Comparative analysis of ABS materials mechanical properties

3D printing, also known as Additive manufacturing (AM), has emerged as a transformative technology with applications across various industries, including the medical sector. This review paper provides an overview of the current status of AM technology, its challenges, and its application in the medical industry. The paper covers the different types of AM technologies, such as fused deposition modeling, stereolithography, selective laser sintering, digital light processing, binder jetting, and electron beam melting, and their suitability for medical applications. The most commonly used biomedical materials in AM, such as plastic, metal, ceramic, composite, and bio-inks, are also viewed. The challenges of AM technology, such as material selection, accuracy, precision, regulatory compliance, cost and quality control, and standardization, are also discussed. The review also highlights the various applications of AM in the medical sector, including the production of patient-specific surgical guides, prosthetics, orthotics, and implants. Finally, the review highlights the Internet of Medical Things (IoMT) and artificial intelligence (AI) for regulatory frameworks and safety standards for 3D-printed biomedical devices. The review concludes that AM technology can transform the healthcare industry by enabling patients to access more personalized and reasonably priced treatment alternatives. Despite the challenges, integrating AI and IoMT with 3D printing technology is expected to play a vital role in the future of biomedical device applications, leading to further advancements and improvements in patient care. More research is needed to address the challenges and optimize its use for medical applications to utilize AM's potential in the medical industry fully.

Chapter 1 - Overview of additive manufacturing technology and materials

This paper investigates the feasibility of manufacturing hydraulic fittings using additive manufacturing (AM) technologies, specifically Fused Deposition Modeling (FDM) and Stereolithography (SLA). The study addresses the environmental challenge of material waste in conventional fitting production by exploring 3D printing as an alternative manufacturing method. Hydraulic fittings were designed using CAD software: SolidWorks 2022 and fabricated using FDM with PETG (Polyethene Terephthalate Glycol) material and SLA with UV-sensitive photopolymer resin. In present studies, on-destructive leak testing was conducted in accordance with PN-EN 1254-4 and PN-EN 1254, at pressures ranging from 0.1 to 1.0 bar. Dimensional accuracy analysis revealed shrinkage of approximately 1% for SLA-printed parts and 2% for FDM-printed parts. Microscopic examination at 50× and 80× magnification showed superior thread quality in SLA samples compared to FDM, which exhibited visible layer separation and material porosity. Leak testing demonstrated that while the brass reference fitting maintained complete seal integrity, both 3D-printed variants failed to achieve leak tightness under operational pressures, with structural failure occurring at 1.0 bar during tightening. The study showed that FDM with PETG material and SLA with UV-sensitive photopolymer resin, despite achieving acceptable dimensional tolerances (±1-2%), do not meet hydraulic leak tightness requirements at pressures exceeding 0.5 bar in their raw state after printing. The results suggest that alternative material formulations (e.g., carbon fiber-reinforced PEEK for FDM or epoxy engineering resins for SLA) warrant further investigation. Potential avenues for improvement include advanced surface treatment, optimization of printing parameters, and modifications to thread geometry to reduce interthread gaps.

Additive manufacturing (AM) technologies can enable the direct fabrication of customized physical objects with complex shapes, based on computer-aided design models. This technology is changing the digital manufacturing industry and has become a subject of considerable interest in digital implant dentistry. Personalized dentistry implant treatments for individual patients can be achieved through Additive manufacturing. Herein, we review the applications of Additive manufacturing technologies in oral implantology, including implant surgery, and implant and restoration products, such as surgical guides for implantation, custom titanium meshes for bone augmentation, personalized or non-personalized dental implants, custom trays, implant casts, and implant-support frameworks, among others. In addition, this review also focuses on Additive manufacturing technologies commonly used in oral implantology. Stereolithography, digital light processing, and fused deposition modeling are often used to construct surgical guides and implant casts, whereas direct metal laser sintering, selective laser melting, and electron beam melting can be applied to fabricate dental implants, personalized titanium meshes, and denture frameworks. Moreover, it is sometimes required to combine Additive manufacturing technology with milling and other cutting and finishing techniques to ensure that the product is suitable for its final application.

14 - Medical additive manufacturing then, now, and will

Additive manufacturing of cementitious composites: Materials, methods, potentials, and challenges

In this work, we assess the effects of sterilization in materials manufactured using additive manufacturing by employing a sterilization technique used in the food industry. To estimate the feasibility of the hydrostatic high-pressure (HHP) sterilization of biomedical devices, we have evaluated the mechanical properties of specimens produced by commercial 3D printers. Evaluations of the potential advantages and drawbacks of Fused Deposition Modeling (FDM), Digital Light Processing (DLP) technology, and Stereolithography (SLA) were considered for this study due to their widespread availability. Changes in mechanical properties due to the proposed sterilization technique were compared to values derived from the standardized autoclaving methodology. Enhancement of the mechanical properties of samples treated with Hydrostatic high-pressure processing enhanced mechanical properties, with a 30.30% increase in the tensile modulus and a 26.36% increase in the ultimate tensile strength. While traditional autoclaving was shown to systematically reduce the mechanical properties of the materials employed and damages and deformation on the surfaces were observed, HHP offered an alternative for sterilization without employing heat. These results suggest that while forgoing high-temperature for sanitization, HHP processing can be employed to take advantage of the flexibility of additive manufacturing technologies for manufacturing implants, instruments, and other devices.

Impact of intragranular misorientation on void swelling and inter-granular cavities after ion irradiation in standard and additive manufacturing 316L austenitic steels

Analysis of flexural strength and Weibull modulus of printed and milled zirconia: A systematic review.

Background: Accuracy of fit is a critical determinant of the clinical success and longevity of dental restorations, particularly for implant-supported and partial coverage posterior restorations. Although subtractive milling techniques have been widely used in dentistry, additive manufacturing technologies, have emerged as promising alternatives, offering the potential for greater accuracy, customization and cost-efficiency. This systematic review aimed to compare the accuracy of fit of additive 3D-printed implant-supported and partial coverage posterior restorations. with subtractive milling and conventional techniques. Material and Methods: The review followed PRISMA guidelines. A comprehensive electronic search was conducted across PubMed, Cochrane Library, Web of Science, Embase and Scopus to identify relevant studies. Studies were included if they evaluated the accuracy of fit of additive 3D-printed implant-supported restorations and partial coverage posterior restorations, compared to subtractive milling or conventional techniques. The modified CONSORT checklist for in vitro studies was used to assess methodological quality and risk of bias. Results: A total of 1,913 records were identified and after removing duplicates and screening for eligibility, eight in vitro studies were included. The studies evaluated 322 samples across a range of implant-supported frameworks, inlays and onlays. Technologies assessed included Selective Laser Melting (SLM), stereolithography (SLA), Digital Light Processing (DLP) and multijet 3D printing, alongside CAD/CAM milling and conventional casting. The findings consistently demonstrated that additive manufacturing achieved accuracy of fit comparable to subtractive milling in simple designs, while three-dimensional printed restorations exhibited better marginal and internal adaptation, especially for complex geometries. Conventional casting and milling techniques showed larger discrepancies, particularly for multiunit frameworks. The risk of bias was generally low across all included studies, although variation in measurement techniques and the lack of sample size justification were noted as limitations. Conclusion: This systematic review indicates that additive manufacturing techniques offer improved accuracy of fit compared to subtractive milling and conventional methods for implant-supported restorations and partial coverage posterior restorations. However, the in vitro design of the studies limits the direct clinical applicability of the findings.

Rapid vacuum casting has been proven to be a successful method in producing high-quality parts in small series. However, a challenge lies in the selection of proper Additive Manufacturing (AM) technologies for the development of a master pattern for the vacuum casting process. Each AM technologies differ from one another in terms of dimensional accuracy, surface finish, cost and lead times. The aim of this study is to investigate the performance of casting mating parts based on different additive manufacturing patterns for small batch. Three types of AM-based patterns: Fused Deposition Modeling (FDM), Stereolithography (SLA) and Multi-Jet Fusion (MJF) were compared. The Taguchi method, Signal to Noise ratio (S/N), Analysis of Variance (ANOVA) and T-test were conducted in determining the optimized parameters. From the findings, curing time is shown to be a significant parameter for dimensional accuracy and surface finish. Dimensional deviation varies in different directions of parts. For surface finish, there was only a slight change from the master pattern whereas the surface roughness of casting parts decreased within the range 0.23% to 2.85%. Tolerance grades for the selected dimensions of the parts were in the permissible range, based on ISO286-1:2010. When using distinct kinds of AM patterns to create replacement components, design tolerance is needed. It was suggested to select AM technology similar to that had been used for the original components. Battery cover was selected as a case study to represent the mating application parts.

Plant-based resins have emerged as environmentally sustainable alternatives in dental additive manufacturing. However, information on their clinical applicability is limited, particularly when different additive manufacturing technologies are used. The purpose of this in vitro study was to compare the dimensional stability of additively manufactured maxillary casts using plant-based and conventional dental cast resins and different 3-dimensional (3D) printers over 4 weeks. The scan file of a dentate maxillary typodont model was used to fabricate diagnostic casts from soy-based (SB), corn-based (CB), and conventional (KM) resins using either a digital light processing (DLP) or liquid crystal display (LCD) 3D printer (n=10). Each cast was scanned with a laboratory scanner the day after fabrication and weekly for 4 weeks. The scan files were superimposed over the reference file using a 3D analysis software program to calculate root mean square (RMS) values (anterior, posterior, entire arch, soft tissue, and entire cast). Statistical analysis was performed using a generalized linear model (α=.05). Dimensional stability was affected by resin, printer, and their interaction (P≤.004). Storage duration and its interactions did not affect the dimensional stability (P≥.471). In the anterior region, SB casts printed with the DLP printer had the lowest RMS, while those printed with the LCD printer had the highest (P<.001). For other regions, CB casts printed with the DLP printer mostly had the lowest RMS, whereas SB casts printed with the LCD printer mostly had the highest (P≤.023). The CB casts printed with the DLP printer exhibited dimensional stability comparable with or higher than that of the KM casts printed with the same printer. One month of storage time did not substantially affect the dimensional stability of the tested casts.

Additive manufacturing (AM) of ceramics has rapidly evolved over the past decade, enabling the production of complex, high-precision components with tailored porosity and geometry. Among AM techniques, stereolithography (SLA) and digital light processing (DLP) are particularly promising for fabricating dense and functional oxide ceramics. However, the final properties of printed ceramics are strongly affected by sintering conditions, layer geometry, and microstructural uniformity. This study presents a two-stage experimental approach to evaluate the influence of sample geometry, layer thickness, and sintering schedule on the mechanical and microstructural performance of SLA-printed ceramic parts. In Stage I, the relationships between elastic modulus (Ec) and compressive strength (σc) were examined as a function of sample height, layer thickness (0.05 and 0.10 mm), and firing program. In Stage II, the effects of sintering temperature (1250, 1271, and 1300 °C) and holding time (2–20 min) were analyzed for the reference geometry. Microstructural characterization, including pore size distribution and quantitative porosity analysis, was conducted to establish correlations with the mechanical results (Stage III). The findings reveal that optimized sintering and geometry parameters can significantly enhance mechanical performance and reduce porosity variations. The study provides both scientific insights and engineering guidelines for improving the structural reliability of SLA-fabricated ceramic components.

This study evaluates the accuracy of drill guides fabricated in medical-grade, biocompatible materials for static, computer-aided implant surgery (sCAIS). The virtually planned drill guides of ten completed patient cases were printed (n = 40) using professional (Material Jetting (MJ)) and consumer-level three-dimensional (3D) printing technologies, namely, Stereolithography (SLA), Fused Filament Fabrication (FFF), and Digital Light Processing (DLP). After printing and post-processing, the drill guides were digitized using an optical scanner. Subsequently, the drill guide’s original (reference) data and the surface scans of the digitized 3D-printed drill guide were superimposed to evaluate their incongruencies. The accuracy of the 3D-printed drill guides was calculated by determining the root mean square (RMS) values. Additionally, cast models of the planned cases were used to check that the drill guides fitted manually. The RMS (mean ± SD) values for the accuracy of 3D-printed drill guides were—MJ (0.09 ± 0.01 mm), SLA (0.12 ± 0.02 mm), FFF (0.18 ± 0.04 mm), and DLP (0.25 ± 0.05 mm). Upon a subjective assessment, all drill guides could be mounted on the cast models without hindrance. The results revealed statistically significant differences (p < 0.01) in all except the MJ- and SLA-printed drill guides. Although the measured differences in accuracy were statistically significant, the deviations were negligible from a clinical point of view. Within the limits of this study, we conclude that consumer-level 3D printers can produce surgical guides with a similar accuracy to a high-end, professional 3D printer with reduced costs.

Three-dimensional printing is a rapidly developing area of technology and manufacturing in the field of oral surgery. The aim of this study was comparison of presurgical models made by two different types of three-dimensional (3D) printing technology. Digital reference models were printed 10 times using fused deposition modelling (FDM) and digital light processing (DLP) techniques. All 3D printed models were scanned using a technical scanner. The trueness, linear measurements, and printing time were evaluated. The diagnostic models were compared with the reference models using linear and mean deviation for trueness measurements with computer software. Paired t-tests were performed to compare the two types of 3D printing technology. A P value < 0.05 was considered statistically significant. For FDM printing, all average distances between the reference points were smaller than the corresponding distances measured on the reference model. For the DLP models, the average distances in the three measurements were smaller than the original. Only one average distance measurement was greater. The mean deviation for trueness was 0.1775 mm for the FDM group and 0.0861 mm for the DLP group. Mean printing time for a single model was 517.6 minutes in FDM technology and 285.3 minutes in DLP. This study confirms that presurgical models manufactured with FDM and DLP technologies are usable in oral surgery. Our findings will facilitate clinical decision-making regarding the best 3D printing technology to use when planning a surgical procedure.