Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 64-69).

Thesis (M.D.S.)--University of Hong Kong, 1995. / Includes bibliographical references (leaf 89-107).

Thesis (M.D.S.)--University of Hong Kong, 1995. / Includes bibliographical references (leaf 89-107). Also available in print.

Made available in DSpace on 2014-06-11T19:33:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-31Bitstream added on 2014-06-13T20:44:35Z : No. of bitstreams: 1 ricci_ha_dr_arafo.pdf: 2721593 bytes, checksum: 4217c4bca9ee0836b6bc0623a2ea8400 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo geral deste trabalho, o qual foi dividido em três estudos, foi avaliar o efeito da clorexidina (CLX) em diferentes excipientes, etanol e água, na produção e estabilidade mecânica da união resina-dentina afetada por cárie. Materiais e Métodos. No primeiro estudo foi avaliada a influência da CLX em solução aquosa ou alcoólica na umectabilidade da dentina hígida e afetada por cárie por um sistema adesivo. Foram preparadas superfícies planas de dentina em 100 terceiros molares hígidos, das quais 50 foram submetidas ao processo microbiológico de indução de cárie. Dentro de cada condição de substrato, hígido e afetado por cárie, as superfícies foram divididas em 5 grupos (n=10): com smear layer (SL), sem smear layer impregnada com água, sem smear layer impregnada com CLX em água, sem smear layer impregnada com etanol e sem smear layer impregnada com CLX em etanol. Ângulos de contato entre a superfície de dentina e o sistema adesivo Single Bond 2 foram mensurados por meio de um goniômetro, e os dados submetidos aos testes de ANOVA e Tukey ( =0,05). No segundo estudo foi avaliado o efeito da solução de CLX em diferentes excipientes, etanol ou água, na presença de colágeno exposto na união resina-dentina hígida e dentina afetada por cárie. Foram produzidas superfícies planas de dentina em 24 molares humanos hígidos, sendo metade delas cariadas artificialmente. Os dentes foram divididos em 8 grupos (n=3) segundo o tratamento da dentina após o condicionamento ácido (CLX associada a etanol, CLX associada a água, somente etanol ou somente água) e segundo o tipo de substrato utilizado para a adesão. Espécimes foram produzidos de cada dente e preparados histologicamente para coloração com tricrômico de Goldner. A zona de colágeno exposta (ZC) foi quantificada (μm) em... / Purpose. The overall purpose of this work, divided into three studies, was to evaluate the effect of chlorhexidine (CHX) in different excipients, ethanol and water, on the production and mechanical stability of resin-caries affected dentin bonds. Materials and Methods. In the first study, it was evaluated the influence of aqueous and alcoholic solution of CHX on the wettability of noncarious and caries-affected dentin by an adhesive system. Flat dentin surfaces (n=100) were produced, and 50 were submitted to a biological method of artificial caries induction. Within each type of substrate, noncarious and caries-affected dentin, the surfaces were divided into 5 groups (n=10): with smear layer, smear layer-free impregnated with water, smear layer-free impregnated with CHX in water, smear layer-free impregnated with ethanol and smear layer-free impregnated with CHX in ethanol. Contact angles between the dentin surface and the adhesive system Single Bond Plus were measured by using a goniometer and the data were submitted to ANOVA and Tukey tests ( =0.05). In the second study, it was evaluated the effect of CHX in different excipients, ethanol or water, on the collagen exposure in interfaces produced on noncarious and caries-affected dentin. Flat dentin surfaces were prepared in 24 noncarious human molars, and half of them were artificially decayed. The surfaces were divided into 8 groups (n=3) according to the treatment of the dentin after its conditioning with phosphoric acid (CHX in ethanol, CHX in water, water and ethanol) and to the type of substrate used for the adhesive procedures. Specimens were produced from each tooth and histologically prepared to be stained by Goldner’s trichrome. The zone of exposed collagen (CZ) was quantified (μm) under a light microscope and the data submitted to... (Complete abstract click electronic access below)

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No. of bitstreams: 1 vieira_apm_me_araca_int.pdf: 1718785 bytes, checksum: f8a4ee381763d62564106bf81536ad0b (MD5) Previous issue date: 2018-02-23 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Objetivo: Este estudo sintetizou um novo nanosistema carreador de clorexidina (CLX) baseado em nanopartículas magnéticas de óxido de ferro (NMOFs) e quitosana (QS), e avaliou seu efeito antimicrobiano sobre biofilmes de Candida albicans e Streptococcus mutans: Metodologia: O nanosistema NMOFs-QS-CLX foi preparado pela interação de CLX sobre NMOFs revestidas com QS, e caracterizado por difração de raios X, espectroscopia de absorção na região do infravermelho médio com transformada de Fourier, microscopia eletrônica de transmissão e dispersão dinâmica de luz. A concentração inibitória mínima (CIM) do nanosistema NMOFs-QS-CLX capaz de inibir as cepas no estado planctônico foi determinada de acordo com o método de microdiluição em caldo. Na sequência, biofilmes simples e mistos de C. albicans e S. mutans foram formados durante 24 horas em poços de placas de 96 poços na presença do nanosistema contendo CLX a 39 (NMOFs-QS-CLX39) ou 78 μg/mL (NMOFs-QS-CLX78). Ainda, biofilmes pré-formados (24 horas) foram tratados durante 24 horas com o nanosistema nas mesmas concentrações. O efeito antibiofilme foi avaliado através da contagem do número de células cultiváveis, quantificação da biomassa total e avaliação da atividade metabólica. Controles apropriados foram incluídos em todas as análises. Os dados foram analisados pelo teste de Kruskal-Wallis e por ANOVA a um critério, seguidos dos testes Student-Newman-Keuls e Holm-Sidak, respectivamente (α = 0,05). Resultados: Os resultados de caracterização confirmaram a formação do nanosistema NMOFs-QS-CLX, sem alteração das propriedades cristalinas das NMOFs. Além disso, as bandas de absorção características de cada composto foram identificadas no espectro do infravermelho, e o diâmetro médio do nanosistema foi menor que 40 nm. Os resultados de CIM mostraram que o nanosistema foi ligeiramente mais efetivo do que a CLX na inibição do crescimento dos microrganismos testados. Biofilmes formados na presença do nanosistema NMOFs-QS-CLX39 atingiram patamares quantitativos similares àqueles observados para CLX a 78 µg/mL. Ainda, para os biofilmes simples e mistos, o nanosistema NMOFs-QS-CLX78 mostrou efeitos redutores superiores ou similares àqueles encontrados para CLX a 78 µg/mL e NMOFs-QS-CLX39. Conclusão: O nanosistema NMOFs-QS-CLX foi efetivo tanto na inibição da formação de biofilmes como sobre biofilmes pré-formados de C. albicans e S. mutans em culturas simples ou mistas. O desenvolvimento desse nanosistema instaura inúmeras possibilidades para exploração de terapias baseadas em nanopartículas magnéticas como carreadoras de drogas usadas na área médico-odontológica. / Aim: This study synthesized a new chlorhexidine(CHX)-carrier nanosystem based on iron oxide magnetic nanoparticles (IONPs) and chitosan (CS), as well as evaluated its antimicrobial effect on biofilms of Candida albicans and Streptococcus mutans. Method: The IONPs-CS-CHX nanosystem was prepared by CHX interaction to CS-coated IONPs and characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. Minimum inhibitory concentration (MIC) of the IONPs-CS-CHX nanosystem was determined according to the broth microdilution assay. After, mono- and dual-species biofilms of C. albicans and S. mutans were formed for 24 hours into wells of 96-well plates in the presence of the nanosystem containing CHX at 39 (IONPs-CS-CHX39) or 78 μg/mL (IONPs-CS-CHX78). Moreover, pre-formed biofilms (24 h) were treated for 24 h with the nanosystem at the same concentrations. The antibiofilm effect was determined by quantification of cultivable cells, total biomass and metabolic activity. Appropriate controls were included in all analyzes. Data were analyzed by Kruskal-Wallis’ test and one-way ANOVA, followed by Student-Newman-Keuls and Holm-Sidak tests (α = 0.05). Results: Characterization results confirmed the nanosystem formation without altering the crystalline properties of the IONPs. In addition, the characteristic absorption bands of each compound were identified in the infrared spectrum, and the mean diameter of the nanosystem was lower than 40 nm. MIC results showed that the nanosystem was slightly more effective than CLX in inhibiting the growth of the microorganisms tested. Biofilms formed in the presence of IONPs-CS-CHX39 attained similar quantitative levels to those observed for CHX at 78 μg/mL. Further, for mono- and dual-species biofilms, IONPs-CS-CHX78 showed similar or superior antibiofilm effects when compared with IONPs-CS-CHX39 and free CHX at 78 μg/mL. Conclusion: The IONPs-CS-CHX nanosystem was able to reduce biofilm formation and pre-formed biofilms of C. albicans and S. mutans in single or mixed cultures. The development of this nanosystem establishes several possibilities for exploration of magnetic nanoparticle-based therapy as drug carrier used in health area. / 16-18/404721

Orientador: Brenda Paula Figueiredo de Almeida Gomes / Dissertação (mestrado) - Universidade Estadual de Campinas. Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-15T12:19:46Z (GMT). No. of bitstreams: 1 Abi-Rached_GisellePriscillaCruz_M.pdf: 6457188 bytes, checksum: fd484fdf154af874fb1bd6317360f976 (MD5) Previous issue date: 2010 / Resumo: A limpeza e desinfecção do canal radicular são fundamentais para o sucesso do tratamento endodôntico. Para tanto, uma variada gama de substâncias químicas auxiliares e medicações intracanais são utilizadas em associação à instrumentação do sistema de canais radiculares. Acredita-se que a medicação intracanal deva ser removida completamente antes da obturação para que um selamento hermético seja alcançado. O objetivo desse estudo foi avaliar a eficiência do uso da clorexidina 2% gel (CHX), do NaOCl 1%, do EDTA 17% e do soro fisiológico (SS) na remoção das seguintes medicações intracanais: Ca(OH)2 + CHX e Ca(OH)2 + SS por meio da Microscopia Eletrônica de Varredura (MEV). Cento e vinte dentes extraídos foram utilizados nesse estudo. Os terços cervical e médio de cada canal foram preparados com lima rotatória e brocas de Gates-Glidden e o terço apical com limas manuais. Após sete dias, a medicação foi removida com instrumentação e uso de um dos protocolos testados. Um sistema de escore de 0 a 2 foi utilizado para avaliar a presença de hidróxido de cálcio nos terços cervical, médio e apical dos canais. Os dados foram submetidos à análise estatística e comparados pelo teste Kruskal-Wallis (p<0.05). Foram encontrados restos de medicamentos em todos os canais radiculares, independente da substância utilizada. Foi concluído que nenhuma das substâncias testadas avaliadas foi completamente eficiente na remoção da medicação intracanal. / Abstract: Cleaning and disinfection of the canal are important to the success of endodontic treatment. To this end a wide range of chemical auxiliary substances and intracanal medications are used in association with the instrumentation of the root canal system. It is believed that the temporary dressing should be completely removed before the root filling so that a hermetic sealing is achieved. The purpose of this study was to assess the efficiency of 2% chlohrexidine gel (CHX), 1% NaOCl, 17% EDTA and sterile saline (SS) in removing root canal dressings such as Ca(OH)2 + CHX, Ca(OH)2 + SS by scanning electron microscopy analysis (SEM). One hundred and twenty extracted teeth were used in this study. The cervical and middle thirds of each canal were prepared using rotary file and Gates-Glidden and the apical third was prepared with manual files. After seven days, the medicaments were removed by instrumentation and use with one of the tested protocols. A scoring system of 0 to 2 was used to assess the presence of calcium hydroxide on the cervical, middle and apical third of the canals. Data were subjected to statistical analysis using the Kruskal-Wallis test (p<0.05). Traces of medicament were found in all root canals, regardless the chemical substance used. It was concluded that none of the substances tested were completely efficient in removing the root canal dressing. / Mestrado / Endodontia / Mestre em Clínica Odontológica

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Durante um longo perÃodo de tempo, plantas tÃm sido avaliadas como fonte de produtos naturais para prevenÃÃo de doenÃas orais, especialmente cÃrie e doenÃa periodontal. A atividade antimicrobiana dessas plantas tem sido estudada para combater os microorganismos patogÃnicos da boca, dentre elas a Lippia sidoides Cham. Tendo em vista a cÃrie ser a principal doenÃa bucal que afeta crianÃas na idade escolar, deve-se encontrar uma forma segura e eficaz de prevenÃÃo desta doenÃa. O presente trabalho objetivou realizar um ensaio clÃnico randomizado, a partir de um estudo piloto, para avaliar a eficÃcia de trÃs diferentes formas farmacÃuticas, bochecho, gel e dentifrÃcio, do Ãleo essencial de Lippia sidoides Cham, frente a uma das principais bactÃrias relacionadas à doenÃa cÃrie: os Streptococcus mutans. A pesquisa foi realizada em trÃs fases: a primeira consistiu em um estudo piloto no qual 20 pacientes foram randomicamente distribuÃdos em quatro diferentes grupos, com 5 pacientes em cada grupo. O grupo I recebeu tratamento tÃpico com Lippia sidoides bochecho a 0,6%, o grupo II Lippia sidoides bochecho a 0,8%, o grupo III a 1% e o grupo IV usou bochecho a concentraÃÃo de 1,2%. A partir da melhor concentraÃÃo encontrada (0,8%) procedeu-se da mesma maneira com o gel de Lippia sidoides, tambÃm para se verificar a melhor concentraÃÃo (1,4%). A segunda fase do estudo consistiu de 100 crianÃas que foram divididas em cinco diferentes grupos, de forma randomizada. O grupo I recebeu tratamento tÃpico com Lippia sidoides bochecho, o grupo II Lippia sidoides gel, o grupo III clorexidina bochecho, o grupo IV recebeu clorexidina gel e o grupo V recebeu dentifrÃcio de Lippia sidoides. Tratando-se das formulaÃÃes bochecho e gel, a identificaÃÃo de cada substÃncia foi feita com letras de modo a nÃo saber qual antimicrobiano estava sendo aplicado. O paciente tambÃm desconhecia qual substÃncia estava sendo aplicada a ele, garantindo o estudo duplo-cego. Em cada um dos tratamentos com bochecho foram utilizados 5ml, durante 1 minuto, 1 vez ao dia, durante 5 dias consecutivos. Em cada tratamento com gel, foram utilizados 5ml, aplicados em moldeiras individuais por 4 minutos, 1 vez ao dia, durante 5 dias consecutivos. No tratamento com dentifrÃcio foi utilizada uma quantidade correspondente a um caroÃo de ervilha, durante 1 minuto, 1 vez ao dia, durante 5 dias consecutivos. A saliva de cada paciente foi coletada antes de se iniciar o tratamento (D1), no Ãltimo dia do tratamento (D5), 30 dias apÃs o dia 1 (D30), 60 dias apÃs o dia 1 (D60), 6 meses apÃs o inÃcio do tratamento (D180) e 1 ano apÃs o inÃcio do tratamento (D360), para se verificar a eficÃcia das formas farmacÃuticas de Lippia sidoides na reduÃÃo dos Streptococcus mutans. Antes do inÃcio do tratamento foi feito um exame por apenas um examinador atravÃs do mÃtodo visual/tÃtico para se calcular o nÃmero de superfÃcies cariadas, perdidas e obturadas (CPOS) para avaliar o aparecimento de novas lesÃes de cÃrie no decorrer de um ano apÃs o tratamento. A melhor formulaÃÃo encontrada foi o dentifrÃcio, embora quando todas as formulaÃÃes foram comparadas à clorexidina, esta demonstrou possuir maior eficÃcia na reduÃÃo de Streptococcus mutans. Isso nos levou a concluir que o problema poderia estar relacionado ao nÃmero de aplicaÃÃes insuficientes (apenas 1 vez ao dia). Logo, deu-se inÃcio à terceira fase do estudo, que consistiu nos mesmos princÃpios descritos anteriormente, porÃm foram selecionadas apenas 20 crianÃas com cÃrie, que foram submetidas à aplicaÃÃo de dentifrÃcio de Lippia sidoides durante 1 mÃs, com escovaÃÃo 3 vezes ao dia. Outras 20 crianÃas, tambÃm com cÃrie, foram selecionadas para fazerem escovaÃÃo com pasta fluoretada comum, pelo mesmo perÃodo, com o mesmo nÃmero de escovaÃÃes diÃrias. Todas as crianÃas receberam instruÃÃo de higiene de forma padronizada, para que as escovaÃÃes feitas no domicÃlio se aproximassem ao mÃximo da maneira a qual foi estabelecida. A melhor eficÃcia na reduÃÃo dos Ãndices de Streptococcus mutans foi observada no grupo do dentifrÃcio de Lippia sidoides em relaÃÃo ao grupo que utilizou a pasta comum. NÃo foram relatados efeitos colaterais, pelo contrÃrio, alguns responsÃveis relataram melhora no hÃlito das crianÃas que utilizaram o dentifrÃcio de alecrim. Esses dados indicam que a planta estudada pode servir como uma alternativa de baixo custo e culturalmente aceitÃvel para a prevenÃÃo da cÃrie em crianÃas de 6 a 12 anos quando utilizada 3 vezes ao dia na forma de dentifrÃcio. / During a long period of time, plants have been evaluated as a source of natural products for prevention of oral diseases, especially caries and periodontal disease. The antimicrobial activity of these plants has been studied to combat pathogenic microorganisms of the mouth, among them the Lippia sidoides Cham. Considering that caries are the main oral disease affecting children at school age, it is necessary to find a safe and effective prevention of this disease. This study aimed to conduct a randomized clinical trial, from a pilot study to evaluate the effectiveness of three different dosage forms, rinses, gels and toothpaste, essential oil of Lippia sidoides Cham, facing one of the major bacteria-related disease caries: Streptococcus mutans. The survey was conducted in three phases: the first consisted of a pilot study in which 20 patients were randomly assigned to four different groups, with 5 patients in each group. Group I was treated with topical Lippia sidoides mouthrinse with 0.6%, group II Lippia sidoides mouthrinse to 0.8%, group III at 1% and group IV used mouthwash concentration of 1.2%. From the best dosage (0.8%) proceeded in the same way with the gel Lippia sidoides, also to study the best concentration (1.4%), this concentration was also used for toothpaste. The second phase of the study consisted of 100 children who were divided into five different groups at random. Group I was treated with topical Lippia sidoides mouthrinse, group II Lippia sidoides gel, chlorhexidine mouthwash group III, group IV received chlorhexidine gel and group V received toothpaste Lippia sidoides. In the case of mouthwash and gel formulations, the identification of each substance was made with letters so as not to know which antimicrobials were being applied. The patient was also unaware of which substance was being applied to it, ensuring the double-blind study. In each of the treatments were used with mouthwash 5ml, 1 minute, 1 time a day for 5 consecutive days. In each treatment gel, were used 5ml, applied in individual trays for 4 minutes, 1 time a day for 5 consecutive days. In the treatment with toothpaste was used an amount corresponding to a lump of sweet, 1 minute, 1 time a day for 5 consecutive days. The saliva of each patient was collected before starting treatment (D1), the last day of treatment (D5), 30 days after day 1 (D30), 60 days after day 1 (D60), 6 months after initiation of treatment (D180) and 1 year after initiation of treatment (D360), to verify the effectiveness of dosage forms of Lippia sidoides in the reduction of Streptococcus mutans. Before the start of treatment was a survey done by a single examiner using the visual method / tactic to calculate the number of surfaces decayed, missing and filled (DMF) to assess the emergence of new carious lesions during the course of one year after treatment. The best formulation was found the toothpaste, although when all the formulations were compared to chlorhexidine, it has shown greater efficacy in the reduction of Streptococcus mutans. This led us to conclude that the problem could be related to insufficient number of applications (only 1 time a day). So has begun the third phase of the study, which consisted of the same principles described above, but were selected only 20 children with caries, which were sprayed with Lippia sidoides dentifrice for 1 month, brushing 3 times a day. Another 20 children, also with caries, were selected to make brushing with fluoridated common folder for the same period, with the same number of daily brushings. All children received hygiene instruction in a standardized manner, so that the brushing done at home to approach the maximum of the way it has been established. The best efficacy in reducing the levels of Streptococcus mutans was observed in the dentifrice of Lippia sidoides in the group that used the common folder. There were no reported side effects; however, it was reported some improvement in the breath of children who used toothpaste rosemary. These data indicate that the plant studied can serve as an low cost alternative and culturally acceptable to the prevention of dental caries in children aged 6 to 12 years if used 3 times a day as toothpaste.

Thesis (M.S.)--University of Michigan, 1996. / Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 2000. / Includes bibliographical references.

One of the most concerning characteristics of microbial biofilms is that of increased resistance to antimicrobial agents such as the commonly used biocide chlorhexidine (CHX). This can have huge impact on clinical, household and environmental settings. This is particularly alarming when it involves opportunistic pathogenic environmental organisms such as Delftia acidovorans as routine mitigation practices may fail to be effective. This thesis examines tolerance mechanisms of D. acidovorans biofilms exposed to CHX at inhibitory and sub-inhibitory concentrations. To achieve the study goals and objectives, a CHX-tolerant D. acidovorans strain (WT15), (Minimum Inhibitory Concentration; MIC-15 μg ml-1) was compared to a CHX-sensitive strain (MT51, MIC-1 μg ml-1) that was obtained by mutating the wild type strain using transposon mutagenesis. Specific morphological, structural and chemical compositional differences between the CHX-treated and untreated biofilms of wild type and mutant strains were documented using microscopic techniques including confocal laser scanning microscopy (CLSM), scanning transmission x-ray microscopy (STXM), transmission electron microscopy (TEM) and infrared (IR) spectroscopy. Molecular level changes between biofilms formed by these two strains due to CHX treatment were compared using whole-cell proteomic analysis (determined using differential in-gel electrophoresis, or DIGE) along with fatty acid methyl ester (FAME) analysis. The gene disrupted by transposon insertion that led to increased susceptibility to CHX in the mutant strain was identified as tolQ. CLSM revealed differences in biofilm architecture and thickness between the biofilms formed by strains WT15 and MT51. STXM analyses showed that WT15 biofilms contained two morpho-chemical cell variants; whereas, only one type was detected in MT51 biofilms. STXM and IR spectral analyses revealed that CHX-susceptible MT51 cells accumulated the highest levels of CHX, an observation supported by TEM wherein prominent changes in the cell envelope of CHX-susceptible MT51 cells were observed. DIGE analysis demonstrated that numerous changes in protein abundance occurred in biofilm cells following CHX exposure and that most of these proteins were associated with amino acid and lipid biosynthesis, protein translation, energy metabolism and stress-related functions. Overall, these studies indicate the probable role of the cell membrane and TolQ protein in CHX tolerance in D. acidovorans biofilms, in association with various proteins that are differentially-expressed.