Search Results (285)

Although dental implants appear to be an alternative for treatment of tooth loss, fixed prosthetic restorations are an irreplaceable part of oral rehabilitation. Regarding the EU directives concerning cobalt health risks, titanium alloys may be an alternative to cobalt–chromium and nickel–chromium for metal–ceramic dental restorations. The presented review briefly describes the specific properties of titanium, and the challenges met during production and use of titanium–ceramic fixed prosthetic restorations. Full article

Introduction: Guided bone regeneration (GBR) is a key approach for managing alveolar ridge defects. Although titanium meshes are widely used for non-resorbable space maintenance, their limitations have prompted interest in alternative materials. Polyetheretherketone (PEEK), a high-performance thermoplastic, has emerged as a potential barrier due to its mechanical strength, radiolucency, and compatibility with digital workflows. Objective: To map the current evidence on the use of PEEK barriers in GBR, focusing on biological performance, mechanical properties, and clinical outcomes in animal and human studies. Methods: A scoping review was conducted following PRISMA-ScR guidelines. Eligible studies included in vivo animal models or clinical trials involving PEEK barriers for alveolar bone regeneration. Data on study design, defect type, barrier characteristics, surgical protocol, outcomes, and complications were extracted. Results: Five studies met the inclusion criteria: two animal models and three clinical trials. All reported successful space maintenance and bone gain with PEEK barriers, with outcomes comparable to titanium meshes. Customization through CAD/CAM or 3D printing was common. Complications such as soft tissue dehiscence and exposure occurred but generally did not affect regeneration. Evidence was limited by small sample sizes, short follow-up, and single-center designs. Conclusions: PEEK barriers show promise as customizable alternatives to traditional GBR membranes. However, current evidence is limited and geographically concentrated. Future multicenter studies with long-term follow-up and standardized outcome measures are needed to validate the clinical potential of PEEK in bone regeneration. Full article

Background/Objectives: The success of lumbar interbody fusion depends on the implant design and the surgical approach used. This study evaluated the clinical and radiographic outcomes of lateral lumbar interbody fusion (LLIF) and anterior lumbar interbody fusion (ALIF) using a 3D-printed porous titanium interbody cage system. Methods: A retrospective, single-center review of 48 patients treated for degenerative lumbar spine disease was conducted. Patients underwent LLIF, ALIF, or a combination of both using a 3D-printed titanium cage system (J&J MedTech, Raynham, MA, USA). The Oswestry disability index (ODI) and Patient-Reported Outcomes Measurement Information System (PROMIS) metrics were assessed after 6 weeks, 3 months, 6 months, and 12 months. Linear mixed-effects models evaluated the pre- and post-operative differences. Fusion performance and complications were assessed using the Bridwell grading system over 24 months. Results: A total of 78 levels (62 LLIF and 16 ALIF) were analyzed. Fusion rates were 90.3% (56/62) for LLIF levels and 81.3% (13/16) for ALIF levels by the end of 12 months. ODI scores improved significantly after 3 months (MD −13.0, p < 0.001), 6 months (MD −12.3, p < 0.001), and 12 months (MD −14.9, p < 0.001). PROMIS Pain Interference scores improved after 3 months (MD −6.1, p < 0.001), 6 months (MD −3.4, p < 0.001), and 12 months (MD −5.8, p < 0.001). PROMIS Physical Function scores improved after 3 months (MD +3.4, p = 0.032) and 12 months (MD +4.9, p < 0.001). Conclusions: This novel interbody cage demonstrated high fusion rates, significant pain and function improvements, and a favorable safety profile, warranting further comparative studies. Full article

Objectives: This study aimed to compare the clinical durability, mechanical performance, and stress behavior of three NiTi rotary systems—BlueShaper (Blue), BlueShaper Pro (Dual Wire), and BlueShaper Gold (fully gold-treated NiTi)—through a multimodal evaluation that included simulated instrumentation in 3D-printed replicas, mechanical testing, and finite element analysis (FEA). Methods: Sixty instruments (n = 20 per group) were tested. Simulated canal preparation was conducted in standardized 3D-printed mandibular molars with a 40° mesial root curvature until fracture occurred. Mechanical tests included torsional and flexural loading using a universal testing machine and stainless steel blocks with a standardized 40° curvature. FEA simulations evaluated von Mises stress, shear stress, total deformation, cyclic fatigue behavior, and contact pressure between the instrument and canal wall. Results: BlueShaper Gold prepared an average of 7.5 canals before fracture, followed by BlueShaper Pro (5.67 canals) and Blue (5.00 canals) (p < 0.001). Gold exhibited the highest torsional resistance (6.08 ± 3.08 N) and the longest fatigue life (325 ± 55.7 cycles), with the lowest von Mises stress and damage factor in FEA. BlueShaper Pro showed the longest time to fracture in mechanical testing (73.85 ± 7.10 s) and balanced mechanical behavior. Blue demonstrated the lowest performance across most parameters, including the shortest fatigue life and highest stress concentration. Conclusions: BlueShaper Gold exhibited the highest mechanical strength and fatigue resistance. BlueShaper Pro demonstrated the longest fatigue life and balanced mechanical behavior. Blue showed the lowest performance across most parameters. The strong correlation among clinical, mechanical, and FEA data reinforces the critical role of alloy composition in determining instrument durability, even when design remains constant. Full article

This research presents a novel methodology for lightweighting and cost reduction of components with high structural demands by integrating advanced design and manufacturing techniques. Specifically, it combines topology optimization (TO) with additive manufacturing (AM), also known as 3D printing. Unlike conventional approaches, the proposed method first determines the optimal geometry using an artificially stiff material, and only then evaluates real materials for structural and manufacturing feasibility. This design-first, material-second strategy enables broader material screening and maximizes weight reduction without compromising performance. The proposed workflow is applied to the design of a turbofan air intake—an aeronautical component operating under supersonic conditions—addressing both structural integrity and manufacturing feasibility. Three materials from distinct classes are assessed: two metallic alloys (aluminum alloy 6061 and titanium alloy, Ti6Al4V) and a high-performance polymer (polyetheretherketone, PEEK). This last option is preliminarily discarded after being analyzed for this specific application. Finite element (FE) simulations are used to evaluate the mechanical behavior of the optimized geometries, including bird-strike conditions. Among the evaluated manufacturing techniques, Selective Laser Melting (SLM) is identified as the most suitable for the metallic materials selected, providing an effective balance between performance, manufacturability, and aerospace compliance. This study illustrates the potential of TO–AM synergy as a sustainable and efficient design approach for next-generation aerospace components. Simulation results demonstrate a weight reduction of up to 71% while preserving critical functional regions and maintaining structural integrity in Al 6061 and Ti6Al4V cases, under the diverse loading conditions typical of real flight scenarios, while PEEK remains an attractive option for uses where mechanical demands are less stringent. Full article

Intraosseous hemangiomas (IH) are rare intrabony lesions that represent less than 1% of intraosseous tumors. IH are mostly seen in the axial skeleton and skull. Most commonly, the frontal bone, zygomatic, sphenoid, maxilla, ethmoid, and lacrimal bone can manifest IH. Currently, IH is classified as a developmental condition of endothelial origin. According to WHO, the five histological types of IH are cavernous, capillary, epithelioid, histiocytoid, and sclerosing. IH of the zygoma is an extremely rare condition with female predominance. A systematic review recently estimated that there were 78 cases published in the literature until 2023. The lesion is usually asymptomatic and presents with a gradually deteriorating deformity of the malar area, and the patient might be able to recall a history of trauma. Numbness due to involvement of the infraorbital nerve might also be present; however, atypical skin and bone sensations might also occur. Other symptoms include painful swelling, bone asymmetry, skin irritation, sinus pressure, paresthesia, diplopia, enophthalmos, or atypical neuralgia. A bony lesion with a trabecular pattern in a radiating formation (sunburst pattern) or a multilocal lytic lesion pattern created by the multiple cavernous spaces (honeycomb pattern) is commonly observed during radiologic evaluation. We present a rare case of IH of the zygoma in a 65-year-old generally healthy woman. A cyst-like bone tumor was revealed from the CT scan, which made preoperative biopsy of the lesion problematic. A careful radiological diagnostic differentiation of the lesion should always be conducted in such cases to outline a safe surgical plan and possible alternatives if needed. The patient underwent total tumor resection in the operating room, and the defect was reconstructed with the use of a titanium mesh and a synthetic hydroxyapatite bone graft based on a 3D surgical guide printed model. Full article

This article presents the results of the tribological performance of 20MnCr5 (1.7147) tool steel countersamples produced by Direct Metal Laser Sintering (DMLS), as a potential material for inserts or working layers of sheet metal forming tools. Tribological tests were performed using a roller-block tribotester. The samples were sheet metals made of materials with significantly different properties: Inconel 625, titanium-stabilised stainless steel 321, EN AW-6061 T0 aluminium alloy, and pure copper. The samples and countersamples were analysed in terms of their wear resistance, coefficient of friction (COF), changes in friction force during testing, and surface morphology after tribological contact under dry friction conditions. The tests were performed on DMLSed countersamples in the as-received state. The largest gain of countersample mass was observed for the 20MnCr5/EN AW-6061 T0 friction pair. The sample mass loss in this combination was also the largest, amounting to 19.96% of the initial mass. On the other hand, in the 20MnCr5/Inconel 625 friction pair, no significant changes in the mass of materials were recorded. For the Inconel 625 sample, a mass loss of 0.04% was observed. The basic wear mechanism of the samples was identified as abrasive wear. The highest friction forces were observed in the 20MnCr5/Cu friction pair (COF = 0.913) and 20MnCr5/EN AW-6061 T0 friction pair (COF = 1.234). The other two samples (Inconel 625, 321 steel) showed a very stable value of the friction force during the roller-block test resulting in a COF between 0.194 and 0.213. Based on the changes in friction force, COFs, and mass changes in friction pair components during wear tests, it can be concluded that potential tools in the form of inserts or working layers manufactured using 3D printing technology, the DMLS method, without additional surface treatment can be successfully used for forming sheets of 321 steel and Inconel 625. Full article

Recent evidence suggests that nano-TiO₂ particles improve antimicrobial and physical properties when incorporated into dental prosthetic materials. However, there exists a paucity of information regarding their impact on material properties when the prosthetic materials are 3D-printed over time. The purpose of this study was to evaluate the time-dependent printability and surface property changes occurring in a 3D-printed denture base resin containing nano-titanium dioxide (TiO₂) particles. A 0.4 wt% concentration of 30 nm rutile TiO₂ nanoparticles was ultrasonically dispersed into a denture base resin. Disks were printed weekly using a Form 2 SLA printer until printing failed. Printability, surface roughness (R_a), color difference (ΔE_ab), and translucency parameters were measured across timepoints. Surface roughness was assessed via profilometry, while color and translucency were evaluated using a spectrophotometer under standardized conditions. Print failure occurred at week 8, beyond which the resin could no longer reliably produce full specimens. R_a roughness decreased from 3.83 µm to 0.48 µm, which denoted a significant time-dependent decrease (ρ = −0.733, p = 0.016). Color difference with the unmodified control declined from 26.32 to 17.13 ΔE_ab units (ρ = −0.976, p < 0.001). All printed samples exceeded the clinically acceptable thresholds for both R_a (0.2 µm) and ΔE_ab (<3.7). Although the printability of the resin–TiO2 mixture was maintained for 7 weeks, mixture homogeneity declined over time. TiO₂ additions to a denture polymer produced significant changes in surface roughness and color that were not clinically acceptable. Results from this study illustrate the time dependence required for retaining surface properties in 3D-printed dentures containing nano-TiO₂. Full article

Polyetheretherketone (PEEK) is a high-performance thermoplastic polymer widely recognized for its distinct mechanical strength, chemical resistance, and biocompatibility. These characteristics make it suitable for a wide range of applications, particularly in medical, aerospace, chemical, and electronics fields. Conventional processing techniques, such as 3D printing, molding, and extrusion, are widely employed for PEEK fabrication. This review critically examines recent advancements in PEEK research, with an emphasis on additive manufacturing techniques that are expanding its applications in the medical field. We provide an in-depth analysis of PEEK’s intrinsic properties, diverse processing methods, and current challenges that hinder its wider adoption. In addition to evaluating PEEK’s performance, this review compares it with alternative biomaterials—such as titanium and ultra-high molecular weight polyethylene (UHMWPE)—to explore its advantages and limitations in biomedical applications. Furthermore, this review discusses cost considerations, regulatory constraints, long-term clinical performance challenges, and failure modes that are essential for validating and ensuring the reliability of PEEK in clinical use. By synthesizing the recent literature, particularly from the last decade, this review highlights the significant potential of PEEK and underscores ongoing research efforts aimed at overcoming its limitations, paving the way for its broader implementation in advanced technological applications. Full article

Background: Lumbar Interbody Fusion (LIF) is a surgical procedure aimed at addressing a range of pathological conditions affecting the structure and function of the spine. Patient-Specific Interbody Cages (PSICs) are an emerging technology that are used in LIF; however, there is a lack of clinical outcome data, making it difficult to assess the potential risks, benefits, and value of PSICs. The purpose of this present study is to contribute data to the field on this new emerging technology. The aims were to investigate Quality of Life (QoL), pain, and the complications of PSICs in LIF. To provide a comparative cohort, we performed a systematic review of patient-reported outcomes of conventional fusion techniques. Methods: This study reports on a multi-surgeon, multi-centre clinical trial of patients with lumbar degenerative disc disease, necessitating discectomy and fusion. All patients underwent LIF procedures with 3D-printed PSICs. Pain Visual Analogue Scale (VAS) and QoL (EQ-5D) scores were collected pre-operatively and at 6m, 12m, and 24m post-operatively. For comparative purposes, we performed a systematic review of the VAS scores from traditional LIF cages and analysed the Australian Spine Registry QoL data. Results: The literature search yielded 4272 publications. The studies were subdivided into four groups based on the interbody device type. All the groups demonstrated improvements in the VAS (for back pain) scores post-operatively. In total, 78 patients (109 instrumented levels) underwent LIF procedures with 3DP PSICs. There were three reoperations (3.8%) and no revisions of any PSIC. The mean VAS scores improved significantly (p < 0.01) from 7.85 (1.50 SD) pre-operatively to 2.03 (2.13 SD) at 24 months post-operatively. The mean QoL index scores improved significantly (p < 0.01) from a pre-operative 0.257 (0.332 SD) to 0.815 (0.208 SD) at 24 months. Conclusions: The systematic review indicated that device fixation to the interbody space was associated with lower VAS scores. The results from the investigational cohort suggest that PSICs may represent a new progression in implant design for spinal fusion, with an associated clinical benefit for LIF. Full article

Hip implant optimization is increasingly receiving attention due to the development of manufacturing technology and artificial intelligence interaction in the current research. This study investigates the development of hip implant stem design with the application of lattice structures, and the utilization of the MATLAB regression learner app in finding the best predictive regression model to calculate the mechanical behavior of the implant’s stem based on some of the design parameters. Many cases of latticed hip implants (using 3D lattice infill type) were designed in the ANSYS software, and then 3D printed to undergo simulations and lab experiments. A surrogate model of the implant was used in the finite element analysis (FEA) instead of the geometrically latticed model to save computation time. The model was then generalized and used to calculate the mechanical behavior of new variables of hip implant stem and a database was generated for surgeon so they can choose the lattice parameters for desirable mechanical behavior. This study shows that neural networks algorithms showed the highest accuracy with predicting the mechanical behavior reaching a percentage above 90%. Patients’ weight and shell thickness were proven to be the most affecting factors on the implant’s mechanical behavior. Full article

Background and Objectives: Bone regeneration (BR) is a cornerstone technique in reconstructive dental surgery, traditionally using either barrier membranes, titanium meshes, or perforated non-resorbable membranes to facilitate bone regeneration. Recent advancements in 3D technology, including CAD/CAM and additive manufacturing, have enabled the development of customized scaffolds tailored to patient needs, potentially overcoming the limitations of conventional methods. Materials and Methods: A scoping review was conducted according to the PRISMA guidelines. Electronic searches were performed in MEDLINE (PubMed), the Cochrane Library, Scopus, and Web of Science up to January 2025 to identify studies on digital technologies applied to bone augmentation. Eligible studies encompassed randomized controlled trials, cohort studies, case series, and case reports, all published in English. Data regarding digital workflows, software, materials, printing techniques, and sterilization methods were extracted from 23 studies published between 2015 and 2024. Results: The review highlights a diverse range of digital workflows, beginning with CBCT-based DICOM to STL conversion using software such as Mimics and Btk-3D^®. Customized titanium meshes and other meshes like Poly Ether-Ether Ketone (PEEK) meshes were produced via techniques including direct metal laser sintering (DMLS), selective laser melting (SLM), and five-axis milling. Although titanium remained the predominant material, studies reported variations in mesh design, thickness, and sterilization protocols. The findings underscore that digital customization enhances surgical precision and efficiency in BR, with several studies demonstrating improved bone gain and reduced operative time compared to conventional approaches. Conclusions: This scoping review confirms that 3D techniques represent a promising advancement in BR. Customized digital workflows provide superior accuracy and support for BR procedures, yet variability in protocols and limited high-quality trials underscore the need for further clinical research to standardize techniques and validate long-term outcomes. Full article

This study aimed to investigate the bonding strength and durability of titanium alloys bonded to zirconia-based materials produced using subtractive and additive digital methods. Two titanium alloy groups (N = 20) and two zirconia ceramic groups (N = 60) were fabricated using CAD/CAM milling from prefabricated discs (Ti-ML and Zr-ML), and 3D printing via SLM (Ti-3D) and DLP/LCM systems (Zr-3D). The specimens were bonded with dental cement to form four test groups: Zr-ML/Ti-ML, Zr-ML/Ti-3D, Zr-3D/Ti-ML, and Zr-3D/Ti-3D. Half of the specimens in each group underwent thermocycling to assess the effect of aging on bond strength. The density, microhardness, and surface morphology were evaluated, along with the shear bond strength and failure modes of the resin composites. Statistical differences were analyzed using one-way ANOVA and Tukey’s HSD test across all groups. The 3D-printed specimens of both materials exhibited higher microhardness and lower surface roughness than the milled specimens. The shear bond strength (SBS) was the highest in the Ti-ML/Zr-ML combination group before and after thermocycling, which had more cohesive failures, whereas the lowest bond strength was observed in the Ti-3D/Zr-ML group. The adhesion between titanium and zirconia-based materials was the strongest when both were fabricated using subtractive methods, followed by additive and mixed-method combinations. Full article

In this paper, titanium oxide nanoparticles (TiO₂-NPs) with complex surface topologies were obtained for the first time using simple procedures applied in laser sintering. Based on the obtained nanoparticles and polymethyl methacrylate-like photopolymer resin, a composite material (MPR/TiO₂-NPs) for 3D printing was created using the MSLA technology. Products made of the material containing from 0.001 to 0.1% wt. TiO₂-NPs didn’t contain internal defects and were less brittle than the resin without nanoparticles. Products made of the MPR/TiO₂-NPs material were well polished; after polishing, areas with a variation in the surface profile height of less than 10 nm were found on the surfaces. Nanoparticles in the volume of products made of the material are apparently unevenly distributed; there are alternating areas of micrometer sizes with slightly higher and slightly lower concentrations of nanoparticles. Spectroscopy showed that adding the developed nanoparticles promoted better polymerization of the MPR resin. The addition of nanoparticles to the material slightly increased its ability to generate active forms of oxygen and damage biomacromolecules. At the same time, the resulting material exhibits significant antibacterial properties and doen’t affect the growth and reproduction of animal cells. The created material can be a very effective basis for the additive manufacturing of products with improved physical and chemical properties and balanced biological activity. Full article

The advent of additive manufacturing (AM), also known as 3D printing, has revolutionized the production of titanium alloys, offering significant advantages in fabricating complex geometries with enhanced mechanical properties. This study investigates the variant-specific deformation mechanisms in HIP-treated TA15 (Ti-6.5Al-2Zr-1Mo-1V) titanium alloy, fabricated via selective electron beam melting (SEBM). The alloy exhibits a dual-phase (α+β) microstructure, where six distinct α variants are formed through the β→α phase transformation following the Burgers orientation relationship. Variant selection during AM leads to a non-uniform distribution of these α variants, with α6 (22.3%) dominating due to preferential growth. Analysis of the prismatic slip Schmid factor reveals that α4–α6 variants, with higher Schmid factors (>0.45), primarily undergo prismatic slip, while α1–α3 variants, with lower Schmid factors (<0.3), rely on basal or pyramidal slip and twinning for plastic deformation. In-grain misorientation axis (IGMA) analysis further reveals strain-dependent slip transitions: pyramidal slip is activated in α1–α3 variants at lower strains, while prismatic slip becomes the dominant deformation mechanism in α4–α6 variants at higher strains. Additionally, deformation twins, primarily {10–12}<1–101> extension twins (7.1%), contribute to the plasticity of hard-oriented α variants. These findings significantly enhance the understanding of the orientation-dependent deformation mechanisms in HIPed TA15 alloy and provide a crucial basis for optimizing the performance of additively-manufactured titanium alloys. Full article