Thesis (M.A.)--University of New Brunswick, 2003. / Copyright (2003) held by author. Includes bibliographical references (p. 97-100).

Please read the abstract in the 00front part of this document / Thesis (PhD (Chemistry))--University of Pretoria, 2007. / Chemistry / unrestricted

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Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 206-219). Available also in a digital version from Dissertation Abstracts.

O presente estudo teve por objetivo desenvolver um cimento reparador injetável a base de cimento Portland (CP) e, uma vez determinada a formulação deste cimento experimental (CE), avaliar suas propriedades físico-químicas, mecânicas e ópticas em comparação ao Agregado Trioxido Mineral (MTA). Partiu-se de uma mistura de CP branco e 20% de oxido de bismuto, que foi utilizada como Modelo de MTA para realização de ensaios piloto realizados para determinar a proporção po/liquido (PPL), os agentes radiopacificador, antimicrobiano, plastificante e acelerador de presa. Apos determinação dos constituintes do CE de forma a obter um material com características adequadas ao uso clinico, seu desempenho foi comparado ao MTA frente aos ensaios de injetabilidade, tempo de presa, escoamento, pH, liberação de íons cálcio e arsênio, resistência a compressão (RC), avaliação da estabilidade de cor e MEV. O cimento experimental foi totalmente injetado por meio de seringa comum acoplada a agulha 19 G, diferente do MTA (p<0,05) que atingiu a forca de injeção máxima estabelecida para o teste (100 N) com apenas 10% da massa injetada. O MTA apresentou a menor media de tempo de presa inicial e final, com diferença estatisticamente significante em relação ao CE. Enquanto o escoamento do MTA foi nulo, o CE apresentou bom escoamento segundo a norma n&ordm; 57 da ADA. Não houve diferença estatisticamente significante (p>0,05) entre o pH dos cimentos testados nos períodos de 2 h e 24 h, porem, apos 168 h, o MTA apresentou pH mais elevado, diferente estatisticamente (p<0,05) do CE. No período de 2 h, ambos os cimentos tiveram liberação semelhante de íons Ca+ (p>0,05), entretanto, após 24 h e 168 h, o CE teve liberação de Ca+ significativamente maior (p<0,05) do que o MTA. Não foi detectada liberação de íons arsênio nos cimentos avaliados. O CE apresentou maiores valores de RC que o MTA em todos os tempos estudados, com diferença estatisticamente significante (p<0,05) apos 24 h e 7 d. Ambos os cimentos apresentaram alteração de cor (&Delta;E) em níveis clinicamente inaceitáveis (&Delta;E3,3), no entanto, quando o CE foi testado sem adição de prata, apresentou (&Delta;E) semelhante (p>0,05) ao grupo controle (sem cimento). De acordo com os resultados obtidos, conclui-se que a combinação dos aditivos utilizada no estudo foi capaz de proporcionar ao cimento experimental boas propriedades, o que permitiu a obtenção de um cimento reparador injetável com atividade antimicrobiana melhorada / The aim of this study was to develop an injectable repair cement based on Portland cement (PC) and, once the formulation of this experimental cement (EC) was defined, to assess its physical-chemical, mechanical and optical properties in comparison to the Mineral Trioxide Aggregate (MTA). A mixture of white PC and 20% bismuth oxide, was used as a MTA Model to perform the pilot tests in order to choose the powder-to-liquid ratio (PLR), radiopacifier agent, antimicrobial agent, liquefier and setting accelerator for the EC. Once all the constituents of the EC were chosen and after it demonstrated to be suitable for clinical application, its performance was compared to MTA through injetability tests, setting time, flow, pH, calcium and arsenic ion release, compressive strength (CS), evaluation of color stability and SEM. The EC was fully injected through a 19G needle coupled to a common syringe, different (p <0.05) from MTA, which reached the maximum injection force (100N) with only 10% of its mass injected. The MTA had statistically significant lower initial and final setting times compared to EC. MTA did not flow, while EC showed good flow according to n&ordm; 57 ADA standard. There was no statistically significant difference (p> 0.05) between the pH of the cements after 2 h and 24 h, but after 168 h, MTA had higher pH, different (p <0.05) from EC. Regarding calcion ion release, both cements had similar results (p> 0.05) after 2 h, however, after 24 h and 168 h, Ca+2 release was significantly greater (p <0.05) for EC. Arsenic ions were not detected in any cement. The EC had higher RC values than MTA in all periods evaluated, with a statistically significant difference (p <0.05) after 24h and 7d. Both cements showed color change (&Delta;E) at clinically unacceptable levels (&Delta;E3,3), however, when the EC was tested without the addition of silver had (&Delta;E) similar (p> 0,05) to control group (without cement). According to the results, it can be concluded that the combination of additives selected in the study was able to provide good properties to the EC, allowing the obtainancy of an injectable repair cement with improved antimicrobial activity

O objetivo do estudo foi avaliar as propriedades físicas, químicas e biológicas de um cimento experimental à base de Portland contendo diferentes agentes radiopacificadores. Os cimentos foram divididos em 6 grupos: 1. MTA-Angelus branco (controle), 2. cimento Portland branco (CP), 3. CP com 20% de óxido de zircônio (OZ), 4. CP/50% OZ, 5. CP com 20% de tungstato de cálcio (TC) e 6. CP/50% TC. As proporções foram determinadas em peso (80 e 50% de CP para 20 e 50% de radiopacificadores, respectivamente). Os cimentos experimentais foram manipulados utilizando 0,3 mL de líquido composto por 80% de água destilada e 20% de propilenoglicol, em volume. A caracterização dos materiais foi realizada em microscopia eletrônica de varredura (MEV), no modo EDS e em difratômetro de raios-X (XRD). Para os testes de radiopacidade, escoamento, espessura de filme e solubilidade foram seguidas as especificações no 57 da ANSI/ADA (2000). Na determinação do tempo de presa, foi empregada a norma ASTM C266/2008. Na análise do pH e liberação de íons cálcio foram analisados os períodos de 3, 24, 72 e 168 horas. Para análise da descoloração dentária, foram realizadas análises em espectrofotômetro, estereomicroscopia e MEV. Para análise da resposta inflamatória, foi utilizado o teste de implantação em subcutâneo de ratos. A utilização do óxido de zircônio e do tungstato de cálcio em combinação com o cimento Portland resultou no desenvolvimento de cimentos que exibiram uma radiopacidade próxima (20% de radiopacificadores) ou acima (50%) do recomendado pela norma no 57 da ANSI/ADA; tempo de presa mais prolongado, espessura de filme menor e escoamento mais elevado em comparação com o MTA-Angelus; solubilidade adequada e comparável ao MTA-Angelus, elevado pH e liberação de íons cálcio superior ao MTA-Angelus nos períodos iniciais e similar aos 7 dias, ausência de descoloração dentária e resposta inflamatória semelhante ao MTA-Angelus. / The aim of the study was to evaluate the physical, chemical and biological properties of an experimental calcium silicate-based cement with different concentrations of the radiopacifiers zirconium oxide and calcium tungstate. The materials were divided in 6 groups: 1. White MTA (control), 2. White Portland cement (PC), 3. PC with 20% zirconium oxide (ZO), 4. PC/50% ZO, 5. PC with 20% calcium tungstate (CT) and 6. PC/50% CT. The proportions were determined by weight. The cements were manipulated using 0.3 mL of liquid composed of 80% distilled water and 20% propylene glycol. The control was manipulated according to manufacturers instructions. The characterization of the materials was performed using scanning electron microscopy (SEM) in EDS mode and X-ray diffractometrer (XRD). For radiopacity, flowability, film thickness and solubility test, the specifications no 57 of ADA (2000) was followed. To determine the setting time, ASTM C266/2008 specifications was followed. For pH and calcium ion release assessment, the periods of 3, 24, 72 and 168 hours were evaluated. The analysis of dental discolouration was performed using spectrophotometer, stereomicroscopy and SEM. To evaluate the inflammatory response, the test of subcutaneous implantation in rats was used. The use of zirconium oxide and calcium tungstate in association with Portland cement resulted in development of cements with radiopacity nearly (20% radiopacifiers) or above (50%) the recommended by ANSI/ADA specifications n a 57, more prolonged setting time, lower film thickness and higher flowability in comparison with MTAAngelus, an adequate and comparable solubility with MTA-Angelus, high pH and calcium ion release higher than MTA-Angelus in the initial periods and similar at 7 days, absence of dental discolouration and inflammatory response similar to that presented by MTA-Angelus.

Shu King-hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 80-81). / ABSTRACT --- p.1 / Chapter CHAPTER I. --- INTRODUCTION --- p.3 / REFERENCES --- p.6 / Chapter CHAPTER II. --- BRIEF REVIEW OF THE ANALYTICAL METHODS USED / Chapter 1. --- Spectrophotometry --- p.8 / Chapter 2. --- Derivative spectrophotometry --- p.9 / Chapter 3. --- Atomic absorption spectrometry --- p.12 / Chapter 4. --- X - Ray fluorescence --- p.12 / REFERENCES --- p.14 / Chapter CHAPTER III. --- SIMULTANEOUS DETERMINATION OF ALUMINIUM OXIDE AND IRON (III) OXIDE / Chapter 1. --- Introduction / Review of the reported methods --- p.15 / Determination of aluminium and iron with / 8-hydroxyquinoline --- p.18 / Chapter 2. --- Experimental --- p.21 / Chapter 3. --- Results and discussion / Determination of iron --- p.28 / Determination of aluminium --- p.38 / Chapter 4. --- Conclusion --- p.52 / REFERENCES --- p.53 / Chapter CHAPTER IV. --- RAPID DETERMINATION OF CALCIUM OXIDE / Chapter 1. --- Introduction --- p.56 / Chapter 2. --- Experimental --- p.62 / Chapter 3. --- Results and discussion --- p.66 / Chapter 4. --- Conclusion --- p.79 / REFERENCES --- p.80 / FIGURES / Chapter II-1 --- Attenuation of a beam of radiation by an absorbing solution --- p.8 / Chapter II-2 --- Gaussian curve and its first to fourth derivatives --- p.11 / Chapter III-l --- Effect of pH on the extraction of metals with8- hydroxyquinoline --- p.19 / Chapter III-2 --- "Normal absorbance spectra of the metal - oxinates: A1 (5ppm), Fe (5ppm)" --- p.20 / Chapter III-3 --- Effect of pH on the determination of iron (5ppm) --- p.29 / Chapter III-4 --- Calibration curve for the determination of iron (III) by spectrophotometry at 580 nm --- p.33 / Chapter III-5 --- "The first derivative spectra of metal-oxinates A1: 5ppm, Fe : 5ppm" --- p.39 / Chapter III-6 --- "The second derivative spectra of metal-oxinates, A1: 5ppm, Fe : 5ppm" --- p.39 / Chapter III-7 --- "Normal absorption spectra of the metal-oxinates : A1(5 ppm), Ti (5 ppm)" --- p.41 / Chapter III-8 --- Effect of pH on the determination of aluminium --- p.43 / Chapter III-9 --- Calibration curve for the determination of aluminium by second derivative spectrophotometry at 390 nm --- p.47 / Chapter IV-1 --- "Effect of pH on the development of colour of Ca- GBHA complex. Ca : 1.2 ppm, wavelength : 530 nm" --- p.68

by Wong Chi Kin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 131-133). / Acknowledgement / Abstract --- p.1 / General introduction --- p.4 / Part I Determination of Some Minor Elements in Cement by Energy Dispersive X-Ray Fluorescence Spectrometry / Introduction --- p.7 / Experimental --- p.14 / Results and discussions --- p.18 / Part II Determination of Mercury in Water by Static Cold Vapour Atomic Absorption Spectrometry / Introduction --- p.78 / Experimental --- p.84 / Results and discussions --- p.89 / Conclusion --- p.130 / References --- p.131

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