Laser Sintering Research Articles

On design, fabrication, and pre-clinical validation of customized 3D-printed dental implant assembly.

In the past few decades, 3D-printed dental implants have been manufactured, and significant studies have demonstrated the pre-clinical validation of such systems. However, studies have yet to tackle the ever-present issue of preventing the jumping gap to enhance overall outcomes. The present study details the utilization of patient computed tomography (CT) data to design and subsequently fabricate a multi-component customized dental implant assembly and customized instruments using direct metal laser sintering (DMLS) technology. The workflow was validated for two patient data sets (cases 1 and 2), which were used to render and print custom implant assemblies; the simulation data for these were compared with a commercially available solution. The present study incorporated a prototype stage as well as subjecting the customized implant assemblies to both static (Case 1: 38.889-77.815 MPa vs 75.47-158.09 MPa; Case 2: 83.947-106.65 MPa vs 55.225-126.57 MPa) and dynamic finite element analysis (Case 1: 41.076-84.09 MPa vs 75.448-187.91 MPa; Case 2: 106.81-108.7 MPa vs 79.176-135.48 MPa) along with resonance frequency analysis (Case 1: 7763.2 Hz vs 7003.6 Hz; Case 2: 7910.1 Hz vs 7102.1 Hz) as well as residual stress analysis. The assembly's stress patterns and resonance frequencies were evaluated against a commercially available implant system. It was observed that the customized implant assemblies tended to outperform the commercially available solution in most simulated scenarios.

Fabrication method for electrically conductive patterns on a plastic substrate via direct laser sintering

Fabrication method for electrically conductive patterns on a plastic substrate via direct laser sintering

Polyamide composites manufactured by selective laser sintering: effect of glass particle reinforcement on mechanical properties

Polyamide composites manufactured by selective laser sintering: effect of glass particle reinforcement on mechanical properties

Application of 3D Printing Technology for Medical Purposes: A State of the Art

Introduction: The application of 3D printing technology in healthcare has revolutionized various medical practices, allowing for personalized solutions tailored to individual patient needs. This study explores the current state of 3D printing in medical applications, highlighting its benefits and challenges. Method: A comprehensive review of existing literature was conducted, focusing on the utilization of 3D printing for creating anatomical models, prosthetics, and bioprinting of living tissues. The analysis included a survey of various additive manufacturing techniques, such as Selective Laser Sintering (SLS) and Stereolithography (SLA), to assess their effectiveness in medical contexts. Results: The findings indicate that 3D printing enhances surgical planning by providing accurate anatomical models, thereby improving surgical outcomes. Additionally, the technology facilitates the production of custom implants and prosthetics, leading to better integration with patients' anatomy. Bioprinting has shown promise in developing artificial organs and regenerative therapies, significantly impacting transplant medicine. Discussion: While 3D printing offers substantial advantages, challenges such as regulatory hurdles, ethical considerations, and the need for standardized practices remain. The technology's potential in personalized medicine is vast, suggesting a future where individualized treatments are commonplace. Continued research and collaboration among medical professionals, technologists, and regulatory bodies are essential to address these challenges and optimize the benefits of 3D printing in healthcare. This study underscores the transformative impact of 3D printing in medicine and its potential to enhance patient care and outcomes across various applications.

3D printed tablets for personalised dose titration of prednisone using selective laser sintering.

3D printed tablets for personalised dose titration of prednisone using selective laser sintering.

A 3D-printed high-hardness die steel microchip GC column: 3-meter long, low-cost, and exhibiting superior separation performance.

A 3D-printed high-hardness die steel microchip GC column: 3-meter long, low-cost, and exhibiting superior separation performance.

Production and analysis of additively manufactured SS316L using Direct Metal Laser Sintering (DMLS) technique based on hybrid Taguchi-Grey grade relational analysis

Production and analysis of additively manufactured SS316L using Direct Metal Laser Sintering (DMLS) technique based on hybrid Taguchi-Grey grade relational analysis

Exchange-coupled bi-magnetic nanoparticles enhance magnetothermal/chemodynamic antibacterial therapy of poly-l-lactide scaffold.

Exchange-coupled bi-magnetic nanoparticles enhance magnetothermal/chemodynamic antibacterial therapy of poly-l-lactide scaffold.

3D-Printed Scaffold Achieves Synergistic Chemo-Sonodynamic Therapy for Tumorous Bone Defect.

Various smart scaffolds have recently been developed to address the regeneration of tumor bone defect. However, the recurrence of residual tumor cells poses a serious challenge to postoperative management, highlighting the need for effective therapeutic interventions. In this study, a multifunctional antitumor nanoplatform (Ti3C2/CuO2) for synergistic chemo-sonodynamic tumor therapy was developed and then rationally integrated into a poly(l-lactic acid) (PLLA) scaffold via selective laser sintering. CuO2 not only releases Cu2+ ions to facilitate chemodynamic antitumor therapy through the Fenton reaction but also generates H2O2, which further oxidizes Ti3C2 to produce TiO2 sonosensitizers. More importantly, the carbon-based substrates after oxidation of Ti3C2 have created favorable conditions for carrier transmission in the sonodynamic process, thereby amplifying the sonodynamic therapy. Additionally, moderate local hyperthermia form periodic sonodynamic therapy produces moderate localized heat therapy to further stimulate bone tissue regeneration. Meanwhile, the sustained release of bioactive ions (such as Cu and Ti ions) from the scaffold also fosters vascularization, further accelerating bone regeneration. This work presents a viable approach to developing multifunctional scaffolds for repairing tumorous bone defects.

A comprehensive review of emerging 3D-printing materials against bacterial biofilm growth on the surface of healthcare settings.

A significant burden on the healthcare system, microbial contamination of biomedical surfaces can result in hospital-acquired illnesses (HAIs). Bacteria, viruses, and fungi may live on surfaces for days or months and spread to patients and medical personnel. This article describes the 3D printing technologies, such as fused deposition modelling, bioprinting, binder jetting/inkjet, poly-jet, electron beam manufacturing, stereolithography, selective laser sintering, and laminated object manufacturing used for manufacturing the healthcare setting's surface to reduce bacterial contamination with exploring anti-biofilm activity against different bacterial species responsible for infections, based on the critical evaluation of published reports. This strategy has immense potential to become an upcoming approach for advancing the coating concept on the material's surface in healthcare settings. Our literature evaluation identifies beneficial 3D printing materials and associated technologies against microorganisms' growth, mainly bacteria involved in implant-based infection, emphasizing the development of anti-biofilm 3D-printed surfaces. Additionally, the authors have identified a few key areas where research and development are critically required to advance 3D-printing technology in healthcare settings.

Effect of manufacturing type and aging on the fit of metal frameworks: an in vitro Micro-CT study

Statement of problemIt is very important to determine how the marginal and internal fit of the restoration just before cementation changes after the specified period and which technique preserves the fit of the metal framework, and it has not been discussed in the literature.PurposeThis in vitro study aims to evaluate the effect of conventional casting, CAD/CAM milling, and laser sintering manufacturing methods on the marginal and internal fit of Co-Cr metal frameworks and how the fit will be affected following thermomechanical aging using Micro-CT.Materials and methodsDigital impressions were taken from the prepared typodont and metal frameworks were designed with ExoCAD software. Co-Cr metal frameworks were manufactured with 3 production methods (n = 15). In order to reflect the clinical conditions, a ceramic firing simulation was performed on metal frameworks. Thermomechanical aging was applied to the samples, equivalent to 1 year of use. For statistical comparison, the differences between the manufacturing techniques ANOVA followed by Tukey and, for aging Wilcoxon Test were used (α = 0.05).ResultsCompared to the conventional casting method, computer-aided methods showed a better fit. Thermomechanical aging increased misfit in all three production methods. At all determined points, before and after aging, the highest gaps were measured in the conventional casting method. In volumetric evaluations, both before and after aging, it was seen that the highest fit was in the laser sintering method, and the lowest fit was in the conventional casting method.ConclusionsProduction technique and aging have an impact on the fit of metal substructures. Following aging, misfit increased more in computer aided manufacturing than conventional casting.Graphical abstract

Mechanical Strengthening and Degradation Regulation of Iron Foam-Polycaprolactone Interpenetrating Composite Scaffolds.

Porous materials, owing to their unique pore networks, are expected to positively influence the enhancement of mechanical properties and modulation of degradation behavior. Herein, composite scaffolds were fabricated by a combination of triply periodic minimal surfaces (TPMS) design, selective laser sintering (SLS), and hot-pressing technology, in which iron foam (FFe) and polycaprolactone (PCL) were the reinforcing phase and matrix, respectively. Mechanical strengthening was achieved by forming an interpenetrating structure between the continuously porous FFe and TPMS structure PCL. Regarding degradation regulation, a catalytic degradation microcirculation system (CDMS) was constructed through acid-base neutralization reactions between FFe and PCL degradation products. The results indicated that the compressive and tensile moduli of composite scaffolds were increased by an astonishing 1758.8% and 466.0% compared with the PCL scaffold, which is attributed to the synergistic load sharing and stress transmission efficiency of the interpenetrating structures. In addition, the weight loss of the composite scaffold was 3.6 times higher than that of the PCL scaffold, indicating that the constructed CDMS is expected to achieve degradation regulation. Encouragingly, the composite scaffold also exhibited a good apatite induction ability during in vitro culture. Therefore, the constructed composite scaffold realizes the regulation of mechanical and degradation properties, so that it has potential applications in bone tissue engineering.

Fit accuracy assessment of removable partial denture frameworks produced by direct metal laser sintering – a clinical trial

ObjectivesThe purpose of this cross-over clinical study was to compare the number of framework repetitions, percentage of framework components adjusted, clinical acceptability, and fit accuracy of removable partial denture frameworks produced by the direct metal laser sintering technique (DMLS) and conventional technique.Materials and methodsFor each dental arch (n = 26), two cobalt-chromium frameworks were produced through two protocols: direct metal laser sintering (experimental group) and conventional lost-wax casting technique (control group). The number of framework repetitions, the percentage of components that had to be adjusted, and the clinical acceptability were registered. The fit accuracy of functional components was assessed by a qualitative method using endodontic files to identify maladjustments and compared to a quantitative method based on silicone specimens digitized by micro-computed tomography. The normality was checked (Shapiro-Wilk test), and data were analyzed with McNemar, Wilcoxon and paired-t tests (α = 0.05).ResultsNo statistically significant differences were found between conventional and digital frameworks for most of the variables tested (p > 0.05) except the fewer laboratory repetitions (p = 0.046), higher percentage of components adjusted (p = 0.011), and better reciprocal arms fit (p = 0.044) in the frameworks produced by DMLS protocol. No statistically significant (p = 0.174) difference was found between the fit accuracy qualitative and quantitative assessment methods.ConclusionsThe DMLS and conventional protocols were similar. Despite the DMLS protocol exhibiting a higher percentage of components adjusted, it presented better reciprocal arms fit accuracy with no framework repetition.Clinical relevanceMetal frameworks can be produced using DMLS eliminating casting problems.

Novel preparation and characterization of PA12/DMAc microspheres for selective laser sintering

Novel preparation and characterization of <scp>PA12</scp>/<scp>DMAc</scp> microspheres for selective laser sintering

Study of TPU/TiO2 and TPU/SiO2 self‐cleaning composites based on selective laser sintering

AbstractIn this paper, commercially pure thermoplastic polyurethane (TPU) powder with photocatalytic filler titanium dioxide (TiO2) and low surface energy filler silicon dioxide (SiO2) as composite powders was used to prepare TPU/TiO2 and TPU/SiO2 self‐cleaning composites, using selective laser sintering (SLS) technology. The effects of TiO2 and SiO2 fillers on the leveling and sintering properties of TPU lay‐up powder, as well as on the self‐cleaning and other properties of TPU parts were investigated. The results show that the addition of TiO2 and SiO2 fillers had a small effect on the leveling of TPU composite powders, sintering windows, and the dimensional accuracy and density of TPU parts, etc. The addition of TiO2 and SiO2 filler increased the surface roughness of TPU parts, the water contact angle from 123.82° of pure TPU to 140.25° of TPU/20TiO2. As a result, the surface of the TPU surface water droplets easily formed a near‐spherical shape with the pollutants rolled off. The addition of TiO2 gave TPU parts photocatalytic performance, which could decompose organic pollutants on the surface. TiO2 and SiO2 gave TPU parts self‐cleaning performance through the above mechanism. After the addition of TiO2 and SiO2, the thermal stability of TPU parts was improved, and the mechanical properties were slightly decreased.Highlights TPUs with both hydrophobic and photocatalytic properties are prepared by SLS technology. The addition of TiO2 and SiO2 has little effect on the process performance of SLS. Improvement of thermal stability and a slight decrease in mechanical properties of TPU parts.

Characterization of 3D-Printed Ti-6Al-4V Alloy Behavior During Cold Deformation.

In this paper, the characterization of the deformation behavior of additively manufactured 3D-printed Ti-6Al-4V alloys during elastic and plastic deformation was carried out on the test samples deformation zone during cold deformation at room temperature. The additive manufacturing process direct metal laser sintering (DMLS) was used to 3D print the Ti-6Al-4V test samples. The temperature, i.e., stress, changes, strain, and strain rate distribution in the deformation zone of the 3D-printed Ti-6Al-4V alloy during elastic and plastic deformation were compared using static tensile tests, thermography, and digital image correlation (DIC) simultaneously. Periodic oscillations of the maximum temperature changes during elastic and plastic deformation were observed in the deformation zone. The thermoelastic effect with the lowest temperature drop between -0.47 °C and -0.54 °C was observed in the deformation zone of the 3D-printed Ti-6Al-4V testing samples during elastic deformation. A significant difference between strain and strain rate localization in the deformation zone was found immediately before fracture of the test sample. Maximum strain amounts in the range of 0.078-0.080 and strain rates of 0.025-0.027 s-1 were determined. Static tensile tests, thermography, and digital image correlation were proved to be valid methods for determining the localization of stress, strain, and strain rate in the deformation zone of 3D-printed Ti-6Al-4V test samples.

Three-Dimensional Printing and Its Impact on the Diagnosis and Treatment of Neurodegenerative Disease

Neurodegenerative disorders include Alzheimer’s and Parkinson’s, both of which lead to progressive loss of neurons resulting in the severe loss of cognitive and motor functions. These diseases are among the heavy burdens on global healthcare systems largely because there is no cure, and current treatments apply almost entirely to controlling symptoms rather than disease progression. Recent advances in 3D printing and bioprinting technologies now open the way to overcome these challenges and form patient-specific models and therapeutical tools closely simulating the complex environment of the human brain. It then further illustrates how this technological integration with the aid of 3D printing, coupled with microfabrication and biosensing technologies, transforms drug-screening platforms as well as develops customization in medicine. For example, one can form highly intricate and multi-materially composed structures to better facilitate one’s study or test into some new therapeutic possibilities using methodologies of stereolithography and selective laser sintering. Moreover, 3D printing allows the creation of organ-on-a-chip models that simulate brain-like conditions, which may help identify specific biomarkers and evaluate new options of therapy. On the other hand, bioprinting methods based on neural cells combined with scaffolds mimicking native tissue dramatically transform regenerative medicine. New pathways in neural tissue development and implantable devices are now being brought forth, which can be tailored to the needs of individual patients. These advances bring not only greater precision in terms of the therapy that can be delivered but also 3D printing of implantable microelectrodes able to determine real-time biomarkers responsible for neurodegenerative diseases. Thus, this review highlights the robust impact that might be brought forth on the diagnosis and treatment of these neurodegenerative diseases via 3D printing technologies toward more effective management and personal solutions for healthcare.

Precision and Customization: The Role of 3D Printing in Modern Prosthodontics.

Prosthodontics focuses on the design and fitting of dental prostheses. The advent of three-dimensional (3D) printing has revolutionized this field by transitioning from labor-intensive methods to precise, computer-aided techniques. This review assesses the impact of 3D printing on prosthodontics, highlighting technological advancements, applications, clinical outcomes, and future directions. A literature review was conducted on recent advancements in 3D printing technologies and materials, focusing on their precision and customization capabilities in dental prostheses. 3D printing technologies such as fused deposition modelling, stereolithography, selective laser sintering, continuous liquid interface production, digital light processing, and material jetting offer high precision and customization, enhancing the creation of dental implants, crowns, bridges, removable prosthodontics, orthodontic devices, and maxillofacial prosthetics. 3D printing has improved the accuracy, efficiency, and customization of dental prostheses, leading to better patient outcomes. Multimaterial printing technologies like lithography-based ceramic manufacturing enable the integration of various materials in a single print, further advancing the field. Challenges such as material limitations, cost, and technical expertise remain, necessitating ongoing research and development.

Tuneable dissolution profile of tinidazole through thermoplastic polymer composites in low temperature 3D printing settings for pharmaceutical additive manufacturing applications.

In this study the first-time introduction of Kollidon® 25 (K25) thermoplastic polymer, which was not earlier explored in PBF-based 3D printing technology along with the simultaneous usage of Kollidon® SR (KSR) to form a thermoplastic polymer composite for the development of tunable solid oral dosage form (SODFs). In addition to this, a novel laser-absorbing dye i.e., Pigment Green 7 (PG-7) was also introduced to facilitate the laser sintering process of the used thermoplastic polymer composites. Sintered tablets obtained from the used thermoplastic polymer bed composites were systematically characterized using various analytical tools and in vitro examinations as well. The physicochemical characterization of all sintered tablet batches (B1-B7) was within the acceptable limit. Thermal and chemical analyses revealed no detrimental physical or chemical interactions between the components, as well as after exposure of sintered tablet batches to laser and temperature. Powder X-ray diffraction diffractograms suggested a change in the native state of tinidazole (TNZ, used as an active pharmaceutical ingredient) to amorphous due to the exposure of sintering parameters. Scanning electron microscopy micrographs of all batches showed intense fusion of the particles in the polymer composite. The sintered tablet batches B1 to B7 exhibited a drug content ranging from 90.36 ± 4.32% to 99.36 ± 1.24%. TNZ released in an acidic medium for up to 2.0 h from different sintered tablets were around 100% to 12% from B1 to B7 batches, respectively following alkaline medium for up to 12.0 h. TNZ release pattern was fine tuned in accordance with the changes in the composition ratio of Kollidon® 25 and Kollidon® SR polymers in order to get quick release to sustained release. This prepared unique thermoplastic pharmaceutical grade polymer composite might broaden the range of materials accessible for PBF-mediated 3D printing in pharmaceutical industrial applications in near future.

Tailoring the mechanical properties of Ti6Al4V diamond metal lattice structures through a novel node-compensation technique targeting cortical bone.

Abstract This study introduces a novel node compensation (NC) technique for Ti6Al4V-based diamond metal lattice structures (MLSs). This approach reduces the stress concentration at strut junctions while enhancing the energy absorption capacity of the MLS. Node compensation involves removing one spherical node from a representative volume element (RVE) and compensating by increasing the diameters of the remaining nodes. This adjustment improves porosity while mitigating stress concentration factors. The NC structure and two purely strut-based designs (D1 and D2) with strut diameters of 500 μm and 575 μm, respectively, were modelled in SolidWorks and fabricated via the direct metal laser sintering (DMLS) technique. The strut and node dimensions were validated through micro-CT imaging. Scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) were used to analyse the phase composition of Ti6Al4V. Quasistatic compression tests at a loading rate of 0.5 mm/min, combined with digital image correlation (DIC), revealed that the NC structure exhibited an extended plateau stress region in the 100–150 MPa range with more uniform deformation with less stress undulation than D1 &amp; D2. D1 and D2 showed earlier densification than did NC. The NC demonstrated a yield strength, ultimate strength, and quasielastic gradient (elastic modulus) of approximately 150 MPa and 200 MPa, 3.572 GPa, respectively, aligning with the mechanical properties of cortical bone.