National Repository of Grey Literature 5 records found  Search took 0.01 seconds. 
Composite Dental Biomaterials - Structure, Analysis and Properties
Matoušek, Aleš ; Vaněk,, Jiří (referee) ; Lapčík,, Lubomír (referee) ; Cihlář, Jaroslav (advisor)
The aim of this work is to define relations between grain size and bioaktivity of oxide ceramics, specifically ZrO2, Al2O3 and HA. Ceramic materials with grain size from 100 nm up to 10 m, with various surface roughness, were tested for its bioactivity. Ceramography analysis was performed for all tested materials to precisely describe microstructures. Biological properties of the ceramic materials were tested via dilation tests directly in-vitro and by in-vitro extraction. Three cell culturing lines: osteoblast MG63, fibroblast L929, and epithelioid HeLa, were used for our testing. An influence of the grain size on the biological response was only found for the ceramic materials which had been thermally etched. The thermally etched nanocrystalline samples had larger areas covered by cells than ceramics with coarse grain microstructure. Biological tests on layered composites Al2O3×ZrO2 showed the cell selection determined by the type of material, where ZrO2 surfaces were preferably covered. Improved biological response of nanocrystalline ZrO2 was demonstrated on ceramic ZrO2, Al2O3 and SiO2 substrates with nanocrystalline coating of ZrO2. In this work a novel technological process for the formation of defect-free coatings was developed. Sintered coatings were tested using in-vitro technique with cell line HeLa, L929 and MG63 for up to 72 hours. The results of the biological tests of nanocrystalline coatings were consistent with results from the bulk nanocrystalline thermally etched ZrO2 ceramics.
Sol-gel synthesis and properties of piezoceramic nanoparticles on the base of (BaxCa1-x)(TiyZr1-y)O3
Vacek, Petr ; Matoušek, Aleš (referee) ; Cihlář, Jaroslav (advisor)
The aim of the work was sol-gel synthesis of piezoceramic nanoparticles on the base of BaxCa1-xTiyZr1-yO3 (BCTZ), preparation of sintered samples and analysis of their structure and properties. Theoretical part includes information about piezoelectricity, piezoelectric materials and preparation of ceramics. Experimental part describes sol-gel synthesis of BCTZ nanoparticles and achieved phase composition and particle size. The next topic of experimental part was preparation of sintered BCTZ samples and analysis of their properties.
Study of bioceramic materials for dental applications
Lokvenc, Martin ; Matoušek, Aleš (referee) ; Novotná, Lenka (advisor)
This thesis deals with bioceramics used in dentistry. The biocompatibility, which is the characteristic property of biomaterials, is described in the opening chapter of the thesis. Advantages and disadvantages of advanced ceramics are also discussed. The main attention was paid particularly to the dental bioceramics, which can be divided according to different criteria. The used classification was based on microstructure, which significantly influences behaviour and properties of biomaterials. The ceramic is viewed as a composite material, where the glass matrix is filled with different amount of crystal phase. The thesis also includes the use of the individual types of bioceramics for the manufacture of dental restorations.
Preparation and properties of machinable ceramic materials
Sláma, Martin ; Matoušek, Aleš (referee) ; Cihlář, Jaroslav (advisor)
The thesis is focused on studying the machinability of ceramic material in dependence on presintering temperature. Alumina was used as an experimental material. The machinability of alumina was observed on samples produced by uniaxial pressing. Presintered and not-presintered disks were machined by cutter. Disks were presintered at 700°C, 800°C, 900°C and 1000°C for one or two hours. Machinability of alumina was tested according to four levels of the milled depth and according to temperature and the effect of dwell.
Thermoplastic extrusion of ceramic materials with ionic and mixed conductivity
Kaštyl, Jaroslav ; Matoušek, Aleš (referee) ; Trunec, Martin (advisor)
In the bachelor thesis, an overview of the existing literature focused on thermoplastic extrusion method was worked out and based on the findings; the conditions for extrusion of mixtures with zirconia were optimized in order to produce rods. Great attention was paid to dimensional and shape precision of ceramic parts. Two methods were applied when preparing the ceramic mixtures – mixing and dissolving. These methods have been compared on the basis of the results achieved in rheological measurements of flow properties, microstructure and dimensional accuracy of the sintered rods. Having verified the efficiency of mixture dissolving, this method was used to prepare mixtures with different contents of cellulose and binder.

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1 Matoušek, Alexander
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