It is well established that bacteria cause pulpal and periradicular disease (Kakehashi et al. 1965). Of the bacteria recovered from failing root canals, Enterococcus faecalis is one of the most prevalent species (Molander et al. 1998; Sundqvist et al. 1998). Many laboratory studies have investigated the effectiveness of root canal irrigants and medicaments against E. faecalis. Most used planktonic cultures, which are not representative of the in vivo growth conditions of an infected root canal system, where bacteria grow as a biofilm adhering to the dentinal wall (Nair 1987). Organisation of bacteria within biofilms confers a range of phenotypic properties that are not evident in their planktonic counterparts, including a markedly reduced susceptibility to antimicrobial killing (Wilson 1996). Objectives: The aims of this study were: 1) To compare the efficacy of commonly used endodontic medicaments against E. faecalis cultured as a biofilm. The medicaments tested were Ledermix paste, calcium hydroxide, Odontopaste, 0.2% chlorhexidine gel and 50:50 combinations of Ledermix/calcium hydroxide and Odontopaste/calcium hydroxide. 2) To compare the antimicrobial effect achieved through exposure to endodontic medicaments with that achieved by exposure to a constant concentration of sodium hypochlorite for varying times. Methods: A biofilm was established using a continuous flow cell. E. faecalis inoculum was introduced into the flow cell and allowed to establish on human dentine slices over 4 weeks. Each test medicament was introduced into the flow cell for a period of 24 or 48 hours, while sodium hypochlorite was evaluated after 1, 10, 30 and 60 minutes. Biofilms were harvested by sonication in sterile PBS. Cellular protein levels were measured to quantitate the amount of biofilm harvested. Cellular viability was determined using serial plating. The number of colony forming units was then adjusted for cellular protein levels to allow treatment protocols to be compared. Qualitative SEM analyses of the biofilm was performed following exposure to each test agent. Results: Sodium hypochlorite was the only agent that achieved total bacterial elimination. Ledermix and Odontopaste had no significant effect on the E. faecalis biofilm, while calcium hydroxide and 50:50 combinations of calcium hydroxide with either Ledermix or Odontopaste were able to reduce viability by > 99%. Conclusion: When used in isolation, antibiotic containing medicaments had no appreciable effect on the viability of Enterococcus faecalis. Sodium hypochlorite remains the gold standard for bacterial elimination in root canal therapy. / Thesis (D.Clin.Dent.) -- University of Adelaide, School of Dentistry, 2009

It is well established that bacteria cause pulpal and periradicular disease (Kakehashi et al. 1965). Of the bacteria recovered from failing root canals, Enterococcus faecalis is one of the most prevalent species (Molander et al. 1998; Sundqvist et al. 1998). Many laboratory studies have investigated the effectiveness of root canal irrigants and medicaments against E. faecalis. Most used planktonic cultures, which are not representative of the in vivo growth conditions of an infected root canal system, where bacteria grow as a biofilm adhering to the dentinal wall (Nair 1987). Organisation of bacteria within biofilms confers a range of phenotypic properties that are not evident in their planktonic counterparts, including a markedly reduced susceptibility to antimicrobial killing (Wilson 1996). Objectives: The aims of this study were: 1) To compare the efficacy of commonly used endodontic medicaments against E. faecalis cultured as a biofilm. The medicaments tested were Ledermix paste, calcium hydroxide, Odontopaste, 0.2% chlorhexidine gel and 50:50 combinations of Ledermix/calcium hydroxide and Odontopaste/calcium hydroxide. 2) To compare the antimicrobial effect achieved through exposure to endodontic medicaments with that achieved by exposure to a constant concentration of sodium hypochlorite for varying times. Methods: A biofilm was established using a continuous flow cell. E. faecalis inoculum was introduced into the flow cell and allowed to establish on human dentine slices over 4 weeks. Each test medicament was introduced into the flow cell for a period of 24 or 48 hours, while sodium hypochlorite was evaluated after 1, 10, 30 and 60 minutes. Biofilms were harvested by sonication in sterile PBS. Cellular protein levels were measured to quantitate the amount of biofilm harvested. Cellular viability was determined using serial plating. The number of colony forming units was then adjusted for cellular protein levels to allow treatment protocols to be compared. Qualitative SEM analyses of the biofilm was performed following exposure to each test agent. Results: Sodium hypochlorite was the only agent that achieved total bacterial elimination. Ledermix and Odontopaste had no significant effect on the E. faecalis biofilm, while calcium hydroxide and 50:50 combinations of calcium hydroxide with either Ledermix or Odontopaste were able to reduce viability by > 99%. Conclusion: When used in isolation, antibiotic containing medicaments had no appreciable effect on the viability of Enterococcus faecalis. Sodium hypochlorite remains the gold standard for bacterial elimination in root canal therapy. / Thesis (D.Clin.Dent.) -- University of Adelaide, School of Dentistry, 2009

Thesis (M.S.)--University of Alabama at Birmingham, 2009. / Title from PDF title page (viewed on Sept. 3, 2009). Includes bibliographical references (p. 44-49).

SOUZA, L. R. Estudo da degradação microbiana in vitro do Poli (1,4-trans-isopreno) (in natura) e em cones dentários. 2012. 80 f. Dissertação (Mestrado em Química) - Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2012. / Submitted by Daniel Eduardo Alencar da Silva (dealencar.silva@gmail.com) on 2014-11-24T21:40:13Z No. of bitstreams: 1 2012_dis_lrsouza.pdf: 1340876 bytes, checksum: 7896c730622fb70cb15cf7a6f3caedb4 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa(jairo@ufc.br) on 2016-01-27T22:32:46Z (GMT) No. of bitstreams: 1 2012_dis_lrsouza.pdf: 1340876 bytes, checksum: 7896c730622fb70cb15cf7a6f3caedb4 (MD5) / Made available in DSpace on 2016-01-27T22:32:46Z (GMT). No. of bitstreams: 1 2012_dis_lrsouza.pdf: 1340876 bytes, checksum: 7896c730622fb70cb15cf7a6f3caedb4 (MD5) Previous issue date: 2012 / The gutta-percha cones used in endodontic therapy, consisting of poly (1,4-trans-isoprene), ZnO and/or BaSO4 and wax/resin, were meant to last a lifetime in root canals filled by them. However, there is evidence that these materials suffer degradation with the passage of time when there shutter intensified infections by microorganisms. The bacterium Enterococcus faecalis is one of those microorganisms commonly associated with persistent periapical infections. The prevalence of this bacterium in cases of re-treatment is between 29% and 79% of cases. The objective is to study the bacterial degradation of gutta-percha in medium containing E. faecalis, with the focus on organic matter, polyisoprene. Each sample cone was immersed in mineral salts medium with inoculum concentration of 5.4 x 105 CFU/mL for periods of 10 to 100 days. The cones were removed from contact with the inoculum at various times and analized. Were weighed and characterized by TGA, GPC, FTIR, NMR H1 and SEM. The growth of the inoculum was monitored by optical density measurements, determining of percentage of mineralization of CO2, measured dry biomass cells, measurements of pH and cell count. The antimicrobial activity of inorganic constituents of cones was verified by diffusion test pit. Was observed gradual loss of mass of the cones with the degradation time. The increase in the ash content at 800 °C, shows that there was a progressive loss of organic matter and an increased proportion of inorganic constituents. After contact with E. faecalis, polyisoprene isolated cones marks Odous® and Tanari® was analized and compared and the fresh polyisoprene by GPC and FTIR. The results show that in all three cases there is small and gradual loss of the molar mass of the polyisoprene constituents of material, the more evidente in polyisoprene in nature. Infrared spectra show that degradation also ocurrs with strutural modifications of the polymer, especially in the occurrence of deformation bands of C=O and OH/OOH, and variations in the pattern of cristalinity of the bands of C=C-H. The SEM images show that changes may ocurr in the surface morphology of the cones biodegraded, resulting the from selective attack to the organic component. The NMR H1 spectra of polyisoprene fresh show that the material has undergone minor structural changes in the molecules of polyisoprene during bioassay. All bioassays monitoring indicated that the inoculum grows continuously during the period of contact with the cones or polyisoprene in nature. The bacteria degrades the organic matter of the cones using them as a source of substrate and thereby causing voids cones that can cause failure in endodontic treatment. / Os cones de guta-percha usados em endodontia, compostos de poli (1,4-trans-isopreno), ZnO e/ou BaSO4 e ceras/resinas, foram feitos para durar a vida inteira nos canais radiculares por eles preenchidos. Entretanto, existem evidências de que esses materiais sofrem degradação com o decorrer do tempo de obturação intensificada quando existem infecções por microrganismos. A bactéria Enterococcus faecalis é um desses microrganismos, normalmente associada com infecções periapicais persistentes. A prevalência dessa bactéria em casos de re-tratamento ocorre entre 29 e 79% dos casos. O objetivo do trabalho é estudar a degradação bacteriana de cones de guta-percha em meio contendo E. faecalis, com o foco na matéria orgânica, o poliisopreno. Cada amostra de cone foi imersa em meio de sais minerais com inóculo de concentração de 5,4x105 UFC/mL por períodos de 10 a 100 dias. Os cones foram removidos do contato com o inóculo em tempos variados e analisados. Foram pesados e caracterizados por TGA, GPC, FTIR, MEV e RMN H1. O crescimento do inoculo foi monitorado através de medidas de densidade óptica, determinação da porcentagem de mineralização de CO2, medidas da biomassa seca de células, medidas de pH e contagem de células. A atividade antimicrobiana dos constituintes inorgânicos dos cones foi verificada mediante o teste de difusão em poço. Foi observada perda gradual de massa dos cones com o tempo de degradação. O aumento no teor de resíduos em 800°C, mostra que houve uma perda progressiva de matéria orgânica e um aumento na proporção de constituintes inorgânicos. Após o contato com E. faecalis, o poliisopreno isolado dos cones das marcas Odous® e Tanari® foi analisado e comparado com o poliisopreno in natura por GPC e FTIR. Os resultados mostram que nos três casos ocorre uma pequena e gradual perda de massa molar do poliisopreno constituintes do material, mais evidenciada no poliisopreno in natura. Os espectros de infravermelho mostram que a degradação também ocorre com modificações estruturais do polímero, especialmente no surgimento de bandas de deformação de C=O e OH/OOH; e variações no padrão de cristalinidade das bandas de C=C-H. As imagens de MEV mostram que podem ocorrer mudanças na morfologia da superfície dos cones biodegradados, resultado do ataque seletivo ao componente orgânico. Os espectros de RMN de H1 do poliisopreno in natura mostram que o material sofreu pequenas mudanças estruturais nas moléculas de poliisopreno durante o bioensaio. Todos os bioensaios de monitoramento indicaram que o inóculo cresce continuamente durante o período de contato com os cones ou com o poliisopreno in natura. A bactéria degrada a matéria orgânica dos cones usando-os como fonte de substrato e, consequentemente, causando vazios nos cones que podem ocasionar falhas no tratamanto endodôntico.

Este estudo objetivou investigar a distribuição e a relação entre os genes envolvidos com a virulência e formação de biofilme em 196 Enterococcus faecalis isolados de alimentos, clínicos e suabes cloacais de frangos de corte que receberam oocistos de Eimeria maxima e Eimeria acervulina e ração suplementada ou não com anticoccidiano. No primeiro experimento foi investigada a frequência dos genes agg, ace, tet(M), tet(L) e do operon bopABCD; e foi analisada a produção da enzima gelatinase em duas temperaturas de crescimento (36°C e 42°C). Assim como a capacidade de formar biofilme em meio de cultura suplementado com 10% de sangue, 10% de urina ou 0,75% de glicose por 70 Enterococcus faecalis isolados de frangos. Os Enterococcus faecalis isolados de frangos de corte que receberam oocistos de Eimeria maxima e Eimeria acervulina e ração suplementada ou não com anticoccidiano apresentaram capacidade de se adaptar a diferentes nichos biológicos, como por exemplo, sangue e urina. Foi observado um alto percentual dos genes dos fatores de virulência. No segundo experimento, foi avaliada a diversidade filogenética, com base no método de PCR, de 182 cepas isoladas de humanos, frangos de corte e alimentos. Estas cepas formaram quatro grupos filogenéticos (A, B, C e D) e quatro subgrupos (A1, A2, B1 e B2) com índice de similaridade entre 65 a 100%, demonstrando a adaptação de Enterococcus faecalis a diferentes ambientes. No terceiro experimento, foi determinada a capacidade de formação de biofilme de isolados clínicos e alimentares em diferentes meios de cultivo. Observou-se que o meio suplementado com 0,75% de glicose demonstrou ser o mais adequado para estabelecimento de forte aderência e, consequente formação do biofilme microbiano nos isolados de todas as origens. Em contrapartida, o meio suplementado com 10% de sangue foi o que registrou as maiores taxas de fraca formação de biofilme. Os estudos conduzidos demonstram características fenotípicas e genotípicas de Enterococcus faecalis que sugerem uma ampla adaptação ambiental entre os isolados pesquisados. / This study aimed to investigate the distribution and the relationship between genes involved in virulence and biofilm formation in 196 Enterococcus faecalis isolates from food, clinical and cloacal swabs of broilers that received oocysts of Eimeria maxima and Eimeria acervulina and diet supplemented or not with anticoccidial. The first experiment investigated the frequency of agg, ace, tet(M), tet(L) genes and bopABCD operon; production of gelatinase enzyme was analyzed at two growth temperatures (36°C and 42°C). Thus the ability to form biofilm in culture medium supplemented with 10% of blood, 10% of urine and glucose 0.75% for 70 Enterococcus faecalis isolates of chicken. The Enterococcus faecalis isolates from broilers that received oocysts of Eimeria maxima and Eimeria acervulina and supplemented or not with anticoccidial showed the ability to adapt to different biological niches, such as blood and urine. A high percentage of genes of virulence factors were observed. In the second experiment, we evaluated the phylogenetic diversity based on PCR method of 182 strains isolated from humans, broilers and food. These strains formed four phylogenetic groups (A, B, C and D) and four subgroups (A1, A2, B1 and B2) with similarity index between 65 and 100%, demonstrating the adaptation of Enterococcus faecalis to different environments. In the third experiment, the ability of biofilm formation of clinical and food isolates in different culture media was determined. It was observed that the medium supplemented with 0.75% glucose was shown to be more suitable for the establishment of strong adhesion and subsequent formation of the biofilm isolates from all sources. In other hand, medium supplemented with 10% blood was reported that the highest rates of weak biofilm formation. Studies conducted show phenotypic and genotypic characteristics of Enterococcus faecalis that suggest a broad environmental adaptation among the isolates studied.

Made available in DSpace on 2015-06-17T19:33:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-23. Added 1 bitstream(s) on 2015-06-18T12:47:49Z : No. of bitstreams: 1 000830347.pdf: 242986 bytes, checksum: 3957e431d5fb3368b3a93a697bd645dd (MD5) / Enterococcus faecalis é uma bactéria Gram-positiva que pode resistir ao tratamento endodôntico e manter a infecção presente no sistema de canais radiculares. Assim, o uso de cimentos endodônticos com atividade antimicrobiana pode ajudar a eliminar microrganismo residuais que sobreviveram após o tratamento endodôntico. Diante dessa realidade, o presente estudo teve por objetivo avaliar comparativamente a ação antimicrobiana dos cimentos endodônticos Acroseal, Sealapex e AH Plus em um modelo de biofilme in vitro. Para a realização do estudo foram confeccionados 144 espécimes de dentina bovina, sendo doze blocos para cada cimento em cada tempo experimental que permaneceram em placas contendo meio de cultura inoculado com E. faecalis (ATCC 51299) para permitir a formação de biofilme. Decorrido 14 dias, os espécimes foram transferidos para outra placa onde discos dos cimentos testados foram colocados sobre o biofilme formado. As placas de cultura foram deixadas em estufa a 37°C e 5% de CO2 por 2, 7 e 14 dias. Espécimes sem aplicação dos cimentos foram utilizados como controle para cada período. Após cada tempo experimental, as amostras foram agitados em sonicador. As suspensões foram agitadas em vortex e foi realizada uma diluição seriada decimal em solução salina, sendo estas diluições plaqueadas em triplicata em meio de cultura m-Enterococcus ágar. As unidades formadoras de colônia foram contadas e os dados analisados estatisticamente usando os teste ANOVA, Shapiro-Wilk e Kruskal-Wallis one-way (p<0,05) para determinação do potencial antimicrobiano. Resultados: O Sealapex apresentou diferença estatística em todos os tempos experimentais quando comparado com os demais grupos. O AH Plus e o Acroseal mostraram atividade antimicroabina apenas no 14o dia de experimento. Conclusão: Nenhum... / Enterococcus faecalis is a gram positive bacteria that can resist to the endodontic therapy and maintain the infection present in the root canal system. Therefore, the use of endodontic sealers with antimicrobial activity could help to eliminate residual microorganism that have survived after endodontic treatment. The present study aimed to compare the antimicrobial activity of the endodontic sealers Acroseal, Sealapex and AH Plus in vitro biofilm model. It were prepared 144 bovine dentin specimens, twelve blocks for each cement in each experimental time that remained in plates containing culture medium inoculated with E. faecalis (ATCC 51299) for biofilm formation. After 14 days, the samples were transferred to another plate with test sealers and were kept at 37oC and 5% CO2 for 2, 7 and 14 days. Specimens without sealers were used as a control for each period. After each experimental, the samples were agitated in sonicator. The suspensions were agitated in vortex and serially diluted in saline and triple plaqued in m-Enterococcus agar. Colony forming unit were counted and the data were statistically analyzed using ANOVA, Shapiro-Wilk and Kruskal-Wallis one-way test (p<0.05) for the antimicrobial potential determination. Results: Sealapex showed significant difference in all experimental times in comparison to all other groups. AH Plus and Acroseal showed antimicrobial activity just at 14th experimental day. Conclusion: Neither of sealers setting tested was able to remove biofilm . The Sealapex showed higher antimicrobial activity in all experimental periods. All sealers examined the antimicrobial effectiveness was higher with over time

Made available in DSpace on 2015-09-17T15:25:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-05. Added 1 bitstream(s) on 2015-09-17T15:49:25Z : No. of bitstreams: 1 000845518_20160402.pdf: 83963 bytes, checksum: b27fb8e88a318385605bd8bd1405bf1a (MD5) Bitstreams deleted on 2016-04-04T12:10:26Z: 000845518_20160402.pdf,. Added 1 bitstream(s) on 2016-04-04T12:11:06Z : No. of bitstreams: 1 000845518.pdf: 674514 bytes, checksum: 62da913b8ef513635c243ef06495c521 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Cimentos endodônticos associados à amoxicilina têm sido pesquisados como uma alternativa para obturação do canal radicular. Os objetivos do presente estudo foram: Avaliar a citocompatibilidade do AH Plus e do Sealapex associados com amoxicilina em quantidade de 10% do peso total dos cimentos (Capítulo 1) e avaliar o escoamento e o tempo de presa dos cimentos AH Plus e Sealapex associados à amoxicilina em diferentes concentrações e a atividade antibiofilme dos cimentos associados a uma maior concentração de amoxicilina que não altera as propriedades físicas de ambos os cimentos (Capítulo 2). No Capítulo 1 a citocompatibilidade dos materiais foi avaliada utilizando fibroblastos L929 expostos por 24 horas a diferentes diluições dos extratos dos cimentos puros e associados à amoxicilina. Os ensaios de brometo de 3-(4,5-dimetil-2-tiazolil )-2,5-difenil-2Htetrazólio (MTT) e vermelho neutro foram utilizados para avaliação da viabilidade celular e a fluorescência para actina e α-tubulina foram utilizadas para análise do citoesqueleto. Os dados foram analisados empregando a análise de variância a dois critérios e pós teste de Bonferroni, com nível de significância de 5%. Os resultados mostraram que a incorporação de amoxicilina na concentração de 10% do peso total dos cimentos não diminuiu a viabilidade dos fibroblastos e não causou alterações estruturais nos componentes do citoesqueleto estudados. Conclui-se que à amoxicilina poderia ser um agente antimicrobiano promissor para ser incorporada aos cimentos endodônticos. No Capítulo 2 o escoamento a o tempo de presa dos cimentos puros ou associados à amoxicilina em concentrações de 0,25 a 10% foram estudadas de acordo com a especificação no6876 da Organização Internacional de Padronização (ISO 2012). A avaliação antibiofilme dos cimentos puros e associados à amoxicilina 1% foi realizada por teste de contato...(Resumo completo clicar acesso eletrônico) / Sealers associatedwith amoxicillinhave been developed as an alternative to root canal filling. The objectives of this study were to evaluate the cytocompatibility of AH Plus and Sealapex associated with amoxicillin in concentration of 10% of the total weight of sealer (Chapter 1) and evaluate the flow and the setting time of AH Plus sealer and Sealapex associated with amoxicillin at different concentrations and the activity of sealers antibiofilm associated with higher concentrations of amoxicillin which does not alter the physical properties of both sealers (Chapter 2). In Chapter 1 cytocompatibility of the materials was assessed using the L929 fibroblasts exposed for 24 hours with different dilutions of the extracts of pure sealer and associated with amoxicillin. The testing of 3- (4,5-dimethyl-2-thiazolyl) -2,5-diphenyl-2H-tetrazolium (MTT), and neutral red were used for evaluation of cell viability and fluorescence actin and α-tubulin were used for analysis of the cytoskeleton. Data were analyzed using analysis of variance and two criteria Bonferroni post test at 5% significance level. The results showed that incorporation of amoxicillin at a concentration of 10% by weight of the sealer did not decrease the viability of fibroblasts and did not cause structural changes in the cytoskeletal components studied. It is concluded that amoxicillin could be a promising antimicrobial agent to be incorporated in sealers. In chapter 2 the flow and setting time of the sealer pure or associated with amoxicillin from 0.25 to 10% concentrations were evaluated according to no 6876 specification of the International Organization for Standardization (ISO 2012). The antibiofilm evaluation of pure sealer and 1% associated with amoxicillin was performed by direct contact test with Enterococcus faecalis biofilm previously induced in bovine dentin for 14 days. Fresh sealer were in contact with the biofilm... (Complete abstract electronic access below)

Orientador: Idomeo Bonetti Filho / Co-orientador: / Banca: Juliane Maria Guerreiro Tanomaru / Banca: Yara Teresinha Corrêa Silva Sousa / Banca: Gisele Faria / Banca: Flaviana Bombarda de Andrade / Resumo: Cimentos endodônticos associados à amoxicilina têm sido pesquisados como uma alternativa para obturação do canal radicular. Os objetivos do presente estudo foram: Avaliar a citocompatibilidade do AH Plus e do Sealapex associados com amoxicilina em quantidade de 10% do peso total dos cimentos (Capítulo 1) e avaliar o escoamento e o tempo de presa dos cimentos AH Plus e Sealapex associados à amoxicilina em diferentes concentrações e a atividade antibiofilme dos cimentos associados a uma maior concentração de amoxicilina que não altera as propriedades físicas de ambos os cimentos (Capítulo 2). No Capítulo 1 a citocompatibilidade dos materiais foi avaliada utilizando fibroblastos L929 expostos por 24 horas a diferentes diluições dos extratos dos cimentos puros e associados à amoxicilina. Os ensaios de brometo de 3-(4,5-dimetil-2-tiazolil )-2,5-difenil-2Htetrazólio (MTT) e vermelho neutro foram utilizados para avaliação da viabilidade celular e a fluorescência para actina e α-tubulina foram utilizadas para análise do citoesqueleto. Os dados foram analisados empregando a análise de variância a dois critérios e pós teste de Bonferroni, com nível de significância de 5%. Os resultados mostraram que a incorporação de amoxicilina na concentração de 10% do peso total dos cimentos não diminuiu a viabilidade dos fibroblastos e não causou alterações estruturais nos componentes do citoesqueleto estudados. Conclui-se que à amoxicilina poderia ser um agente antimicrobiano promissor para ser incorporada aos cimentos endodônticos. No Capítulo 2 o escoamento a o tempo de presa dos cimentos puros ou associados à amoxicilina em concentrações de 0,25 a 10% foram estudadas de acordo com a especificação no6876 da Organização Internacional de Padronização (ISO 2012). A avaliação antibiofilme dos cimentos puros e associados à amoxicilina 1% foi realizada por teste de contato...(Resumo completo clicar acesso eletrônico) / Abstract: Sealers associatedwith amoxicillinhave been developed as an alternative to root canal filling. The objectives of this study were to evaluate the cytocompatibility of AH Plus and Sealapex associated with amoxicillin in concentration of 10% of the total weight of sealer (Chapter 1) and evaluate the flow and the setting time of AH Plus sealer and Sealapex associated with amoxicillin at different concentrations and the activity of sealers antibiofilm associated with higher concentrations of amoxicillin which does not alter the physical properties of both sealers (Chapter 2). In Chapter 1 cytocompatibility of the materials was assessed using the L929 fibroblasts exposed for 24 hours with different dilutions of the extracts of pure sealer and associated with amoxicillin. The testing of 3- (4,5-dimethyl-2-thiazolyl) -2,5-diphenyl-2H-tetrazolium (MTT), and neutral red were used for evaluation of cell viability and fluorescence actin and α-tubulin were used for analysis of the cytoskeleton. Data were analyzed using analysis of variance and two criteria Bonferroni post test at 5% significance level. The results showed that incorporation of amoxicillin at a concentration of 10% by weight of the sealer did not decrease the viability of fibroblasts and did not cause structural changes in the cytoskeletal components studied. It is concluded that amoxicillin could be a promising antimicrobial agent to be incorporated in sealers. In chapter 2 the flow and setting time of the sealer pure or associated with amoxicillin from 0.25 to 10% concentrations were evaluated according to no 6876 specification of the International Organization for Standardization (ISO 2012). The antibiofilm evaluation of pure sealer and 1% associated with amoxicillin was performed by direct contact test with Enterococcus faecalis biofilm previously induced in bovine dentin for 14 days. Fresh sealer were in contact with the biofilm... (Complete abstract electronic access below) / Doutor

Orientador: Juliane Maria Guerreiro Tanomaru / Resumo: Novos cimentos endodônticos à base de silicatos de cálcio são propostos na busca de materiais com potencial bioativo. Publicação 1: Desenvolvimento e avaliação físico-química de dois cimentos endodônticos experimentais compostos por silicato tricálcico, silicato dicálcico, fosfato de cálcio monobásico, hidróxido de cálcio, óxido de zircônio e tungstato de cálcio; manipulados com polietilenoglicol - Experimental 1 (EXP1) ou com polietilenoglicol e hidrogel de quitosana - Experimental 2 (EXP2). TotalFill BC sealer (TF) e AH Plus (AHP) foram usados para comparação. Tempo de presa, escoamento e radiopacidade foram avaliados com base nas normas ISO 6876. Avaliou-se pH por um pHmetro digital, nos períodos de 3 e 12 horas, 1, 7, 14 e 21 dias. Avaliou-se solubilidade pela perda de massa após imersão em água destilada por 7 e 30 dias. Os dados obtidos foram submetidos aos testes ANOVA e Tukey (α=0,05). EXP2 e EXP1 apresentaram maior tempo de presa (P<0,05). Radiopacidade e escoamento de EXP1 e EXP2 atendem às normas da ISO 6876. EXP1 apresentou radiopacidade semelhante à TF (P>0,05) e maior que EXP2 (P<0,05). EXP1 apresentou escoamento semelhante à AHP (P>0,05) e maior que EXP2 (P<0,05). EXP1 e EXP2 apresentaram maior solubilidade após 7 dias (P<0,05). Após 30 dias de imersão, solubilidade de EXP1 foi semelhante à TF (P>0,05). EXP1, EXP2 e TF apresentaram pH alcalino em todos os períodos experimentais. Conclui-se que EXP1 apresenta tempo de presa, radiopacidade, escoamento, solubilida... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: New calcium silicate-based endodontic cements are proposed in the search for materials with bioactive potential. Publication 1: Development and physical-chemical evaluation of two experimental endodontic cements composed of tricalcium silicate, dicalcium silicate, monobasic calcium phosphate, calcium hydroxide, zirconium oxide and calcium tungstate; handled with polyethylene glycol - Experimental 1 (EXP1) or with polyethylene glycol and chitosan hydrogel - Experimental 2 (EXP2). TotalFill BC sealer (TF) and AH Plus (AHP) were used for comparison. Setting time, flow and radiopacity were evaluated based on ISO 6876. pH was evaluated with a digital pH meter, in the periods 3 and 12 hours, 1, 7, 14 and 21 days. Solubility was evaluated by mass loss after immersion in distilled water for 7 and 30 days. Data were submitted to ANOVA and Tukey tests (α=0.05). EXP2 and EXP1 presented higher setting time (P<0.05). Radiopacity and flow of EXP 1 and EXP2 meet ISO 6876 standards. EXP1 presented radiopacity similar to TF (P>0.05) and higher than EXP2 (P<0.05). EXP1 presented similar flow to AHP (P>0.05) and higher than EXP2 (P<0.05). EXP1 and EXP2 presented higher solubility after 7 days (P<0.05). After 30 days of immersion, solubility of EXP1 was similar to TF (P>0.05). EXP1, EXP2 and TF presented alkaline pH in all experimental periods. It is concluded that EXP1 presents proper setting time, radiopacity, flow, solubility and pH, and it has potential for use as endodontic cement. Publicat... (Complete abstract click electronic access below) / Mestre

Orientador: Eloi Dezan Júnior / Coorientador: Carolina Simonetti Lodi / Banca: João Eduardo Gomes Filho / Banca: Marco Antonio Húngaro Duarte / Resumo: Enterococcus faecalis é uma bactéria Gram-positiva que pode resistir ao tratamento endodôntico e manter a infecção presente no sistema de canais radiculares. Assim, o uso de cimentos endodônticos com atividade antimicrobiana pode ajudar a eliminar microrganismo residuais que sobreviveram após o tratamento endodôntico. Diante dessa realidade, o presente estudo teve por objetivo avaliar comparativamente a ação antimicrobiana dos cimentos endodônticos Acroseal, Sealapex e AH Plus em um modelo de biofilme in vitro. Para a realização do estudo foram confeccionados 144 espécimes de dentina bovina, sendo doze blocos para cada cimento em cada tempo experimental que permaneceram em placas contendo meio de cultura inoculado com E. faecalis (ATCC 51299) para permitir a formação de biofilme. Decorrido 14 dias, os espécimes foram transferidos para outra placa onde discos dos cimentos testados foram colocados sobre o biofilme formado. As placas de cultura foram deixadas em estufa a 37°C e 5% de CO2 por 2, 7 e 14 dias. Espécimes sem aplicação dos cimentos foram utilizados como controle para cada período. Após cada tempo experimental, as amostras foram agitados em sonicador. As suspensões foram agitadas em vortex e foi realizada uma diluição seriada decimal em solução salina, sendo estas diluições plaqueadas em triplicata em meio de cultura m-Enterococcus ágar. As unidades formadoras de colônia foram contadas e os dados analisados estatisticamente usando os teste ANOVA, Shapiro-Wilk e Kruskal-Wallis one-way (p<0,05) para determinação do potencial antimicrobiano. Resultados: O Sealapex apresentou diferença estatística em todos os tempos experimentais quando comparado com os demais grupos. O AH Plus e o Acroseal mostraram atividade antimicroabina apenas no 14o dia de experimento. Conclusão: Nenhum... / Abstract: Enterococcus faecalis is a gram positive bacteria that can resist to the endodontic therapy and maintain the infection present in the root canal system. Therefore, the use of endodontic sealers with antimicrobial activity could help to eliminate residual microorganism that have survived after endodontic treatment. The present study aimed to compare the antimicrobial activity of the endodontic sealers Acroseal, Sealapex and AH Plus in vitro biofilm model. It were prepared 144 bovine dentin specimens, twelve blocks for each cement in each experimental time that remained in plates containing culture medium inoculated with E. faecalis (ATCC 51299) for biofilm formation. After 14 days, the samples were transferred to another plate with test sealers and were kept at 37oC and 5% CO2 for 2, 7 and 14 days. Specimens without sealers were used as a control for each period. After each experimental, the samples were agitated in sonicator. The suspensions were agitated in vortex and serially diluted in saline and triple plaqued in m-Enterococcus agar. Colony forming unit were counted and the data were statistically analyzed using ANOVA, Shapiro-Wilk and Kruskal-Wallis one-way test (p<0.05) for the antimicrobial potential determination. Results: Sealapex showed significant difference in all experimental times in comparison to all other groups. AH Plus and Acroseal showed antimicrobial activity just at 14th experimental day. Conclusion: Neither of sealers setting tested was able to remove biofilm . The Sealapex showed higher antimicrobial activity in all experimental periods. All sealers examined the antimicrobial effectiveness was higher with over time / Mestre