuracy. Experimental validation confirms the impact of the pre-processing workflow, though the data-related dimensional deviation for the base layer is masked by the wetting behavior of the dispensed droplets on the substrate.

CFD simulation for CO2 separation using diamond-structured thermally rearranged (TR) polymer membrane: Effect of CO2 feed concentration, feed pressure and temperature

Abstract CO2 separation in natural gas purification is important in improving the properties of natural gas such as energy content, volume and corrosivity. Membrane separation using TR-450 polymer membrane is a potential approach to remove CO2 from natural gas efficiently. The study of CO2/CH4 binary gas mixture separation was simulated using a thermally-rearranged (TR) HAB- 6FDA membrane at 450 °C with a partial part of Schwarz Diamond structure because it exhibits advanced mechanical properties with low stiffness for relatively high strength. TR-450 membrane exhibits excellent separation performance that has the potential to exceed the Robeson plot 1991. Computational fluid dynamics (CFD) was used to simulate the fluid behavior within the geometry created using CAD software. The effect of feed pressure, temperature and CO2 feed concentration on the separation performance of TR-450 membrane was also studied. The results indicated that an increase in feed pressure leads to a decrease in CO2 recovery, hence the lower separation performance. It was also found that increasing the feed temperature leads to an increase in CO2 recovery. Concerning the concentration of CO2 in the feed, elevated levels impact the performance of membrane separation. The enhanced membrane separation performance demonstrated by the TR-450 membrane under various conditions underscores the necessity for additional investigation to unveil its potential in industrial gas separation applications.

Ceramic Aneurysm Clip with Titanium Spring

ObjectiveTo design and evaluate ceramic aneurysm clips with integrated titanium springs, focusing on ergonomic application and precision in neurosurgical procedures. MethodsThe clip design was executed with precision using Creo Parametric 3D CAD software. It comprises a zirconia body and a titanium spring for durability and consistent tension and features a four-coil hairpin titanium spring for enhanced closing force and a ball-type head for versatile maneuverability during surgery. To assess durability, closing forces were rigorously measured using a force gauge system, comparing the ceramic clip with the standard Mizuho permanent clip over 30 open-close cycles. For MR artifact assessment, both ceramic and Yasargil clips were evaluated using a 3 Tesla magnetic resonance imaging (MRI) scanner with specific imaging sequences. ResultsThe straight type ceramic clip’s initial closing force was 1.70 N, dropping to 1.22 N after 30 cycles, indicating a retention of 72% of its initial force. In MRI, the ceramic clip displayed significantly lower measurement discrepancies compared to the titanium alloy Yasargil clip, particularly in high resolution T1 weighted images. The lowest variance was at measurement point L2, where the ceramic clip showed 3% discrepancy. Further, the ceramic clip yielded clearer images than the titanium alloy clip, particularly at the clip’s end. ConclusionsCeramic clips with titanium springs demonstrated satisfactory closing force and superior MRI compatibility, promising enhancements in surgical application and postoperative assessment.

Study on the Effect of Recycled Brass-Filled Epoxy Mould Inserts for Rapid Tooling

Rapid Tooling able to produce complex prototypes directly from three-dimensional CAD software using materials such as polymer, wax, and paper, but it is typically used for low-volume production. The current technology uses epoxy filled with metal fillers such as aluminum or copper to enhance the mechanical properties of rapid tooling molds. This study aims to investigate the effect of using recycled brass filler mixed with epoxy resin as mold inserts for Rapid Tooling in injection molding applications. An optimal ratio of brass filler particles will be evaluated to determine the best physical and thermal properties for the mold inserts. Significantly, this study will encourage the use of recycled materials such as metal waste from machining to offer great help in environmental sustainability.

RESISTANCE OF STRUCTURAL ELEMENTS OF CIVIL PROTECTION BUILDINGS AND STRUCTURES TO THE IMPACT OF AN EXPLOSION

The article presents the results of a comparison of the stability of the structural elements of the underground parking lot of an erected multistory civil building. The results of calculation of structural load-bearing elements (monolithic floor slab and pylons) to the impact of an explosion in the Lira CAD software with consideration of the requirements of the state Building standards of Ukraine are presented. It is shown that an increase in the instantaneous load of explosive pressure from 20 kPa (DBN B.2.2-5-97) to 100 kPa (DBN B.2.2-5:2023) will increase the maximum displacement of a monolithic floor slab by 11.9 times and the maximum reinforcement section by 5.8 times. This creates a real opportunity to develop new approaches to the planning of civil protection buildings and structures to ensure their operational reliability and resistance to the effects of an explosion.

A method for accuracy of placement analysis on radiolucent polyether-ether-keton facial implants: A case series

Facial asymmetry is defined as a bilateral difference between facial components. Correction, often desired by the patient, can be performed with the aim of bone born patient-specific solid implants designed using 3D CAD software. This treatment is embedded in the daily practice of today's healthcare. However, an analysis of the implant's accuracy of placement has not been reported. This case series describes the accuracy analysis of bone born aesthetic facial implants manufactured out of polyether-ether-ketone (PEEK). The accuracy analysis was based on postoperative (cone beam) computed tomography ((CB)CT) data and preoperative 3D planning. The analysis showed a median entry point error of 0.7 mm (min: 0.1, max: 3.3, interquartile range: 0.78). The median maximal orientation error was 5.5° (min: 0.1, max: 36.8, interquartile range: 7.13). Both parameters showed an excellent intraobserver and interobserver agreement with an ICC above 0.84. The described cases show that the analysis method is an objective approach for determining the accuracy of PSI placement and indicates that these implants can be placed accurately on the osseous face.

Blueprint for a Semi-automated Image Processing Tool to Characterize Stent Features: Application to a Pediatric Growth-Adaptive Stent.

The goal of this work was to develop a general blueprint for a semi-automated image processing tool (SIPT) to measure small, complex features of stent prototypes that can replace the current gold standard of manual measurements. The stents were designed using CAD software and manufactured via laser cutting. Stent prototypes were imaged using a Keyence microscope in top and side view orientations. The SIPT algorithm was developed in MATLAB to extract and measure 4 dimensions of the stent (inner and outer diameter, spring bend outer radius, spring bend width). The same dimensions were also manually measured by an experienced metrology technician as a gold standard comparison. We successfully made over 5000 unique measurements across the 4 key dimensions of 15 stents using the SIPT algorithm. Compared to the gold standard manual method, SIPT reduced measurement time by nearly 90% and increased the total number of measurements captured by over 2300%. The two one-sided test and Bland-Altman analysis demonstrated that SIPT achieved equivalency against the manual method of measurement for all 4 dimensions. In summary, we found that our SIPT software could be used to replace manual measurements and provided substantial time savings with consistent accuracy. Overall, this paper presents a generalizable workflow to isolate and measure critical features of stent prototypes that we believe will provide a valuable, cost-effective tool to other medical device designers seeking to rapidly iterate on unique stent designs or other manufactured parts with small and complex structures.

A novel algorithmic approach for automatic virtual articulation to avoid dynamic interferences in dental restoration designs.

There is an ongoing debate about the benefits of the facebow and individual articulator settings in prosthodontics when compared with simpler methods. The present study aims to determine whether the implementation of novel algorithmic articulator concepts may be an alternative to avoid dynamic interference contacts during the design process of fixed posterior restorations, and to what extent the occlusal morphology of the restoration is affected. From a chairside CAD database, a total of 50 clinical patient cases documenting 61 planned fixed restorations in the posterior tooth region were selected. A common CAD software program was used for the automated knowledge-based design process. When designing the restorations, functional concepts were applied, including the pure static occlusion, the average articulation, three different articulator settings as a control, and a combination of a broad range of articulation parameters (the full range dynamic articulation). The resulting dynamic contact points were compared both visually and metrically with a monitoring software program. There is a highly significant difference in avoiding dynamic interference contacts when applying the full range dynamic articulation compared with the pure static occlusion (P < 0.001) and the average articulation (P < 0.001). Furthermore, the superimposition revealed that the surface of the restorations showed nearly no visual morphologic changes after virtually grinding-in the interpenetrating contact points. The full range dynamic articulation can be used for the design of small fixed posterior restorations to avoid most dynamic interference contacts without the need for determining individual parameters for each patient.