O estudo teve o objetivo de avaliar a resistência adesiva e a degradação da interface entre uma cerâmica tratada com laser e cimentos resinosos. Sessenta e quatro blocos cerâmicos foram distribuídos em 16 grupos distribuídos de acordo com os fatores em estudo: tratamento da superfície interna da cerâmica: Oxido de Alumínio (Ox), Rocatec (R), Laser de Nd:YAG 141,54 J/cm2 (Nd) e Laser de Nd:YAG + Rocatec (NdR); cimentos resinosos: Panavia F (Kuraray) e Relyx Unicem (3M ESPE); e método de envelhecimento: água destilada (W) e hipoclorito de sódio 10% (H). Após os procedimentos de cimentação e corte dos blocos, metade dos palitos foi armazenada em solução de hipoclorito de sódio 10% para simular envelhecimento in vitro. A resistência de união foi avaliada através do ensaio de microtração (0,5 mm/min) e os padrões de fratura foram classificados em adesivo, coesivo ou misto. Blocos cerâmicos adionciais foram confeccionados e analisados em Microscopia Eletrônica de Varredura e em Microscópio de Força Atômica para verificação dos padrões gerados pelos tratamentos. Os grupos tratados com laser de Nd:YAG apresentaram os maiores valores de resistência de união. Para os grupos cimentados com Panavia F, os valores de resistência de união foram: OxW: 27,71±6,3; RW: 35,67±5,13; NdW: 42,49±6,8; NdRW: 37,41±4,76; OxH: 22,27±6,05; RH: 27,49±8,83; NdH: 32,24±6,94; NdRH: 31,75±7,77. Para os grupos com RelyX Unicem: OxW: 26,74±6,34; RW: 35,07±6,02; NdW: 41,05±7,71; NdRW: 33,85±6,03; OxH: 22,77±7,37; RH: 27,84±6,26; NdH: 36,42±5,08; NdRH: 27,6±5,8. Pode-se concluir que o laser de Nd:YAG foi o tratamento mais efetivo, seguido da associação entre o laser de Nd:YAG+Rocatec, Rocatec e jateamento com Al2O3. Os cimentos testados apresentam comportamentos similares. O envelhecimento in vitro com hipoclorito de sódio diminuiu os valores de resistência de união. / The aim of this study was to evaluate the influence of different surface treatments on resistance to degradation between In-Ceram Alumina and two resin-based cements. Sixteen experimental groups were formed according to ceramic treatment: Sandblasting (S), Rocatec System (R), Nd:YAG Laser (Nd), Nd:YAG Laser plus Rocatec System (NR); luting cement: Panavia F (Kuraray) or Relyx Unicem (3M ESPE); and aging method: water (W) or sodium hypochlorite (H). Sixty four In-Ceram Alumina blocks (10x10x6mm) received four surface treatments: Al2O3 sandblasting; Al2O3 sandblasting + Rocatec Plus; Al2O3 sandblasting + Nd:YAG Lase; Al2O3 sandblasting + Nd:YAG Laser + Rocatec Plus. Each conditioned ceramic block was bonded to a composite block using a resin cement system. After 24h storage time, the blocks were sectioned to obtain sticks with cross-sectional area of 1.0mm2. The specimens were loaded to failure in a universal testing machine at a crosshead speed of 0.5mm/min. The fractured surface morphology of the debonded specimens was observed (40X) to evaluate the fracture pattern. Failure modes were classified as adhesive, cohesive in ceramic, cohesive in resin cement and mixed. The ceramic treatment and the aging method significantly affected the microtensile bond strength. Nd:YAG surface treatment resulted in the best bond strength values. To groups luted with Panavia F cement the microtensile bond strength values were: SW: 27,71±6,3; RW: 35,67±5,13; NdW: 42,49±6,8; NdRW: 37,41±4,76; SH: 22,27±6,05; RH: 27,49±8,83; NdH: 32,24±6,94; NdRH: 31,75±7,77. To groups luted with RelyX cement: SW: 26,74±6,34; RW: 35,07±6,02; NdW: 41,05±7,71; NdRW: 33,85±6,03; SH: 22,77±7,37; RH: 27,84±6,26; NdH: 36,42±5,08; NdRH: 27,6±5,8. Nd:YAG laser was the most effective surface treatment, followed by Nd:YAG+Rocatec, Rocatec and Al2O3 sandblasting. Resin cements presented similar behaviors in spite of aging. NaOCl 12h-immersion decreased Bond strength values.

O objetivo deste trabalho foi avaliar o efeito da aplicação de ácido ascórbico após a desproteinização da dentina radicular, utilizando um cimento auto-adesivo e comparando-o a outros dois sistemas adesivos. Possíveis diferenças de união adesiva entre os terços radiculares também foram avaliadas. Quarenta e cinco raízes de incisivos bovinos foram divididas em três grupos, conforme o tratamento da raiz: irrigação com soro fisiológico; desproteinização com NaOCl (5%) por 10 minutos; irrigação com NaOCl por 10 min seguida da aplicação de ácido ascórbico por 10 min. O cimento autoadesivo Rely X U100 foi utilizado para cada um dos grupos citados. O cimento Rely X ARC foi utilizado com outros dois adesivos, para efeito de comparação: Single Bond e Clearfil SE Bond. Os espécimes foram armazenados em água destilada por 24 horas e testados quanto à resistência à extrusão (push-out). Os resultados foram submetidos ao teste ANOVA a três critérios e Dunnet T3 (=0.05). Não foram encontradas diferenças estatisticas entre os materiais utilizados. A desproteinização resultou em resistência adesiva diminuída, enquanto o tratamento subsequente com ácido ascórbico foi capaz de devolver a resistência adesiva em valores semelhantes aos do grupo controle. Diferenças entre os terços radiculares foram encontradas na seguinte sequência: coronal>médio>apical. O cimento auto-adesivo utilizado se comportou da mesma forma que os demais sistemas adesivos. O ácido ascórbico foi capaz de reverter o efeito de oxidação causado pela desproteinização. / The aim of this study was to evaluate the effect of ascorbic acid after root dentin treatment with sodium hypochlorite. A self-adhesive cement was compared with other two adhesive systems. The bond strength was also evaluated at different depths (coronal, middle, apical). Forty five single-rooted standard bovine teeth were divided in three groups. Specimens in each group were treated as follows: irrigation with physiologic serum; with NaOCl (5%) for 10 min; with NaOCl for 10 min and ascorbic acid for 10 min. The self-adhesive cement Rely X U100 was used for each one of the mentioned groups. The cement Rely X ARC was used with other two adhesives (Single Bond and Clearfil SE Bond). Specimens were stored in distilled water for 24 hours. Push-out tests were performed by using a universal testing machine, and the data was statistically analyzed (analysis of variance [ANOVA] and Dunnet T3; P < .05) A significant difference was not found among the materials tested. The deproteinization resulted in reduced bond strengths; though the subsequent treatment with ascorbic acid was capable to return the bond strengths. Differences among the region of post space were found: coronal>middle>apical. The ascorbic acid was capable to reverse the oxidation effect of the dentin deproteinization; the self-adhesive cement was similar to the other systems tested.

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2016-12-16T17:33:32Z No. of bitstreams: 2 Dissertação - Alessandra Rossi Coelho - 2015.pdf: 1908871 bytes, checksum: 877bc61729d067f31c137085853a9b95 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-12-26T12:25:27Z (GMT) No. of bitstreams: 2 Dissertação - Alessandra Rossi Coelho - 2015.pdf: 1908871 bytes, checksum: 877bc61729d067f31c137085853a9b95 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-12-26T12:25:27Z (GMT). No. of bitstreams: 2 Dissertação - Alessandra Rossi Coelho - 2015.pdf: 1908871 bytes, checksum: 877bc61729d067f31c137085853a9b95 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-03-12 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Objectives: To determine the antibacterial effect provided by Endox system associated with different irrigation protocols in the preparation of infected root canals. Material and methods: A total of 18 extracted human teeth with anatomical diameters corresponding to approximately 350-400 micrometers were selected. The teeth were contaminated with suspension of Enterococcus faecalis (ATCC 29212) for 60 days and randomly divided into five groups: 1. root canal preparation (RCP) + passive ultrasonic irrigation (PUI) with NaOCl + EDTA; 2. RCP + PUI with NaOCl + EDTA + Endox system; 3. RCP + conventional irrigation (CI) with NaOCl + EDTA 4. RCP + CI with NaOCl + EDTA + Endox system; 5. RCP + PUI with distilled water + EDTA + Endox system. Three teeth uncontaminated were the negative control (group 6). Samples were taken from the root canals before the RCP after 20 minutes and 72 hours, immersed in 7 ml of Brain Heart Infusion (BHI) for a period of 48 hours, incubated at 37 °C. The presence of bacterial was assessed by turbidity of the culture medium followed by optical density analysis using UV spectrophotometer. The differences between groups were statistically analyzed by mean, standard deviation, variance analysis and Tukey test (post hoc). The significance level was 5%. Results: The presence of E. faecalis was observed after 72 h in all experimental groups. In Groups 2 and 4 decreased the optical density of the culture medium after 72 h, with no significant difference between them, while in Groups 1, 3 and 5 was increased. The average optical density of the culture medium was zero in Group 6. Conclusion: The Endox system used after the root canal preparation, associated with conventional irrigation or passive ultrasonic irrigation with NaOCl 2,5% / EDTA, was not effective in eliminating E. faecalis. / Objetivo: Avaliar o efeito antibacteriano proporcionado pelo sistema Endox associado a diferentes protocolos de irrigação durante o preparo de canais radiculares (PCR) infectados. Material e método: Foram selecionados 18 dentes humanos anteriores extraídos com diâmetros anatômicos correspondentes a aproximadamente 350-400 micrômetros. Os dentes foram contaminados com suspensão de Enterococcus faecalis (ATCC 29212) por 60 dias, e aleatoriamente distribuídos em cinco grupos experimentais: Grupo 1. PCR + irrigação ultrassônica passiva (IUP) com NaOCl 2,5% + EDTA; Grupo 2. PCR + IUP com NaOCL 2,5% + EDTA + sistema Endox; Grupo 3. PCR + irrigação convencional (IC) com NaOCl 2,5% + EDTA Grupo 4. PCR + IC com NaOCl 2,5% + EDTA + sistema Endox; Grupo 5. PCR + IUP com água destilada + EDTA + sistema Endox. Três dentes não contaminados constituíram o grupo controle negativo (Grupo 6). Amostras foram coletadas dos canais radiculares antes do PCR, após 20 minutos e 72 horas, imersas em 7 mL de Brain Heart Infusion (BHI) por um período de 48 horas, incubadas a 37ºC. A presença bacteriana foi analisado pela turvação do meio de cultura seguido pela mensuração da densidade óptica utilizando espectrofotômetro UV. As diferenças entre os grupos foram analisadas estatisticamente pela média, desvio padrão, análise de variância e teste de Tukey (post hoc). O nível de significância foi de 5%. Resultados: A presença de E. faecalis foi observada, após 72 h, em todos os grupos experimentais. Nos Grupos 2 e 4 houve redução da densidade óptica do meio de cultura após 72 h, não havendo diferença significativa entre ambos, enquanto que nos Grupos 1, 3 e 5 houve aumento. A média da densidade óptica do meio de cultura no Grupo 6 foi zero. Conclusão: O sistema Endox, utilizado após o preparo do canal radicular, associado a irrigação convencional ou irrigação ultrassônica passiva, com NaOCl a 2,5%/ EDTA, não foi efetivo na eliminação do E. faecalis.

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2017-06-27T13:29:40Z No. of bitstreams: 2 Dissertação - Mônica Misaé Endo - 2015.pdf: 2157390 bytes, checksum: 65185e5c03de4e1f17fae411e86b3b3b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-10T14:11:42Z (GMT) No. of bitstreams: 2 Dissertação - Mônica Misaé Endo - 2015.pdf: 2157390 bytes, checksum: 65185e5c03de4e1f17fae411e86b3b3b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-10T14:11:42Z (GMT). No. of bitstreams: 2 Dissertação - Mônica Misaé Endo - 2015.pdf: 2157390 bytes, checksum: 65185e5c03de4e1f17fae411e86b3b3b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-03-20 / The objective of this study was to investigate the antibacterial effect of alcoholic extracts of 30% red propolis, 40% green propolis and 2.5% sodium hypochlorite in different irrigation protocols in root canals infected Enterococcus faecalis. Twenty-four extracted teeth with one root canal were selected, the prepared root canals and inoculated with E. faecalis for 60 days. The teeth were randomly divided into eight experimental groups (n = 3) and 2 control groups (n = 3). In all experimental groups were performed root canal preparation and two irrigation protocols - passive ultrasonic irrigation and conventional irrigation. In the groups 1, 3, 5 and 7 was made ready root canal associated with conventional irrigation to 30% propolis, 40% propolis, 2.5% sodium hypochlorite and distilled water, respectively. In groups 2, 4, 6 and 8 was performed root canal preparation associated with passive ultrasonic irrigation and irrigated with the same solutions described above. In the groups 9 and 10 were the controls - negative (root canals uncontaminated) and positive (root canals contaminated untreated). Samples of root canals were collected and immersed in 7 mL of BHI for 48 hours, incubated at 37 °C. The bacterial growth was assessed by turbidity of the culture medium. The results showed antibacterial effectiveness of the alcoholic extract of 30% red propolis and 2.5% sodium hypochlorite when used conventional irrigation and passive irrigation, only after 20 minutes. The irrigation protocols and the substances tested were not effective to eliminate bacterial dentin contamination with E. faecalis. / objetivo deste estudo foi verificar o efeito antibacteriano dos extratos alcoólicos de própolis vermelha a 30%, própolis verde a 40% e hipoclorito de sódio a 2,5% com diferentes protocolos de irrigação em canais radiculares infectados por Enterococcus faecalis. Vinte e quatro dentes unirradiculares extraídos foram selecionados, os canais radiculares preparados e inoculados com E. faecalis durante 60 dias. Os dentes foram aleatoriamente distribuídos em 8 grupos experimentais (n=3) e 2 grupos controles (n=3). Em todos os grupos experimentais foi realizado preparo do canal radicular e dois protocolos de irrigação - irrigação ultrassônica passiva e irrigação convencional. Nos grupos 1, 3, 5 e 7 foi feito o preparo do canal radicular associado à irrigação convencional com própolis vermelha a 30%, própolis verde a 40%, hipoclorito de sódio a 2,5% e água destilada, respectivamente. Nos grupos 2, 4, 6 e 8 foi realizado o preparo do canal radicular associado a irrigação ultrassônica passiva e irrigados com as mesmas soluções descritas anteriormente. Os grupos 9 e 10 constituíram os controles – negativo (canais radiculares não contaminados) e positivo (canais radiculares contaminados sem tratamento). Amostras dos canais radiculares foram coletadas e imersas em 7 mL de BHI por um período de 48 horas, com incubação a 37ºC. O crescimento bacteriano foi analisado pela turbidez do meio de cultura. Os resultados mostraram efetividade antibacteriana do extrato alcoólico de própolis vermelha a 30% e hipoclorito de sódio a 2,5%, quando utilizada irrigação convencional e irrigação passiva, somente após 20 minutos. Os protocolos de irrigação e as substâncias testadas não foram efetivos para eliminar a contaminação dentinária bacteriana com E. faecalis.

Soluções higienizadoras podem acarretar efeitos prejudiciais para as próteses, como deterioração da base da prótese e pigmentação. Porém, pouco se conhece sobre os efeitos destas na vida útil dos sistemas de retenção de uma overdenture. Deste modo, este estudo buscou avaliar se imersões diárias em clorexidina 2%, hipoclorito de sódio 1%, Corega® Tabs e água (controle) poderia acelerar a perda de retenção em attachments do tipo o´ring (S.I.N sistema de implantes®). Foram confeccionados 40 corpos de prova contendo cápsulas com anéis de borracha, simulando uma overdenture, e apenas 01 contendo o implante com o pilar o´ring. Eles foram separados em quatro grupos (n=10) e simulados noventa dias de imersões. Após, foram realizados testes de resistência à tração em uma máquina de ensaios mecânicos (MTS 810), antes e após a ciclagem com 270 ciclos, equivalentes a remoção e inserção da prótese três vezes ao dia, durante um período de três meses. Os resultados foram avaliados estatisticamente através dos testes ANOVA a dois critérios e do teste de Tukey (p&#x2264;0.05). Os valores médios (Newton) encontrados antes e após a imersão foram, respectivamente: Água - 9,482 / 6,081; Clorexidina - 9,972 / 7,390; Hipoclorito: 6,954 / 6,265 e Corega® Tabs: 12,464 / 11,121. Entre os grupos Clorexidina, Hipoclorito de sódio e Água não houve diferenças significativas. Houve diferenças estatisticamente significativas entre o grupo Corega® Tabs e os grupos controle e Hipoclorito de sódio, mas não com a Clorexidina. Assim, pôde-se concluir que soluções higienizadoras tiveram efeitos significativos na capacidade de retenção dos o´rings após o período simulado de três meses de imersão. / Denture cleansers can cause adverse effects on the prostheses, as deterioration of the denture base and pigmentation. However, little is known about its impacts on the life of an overdenture retention systems. Thus, this study sought to evaluate whether daily immersion in chlorhexidine 2%, sodium hypochlorite 1%, Corega® Tabs and water (control) would increase the retention loss in the O-ring type attachments (SIN implantes® system). Forty specimens containing capsules were made with rubber rings, simulating an overdenture, and only one containing the implant with the O-ring abutment. They were divided into four groups (n = 10) and ninety days in immersion were simulated, thereafter, conducted tensile strength tests on a testing machine (MTS - 810) before and after cycling of 270 cycles, equivalent to removal and insertion of the prosthesis three times a day for a period of three months. The results were statistically evaluated by the ANOVA two criteria and the Tukey test (p&#x2264;0.05). The mean values (Newton) found before and after immersion were: Water - 9,482 / 6,081; Chlorhexidine - 9,972 / 7,390; Hypochlorite: 6,954 / 6,265 and Corega® Tabs: 12.464 / 11.121. Among the groups chlorhexidine, sodium hypochlorite and water there were no significant differences. There were statistically significant differences between the group Corega® Tabs and controls and sodium hypochlorite groups, but not with the chlorhexidine. Thus, it concluded that denture cleansers had significant effects on retention capacity of orings after the simulated period of three months of immersion.

O objetivo deste trabalho foi avaliar, por meio de estudo laboratorial e clínico, a eficácia de soluções de hipoclorito alcalino (0,25% e 0,5%) e à base de mamona (Ricinus communis) a 10% quanto à ação antimicrobiana frente a micro-organismos específicos, por meio da contagem de Unidades Formadoras de Colônias (UFC). No estudo laboratorial, a partir de matrizes metálicas quadrangulares (10 x 2 mm), foram confeccionados 360 corpos de prova de resina acrílica termopolimerizável (Lucitone 550), os quais foram esterilizados em micro-ondas (650W, por 6 minutos), contaminados com cepas de Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Bacillus subtilis, Escherichia coli, Streptococcus mutans, Enterococcus faecalis e Candida glabrata e imersos (20 minutos) em soluções higienizadoras (n=10): Grupo A - Hipoclorito de sódio 0,25%; Grupo B - Hipoclorito de sódio 0,5%; Grupo C - Solução de mamona a 10%; Grupo D (Controle positivo) - solução salina e Grupo E (Controle negativo) - sem contaminação e imerso em solução salina (n=5). Em seguida, foram lavados em solução salina e imersos em meio de cultura líquido (Letheen), a partir do qual foram obtidas diluições seriadas (100 e 10-3), as quais foram semeadas em meios de cultura seletivos. Após incubação a 37ºC por 24 horas, as colônias foram contadas e os valores de UFC/mL calculados. No estudo clínico, 64 pacientes, usuários de próteses totais, foram orientados a escovar suas próteses (escova Bitufo® e sabonete líquido neutro) três vezes ao dia e imergí-las (20 minutos), uma vez ao dia, em soluções: Solução 1 - Hipoclorito de sódio 0,25%; Solução 2 - Hipoclorito de sódio 0,5%; Solução 3 - Solução de mamona a 10% e Solução 4 - solução salina (controle). De acordo com uma sequência aleatorizada, cada solução foi utilizada por 7 dias, com um período de wash out entre elas. A avaliação da ação antimicrobiana foi realizada antes dos uso dos produtos (Baseline) e após os 7 dias de uso de cada uma das soluções, por meio da contagem de Unidades Formadoras de Colônias (UFC) de Streptococcus mutans, Candida spp. e gram negativos. Para coleta do biofilme, cada prótese total superior foi colocada em placa de Petri e a superfície interna escovada (escova Tek e solução salina) por 2 minutos, sendo a suspensão transferida para tubo de ensaio. Após diluições decimais (100 até 10-3), alíquotas de 50 &mu;L foram semeadas em placas de Petri contendo Mitis Salivarius Agar Base, Chromagar® Candida e Mac Conkey Agar para a detecção de Streptococcus mutans, Candida spp. ou gram negativo, respectivamente. Após incubação a 37ºC (em microaerofilia durante 48-72 horas para grupo mutans e aerobiose durante 48 horas para Candida spp. e gram negativo), de acordo com morfologia típica, o número de colônias características foi mensurado e o número de UFC/mL calculado. Os dados obtidos foram transformados de acordo com a fórmula log10 (UFC+1) e analisados estatisticamente por meio do teste t de Student (&alpha;=0,05), para a análise laboratorial, e teste de Friedman (&alpha;=0,05), para a análise clínica. Os resultados mostraram que, no estudo laboratorial, as soluções de hipoclorito de sódio (0,25% e 0,5%) eliminaram completamente todos os micro-organismos. A solução de mamona eliminou completamente B. subtilis, não apresentou efeito sobre E. faecalis e apresentou ação antimicrobiana moderada frente às demais cepas, havendo redução significante (p < 0,05) do número de UFC quando comparado com o grupo D (controle positivo). No estudo clínico, houve diferença significante entre as soluções (P < 0,001), sendo que o hipoclorito de sódio a 0,5% apresentou ação efetiva sobre todos os micro-organismos avaliados (Candida spp., S. mutans e gram negativos); o hipoclorito de sódio 0,25%, ação efetiva sobre S. mutans e moderada sobre Candida spp. e gram negativos, e a solução de mamona, ação efetiva sobre S. mutans e moderada contra Candida spp. A espécie de Candida mais frequentemente isolada foi C. albicans, seguida pelas espécies C. tropicalis e C. glabrata. Concluiu-se que a solução de hipoclorito de sódio 0,5% foi a mais efetiva, apresentando ação antimicrobiana sobre ambos os biofilmes (in vitro e in vivo), seguida pela solução de hipoclorito de sódio 0,25% que apresentou ação antimicrobiana sobre o biofilme in vitro e sobre S. mutans (biofilme in vivo). A solução de mamona (10%) foi a menos efetiva, apresentando ação antimicrobiana sobre B. subtilis (biofilme in vitro) e S. mutans (biofilme in vivo). / The objective of this study was to evaluate, through laboratory and clinical study, the efficacy of alkaline hypochlorite solutions (0.25% and 0.5%) and 10% castor oil solution (Ricinus communis) about the antimicrobial action against specific microorganisms, by counting the number of Colony Forming Units (CFU). In the laboratory study, 360 denture base acrylic resin specimens (Lucitone 550) were obtained from square metal matrix (10 mm x 2 mm), which were sterilized with microwave (650W, for 6 minutes), contaminated with Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Bacillus subtilis, Escherichia coli, Streptococcus mutans, Enterococcus faecalis and Candida glabrata and immersed (20 minutes) in the hygiene solutions (n = 10): Group A - 0.25% Sodium Hypochlorite; Group - B - 0.5% Sodium hypochlorite; Group C - 10% Castor oil solution; Group D (Positive Control) - saline and Group E (Negative Control) - no contamination and immersed in saline (n = 5). The specimens were washed in saline solution and immersed in liquid culture medium (Letheen), from which were obtained serial dilutions (100 to 10-3) and seeded into selective solid media. After incubation at 37º C for 24 hours, the colonies were counted and the values of CFU/mL calculated. In the clinical study, 64 complete denture wearers were instructed to brush their dentures (Bitufo ® brush and liquid neutral soap) three times a day and to soak them (20 minutes), once a day, in the solutions: Solution 1 - 0.25% Sodium Hypochlorite; Solution 2 - 0.5% Sodium hypochlorite; Solution 3 - 10% Castor oil and Solution 4 - saline (control). According to a randomized sequence, each solution was used for 7 days, with a period of wash out between them. The evaluation of the antimicrobial action was performed before the use of the products (Baseline) and after 7 days after using each solution, by counting the Colony Forming Units (CFU) of Streptococcus mutans, Candida spp. and gram negative. For collection of the biofilm, each upper complete denture was placed in a Petri dish, the internal surface was brushed with saline solution for 2 minutes and the suspension was transferred to a test tube. After decimal dilutions (100 to 10-3), aliquots of 50 uL were seeded inside Petri dishes containing Mitis Salivarius Agar Base, Candida Chromagar ® and Mac Conkey Agar for the detection of Streptococcus mutans, Candida spp. or gram negative, respectively. After incubation at 37° C (in microaerophilic conditions for 48-72 hours for mutans and aerobiosis for 48 hours for Candida spp. and gram negative), in accordance with characteristic morphology, the number of characteristic colonies was countedand the number of CFU/ml calculated. Data were processed following transformation into the formula log10 (CFU +1) and statistically analyzed using the Student t test (&alpha; = 0.05) for laboratory analysis, and Friedman test (&alpha; = 0.05), for clinical analysis. The results showed that, in the laboratory study, sodium hypochlorite (0.25% and 0.5%) eliminated completely all microorganisms. The Castor oil solution eliminated B. subtilis, had no effect on E. faecalis and showed moderate antimicrobial activity against other strains, with a significant reduction (p <0.05) in the number of CFU compared with group D (positive control). In the clinical study, there was significant difference between the solutions (P <0.001), and 0.5% sodium hypochlorite had effective action on all evaluated microorganisms (Candida spp., S. mutans and gram negative); 0.25% sodium hypochlorite had effective action on S. mutans and moderate on Candida spp. and gram negative, and the castor oil solution had effective action on S. mutans and moderate against Candida spp. . The Candida species most often isolated was C. albicans, followed by the species C. tropicalis and C. glabrata. It was concluded that the solution of 0.5% sodium hypochlorite was the most effective presenting antimicrobial action on both biofilms (in vitro and in vivo), followed by 0.25% sodium hypochlorite solution that showed antimicrobial activity on biofilms in vitro and on S. mutans (biofilm in vivo). The 10% castor oil was less effective, with antimicrobial action on Bacillus subtilis (biofilm in vitro) and S. mutans (biofilm in vivo).

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-02T18:10:09Z No. of bitstreams: 1 tatianadiascosta.pdf: 1327074 bytes, checksum: 1b54c16084ca39ba9080752f52aa5c43 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-06-03T15:35:41Z (GMT) No. of bitstreams: 1 tatianadiascosta.pdf: 1327074 bytes, checksum: 1b54c16084ca39ba9080752f52aa5c43 (MD5) / Made available in DSpace on 2016-06-03T15:35:41Z (GMT). No. of bitstreams: 1 tatianadiascosta.pdf: 1327074 bytes, checksum: 1b54c16084ca39ba9080752f52aa5c43 (MD5) Previous issue date: 2014-08-29 / Neste estudo foi testada a hipótese de que instrumentos endodônticos fabricados com a liga de NiTi com tratamento térmico M-Wire são mais resistentes à corrosão em solução de NaOCl. Avaliou-se, por ensaio de polarização potenciodinâmica, a resistência à corrosão de 14 limas de NiTi sem tratamento de superfície (ProTaper® Universal Finishing 2 – F2, n = 7 e Mtwo® 25.07, n = 7) e de 14 limas de NiTi com tratamento de superfície (Reciproc® R25 25.08, n = 7 e Wave- One® Primary 25.08, n = 7), quando imersas em solução irrigante de NaOCl a 5,25%. Em miscroscópio eletrônico de varredura, as micromorfologias das 28 limas testadas foram analisadas antes e após o ensaio eletroquímico. As curvas de polarização anódica foram obtidas com potencial de varredura que iniciou no Ecorr de cada lima, com uma taxa de 0,333 mV/segundos (1,2 V/hora) até os Epite, sendo considerada como faixa passiva, a região onde os valores de potencial tinham densidade de corrente inferior a 10-5 A/cm2. A fim de se comparar as médias dos grupos aos pares foi empregada a prova não paramétrica de Mann-Whitney, utilizando-se o software estatístico SPSS-15 e o nível de significância adotado foi de p < 0,05. As curvas de polarização anódica demonstraram que todas as limas testadas foram passíveis de corrosão na solução de NaOCl a 5,25% (pH = 6,5). Observou-se que, no geral, apenas entre as limas Mtwo® (sem tratamento térmico) e Reciproc® (com tratamento térmico) não houve diferença estatisticamente significante para Epite ECS e Epite-Ecorr (p = 1,000). Ao se comparar, aos pares, as limas sem tratamento térmico (ProTaper® Universal F2 e Mtwo®) com as limas com tratamento térmico (Reciproc® e Wave-One®) não houve diferença estatisticamente significante (Ecorr ECS, p = 1,000; Epite ECS, p = 0,265; Epite-Ecorr, p = 0,265). A lima Reciproc® foi a que se apresentou mais resistente à corrosão e a ProTaper® foi a lima que mais sofreu corrosão na solução testada. Assim, a hipótese inicial de que instrumentos endodônticos fabricados com a liga de NiTi com tratamento térmico MWire são mais resistentes à corrosão em solução de NaOCl foi negada. / This study tested the hypothesis that endodontic instruments manufactured with the NiTi alloy heat treated M-Wire are more resistant to corrosion in NaOCl solution. Was evaluated by potentiodynamic polarization test, the corrosion resistance of NiTi files 14 without surface treatment (Universal ProTaper® Finishing 2 - F2, n = 7 and Mtwo® 25.07, n = 7) and 14 files NiTi with surface treatment (R25 Reciproc® 25.08, n = 7 and Primary Wave-One® 25.08, n = 7), when immersed in irrigating solution of NaOCl 5.25%. In electronic scanning microscopy, the micromorfologies of 28 tested files analyzed before and after the electrochemical test. The anodic polarization curves obtained by scanning the potential Ecorr that initiated in each file with a rate of 0.333 mV/sec (1.2 V/minute) to the Epite, being considered passive track, the region where the values potential had density of less than 10-5 A/cm2 current. In order to compare the averages of the groups in pairs used to non-parametric Mann-Whitney test, using the SPSS-15 statistical software and the significance level was p < 0.05. The anodic polarization curves show that all tested files are liable to the corrosion solution of 5.25% NaOCl (pH = 6.5). It was observed that, in general, only between Mtwo® (without heat treatment) and Reciproc® (heat treated) files there was no statistically significant difference for Epite ECS and Epite- Ecorr (p = 1.000). When comparing in pairs, the files without heat treatment (ProTaper® Universal F2 and Mtwo®) with files with heat treatment (Reciproc® and Wave-One®) there was no statistically significant difference (Ecorr ECS, p = 1.000; Epite ECS, p = 0.265; Epite-Ecorr, p = 0.265). The Reciproc® file introduced more resistant to corrosion and the ProTaper® was the file that suffered most corrosion in the tested solution. Thus, the initial hypothesis that endodontic instruments manufactured with the NiTi heat treated M-Wire are more resistant to corrosion in a solution of NaOCl was refused.

Les processus de lavage, et plus particulièrement l'utilisation de solutions chlorées, peuvent engendrer une dégradation prématurée des membranes de filtration d'eau. Alors que le marché des technologies membranaires en PVDF est en pleine expansion, peu de travaux portent sur l'étude de leur dégradation sur le long terme. Dans ce contexte, la thèse a porté sur l'étude du vieillissement de membranes de filtration commercialisées en PVDF. Les échantillons sont immergés dans une solution d'hypochlorite de sodium et l'effet du pH sur leur dégradation est approfondi. Les propriétés mécaniques, d'hydrophilie, les performances hydrauliques ainsi que la porosité sont étudiées. L'évolution des propriétés est mise en relation avec la structure chimique étudiée à différentes échelles : moléculaire, macromoléculaire et supramoléculaire. Cette approche n'a à ce jour jamais été utilisée dans le cas des membranes fibres creuses en PVDF. Les analyses en chromatographie d'exclusion stérique révèlent les modifications les plus importantes. La dégradation du PVDF des membranes se traduit par un phénomène prédominant de coupures de la chaîne principale du PVDF accompagné, dans une moindre mesure, d'un phénomène de réticulation. Les principales modifications sont constatées à des pHs inférieurs à 10 révélant la possible action conjointe des radicaux OH•, ClO• et Cl•. Le vieillissement d'une membrane PVDF additivée montre à la fois une dégradation du PVDF et une élimination des additifs. Alors que la membrane sans additif conserve une stabilité de ses propriétés, l'élimination des additifs entraine une évolution de la porosité et une propension au colmatage plus importante. Cependant, les membranes PVDF conservent des propriétés d'utilisation acceptables au regard des conditions extrêmes de vieillissement étudiées. / The cleaning processes, especially the use of chlorine solutions, may cause the untimely degradation of the water filtration membranes. While the market for PVDF membrane-based treatment technologies is rapidly expending, only few works deal with the study of their ageing on a long-term basis. In this context, this project focuses on the study of the ageing of two PVDF filtration membranes. Samples are immersed in a sodium hypochlorite solution and the effect of the chlorine solution pH is investigated. The properties of the membranes are characterized throughout the study by tensile tests, hydrophilicity, hydraulic performances and porosity analysis. The evolution of properties is related to the chemical structure of the membranes at a molecular, a macromolecular and a supramolecular scale. Until now, this approach has never been used in the case of PVDF membranes under chlorine conditions. The size exclusion chromatography analyses revealed the most important modifications. The degradation occurs mainly by chain scissions of the PVDF and crosslinking phenomenon in lesser extent. The main modifications occurred at pH less than 10 proving the joint action of OH•, ClO• and Cl• radicals. The ageing of the PVDF membrane containing additives showed at the same time the PVDF degradation and the elimination of the additives. Whereas the properties of the additive-free PVDF membrane were preserved, the elimination of additives led to a modification of the porosity and an increased fouling. However, even if the PVDF degradation is proved, the using properties of the PVDF membranes remain acceptable taking into consideration extreme conditions of ageing studied.

>Magister Scientiae - MSc / To address the urgent need for safe potable water in South Africa’s rural areas, sustainable systems for water disinfection at the village-scale of operation are required.In this thesis, the development of a small-scale water chlorination system that runs on salt and solar panels is described. The system combines a membrane-based hypochlorite generator, or “membrane electrolyser”, with an automated hypochlorite dosing system.The system was designed to (i) coordinate hypochlorite production and dosing automatically in a flow-through system, and (ii) fit inline with low pressure pipelines from overhead storage tanks or raised water sources. Low cost materials were used for construction, and water-powered mechanisms were devised to control both brine supply to the electrolyser and regulation of water flow. The capacity of the system was based on the maximum daily output of the electrolyser at ~20 g of sodium hypochlorite. This was sufficient chlorinate up to 10 kL of water per day using less than 80 g of salt and less than 0.1 kW.h of electricity. The cost of the system was estimated at ~R10 000 and therefore potentially affordable for communities up to 100 people, e.g. small farms and villages.Testing of the system was carried out at a farm site in Worcester (Western Cape) using remote monitoring of current levels in the electrolyser. Operation of the system over a two month test period, dosing at ~4 mg/L, produced consistent chlorination measured as(FAC). Community participation in maintenance of the brine supply was managed and chlorinated water was made available to the community after a brief social survey was conducted. Community awareness of chlorination was minimal. No significant history of diarrhoea was reported. However, the community regularly boiled their tap water in response to turbidity increase in summer.The system was affected by turbidity increase in the local water, which caused a drop in electrolyser current and chlorine production due to particle blockage of the membrane in the electrolyser. However, turbidity at acceptable levels for chlorination was found to have no detrimental effect on the system’s performance. The system showed promise for rural implementation providing low turbidity was maintained. Therefore,groundwater sites, and surface waters with appropriate clarification systems are recommended for the system’s installation. Further testing of the system will be required to establish its long term viability in the hands of a rural community.

Poor sanitation, unhygienic practices and close living associations between people and animals in rural communities increase the risk of zoonoses and add to faecal contamination of stored drinking water. Point-of-use interventions can improve the microbiological quality of household drinking water and a combination of microbial and chemical indicator tests could identify the origin of faecal pollution. The improvement of the microbiological quality of drinking water in rural households by the implementation of intervention strategies which included the use of traditional storage containers as well as an improved safe storage container (CDC, USA), with or without the addition of a sodium hypochlorite solution were determined. The origin of faecal contamination in the water sources and household stored water were determined using male specific F-RNA subgroup genotyping. This study attempted to assess the survival of indicator microorganisms and selected bacterial pathogens and viruses in the improved safe storage container in borehole and river water samples. An intervention study was conducted in two rural villages utilising different source water. Results indicated that the improved safe storage container without the addition of a stabilized sodium hypochlorite solution did not improve the microbiological quality of the stored drinking water and had counts of indicator microorganisms similar to that found in the traditional storage containers. However, the households using the 1% and the 3.5% sodium hypochlorite solutions have shown an effective reduction in the counts of indicator microorganisms in both the traditional and the improved safe storage containers. The compliance with the use of the sodium hypochlorite interventions ranged between 60% and 100%, which was in agreement with similar studies carried out in other developing countries. One village complied with the intervention while the other village did not. Reasons for this included financial factors, an unsupportive infrastructures and lack of education and knowledge on health risks by the households. Male specific F-RNA bacteriophage genotyping showed that faecal contamination in the water source samples and both the traditional and improved safe storage containers at the point-of-use were primarily of animal origin (Subgroup I). Households using river water had subgroup II F-RNA bacteriophages present in the stored household water, which was associated with human faecal pollution. However, subgroup II F-RNA bacteriophages has been isolated from faeces of cattle and poultry, which indicated that F-RNA subgroup typing might not be a specific tool to determine the origin of faecal pollution in water sources. Laboratory seeding experiments indicated that 1% sodium hypochlorite solution were less effective in reducing heterotrophic bacteria, Escherichia coli, Salmonella typhimurium, Clostridium perfringens, F-RNA bacteriophages and coxsackie B1 virus counts in the improved safe storage containers filled with river water with a high turbidity. However, the 1% sodium hypochlorite solution did reduce the indicator and seeded microorganisms within 60 min in containers filled with borehole water with a low turbidity. The 3.5% sodium hypochlorite solution effectively decreased the numbers of microorganisms to undetectable limits within 60 min in both the borehole and river filled storage containers irrespective of the turbidity values. This study has showed that a combination of intervention strategies can provide rural communities with microbiologically safe drinking water. / Thesis (PhD (Medical Virology))--University of Pretoria, 2008. / Medical Virology / PhD / unrestricted