|
|
Alimentary intake of fluoride in preschool children in dental caries prevention
Oganessian, Edgar ; Broukal, Zdeněk (advisor) ; Štípek, Stanislav (referee) ; Veverka, Jan (referee)
The primary prevention of dental caries includes the regular reduction of dental plaque, the adequate nutrition with reduced frequency of sugar intake and the application of topical and/or alimentary fluorides. The caries-protective effect of fluorides is based on the stabilization of demineralization/remineralization processes in the surface of teeth. The alimentary fluoride intake involves its nutritional sources, fluoride supplements when administered and unintentionally swallowed fluoride toothpastes. The fluoride intake, besides its verifiable and significant contribution to the control of cariogenic conditions in the oral cavity, brings some risk in the period of permanent teeth development. That is why the fluoride intake in childhood ought to be well set up and controlled for achieving the maximum benefit in caries reduction and for minimizing the risk for the enamel development. The assessment on fluoride content in its most significant nutritional sources and the model estimates of fluoride intake in preschool children have been conducted with the aim at contributing the solution of the benefit/risk strategy of fluoride caries prevention. The fluoride content was estimated in bottled waters for preschool children, in instant milk formulas, in herbal teas for children and in instant products of...
|
|
|
Prevention of dental tissue loss by composite restoration repairs. Long-term durabillity of composite to composite bond in various environments.
Comba, Lukáš ; Bradna, Pavel (advisor) ; Veverka, Jan (referee) ; Roubalíková, Lenka (referee)
in english Introduction: Composite restorations in the oral cavity are exposed to an aggressive environment and mechanical challenge that gradually impairs their physical and mechanical properties. This may result in an enhanced wear rate, loss of esthetic properties and an increased risk of a restoration fracture or its marginal failure with a negative impact on the restoration's durability. Worn or failed restorations are usually completely replaced, which increases the irreversible loss of dental hard tissues. Repair of composite restorations by their partial replacement is therefore a minimally invasive, preventive and less time-consuming alternative to their complete replacement and increases their longevity. In the oral cavity, the adhesive bond between the existing composite restoration and the repair composite resin is exposed to various chemical substances and mechanical stress, e.g. surfactants in toothpastes, which can initiate its degradation. By decreasing the surface tension, the penetration of water into the adhesive joint can be enhanced, accelerating the hydrolysis of the adhesive and reducing the composite repair strength. The major and not yet fully resolved issue of composite repairs is how to achieve a strong and durable bond between the existing and repair composite materials....
|
|
|
Oral Health in Patients with Cardiovascular Diseases
Chalupová, Miroslava ; Hecová, Hana (advisor) ; Bartáková, Věra (referee) ; Veverka, Jan (referee)
Cardiovascular diseases are some of the most common health and society problems in the present population. The question of influencing cardiovascular diseases by the state of oral health has been discussed for a long time. Opinions on this issue have undergone long-term development. The state of oral health influencing the overall health has been overestimated and underestimated over the years. This thesis has summarized contemporary knowledge of the metastatic opportunistic infection of oral etiology and evaluated the state of oral health of 187 patients from the Department of Stomatology, Faculty of Medicine and University Hospital in Pilsen, Charles University, who were examined by a dentist as a part of the preoperative examinations before planned cardiac surgery in 2015-2018. The experimental part of the study was focused on the detection of oral bacteria on pathologically changed heart valves from 41 patients operated on the Department of Cardiosurgery, Faculty of Medicine and University Hospital in Pilsen, Charles University. The summary of the results of the prospective epidemiological study of 187 patients undergoing a planned cardiosurgical operation has brought information about the neglected state of oral health of these patients. More than half of the examined patients (64.17%) were at...
|
|
|
The return of Poland and Czechoslovakia and the entry of Hungary to International Monetary Fund.
Veverka, Jan ; Svoboda, Karel (advisor) ; Mlsna, Petr (referee)
Bachelor thesis "The Return of Poland and Czechoslovakia and the Entry of Hungary to International Monetary Fund" deals with the early membership of these three central European countries - Czechoslovakia, Poland and Hungary - in the International Monetary Fund. First the thesis deals with how both Czechoslovakia and Poland were involved in the process of setting up the IMF and how they both terminated their membership in the beginning of the fifties, later the thesis deals with the circumstances leading to the Hungarian membership in the International Monetary Fund in 1982, to Polish membership renewal in 1986 as well as to Czechoslovak membership renewal talks in the 1980s. There has been a substantial change in economic and political setting in Hungary, Czechoslovakia and Poland after thirty years of disparate economic evolution and political separation via "iron curtain". At the same time, the character of IFM changed as well, and it was this coincidence that lead to the change in the attitude towards the IMF membership on the side of all above mentioned states as well as of the international organization itself.
|
|
|
Long-term durability of composite restoration margins in environments with increased corrosion risk
Roubíčková, Adéla ; Bradna, Pavel (advisor) ; Veverka, Jan (referee) ; Halačková, Zdena (referee)
Introduction: An adhesive bond between hard dental tissues and composite reconstructions is exposed to mechanical load, water, bacteria, enzymes and different chemical compounds. These factors could impair durability and resistance of composite reconstructions. In contrast with extensive research of negative influence of water on degradation of adhesive bonds, the influence of chemical substances on adhesive bond has not been investigated to a greater extent. Aim: The aim of the experimental part of the thesis was to evaluate the influence of hydrogen peroxide containing tooth-whitening products and mouth rinses containing chlorhexidine and fluoride on a long-term stability of class V composite restorations created using four contemporary adhesive systems by a microleakage method. Materials and methods: The following adhesive systems were investigated: total-etch Gluma Comfort Bond (GLU), and self-etch adhesives Clearfil SE Bond (CLF), Adper Prompt (ADP) and iBond (IBO). Standardized class V cavities were prepared in 192 extracted human teeth (one cervical margin in the cementum and one in the enamel). Subsequently, the cavities were restored using microhybride composite Charisma. The specimens were then exposed to the tooth whitening system Opalescence PF 20, mouth rinse Corsodyl containing...
|
|
|
Effect of corrosion environment on the long-term stability of composite material to enamel and dentin bonds
Dudek, Michal ; Bradna, Pavel (advisor) ; Veverka, Jan (referee) ; Halačková, Zdena (referee)
Introduction: Adhesive technology represents a significant advancement among different treatment options of dental caries. Its advantages involve not only highly aesthetic reconstructions, but also ability to preserve hard dental tissues compared to more traditional filling materials such as amalgam, where the material retention was achieved through undercuts. A potential of adhesive technology to arrest progression of an incipient caries has triggered its wider use in dental caries management, potentiated by an ongoing development of new adhesive systems and composite materials that assure an acceptable long-term stability of adhesive reconstructions. Adhesive bonds of dental reconstructions are in the oral cavity constantly challenged by various mechanical, chemical and biological factors. One of the chemical agents with detrimental potential is peroxide bleaching gel used for teeth brightening. Currently bleaching belongs to the most frequent cosmetic dental procedures. The active ingredient of bleaching gels is hydrogen peroxide or its precursors. It is assumed that free oxygen radicals released from peroxides attack double bonds of chromophore molecules captured within the tooth tissues. Because of the high reactivity and nonspecific nature of these oxygen radicals, they may affect also dental...
|
|
|
Alimentary intake of fluoride in preschool children in dental caries prevention
Oganessian, Edgar ; Broukal, Zdeněk (advisor) ; Štípek, Stanislav (referee) ; Veverka, Jan (referee)
The primary prevention of dental caries includes the regular reduction of dental plaque, the adequate nutrition with reduced frequency of sugar intake and the application of topical and/or alimentary fluorides. The caries-protective effect of fluorides is based on the stabilization of demineralization/remineralization processes in the surface of teeth. The alimentary fluoride intake involves its nutritional sources, fluoride supplements when administered and unintentionally swallowed fluoride toothpastes. The fluoride intake, besides its verifiable and significant contribution to the control of cariogenic conditions in the oral cavity, brings some risk in the period of permanent teeth development. That is why the fluoride intake in childhood ought to be well set up and controlled for achieving the maximum benefit in caries reduction and for minimizing the risk for the enamel development. The assessment on fluoride content in its most significant nutritional sources and the model estimates of fluoride intake in preschool children have been conducted with the aim at contributing the solution of the benefit/risk strategy of fluoride caries prevention. The fluoride content was estimated in bottled waters for preschool children, in instant milk formulas, in herbal teas for children and in instant products of...
|
|
|
Effect of polymerization light units on setting of composite materials with different photoinitiator systems
Froněk, Jan ; Bradna, Pavel (advisor) ; Veverka, Jan (referee)
The work is focused on monitoring the impact of several different types of polymerization lamps to hardening of dimethacrylate based composite materials with camphorquinone and acylphoshine oxide initiation systems and epoxy based composite material. Variable parameters of the polymerization lamps were light output power, the emission spectrum, the thermal emission and the power distribution across the face of light guides. Extent of polymerization was evaluated by measuring the surface hardness, parameters of lamps were evaluated by radiometric methods, the temperature change by a thermocouple. The power distribution across the face of light guides was measured by image analysis and verified by measuring the distribution of hardness in the irradiated area of polymerized material. The goal was to obtain independent data on the influence of controlled parameters on the polymerization of composite materials used in dentistry, with an impact on the life of composite reconstruction of teeth and body burden of substances leached from poorly polymerized material.
|
|
|
Lepidopteran fauna of the Hořovice region and its using in pedagogical practise
Veverka, Jan ; Hanel, Lubomír (referee) ; Dostál, Petr (referee)
Results of a survey of the lepidopteran fauna of the Hořovice region (Beroun District, Central Bohemia) carried out in the years 1982-2009 are presented. 49 localities were explored altogether, emphasis was given on the cadastre of Hořovice town (grid mapping code 6149) and Kleštěnice village (grid mapping code 6249). Most of the studied area is strongly influenced by industrial and agricultural use; large forests of the Křivoklátsko area and the Brdy highlands reach only marginally there. The three main goals of the rigorous theses are as follows: 1) to map distribution of all species of butterflies and moths of group so-called Macrolepidoptera (Lepidoptera: Macrolepidoptera) that belong to the fauna of the Hořovice region; 2) site class assessment on the basis of results of a survey of the lepidopteran fauna; 3) Lepidoptera in the pedagogical process. Altogether, 493 species in 16 families of Macrolepidoptera have been found (41% of the macrolepidopteran fauna of the Czech Republic). Relativelly most species have been recorded in the families Drepanidae, Sphingidae, Lasiocampidae and Notodontidae. Rare and otherwise remarkable species are commented.
|
|
|
Sǿren Aabye Kierkegaard (1813 - 1855) - Life, Faith and Theology
Králik, Roman ; Kučera, Zdeněk (advisor) ; Veverka, Lukáč Ján (referee) ; Sapík, Miroslav (referee)
Søren Aabye Kierkegaard (1813 - 1855) Život, víra a teologie Søren Aabye Kierkegaard (1813-1855) Life, Faith and Theology PaedDr. Roman Králik The following dissertation pursues the topic of systematic theology. Its title is Søren Aabye Kierkegaard (1813-1855) with the subtitle Life, Faith and Theology. The aim of the dissertation is to acquaint the reader with the life, way of thinking and the spiritual struggle of one of the main figures of modern theology, Søren Kierkegaard.
|
guest ::
RSS feed.