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Effect of 3D printing technology on the properties of model femur segment
Nečas, Aleš ; Svatík, Juraj (referee) ; Jančář, Josef (advisor)
This bachelor thesis deals with the development of a biodegradable 3D anatomical model of the femur segment and the influence of 3D printing technology on tensile strength and tensile modulus of elasticity of 3D standardized tensile test bodies (ASTM_D_638_IV) made from PLA, nylon, acrylonitrile butadiene styrene (ABS), acrylonitrile styrene acrylate (ASA), polymethyl methacrylate (PMMA), polyethylene terephthalate glycol (PETG), and resin. For each material, bodies with body thickness of 1 mm, 2 mm, and 3 mm were 3D printed. Next, a PLA simplified femur segment model was created to determine the most suitable layer thickness for body printing in terms of its compressive strength and compressive modulus of elasticity. The thickness of the printed layer of 0.1 mm was chosen as the mechanically most suitable and was subsequently used in the production of a PLA anatomical model of the femur segment which was 3D printed in 3 variants differing in the density of the filling of the internal structures in the area of compact and cancellous bone tissue of real bone. Then, the compressive strength of these models was determined and compared. The PLA anatomical model of the femur segment was developed according to CT images of real bone with the purpose of its potential use in medicine as a bone tissue replacement in large femoral defects. However, before it can be used in medicine, further research is needed.
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The influence of internal structure on mechanical properties of 3D printed femoral segment from novel optimized biocomposite
Nečas, Aleš ; Schmid, Pavel (referee) ; Přikryl, Radek (advisor)
This diploma thesis presents the development of a new anatomical model of the femur segment based on a biocomposite of poly-3-hydroxybutyrate, polylactic acid, tricalcium phosphate and hydroxyapatite (PHB/PLA/TCP/HA). The model was designed using computed tomography of the patient‘s femur in twelve variants (A1 to A4, B1 to B4, C1 to C4) with different percentages of gyroid filling at the site of the compaction and spongiosis of the real bone. The biocomposite was then 3D printed after the optimized mixture of the new biocomposite (OPT1) was prepared, the printing string‘s chemical and structural characteristics were determined, and the most suitable parameters for 3D printing of the body from this biocomposite were optimized and verified. Furthermore, the pressure load capacity of all twelve variants of 3D printed femur segment models with different percentage densities of their internal gyroid filling was determined. Subsequently, the possibility of predicting the pressure load capacity of the newly developed anatomical femur segment was studied by computer simulation using the numerical model in ANSYS, and the differences in the pressure load capacity values of the PHB/PLA/TCP/HA femur segment in its real mechanical testing were found, compared to the values of the virtual tests using ANSYS. In order to determine the possible tissue resorption rate of this 3D PHB/PLA/TCP/HA biocomposite, the long-term effect (for 4 months) of simulated body fluid on the biodegradation of 3D PHB/PLA/TCP/HA biocomposite bodies with different percentages of gyroid filling (variant I to V) was examined. Subsequently, the biocomposites were subjected to pressure tests while their surface was analyzed by confocal microscopy. The femur segments with 75% filling at the compaction site (variant A) showed the highest average load capacity of 22.20 ± 0.50 kN, while the real femur segment samples had approximately one-quarter lower pressure load capacity compared to the computer simulation. The PHB/PLA/TCP/HA biodegradable bodies with more porous filling (variants II to V) degraded more slowly than the body with 100% filling (variant I), which offers benefits for their clinical use. Their slow degradation also had a beneficial effect on their load-bearing capacity after 4 months.The PHB/PLA/TCP/HA anatomical model of the femoral segment was developed for possible medical use in bone replacement for extensive femoral defects. However, further research is needed before its potential use in medicine.
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Bone regeneration and its analysis
Tesařová, Adéla ; Hovořáková, Mária (advisor) ; Zahradníček, Oldřich (referee)
Bone regeneration can take place throughout life as a natural process (remodeling) or because of trauma when fractures heal in which the damaged or missing part is replaced by new tissue. The aim of my bachelor thesis was to create a literature search on the issue of bone regeneration. The introductory part deals with the bone as such - its structure and the process of new formation (ossification) and remodeling. The following section describes some of the methods used to support bone regeneration in therapy - selected types of carriers and molecules that play an important role in regeneration and are part of the carriers or therapies used. At the end of the thesis, the basic methods used to analyze bone regeneration are described and provide us with an insight into the success of the tested therapeutic approaches, how well the bone heals and how effective the methods used are. The bachelor thesis was processed in the form of a literary search.
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Effect of 3D printing technology on the properties of model femur segment
Nečas, Aleš ; Svatík, Juraj (referee) ; Jančář, Josef (advisor)
This bachelor thesis deals with the development of a biodegradable 3D anatomical model of the femur segment and the influence of 3D printing technology on tensile strength and tensile modulus of elasticity of 3D standardized tensile test bodies (ASTM_D_638_IV) made from PLA, nylon, acrylonitrile butadiene styrene (ABS), acrylonitrile styrene acrylate (ASA), polymethyl methacrylate (PMMA), polyethylene terephthalate glycol (PETG), and resin. For each material, bodies with body thickness of 1 mm, 2 mm, and 3 mm were 3D printed. Next, a PLA simplified femur segment model was created to determine the most suitable layer thickness for body printing in terms of its compressive strength and compressive modulus of elasticity. The thickness of the printed layer of 0.1 mm was chosen as the mechanically most suitable and was subsequently used in the production of a PLA anatomical model of the femur segment which was 3D printed in 3 variants differing in the density of the filling of the internal structures in the area of compact and cancellous bone tissue of real bone. Then, the compressive strength of these models was determined and compared. The PLA anatomical model of the femur segment was developed according to CT images of real bone with the purpose of its potential use in medicine as a bone tissue replacement in large femoral defects. However, before it can be used in medicine, further research is needed.
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Preclinical use and critical evaluation of micro-CT from the perspective of oral and maxillofacial surgery.
Bartoš, Martin ; Foltán, René (advisor) ; Naňka, Ondřej (referee) ; Bulik, Oliver (referee)
The preclinical imaging method micro-CT (microtomography) allows the visualization and quantification of the structure of samples at a resolution of micrometers. Its' importance is increasing globally. In addition to several advantages (non-destructive, the possibility of direct 3D analysis, time efficiency, etc.), micro-CT also has some significant limitations (problematic validation of results, image artifacts, significant influence of image modifications, etc.). This thesis focuses on the application of micro-CT in the field of research and development of metallic and non-metallic materials promoting bone healing with their possible clinical applications. The first part addresses the limitations of micro-CT through several studies. A comparison of pore sizes in biomaterials utilizing scanning electron microscopy (SEM) and micro-CT was performed, and the complications of pore size evaluation were presented. SEM image analysis leads to significantly higher values than micro-CT (approximately three times), which allows for comparison of the studies using only one of these methods. Validation of micro-CT 3D analysis results based on calibration phantoms with complex structure, to date, is not possible. We therefore developed software generating phantom datasets of 3D objects with well-defined...
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Serum concentration of vitamin D in patients with femoral neck fracture
Matoušková, Karolína ; Wenchich, László (advisor) ; Zikán, Vít (referee)
Vitamin D significantly affects metabolism of the bone tissue. It keeps homeostasis of calcium and phosphor and thus contributes to healthier mineralization of bones. Lack of those substances pertains to risk factors for development of osteoporosis and subsequent complications during possible downfalls and fractures. The role of vitamin D in bone disease has been increasing in recent years, but its importance in the early post-fracture period is not yet fully understood. This thesis is a prospective study of metabolism of vitamin D and its metabolites in post-operative stage of patients with femoral neck fractures. It is a basic quantitative research, where received data are analysed. Blood samples obtained from a total of 18 patients, whose blood was taken on the day of surgery and 6 weeks after surgery (± 1 week), were used as material. Resulted values of 25-OH vitamin D increased from 23,02 ± 16,02 nmol/l to 25,75 ± 16,30 nmol/l (diameter ± standard deviation). In contrast, 1,25-(OH)2 vitamin D decreased from 76,81 ± 41,84 pmol/l to 55,88 ± 26,34 pmol/l. Statistically significant results at a significance level of p≤0,05 were only observed for parathyroid hormone (PTH), with values decreasing from 6,31 ± 3,95 pmol/l to 3,96 ± 2,25 pmol/l. Vitamin D examinations in our patients showed reduced...
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