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Badanie wpływu środowiska kwaśnego i zasadowego na degradację powierzchni ceramiki cyrkonowej (Y-TZP)

Kolenda A., Tymowicz-Grzyb P., Jaegermann Z., Mierzwińska-Nastalska E.

Szkło i Ceramika

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2018

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R. 69, nr 2

6--9

PL

Celem pracy badawczej opisanej w niniejszej publikacji było zbadanie wpływu środowiska kwaśnego i zasadowego na degradację powierzchniową ceramiki cyrkonowej stabilizowanej itrem (Y-TZP). Miarą degradacji (starzenia) były zmiany ilości fazy jednoskośnej (m-ZrO2) w materiale i wartości wytrzymałości na zginanie. Próbki wykonane z trzech proszków Y-TZP oznaczonych jako: OLD, CH3 i HT poddano procesowi starzenia w roztworach: 5M H3PO4 (K1), 5M H2SO4 (K2), 5M NaOH (Z) i wodzie destylowanej (W) w temperaturze 90°C przez 72 godziny. Próbą odniesienia były próbki niestarzone (NS), a próbą kontrolną – próbki starzone w wodzie destylowanej (W). Aby ocenić wpływ poszczególnych czynników wykonano analizę fazową XRD, obserwacje powierzchni w mikroskopie skaningowym SEM oraz badania wytrzymałości na zginanie. We wszystkich próbkach starzonych zaobserwowano przyrost ilości fazy jednoskośnej w porównaniu do próbek niestarzonych. Wyniki badań wskazują, że największy przyrost zawartości m-ZrO2 występuje po starzeniu w 5M NaOH oraz że wytrzymałość na zginanie nie jest jednoznacznie skorelowana ani z rodzajem starzenia, ani z przyrostem fazy m-ZrO2 w próbkach.

EN

The aim of the research described in this publication was to investigate the influence of acidic and alkaline environments on the surface degradation of Yttrium-Stabilized Zirconia Ceramics (Y-TZP). The measure of degradation (aging) were changes in the amount of monoclinic zirconia phase (m-ZrO2) in the material and bending strength values. Tests samples were prepared from three Y-TZP powders marked as: OLD, CH3 and HT and were subjected to an aging process in the following solutions: 5M H3PO4 (K1), 5M H2SO4 (K2), 5M NaOH (Z) and distilled water (W) at 90°C during 72 hours. The reference samples were these not aged (NS) and as a control – samples aged in distilled water (W). To assess the impact of individual factors, the XRD phase analysis, surface observations in the SEM scanning microscope and bending strength tests were performed. In all aged samples an increase in the amount of monoclinic phase was observed as compared to not aged samples. The results indicate that the highest increase in m-ZrO2 phase occurs after aging in 5M NaOH and the bending strength is not unequivocally correlated neither with the type of aging nor with the increase in the monoclinic phase in the samples.

2

A comparison of impact force reduction by polymer materials used for mouthguard fabrication

Gawlak D., Mańka-Malara K., Mierzwińska-Nastalska E., Gieleta R., Kamiński T., Łuniewska M.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 1

89--95

EN

Purpose: The essential function of mouthguards is protection against the effects of injuries sustained during sports activities. This purpose will be successfully achieved if appropriate materials ensuring sufficient reduction of the injury force are used for mouthguard fabrication. Objective: The objective of the study was to investigate the force reduction capability of selected materials as well as to identify which material reduces the impact force to the highest degree. Methods: The material for the study were samples of polymers (6 samples in total), obtained during the process of deep pressing (2 samples), flasking (3 samples) and thermal injection (1 sample), which were tested for impact force damping using an impact device – Charpy impact hammer. The control group comprised of the ceramic material samples subjected to the hammer impact. The statistical analysis applied in this study were one-way Welch ANOVA with post-hoc Games-Howell pairwise comparisons. Results: The test materials reduced the impact force of the impact hammer to varying degrees. The greatest damping capability was demonstrated for the following materials: Impak with 1:1 powder-to-liquid weight ratio polymerized with the conventional flasking technique, and Corflex Orthodontic used in the thermal injection technique of mouthguard fabrication. Conclusions: Impak with 1:1 weight ratio and Corflex Orthodontic should be recommended for the fabrication of mouthguards since they demonstrated the most advantageous damping properties.

3

Preparation and characterization of ZnO-PMMA resin nanocomposites for denture bases

Cierech M., Wojnarowicz J., Szmigiel D., Bączkowski B., Grudniak A. M., Wolska K. I., Łojkowski W., Mierzwińska-Nastalska E.

Acta of Bioengineering and Biomechanics

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2016

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Vol. 18, no. 2

31--41

EN

Purpose: The aim of the paper was to investigate the antifungal activity of zinc oxide nanoparticles (ZnONPs) against Candida albicans. Some attempts have been made to find out the best way to introduce ZnONPs into polymethyl methacrylate (PMMA) resin material and to determine some parameters of a newly formed composite. Material and methods: Zinc oxide nanoparticles were manufactured and their basic physical parameters were determined (average particle size, density, specific surface area). Minimal inhibitory concentration (MIC) of ZnONPs was determined for the Candida albicans standard strain. The average size of ZnO conglomerates in the monomer solution of PMMA resin was measured using a dynamic light scattering instrument. PMMA resin samples with incorporated ZnONPs were produced. The morphology of nanopowder and the newly formed composite was examined under a scanning electron microscope (SEM). In addition, the roughness parameter of PMMA resin material was investigated before and after ZnONPs modification. Results: Nanopowder with the average particle size of 30 nm, density of 5.24 g/cm3 and surface area of 39 m2 /g was obtained. MIC was determined at the level of 0.75 mg/mL. The average size of ZnO conglomerates in the monomer solution of acrylic resin dropped by 11 times after ultrasound activation. SEM examination of a newly formed composite showed a successful introduction of ZnONPs confirmed by the energy dispersive X-ray spectroscopy (EDS) analysis. There were no statistically significant differences in the biomaterial roughness before and after the modification of ZnONPs. Conclusion: Zinc oxide nanoparticles were successfully incorporated into acrylic resin used for the production of denture bases. The presence of nanoparticles with sizes below 100 nm was confirmed. Nevertheless a newly created composite needs to be further investigated to improve its homogeneity, and to check its microbiological properties, strength and biocompatibility prior to its possible clinical use.

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Badanie porowatości i nasiąkliwości wybranych tworzyw akrylowych stosowanych w protetyce stomatologicznej w wykonawstwie płyt protez

Osica I., Szlązak K., Kapłan T., Cierech M., Wróbel K., Mierzwińska-Nastalska E., Bucki J. J., Święszkowski W.

Przetwórstwo Tworzyw

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2013

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[R.] 19, nr 1 (151)

32--36

PL

W pracy porównano nasiąkliwość i porowatość wybranych tworzyw akrylowych stosowanych w wykonawstwie płyt ruchomych protez zębowych. W badaniach wykorzystano próbki sześciu szeroko dostępnych na rynku polskim tworzyw akrylowych. Materiały wytworzono trzema różnymi metodami polimeryzacji w zależności od typu tworzywa. Nasiąkliwość tworzyw oznaczono na podstawie normy PN-EN ISO 62. Porowatość określono przy użyciu rentgenowskiej tomografii komputerowej (Computed Tomography - CT). Powierzchnię tworzyw przed i po polerowaniu poddano obserwacjom mikroskopowym przy użyciu skaningowego mikroskopu elektronowego (Scanning Electron Microscope - SEM). Przeprowadzone badania wykazały różnicę w nasiąkliwości wytworzonych materiałów. Tworzywa charakteryzują się niewielką porowatością lub całkowitym jej brakiem. Wykazano, iż polerowanie znacząco wpływa na nasiąkliwość materiałów oraz zmniejsza rozwinięcie powierzchni.

EN

In this study porosity and absorbability of acrylic resins were compared. These polymeric materials are used in dental prosthodontics in order to perform bases of dentures. Six types of popular acrylic were examined. Samples were produced using three different methods of polymerization, corresponding to resin type. Absorbability of acrylic resins was examined according to PN-EN ISO 62 standard. Porosity of acrylic resins was examined using Computed Tomography (CT). Surface of acrylic samples was observed on Scanning Electron Microscope (SEM) before and after polishing. Results show that there is a difference in absorbability of acrylic resins. Samples are characterized by low porosity or even lack of porosity. It was demonstrated, that polishing affect perceptibly on absorbability and significantly decreases surface area.

5

Strength and thickness of the layer of materials used for ceramic veneers bonding

Mazurek K., Mierzwińska-Nastalska E., Molak R., Kożuchowski M., Pakieła Z.

Acta of Bioengineering and Biomechanics

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2012

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Vol. 14, no. 3

75-78

EN

The use of adhesive bonding systems and composites in prosthetic dentistry brought improved and more aesthetic prosthetic restorations. The adhesive bonding of porcelain veneers is based on the micromechanical and chemical bond between tooth surface, cement layer and ceramic material. The aim of the study was to measure the thickness of the material layer formed during cementing of a ceramic restoration, and - in the second part of the study - to test tension of these cements. The materials investigated comprised dual-curing materials: Variolink II, KoNroot Cem, KoNroot Cem Viscous and Panavia F 2.0, as well as a light-curing composite: Variolink Veneer. The thickness was measured with the use of ZIP Lite 250 optical gauging apparatus. SEM microscope - Hitachi Tabletop Microscope TM-100 - was used to analyse the characteristics of an adhesive bond and filler particle size of particular materials. Tension tests of the cements under study were carried out on the MTS Q Test 10 static electrodynamic apparatus. The tests showed that KoNroot Cem exhibited the best mechanical properties of bonding to enamel and dentin among the materials tested. Variolink II base light-curing cement formed the thinnest layer. All the materials tested formed the layer not exceeding 1/3 of ceramic restoration thickness.