Thesis--University of Rochester, 1965.

Thesis (M.S.)--University of Michigan, 1999. / Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1970.

Thesis--University of Rochester, 1965.

Os adesivos são produtos capazes de manter materiais unidos, mediante ligações entre as superfícies. Selantes são produtos capazes de manter preenchido um espaço entre duas superfícies, por meio de uma barreira que se configura como uma ponte entre as duas superfícies. O mastic é um produto obtido por uma mistura de substâncias tendo como principal polímero o butil, com consistência de uma massa não secativa que pode ser utilizada como selante. Os polisiloxanos, também conhecidos como silicones são os mais importantes polímeros sintéticos com estrutura inorgânica, e são matrizes dos adesivos selantes de silicone. Para comprovar como o comportamento das forças de adesão destes produtos acontece, foram utilizadas cinco técnicas diferenciadas. Estes produtos foram submetidos a duas condições distintas para verificar o comportamento da adesão, um em condições ambiente e outro sob influência de radiação ionizante. Os resultados obtidos demonstraram não só a diferença entre produtos (silicone e mastic), mas também que as forças de adesão têm comportamentos diferentes nas condições às quais foram submetidas às amostras. Com isto atingi-se o objetivo desse estudo que é apresentar a diferenciação entre o mastic e o silicone, muitas vezes considerados como um só produto denominado mastic. Desta forma comprova-se que: 1. o silicone pode ser considerado um adesivo selante em condições ambientes, 2. o mastic melhora consideravelmente sua adesão, quando submetido à radiação ionizante, e esta característica de adesão pode ser uma excelente alternativa para o mercado de adesivos. / Adhesives are products that can keep materials together by bonds between the surfaces. Sealants are products that can keep filled a space between two surfaces, through a barrier that is configured as a \"bridge\" between the two surfaces. The mastic is a product made of a mixture of substances with the primary butyl polymer, with the consistency of a mass not dried that can be used as a sealant. The polysiloxane, also known as silicone are the most important synthetic polymers with inorganic structure, and are matrices of silicone adhesive sealants. To demonstrate the behavior of the adhesive forces of these products under different conditions, we used five different techniques. These products were subjected to two different conditions to verify the behavior of adhesion, one at the environmental condition and another under the ionizing radiation. The results showed not only differences between products (silicone and mastic), but also that the adhesive forces have different behaviors under the conditions which the samples were subjected. With this was reached the goal of this study that aspired show the differences between the mastic and silicone, this last one is often considered - erroneously - the same as mastic. Thus it was proven that: 1. silicone can be regarded as an adhesive and a sealant at ambient conditions, 2. mastic improves substantially adhesion in an environment of ionizing radiation and this property can be an excellent alternative to the adhesive market.

Indiana University-Purdue University Indianapolis (IUPUI) / Objective: The objective was to assess a multiple emission peak light-emitting-diode (LED) light-curing unit (LCU) by measuring the polymerization efficiency through the degree of conversion (DC) and Knoop microhardness (KHN) of a resin-based pit and fissure sealant at various light curing times and two distances compared to a single emission peak LED LCU. Method: Sixty disks of resin-based pit and fissure sealant (Delton, DENTSPLY, York, PA) samples (6x1mm) were fabricated (n=5/LCU/group). Prepared samples were polymerized using 10, 20 and 40 second curing time at 2 or 4 mm curing distances. The irradiance and radiant exposure received on the top/bottom surfaces of the samples were measured using the Managing Accurate Resin Curing-Resin Calibrator (MARC-RC) system. The samples were stored at 37°C for one hour. Then, the DC (n=3/surface) and KHN (n=5/surface) measurements were collected on the top and bottom surfaces using Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and a microhardness tester (Instron) utilizing 25-gm at 10 seconds dwell time, respectively. Multiple-way ANOVA was performed followed by Tukey test (α=0.05). Result: The irradiance from the multiple emission peak LED LCU was significantly higher than the single emission peak LED LCU (1312.6 and 768.3 mW/cm2) respectively. Moreover, the multiple emission peak LED LCU displayed significantly higher DC (82.5%) and microhardness (26.2 KHN) compared to the single emission peak LED LCU (75.5% DC and 21.2 KHN) when curing samples at 2 and 4 mm curing distances assessed using 10, 20 and 40-second curing times. The 10 second cure at 4 mm showed significantly lower DC and KHN values compared to the other groups. Conclusion: The multiple emission peak LED LCU demonstrated significantly higher irradiance, DC and KHN compared to the single emission peak LED LCU on a resin-based pit and fissure sealant at 2 and 4 mm curing distances and 10, 20 and 40 second curing times. Therefore, the multiple emission peak LED LCU performed higher than the single emission peak LED LCU.

Indiana University-Purdue University Indianapolis (IUPUI) / The concepts of using a pit and fissure sealant material to prevent dental caries have been well established in dental research. Effectiveness of a pit and fissure sealant material is limited to its ability to remain bonded to the occlusal surfaces. Adding a dentin-bonding agent between the etched enamel and the sealant material has been demonstrated as a way of optimizing bond strength in the face of moisture and salivary contamination. The purpose of this study was to examine if there was a difference in fissure penetration or microleakage between a conventional pit and fissure sealant or a flowable composite when used as a pit and fissure sealant, while using three different adhesive systems. Delton Direct Delivery System (Dentsply), an opaque, light cured pit and fissure sealant and the commercially available flowable composite, Revolution Formula 2 (Kerr) was selected for this study. Three clinically used adhesive systems selected for this study were: conventional phosphoric acid etching; Opti-bond Solo Plus(Kerr), a single bottle system; and Prompt L-Pop (3M ESPE), an all-in-one primer adhesive. One hundred fifty extracted caries-free third molars, selected for well-defined occlusal pits, were randomly divided into six treatment groups. Fissure penetration and microleakage was examined after immersion of the treated teeth in 5.0-percent methylene blue solution for 18 hours; the teeth were removed and thoroughly cleaned. Mesial and distal flat-ground sections were obtained and examined at X20; microleakage was recorded as either present or absent, and penetration was recorded as either complete or incomplete. The interaction between the material and the adhesive system was non-significant based on the logistic regression model for the penetration and the microleakage, so that only the main effects of material and adhesive system were included in the final model. Enamel conditioning with the total-etch and single-bottle adhesive system provided consistently microleakage resistance when compared with the use of the all-in-one bonding system. The all-in-one adhesive system demonstrated the most microleakage regardless of the material used for the pit and fissure sealant. The hypothesis of this thesis was that there would be no significant difference in fissure penetration or microleakage between the conventional pit and fissure sealant or the flowable composite, regardless of the adhesive system used. The results of this study support the hypothesis that there was no significant difference in fissure penetration between the materials. The result did demonstrate that there was significant difference in microleakage between the three different adhesive systems used.

Indiana University-Purdue University Indianapolis (IUPUI) / The concepts of using a pit and fissure sealant material to prevent dental caries have been well established in dental research. Effectiveness of a pit and fissure sealant material is limited to its ability to remain bonded to the occlusal surfaces . Adding a dentin-bonding agent between the etched enamel and the sealant material has been demonstrated as a way of optimizing bond strength in the face of moisture and salivary contamination. The purpose of this study was to examine if there was a difference in fissure penetration or microleakage between a conventional pit and fissure sealant or a flowable composite when used as a pit and fissure sealant, while using three different adhesive systems. Delton Direct Delivery System (Dentsply), an opaque, light cured pit and fissure sealant and the commercially available flowable composite, Revolution Formula 2 (Kerr) was selected for this study. Three clinically used adhesive systems selected for this study were: conventional phosphoric acid etching; Opti-bond Solo Plus(Kerr), a single bottle system; and Prompt L-Pop (3M ESPE), an all-in-one primer adhesive. One hundred fifty extracted caries-free third molars, selected for well-defined occlusal pits, were randomly divided into six treatment groups. Fissure penetration and microleakage was examined after immersion of the treated teeth in 5.0-percent methylene blue solution for 18 hours; the teeth were removed and thoroughly cleaned. Mesial and distal flat-ground sections were obtained and examined at X20; micro leakage was recorded as either present or absent, and penetration was recorded as either complete or incomplete. The interaction between the material and the adhesive system was non-significant based on the logistic regression model for the penetration and the microleakage, so that only the main effects of material and adhesive system were included in the final model. Enamel conditioning with the total-etch and single-bottle adhesive system provided consistently microleakage resistance when compared with the use of the all-in-one bonding system. The all-in-one adhesive system demonstrated the most microleakage regardless of the material used for the pit and fissure sealant. The hypothesis of this thesis was that there would be no significant difference in fissure penetration or microleakage between the conventional pit and fissure sealant or the flowable composite, regardless of the adhesive system used. The results of this study support the hypothesis that there was no significant difference in fissure penetration between the materials. The result did demonstrate that there was significant difference in microleakage between the three different adhesive systems used.

Thesis (M.S.D.)--Indiana University School of Dentistry, 2009. / Title from PDF t.p. (viewed Feb. 5, 2010) Advisor(s): Michael A. Cochran, Chair of the Research Committee, Armando E. Soto Rojas, Margherita R. Fontana, Timothy Carlson, Tien-Min Gabriel Chu. Curriculum vitae. Includes abstract. Includes bibliographical references (leaves 56-61).

Since 2006, research funded by the Texas Department of Transportation (TxDOT) has evaluated the use of coatings and sealers for mitigating expansion due to alkali-silica reaction (ASR) and/or delayed ettringite formation (DEF) in hardened concrete. The report herein includes a project summary of previous work in Phase I, led by Racheal Lute (2008) and Charles Rust (2009). The Phase II research, described in this thesis, established concrete exposure blocks and NCHRP 244 Series II testing as the cornerstones of characterizing coating effectiveness. The studies assessed coating system performance by examining the contribution of steel reinforcement, the effects of aggregate reactivity, the size limitations of treatments, and the impact of painted concrete substrates. Lastly, this thesis describes the preliminary results of a field study site of columns supporting a flyover, and a concrete exposure block site in Houston, Texas. Overall, the results are encouraging as several coatings have reduced expansion by lowering internal relative humidity.