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Biological properties of titanium alloy coated with hydroxyapatite in relation to immediate implant loading
Seydlová, Michaela ; Dostálová, Taťjána (advisor) ; Racek, Jaroslav (referee) ; Jelínková, Helena (referee)
Coating dental implants with hydroxyapatite may give certain advantages such as active encouragement to new bone growth, a lower rejection rate and an improved long-term prosthesis fixation. The biological properties of dental implants coated by the sandwich technique with a thin layer of hydroxyapatite and an interlayer of zirconia were evaluated. The implant samples were covered by pulsed laser deposition. The aim of this study is to evaluate the cytotoxicity and the surface characteristics of the titanium targets modified with zirconia and hydroxyapatite. We used a direct test of cytotoxicity, tests of fibroblasts adhesion and proliferation using counting of harvested cells and providing a MTT assay. No changes in the morphology or the proliferation rate of the cells used were found in the presence of the modified titanium targets. The results show adhesion and cell proliferation, which in turn implies that the studied material is not cytotoxic and is suitable for cell colonization. Titanium modified with zirconia and crystalline hydroxyapatite can improve the biological properties and so can be benefitially employed in oral bone surgery. Powered by TCPDF (www.tcpdf.org)
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Biological and mechanical properties of titanium implant covered with hydroxyapatite and zirconia layers and the approach to the immediate loading of dental implants
Teuberová, Zuzana ; Dostálová, Taťjána (advisor) ; Racek, Jaroslav (referee) ; Jelínková, Helena (referee)
Dental implantology is a branch, which has started a rapid evolution over the last years. All of the experts dealing with implantation are focused on extending indications for the application of the used materials to reduce the time period of therapy. Coating of the implants is a possible way how to treat patients in a shorter time period with the similar results as following the classical Bránemark protocol.Hydroxyapatite is one of the most attractive materials for human hard tissue implants because of its close resemblance to the bone and the teeth. Its positive influence on the healing process called osseointegration is obvious. Hydroxyapatite is of a brittle nature and limits the applications as the main solid material for the dental implants. Zirconia ceramics have several advantages such as the high strength and it is frequently used to reinforce other ceramics. The concept of adding zirconia as the second phase to hydroxyapatite significantly increased the bonding strenght.In the dissertation pulsed laser deposition is shown as one of the coating method. The bioceramic zirconia samples were characterized by methods for thin solid film analysis such as X-ray diffraction, morfology investigation by electrone microscope and measurement of the film thickness. Afterwards we examined the mechanical...
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Oxidative stress, microinflammation and cardiovascular risk in patients with chronic kidney disease
Hodková, Magdalena ; Kalousová, Marta (advisor) ; Průša, Richard (referee) ; Racek, Jaroslav (referee)
Chronic kidney disease (CKD) patients are at a significantly higher risk of atherosclerotic complications when compared to the general population. Oxidative stress and the related chronic microinflammation are possible causes of this increased cardiovascular risk, which is most pronounced in patients undergoing chronic haemodialysis (HD) treatment. Oxidative stress in HD patients can be further increased by routine pharmacological interventions (especially by intravenous - i.v. iron preparations administration). The aim of the thesis was to investigate neutrophil respiratory burst and some molecules related to oxidative stress and chronic inflammation - pregnancy-associated plasma protein-A (PAPPA), advanced oxidation protein products (AOPP), C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1) and E-selectin during HD session and to find out whether they can be pharmacologically affected by i.v. ferric sodium-gluconate and oral vitamin E administration. We focused on studying PAPP-A in chronic renal disease (CKD) patients, patients treated with continuous ambulatory peritoneal dialysis (CAPD) and chronic HD patients. We have observed that HD patients' neutrophils are primed to generate greater quantities of superoxide than those of healthy controls. This production decreases during HD and...
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Experimental research of specific absorbed rate at 3.0 Tesla magnetic rezonance scanner
RÁČEK, Jaroslav
The issue of the Specific Absorbed Rate (SAR) is becoming more interesting mainly due to new installations of MRi scanners of the magnetic field intensity of 3.0 Tesla (T). 3 T devices are characterized by quadruplicated SAR comparing to 1, 5 T devices. As it is possible to exceed set safety limits during examinations, it is important to monitor the SAR level. This thesis describes relations among parameters of examinational sequences, a patient{\crq}s weight and the Specific Absorbed Rate. The SAR also causes so called thermal stress, which can be dangerous namely for patients with impaired thermoregulation. Reaching the maximum allowed level of SAR causes the examination to be discontinued; the examination then can be more affected by artifacts or completely prematurely stopped. Most of the tests, during which the parameters of examinational sequences were changed, were performed using phantom. A part of this thesis is devoted to results of practical examinations of patients. Only standard examinational processes approved by the Ethical Committee of the Central Military Hospital Prague were performed while examining these patients. The results of individual tests are evaluated comprehensively in conclusion of this thesis and put into relations with practically used procedures of examination. Methods and procedures of reductions the SAR level are described in that part of this thesis.
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