|
|
Effect of Structure of FRC and Adhesive on the Bond Strength of Joint between FRC and Particulate Filled Dental Composite
Bystřický, Zdeněk ; Přikryl, Radek (referee) ; Poláček, Petr (advisor)
This bachelor’s thesis investigates how is the strength of adhesive bond between dental FRC (Fiber Reinforced Composite) and adhesive affected by the type of reinforcement of dental FRC and by the type of adhesive. The nature of the fracture was investigated also. The strength of adhesive bond of the experimentally designed samples was measured using universal tensile testing machine in the specially constructed jaws. The nature of the fracture was viewed by the confocal microscope. The obtained results suggest that the strength of adhesive bond is mostly affected by the type of reinforcement of the FRC provided that there is a good wetting on the FRC surface. In this case, interlaminar strength of FRC was the limiting factor. The strength was lower in the case of FRC with multidirectional (spliced) glass fibers. The strength was also affected in a certain manner by the creation of locations where the stress was concentrated. This effect was most notably in the case of adhesives with the high cohesive strength. The impact of aqueous environment on the stability of adhesive joint was most major in the case of the low - crosslinked resins and in the case when the molecules of water penetrates into the interface between materials in consequence of poor wetting.
|
|
|
Optimization of interfaces in long-fiber reinforced dental composites
Henkrichová, Jana ; Poláček, Petr (referee) ; Přikryl, Radek (advisor)
This bachelor's thesis is dealing with study of fiber reinforced dental composites. Important properties of dental polymers, used fibers and options of their treatment were characterized. The aim of the thesis is to design the fiber surface modification by low temperature plasma to improve the adhesive bond strength and fracture characterization of the composite. The strength of the bond was tested by three point tensile tests by special device. Refractive characteristics and impact fibers wetting by matrix was determined by confocal microscopy.
|
|
|
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...
|
|
|
Optimization of interfaces in long-fiber reinforced dental composites
Henkrichová, Jana ; Poláček, Petr (referee) ; Přikryl, Radek (advisor)
This bachelor's thesis is dealing with study of fiber reinforced dental composites. Important properties of dental polymers, used fibers and options of their treatment were characterized. The aim of the thesis is to design the fiber surface modification by low temperature plasma to improve the adhesive bond strength and fracture characterization of the composite. The strength of the bond was tested by three point tensile tests by special device. Refractive characteristics and impact fibers wetting by matrix was determined by confocal microscopy.
|
|
|
Effect of Structure of FRC and Adhesive on the Bond Strength of Joint between FRC and Particulate Filled Dental Composite
Bystřický, Zdeněk ; Přikryl, Radek (referee) ; Poláček, Petr (advisor)
This bachelor’s thesis investigates how is the strength of adhesive bond between dental FRC (Fiber Reinforced Composite) and adhesive affected by the type of reinforcement of dental FRC and by the type of adhesive. The nature of the fracture was investigated also. The strength of adhesive bond of the experimentally designed samples was measured using universal tensile testing machine in the specially constructed jaws. The nature of the fracture was viewed by the confocal microscope. The obtained results suggest that the strength of adhesive bond is mostly affected by the type of reinforcement of the FRC provided that there is a good wetting on the FRC surface. In this case, interlaminar strength of FRC was the limiting factor. The strength was lower in the case of FRC with multidirectional (spliced) glass fibers. The strength was also affected in a certain manner by the creation of locations where the stress was concentrated. This effect was most notably in the case of adhesives with the high cohesive strength. The impact of aqueous environment on the stability of adhesive joint was most major in the case of the low - crosslinked resins and in the case when the molecules of water penetrates into the interface between materials in consequence of poor wetting.
|
guest ::
