Auflistung nach Autor:in "Sharma, Neha"

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Effect of printing parameters on mechanical performance of material-extrusion 3D-printed PEEK specimens at the point-of-care
(MDPI, 17.01.2023) Zarean, Paridokht; Zarean, Parichehr; de Wild, Michael; Thieringer, Florian M.; Sharma, Neha; Seiler, Daniel; Malgaroli, Patrick
Additive manufacturing (AM) of polyetheretherketone (PEEK) biomaterials using the material-extrusion (MEX) method has been studied for years. Because of the challenging manufacturing process, precisely controlling printing parameters is crucial. This study aimed to investigate the effects of printing parameters such as orientation and position of printing on mechanical properties. Thus, 34 samples were printed using PEEK filament and the MEX process. Samples were divided into two main groups (A,B) according to their printing orientations (A: groups 1–3) and positions on the build plate (B: groups 4–8). Mechanical tensile tests were performed to evaluate the effects of different printing orientations and positions on mechanical properties. The means of the tensile modulus in samples 3D-printed in XY (group 1), XZ (group 2), and ZX (group 3) orientations were not significantly different (p-value = 0.063). Groups 1 and 2 had smaller distributions than group 3 in the means of tensile strength. The t-test showed that the overall means of the measurements in groups 4–8 did not differ significantly (p-value = 0.315). The tensile tests indicated that printing in vertical and horizontal orientations had no significant influence on mechanical properties. There were no significant differences in mechanical strength between top/bottom printed samples in five different lateral positions. Reliability of printing with good mechanical properties could be a step forward to manufacturing patient-specific implants.
01A - Beitrag in wissenschaftlicher Zeitschrift
Fabrication and characterization of PCL/HA filament as a 3D printing material using thermal extrusion technology for bone tissue engineering
(MDPI, 11.02.2022) Wang, Fengze; Tankus, Esma Bahar; Santarella, Francesco; Rohr, Nadja; Sharma, Neha; Märtin, Sabrina; Michalscheck, Mirja; Cao, Shuaishuai; Maintz, Michaela; Thieringer, Florian M.
The most common three-dimensional (3D) printing method is material extrusion, where a pre-made filament is deposited layer-by-layer. In recent years, low-cost polycaprolactone (PCL) material has increasingly been used in 3D printing, exhibiting a sufficiently high quality for consideration in cranio-maxillofacial reconstructions. To increase osteoconductivity, prefabricated filaments for bone repair based on PCL can be supplemented with hydroxyapatite (HA). However, few reports on PCL/HA composite filaments for material extrusion applications have been documented. In this study, solvent-free fabrication for PCL/HA composite filaments (HA 0%, 5%, 10%, 15%, 20%, and 25% weight/weight PCL) was addressed, and parameters for scaffold fabrication in a desktop 3D printer were confirmed. Filaments and scaffold fabrication temperatures rose with increased HA content. The pore size and porosity of the six groups’ scaffolds were similar to each other, and all had highly interconnected structures. Six groups’ scaffolds were evaluated by measuring the compressive strength, elastic modulus, water contact angle, and morphology. A higher amount of HA increased surface roughness and hydrophilicity compared to PCL scaffolds. The increase in HA content improved the compressive strength and elastic modulus. The obtained data provide the basis for the biological evaluation and future clinical applications of PCL/HA material.
01A - Beitrag in wissenschaftlicher Zeitschrift
A multi-criteria assessment strategy for 3D printed porous polyetheretherketone (PEEK) patient-specific implants for orbital wall reconstruction
(MDPI, 13.08.2021) Sharma, Neha; Welker, Dennis; Aghlmandi, Soheila; Maintz, Michaela; Zeilhofer, Hans-Florian; Honigmann, Philipp; Seifert, Thomas; Thieringer, Florian
Pure orbital blowout fractures occur within the confines of the internal orbital wall. Restoration of orbital form and volume is paramount to prevent functional and esthetic impairment. The anatomical peculiarity of the orbit has encouraged surgeons to develop implants with customized features to restore its architecture. This has resulted in worldwide clinical demand for patient-specific implants (PSIs) designed to fit precisely in the patient’s unique anatomy. Material extrusion or Fused filament fabrication (FFF) three-dimensional (3D) printing technology has enabled the fabrication of implant-grade polymers such as Polyetheretherketone (PEEK), paving the way for a more sophisticated generation of biomaterials. This study evaluates the FFF 3D printed PEEK orbital mesh customized implants with a metric considering the relevant design, biomechanical, and morphological parameters. The performance of the implants is studied as a function of varying thicknesses and porous design constructs through a finite element (FE) based computational model and a decision matrix based statistical approach. The maximum stress values achieved in our results predict the high durability of the implants, and the maximum deformation values were under one-tenth of a millimeter (mm) domain in all the implant profile configurations. The circular patterned implant (0.9 mm) had the best performance score. The study demonstrates that compounding multi-design computational analysis with 3D printing can be beneficial for the optimal restoration of the orbital floor.
01A - Beitrag in wissenschaftlicher Zeitschrift
Parameter optimization in a finite element mandibular fracture fixation model using the design of experiments approach
(Elsevier, 08/2023) Maintz, Michaela; Msallem, Bilal; de Wild, Michael; Seiler, Daniel; Herrmann, Sven; Feiler, Stefanie; Sharma, Neha; Dalcanale, Federico; Cattin, Philippe; Thieringer, Florian Markus
01A - Beitrag in wissenschaftlicher Zeitschrift
Quantitative assessment of point-of-care 3D-printed patient-specific polyetheretherketone (PEEK) cranial implants
(MDPI, 07.08.2021) Seiler, Daniel; Dalcanale, Federico; Sharma, Neha; Aghlmandi, Soheila; Zeilhofer, Hans-Florian; Thieringer, Florian; Honigmann, Philipp
Recent advancements in medical imaging, virtual surgical planning (VSP), and three-dimensional (3D) printing have potentially changed how today’s craniomaxillofacial surgeons use patient information for customized treatments. Over the years, polyetheretherketone (PEEK) has emerged as the biomaterial of choice to reconstruct craniofacial defects. With advancements in additive manufacturing (AM) systems, prospects for the point-of-care (POC) 3D printing of PEEK patient-specific implants (PSIs) have emerged. Consequently, investigating the clinical reliability of POC-manufactured PEEK implants has become a necessary endeavor. Therefore, this paper aims to provide a quantitative assessment of POC-manufactured, 3D-printed PEEK PSIs for cranial reconstruction through characterization of the geometrical, morphological, and biomechanical aspects of the in-hospital 3D-printed PEEK cranial implants. The study results revealed that the printed customized cranial implants had high dimensional accuracy and repeatability, displaying clinically acceptable morphologic similarity concerning fit and contours continuity. From a biomechanical standpoint, it was noticed that the tested implants had variable peak load values with discrete fracture patterns and failed at a mean (SD) peak load of 798.38 ± 211.45 N. In conclusion, the results of this preclinical study are in line with cranial implant expectations; however, specific attributes have scope for further improvements.
01A - Beitrag in wissenschaftlicher Zeitschrift