Thesis (M.P.H.)--University of Michigan, 1943.

Thesis (M.P.H.)--University of Michigan, 1943.

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Thesis (M.S.)--University of Michigan, 1949.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xiii, 104 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 70-73).

Soluções de nitrato de prata são freqüentemente usadas em testes de micro e nanoinfiltração, apesar de nem todas as suas características estarem definidas claramente na literatura. Neste estudo foram avaliadas soluções aquosas de nitrato de prata quanto ao pH e à quantidade de prata iônica (ppm) em várias concentrações, bem como o desempenho dessas soluções em testes de microinfiltração realizados em dentes decíduos e permanentes. Numa primeira fase foi analisado o pH (pHmetro digital) de solução a 50% (p/v), tendo como variáveis a pureza da água, a marca comercial do sal, a cor do frasco, e a idade pós-preparo. Posteriormente, avaliou-se a quantidade de prata iônica, por espectrometria de emissão atômica, presente nas soluções (1%, 5%, 25% e 50%) ao longo de 168 horas de armazenagem. Em cavidades de classe V, confeccionadas nas faces vestibular e lingual/palatina de molares, foram aplicados dois sistemas adesivos (OptiBond FL ou OptiBond Solo Plus SE). Após a restauração (Filtek Z-250) foi determinado o valor médio de microinfiltração (mm) para diversas concentrações e idade pós-preparo das soluções. Os dados obtidos foram tratados por análise de variância e teste de Tukey (a=0,05). As soluções analisadas na primeira etapa apresentaram pH médio entre 7,9±2,2 a 11,8±0,9, e houve diferenças significativas para todas as variáveis. O teor médio de prata iônica apresentou diferenças significativas para o fator Concentração (4,75±0,5 a 1% e 293±15,3ppm a 50%); porém, não houve diferença para o fator Idade. Nos testes de microinfiltração houve diferença significante apenas para o fator Adesivo (p<0,01); os demais fatores e as interações não apresentaram diferenças significativas. Com base nos resultados obtidos neste estudo pode-se concluir que: 1) o pH de soluções aquosas de nitrato de prata varia de neutro a alcalino; 2) a quantidade de prata iônica e o pH se mantêm estáveis por até 168h; 3) a concentração e a idade pós-preparo das soluções não interferiram nos valores médios de microinfiltração; 4) o sistema adesivo OptiBond FL apresentou menores valores de microinfiltração, em dentes permanentes e decíduos / Silver nitrate solutions are frequently used in micro and nanoleakage tests, although not all of their characteristics are clearly defined in the literature. In this study an assessment was made of aqueous silver nitrate solutions as regards pH and the amount of ionic silver (ppm) in various concentrations, as well as the performance of these solutions in microleakage tests performed in primary and permanent teeth. In the first phase the pH (digital pH meter) of a 50% (w/v) solution was analyzed, having water purity, commercial brand of the salt, the color of the flask, and the storage time as variables. Afterwards, the amount of ionic silver present in the solutions (1%, 5%, 25% and 50%) was evaluated by atomic emission spectrometry, throughout 168 hours of storage. In Class V cavities made on the vestibular and lingual/palatal faces of molars, two adhesive systems were applied (OptiBond FL or OptiBond Solo Plus SE). After restoration (Filtek Z-250) the mean microleakage value (mm) was determined for the various concentrations and post-preparation time of the solutions. The data obtained were submitted to analysis of variance and the Tukey test (a=0.05). The solutions analyzed in the first stage had a mean pH ranging between 7.9±2.2 and 11.8±0.9, and there were significant differences for all the variables. The mean ionic silver content presented with significant differences for the factor Concentration (4.75±0.5 at 1% and 293±15.3 ppm at 50%); but there was no difference for the factor Time. In the microleakage tests there was significant difference only for the factor Adhesive (p<0.01); the other factors and the interactions did not present with any significant differences. Based on the results obtained in this study, it may be concluded that: 1) the pH of aqueous silver nitrate solutions varies from neutral to alkaline; 2) the amount of ionic silver and pH remained stable for up to 168h; 3) the concentration and the post-preparation time of the solutions did not interfere with the mean microleakage values; 4) the adhesive system OptiBond FL presented with the lowest microleakage values in both permanent and primary teeth

Orientador: Mario Fernando de Goes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-06T08:38:04Z (GMT). No. of bitstreams: 1 Salvio_LucianaAndrea_D.pdf: 9815435 bytes, checksum: 9c80659f327995fb1aab0fb6244ecb67 (MD5) Previous issue date: 2006 / Resumo: O objetivo foi avaliar a resistência da união e qualidade de camada híbrida de acordo com o modo de interação de diferentes sistemas adesivos com a dentina. Para a avaliação da resistência da união à tração foram utilizados sete terceiros molares humanos hígidos, os quais foram submetidos cortes perpendiculares ao longo eixo do dente para obtenção de superfícies planas de dentina média. Estas foram secionadas em quatro partes iguais, por dois cortes perpendiculares entre si. Os sistemas de ¿passo único¿ Adper Prompt (ADP) e Xeno III (XE); de ¿dois passos¿ Clearfil SE Bond (SE) e Adhe SE (ADSE); e o Single Bond (SB) foram aplicados sobre as superfícies dentinárias seguindo as instruções dos fabricantes. Sobre a dentina tratada foi construído um bloco de resina composta (Filtek Z250, 3M/ESPE) com 5 mm de altura. Após 24 h, cada espécime foi secionado de modo a obter espécimes com formato de ¿palito¿ com área média de 1mm2 para a realização do teste de tração. Os padrões de fratura foram examinados em microscopia eletrônica de varredura (MEV). Os valores foram submetidos à análise da variância e ao teste Tukey (p<0,05). Para a avaliação da qualidade de camada híbrida foram utilizados 15 terceiros molares, dos quais, através de cortes perpendiculares ao longo eixo, foram obtidas duas superfícies planas e adjacentes de dentina média por dente. Sobre estas duas superfícies adjacentes, foi aplicado o mesmo sistema adesivo. A seguir, entre as superfícies hibridizadas foi aplicada uma resina de baixa viscosidade de modo a uni-las formando um bloco composto por dentina-resina-dentina após a polimerização. Decorridas 24h cada bloco foi cortado no sentido mésio-distal criando 12 interfaces por adesivo; 4 interfaces foram submetidas à técnica de pigmentação com nitrato de prata amoniacal; 4 à técnica de pigmentação com metenamina de prata; e 2 serviram de controle. Todas as interfaces foram observadas sob MEV. As médias de resistência de união, em MPa, foram: SE (51,48 ± 15,24); ADSE (37,08 ± 12,55); XE (36,24 ± 11,95); SB (26,20 ± 4,39) e ADP (24,92 ± 6,17). Houve predominância de fraturas do tipo mista entre adesivo e camada híbrida para SB, ADSE e XE; e fratura coesiva na camada de adesivo para SE e ADP. Em relação à qualidade de camada híbrida, SB mostrou maior intensidade na deposição de grãos de prata metálica na camada híbrida quando comparado aos outros sistemas. SE e ADSE apresentaram deposições de grãos de prata metálica semelhantes entre si e em menor intensidade comparada com os demais grupos. XE e ADP mostraram quantias moderadas de grãos prata metálica na camada híbrida e, diferentemente dos demais, dentro da camada de adesivo. Áreas de nanoinfiltração no interior da interface de união puderam ser identificadas tanto pela solução de nitrato de prata amoniacal como também pela solução de metenamina de prata. De acordo com o modo de interação dos sistemas adesivos com a dentina há formação de diferentes padrões de camada híbrida que, provavelmente, infuenciou nos valores de resistência de união / Abstract: This study evaluated the bond strength and hybrid layer formation between different adhesive systems and dentine. To evaluate the bond strength, seven molars fresh extracted were sectioned in multiple parallel layers. The middle dentine layers were selected and sectioned into four equal pieces perpendicular to the previous sections. The ¿one step¿ self-etching adhesive systems Adper Prompt (ADP) and XENO III (XE); the ¿two steps¿ self-etching adhesive systems Clearfil SE Bond (SE) and Adhe SE (ADSE) and the ¿total-etch¿ adhesive Single Bond (SB) were applied on dentine surfaces according to the manufactures¿ instructions. A block of resin (Filtek Z250, 3M/ESPE) of 5 mm height was built in three increments, each one light cured for 20 seconds, on the treated dentine. The specimens were stored in 37°C distilled water for 24h and then sectioned in X and Y directions to obtain 1 mm2 area sticks. The sticks were submitted to a microtensile bond strength test in a universal testing machine (Instron 4411) at a crosshead speed of 0.5mm/min. The results were submitted to one-way analysis of variance and Tukey¿s test at a 5% level of significance. To evaluate the hybrid layer, 15 third molars were used. Two adjacent flat surfaces of middle dentine were obtained for each tooth. The same adhesive system was applied on these two adjacent surfaces, which were applied according to manufacturers' instructions. A resin ¿sandwich¿ block of dentine/resin/dentine was made filling the two adjacent slices with a low viscosity resin, which was polymerized for 20s. After 24 h, each block was mesio-distally sectioned producing 12 interfaces per adhesive. Four interfaces were stained with ammoniacal silver nitrate solution and 4 with silver methenamine solution. The other four were kept without stain and used as a control group. All the interfaces were observed under SEM. The bond strength means, in MPa, were: SE (51.48 ± 15.24); ADSE (37.08 ± 12.55); XE (36.24 ± 11.95); SB (26.20 ± 4.39) and ADP (24.92 ± 6.17). There was prevalence of mixed failure between adhesive and hybrid layer for SB, ADSE and XE; and prevalence of cohesive failure in the adhesive layer for SE and ADP. According to the hybrid layer, SB showed a greater intensity of silver grains deposition than the other systems. SE and ADSE presented similar silver grains depositions but in a small quantity. XE and ADP differing from the others, not only showed moderate amounts of silver grains in the hybrid layer, but also inside the adhesive layer. It was possible to identify nanoleakage inside the bond interface with both used stains. According to the interactions of the adhesive systems with dentine, there were different hybrid layer patterns, which may influence the bond strength / Doutorado / Materiais Dentarios / Doutor em Materiais Dentários

Soluções de nitrato de prata são freqüentemente usadas em testes de micro e nanoinfiltração, apesar de nem todas as suas características estarem definidas claramente na literatura. Neste estudo foram avaliadas soluções aquosas de nitrato de prata quanto ao pH e à quantidade de prata iônica (ppm) em várias concentrações, bem como o desempenho dessas soluções em testes de microinfiltração realizados em dentes decíduos e permanentes. Numa primeira fase foi analisado o pH (pHmetro digital) de solução a 50% (p/v), tendo como variáveis a pureza da água, a marca comercial do sal, a cor do frasco, e a idade pós-preparo. Posteriormente, avaliou-se a quantidade de prata iônica, por espectrometria de emissão atômica, presente nas soluções (1%, 5%, 25% e 50%) ao longo de 168 horas de armazenagem. Em cavidades de classe V, confeccionadas nas faces vestibular e lingual/palatina de molares, foram aplicados dois sistemas adesivos (OptiBond FL ou OptiBond Solo Plus SE). Após a restauração (Filtek Z-250) foi determinado o valor médio de microinfiltração (mm) para diversas concentrações e idade pós-preparo das soluções. Os dados obtidos foram tratados por análise de variância e teste de Tukey (a=0,05). As soluções analisadas na primeira etapa apresentaram pH médio entre 7,9±2,2 a 11,8±0,9, e houve diferenças significativas para todas as variáveis. O teor médio de prata iônica apresentou diferenças significativas para o fator Concentração (4,75±0,5 a 1% e 293±15,3ppm a 50%); porém, não houve diferença para o fator Idade. Nos testes de microinfiltração houve diferença significante apenas para o fator Adesivo (p<0,01); os demais fatores e as interações não apresentaram diferenças significativas. Com base nos resultados obtidos neste estudo pode-se concluir que: 1) o pH de soluções aquosas de nitrato de prata varia de neutro a alcalino; 2) a quantidade de prata iônica e o pH se mantêm estáveis por até 168h; 3) a concentração e a idade pós-preparo das soluções não interferiram nos valores médios de microinfiltração; 4) o sistema adesivo OptiBond FL apresentou menores valores de microinfiltração, em dentes permanentes e decíduos / Silver nitrate solutions are frequently used in micro and nanoleakage tests, although not all of their characteristics are clearly defined in the literature. In this study an assessment was made of aqueous silver nitrate solutions as regards pH and the amount of ionic silver (ppm) in various concentrations, as well as the performance of these solutions in microleakage tests performed in primary and permanent teeth. In the first phase the pH (digital pH meter) of a 50% (w/v) solution was analyzed, having water purity, commercial brand of the salt, the color of the flask, and the storage time as variables. Afterwards, the amount of ionic silver present in the solutions (1%, 5%, 25% and 50%) was evaluated by atomic emission spectrometry, throughout 168 hours of storage. In Class V cavities made on the vestibular and lingual/palatal faces of molars, two adhesive systems were applied (OptiBond FL or OptiBond Solo Plus SE). After restoration (Filtek Z-250) the mean microleakage value (mm) was determined for the various concentrations and post-preparation time of the solutions. The data obtained were submitted to analysis of variance and the Tukey test (a=0.05). The solutions analyzed in the first stage had a mean pH ranging between 7.9±2.2 and 11.8±0.9, and there were significant differences for all the variables. The mean ionic silver content presented with significant differences for the factor Concentration (4.75±0.5 at 1% and 293±15.3 ppm at 50%); but there was no difference for the factor Time. In the microleakage tests there was significant difference only for the factor Adhesive (p<0.01); the other factors and the interactions did not present with any significant differences. Based on the results obtained in this study, it may be concluded that: 1) the pH of aqueous silver nitrate solutions varies from neutral to alkaline; 2) the amount of ionic silver and pH remained stable for up to 168h; 3) the concentration and the post-preparation time of the solutions did not interfere with the mean microleakage values; 4) the adhesive system OptiBond FL presented with the lowest microleakage values in both permanent and primary teeth

A COMPARISON OF THE ANTIMICROBIAL EFFICACY OF SILVER DIAMINE FLUORIDE AND SILVER NITRATE: AN IN VITRO STUDY By: Nicholas L Luke, D.D.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University, May 2018 Thesis Advisor: William O. Dahlke Jr., D.M.D. Pediatric Dentistry, Department Chair Purpose: To determine the antimicrobial efficacy of SDF and SN/NaF. Methods: Three bacterial species were combined to create an in vitro biofilm. Treatment was completed with SN, SN/NaF, SDF, SDF½ or untreated (control). Results: The untreated group demonstrated significantly higher growth than all other treatment groups across the study. On the BHI-plates (1-day), there were significant differences between all treatments except SDF and SDF½. On the BHI-plates (3-days), SN/NaF was not significantly different from SDF or SDF½. On the L-MRS-plates (1-day), both SN treatment groups yielded significantly higher growth than the SDF groups. On the L-MRS-plates (3-days), SN yielded significantly higher growth than SN/NaF, SDF, and SDF½. Conclusion: SDF is more effective than SN/NaF, with the exception of BHI-plates (3-days) only and SN/NaF is more effective than SN on primarily S. mutans and L. acidophilus. There is evidence of a possible antimicrobial tolerance of oral bacteria to silver.

Chitosan membrane has found applications in biomedical, wastewater treatment, and petrochemical fields that involve the use of silver ions (Ag+). However, mobility of Ag+ in chitosan membranes has seldom been studied. In this study, transport properties of Ag+ in chitosan membranes are studied in-depth, to determine diffusivity coefficient, permeability coefficient, and sorption uptake of Ag+ in chitosan. All parameters are evaluated based on the influence of feed concentration, membrane thickness and operating temperature. The diffusivity is determined from the time lag obtained from transient diffusion experiments. The permeability is determined from the steady state of permeation experimentally. The diffusivity and corresponding permeability coefficients of Ag+ in chitosan range from to 2.0 10-7 (cm2/s) and from 6.6 10-8 to 2.0 10-7 {mol m/[m2 s (mol/L)]}, respectively, over the conditions tested. Temperature dependencies of these two parameters are found to follow the Arrhenius relationship. Sorption uptake of the silver salt in chitosan correlates well with the Langmuir isotherm. Also determined from the sorption tests are degree of membrane swelling at different concentrations. This information allows diffusivity coefficients to be determined from the steady state permeation rate. These values of diffusivity are compared with that obtained using the time lag method.