O objetivo deste trabalho foi avaliar a efetividade do vedamento apical e linear de diferentes materiais utilizados como barreira protetora cervical (BPC) no clareamento interno, localizados ao mesmo nível e 1mm acima da junção amelocementária (JAC). Cento doze dentes bovinos foram divididos em sete grupos de acordo com o material de BPC utilizado, além de um grupo controle, e em dois subgrupos de acordo com a localização, sendo assim distribuídos: grupo GRC com resina composta sem sistema adesivo (Z250); grupo GVR com Cimento de Ionômero de Vidro (CIV) convencional (Vidrion R); grupo GVB com CIV modificado por resina de forramento (Vitrebond); grupo GVTR com CIV modificado por resina restaurador (Vitremer); grupo GCZ com Cimento de Fosfato de Zinco (CIMENTO DE ZINCO); grupo GCT com material restaurador provisório (Coltosol); grupo GCF com material provisório fotopolimerizável (Clip F); e grupo controle com Gutapercha e cimento selador (Fillapex). Os dentes foram clareados pela técnica walking bleach durante sete dias e após esse período foram corados durante 48hrs, enquanto armazenados com temperatura de 37oC e umidade a 100%. Foi realizada avaliação através de inspeção visual. A análise estatística foi feita através da análise de variância a dois critérios (ANOVA-2) e teste de Tukey. Os grupos experimentais revelaram que o único fator que representou importância no vedamento apical (F=26,42; p=0,00) e linear (F=29,73; p=0,00) foi o tipo de material empregado, independente da sua localização. Os grupos GRC e GCZ apresentaram os piores valores de vedamento e apresentaram diferença estatisticamente significativa (p=<0,05) quando comparados com os outros grupos e com o grupo controle. Os melhores resultados foram encontrados nos grupos GCT, GCF, GVB, GVTR e GVR, porém sem diferença estatisticamente significativa entre eles (p=<0,05) e com o grupo controle. Através do teste de correlação de Spearman verificou-se correlação positiva (r=0,911; p=0,00) entre a infiltração apical e linear. Os resultados sugerem que a capacidade de vedamento linear e apical da BPC varia de acordo com o material aplicado, independentemente da localização em relação à JAC. / The aim of this study was to evaluate the apical and linear sealing in different materials placed as a protective cervical barrier (BPC) in internal bleaching at Cementoenamel junction (CEJ) level and 1mm above. 112 bovine teeth were divided into seven groups according to the material to be placed as PCB and a control group, and two subgroups each in relation to their JAC level position: GRC Resin composite without adhesive system (Z250); GVR, Conventional glass ionomer cement (GIC) (VIDRION R); GVB, Lining resin modified GIC (VITREBOND); GVTR, Restorative resin modified GIC (VITREMER); GCZ, Zinc phosphate cement (CEMENTO DE ZINCO); GCT, Temporary restorative material (COLTOSOL), GCF, Light curing temporary material (CLIP F). A control group with gutta-percha and sealer cement (Fillapex) with the two positions was performed too. The teeth were bleached by walking bleach technique for seven days and then stained for 48hrs while stored at 37oC and humidity to 100%. Visual inspection was used to evaluate the specimens. Statistical analyses were performed with the two-factor analysis of variance (ANOVA-2) and Tukey test. The experimental groups showed that the main factor for apical (F=26.42, p=0.00) and linear (F=29.73; p=0.00) sealing was the type of material used regardless of their location. The experimental groups GRC and GCZ had the worst sealing values and were statistically significant different (p= < 0.05) with the other groups and the control group. The groups GCT, GCF, GVB, GVTR and GVR showed better result with no significance difference between them and the control group (p=< 0,05). The Spearman rank correlation coefficient revealed the positive significant correlation (r = 0.911, p = 0.00) between the apical and linear leakage. These results suggest that the ability of linear and apical sealing of PCB, varies according to the applied material regardless of the CEJ position.

Made available in DSpace on 2017-07-24T19:22:07Z (GMT). No. of bitstreams: 1 BEATRIZ ELENA.pdf: 622627 bytes, checksum: eccb1314f7dd53101ee09cc793932516 (MD5) Previous issue date: 2007-11-09 / Discoloration of acrylic resin denture teeth may result in patient dissatisfaction. The purpose of this study was to determine the color stability of three brands of acrylic resin denture teeth (Artplus, Biotone, Trilux) by subjecting them to four liquid foods (coffee, cola, red wine and distilled water). Twenty specimens (upper right central incisor teeth A2 shaded) were used. All specimens were stored in distilled water for 24 h at 37°C. At that time (T0) the color of all specimens was measured with a spectrophotometer (POCKETSPECA Color QA). Specimens were suspended in the liquid foods and after 15-day (T1) and 30-day (T2) periods of immersion the color of the specimens was measured again with the spectrophotometer. Color measurements were recorded using the CIEL*a*b* system with D65 (day light) light. The CIEL*a*b* system for measuring chromaticity was chosen to record color differences because it is well suited for determination of small color differences. Mean ΔE (color changes) values were calculated for each material and compared statistically with a two-way analyses of variance and calculating Tukey intervals at 0.95. In ΔE T0T1 the most severe discoloration was apparent with red wine when compared to the specimens stored in distilled water (P=0.003). In ΔE T0T2 the most staining solution was the red wine. Distilled water was the second staining liquid food which affect all acrylic resin denture teeth (P=0.024) and in the ΔE T1T2 no color differences (P=0.328) were found. The conclusions of this study exhibited the greatest chromatic change in red wine liquid food. The specimens immersed in distilled water exhibited their greatest color change after 24 h and 30 days. In the last period it was not found any differences among brands and liquid foods. / A alteração de cor de dentes artificiais de resina acrílica podem resultar na insatisfação dos pacientes. O propósito deste estudo foi determinar a estabilidade de cor de três marcas comerciais de dentes artificiais de resina acrílica (Artplus, Biotone e Trilux) imersos em quatro alimentos líquidos (café, Coca-cola, vinho tinto e água destilada). Vinte corpos-de-prova (incisivos centrais superiores da cor A2) foram utilizados. Cada corpo-de-prova foi suspenso dentro do alimento líquido com o auxílio de um fio dental para evitar contato com o recipiente. Todos os corpos-deprova foram imersos em água destilada por 24 h a 37 °C. Neste tempo (T0) a cor dos corpos-de-prova foi mensurada com espectrofotômetro (POCKETSPECA Color QA). Após 15 dias (T1) e 30 dias (T2) de imersão nos alimentos líquidos a cor dos corposde- prova for mensurada novamente com o espectrofotômetro. A mensuração de cor foi registrada usando o sistema CIEL*a*b* com iluminante D65 (luz do dia). Foi selecionado o sistema CIEL*a*b* para a mensuração cromática por registrar pequenas diferenças de cor. Os valores das médias de ΔE (alterações de cor) foram calculados para cada material e comparados estatisticamente por meio de análises de variância de dois fatores e calculando-se intervalos Tukey com nível de significância 0,95. Em ΔET0T1 a maior alterações de cor foi obtida com o vinho tinto quando comparada com os corpos-de-prova imersos em água destilada (P=0,003). Em ΔET0T2 a solução que causou maior alteração de cor foi o vinho tinto. A segunda solução que causou alteração de cor nos dentes de resina acrílica foi água destilada (P=0,024) e em ΔET1T2 não foram encontradas diferenças (P=0,328). De acordo com as conclusões deste estudo, o alimento líquido vinho tinto apresentou a maior alteração de cor. Os corpos-de-prova imersos em água destilada apresentaram sua maior alteração de cor após 24 h e 30 dias. No último período não foram encontradas diferenças entre as marcas e alimentos líquidos

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-04-07T12:52:15Z No. of bitstreams: 1 2014 - Carlos Henrique Rocha Gon?alves.pdf: 2447515 bytes, checksum: bcb566dd037e0d15e3e3ab74112d585e (MD5) / Made available in DSpace on 2017-04-07T12:52:15Z (GMT). No. of bitstreams: 1 2014 - Carlos Henrique Rocha Gon?alves.pdf: 2447515 bytes, checksum: bcb566dd037e0d15e3e3ab74112d585e (MD5) Previous issue date: 2014-02-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This work aimed to realize oxidative reactions using ozone in aqueous middle to simulate the aging aspect in Corymbia citriodora K.D. Hill & L.A.S. Johnson wood samples. Ozone that is a very reactive gas, was produced by the ozonizer by the corona effect. In order to evaluate the transformations occurred in the samples submitted to the treatment in different times and pHs (neutral, basic and acid) those samples were analyzed by various tests (color mensuration in the CIELAB colorimetric space; contact angle between water and wood by the goniometer; XPS spectroscopy and Pyrolysis ? GC/MS). The samples were obtained from a Corymbia citriodora tree log harvested in the UFRRJ campus in Serop?dica. Those samples were treated mechanically in order to adequate it to the analysis with 10 x 20 x 2 mm dimensions. It was observed that the 6h acid was the one that presented the best natural aging appearance. All the tests done have shown that the wood components had different behaviors in each treatment, especially when we talk about lignin and its G/S (Guaiacyl:Siringyl). The results have shown that the reactions were well succeed, revealing that the ozone had reacted in the majority of the samples, with the lignin, affecting the G/S ratio for all the treatments. XPS data showed the level of oxidation, for example, in the neutral treatment, showing ozone oxidative effect. In this way, the G/S ratio revealed that the ozone attack have occurred, first with the lignins that have predominantly the guaiacyl units, assuming that the reaction affected mainly the cellular region with high guaiacyl units content. It was also detected in the acid treatment, that the ozone as well reached the extractives group, especially the decanoic acids. All the experimentations were sufficient to discolor and give aging appearance to the wood, as the color changing shown by the color tests with the spectrophotometer. The contact angle has proved that the samples in order absorb more water, becoming more hydrophilic, when related to the L:C ratio (lignin:carbohydrate). / Esse trabalho teve por objetivo realizar rea??es oxidativas utilizando oz?nio em meio aquoso para simular o aspecto de envelhecimento em madeiras de Corymbia citriodora K.D. Hill & L.A.S. Johnson. O oz?nio que ? um g?s extremamente reativo foi produzido pelo ozonizador atrav?s da descarga corona. Para avaliar as modifica??es ocorridas nas amostras ap?s serem submetidas ?s rea??es de ozon?lise em diferentes tempos e pHs (neutro, b?sico e ?cido), essas amostras foram posteriormente submetidas a v?rios testes (mensura??o da cor no espa?o colorim?trico CIELAB; do ?ngulo de contato entre a ?gua e a madeira atrav?s do goni?metro; espectroscopia XPS (Espectroscopia Fotoeletr?nica de Raios-X) e pir?lise ? CG/EM (pir?lise analisada por cromatografia gasosa, acoplada ? um detector de massa)). As amostras foram obtidas de tora de madeira de um esp?cime da esp?cie Corymbia citriodora obtida no campus da UFRRJ em Serop?dica. Essas amostras foram tratadas mecanicamente de maneira a adequ?-la para an?lise, ficando com dimens?o de 10 x 20 x 2 mm. Foi constatado que as amostras do tratamento ?cido durante 6h foram as que ficaram com a apar?ncia mais pr?xima de uma madeira naturalmente envelhecida. Os diversos testes feitos mostraram que os componentes da madeira se comportaram de forma diferente em cada um dos tratamentos especialmente no que tange ? lignina na sua raz?o G/S da mesma. Os resultados mostraram que a rea??es foram bem sucedidas, revelando que o oz?nio reagiu na grande maioria das amostras com a lignina afetando a raz?o G/S para todos os tratamentos. Dados do XPS mostram os n?veis de oxida??o por exemplo dos tratamentos neutros, mostrando o efeito oxidativo do oz?nio. Neste sentido, a raz?o Guacila/Siringila revelou que o ataque do oz?nio aconteceu primeiramente com as ligninas que predominam unidades guaiacila, pressupondo que a rea??o afetou direcionadamente a regi?o da parede celular com mais alto teor de unidade Guaiac?la. Foi tamb?m detectado no tratamento ?cido que o oz?nio atingiu tamb?m o grupo dos extrativos especialmente os ?cidos decan?icos. Todos os experimentos foram suficientes para descolorir e dar apar?ncia de madeira envelhecida, como mudan?as de cor mostradas pelos testes de cor com espectrofot?metro. O ?ngulo de contato mostrou que as amostras em ordem absorvem mais ?gua, tornando-as mais hidrof?lica, quando correlacionada ? raz?o C:L (Carboidratos:Lignina).

<p>Pectinases are a group of enzymes produced by bacteria, fungi, higher plants and animals. Pectinases can modify and degrade pectins, a class of heterogeneous and multifunctional polysaccharides present in middle lamellae and primary cell walls of plants. Pectins have been showed to play diverse roles in cell physiology, growth, adhesion and separation. Pectinases are used technically in the processing of fiber production and fruit juice or wine making. We have studied the mechanisms and applications of pectinases, especially in retting, a microbiological process where bast fibers in flax and other bast fiber cultivars are released from each other and from the woody core.</p><p>A strong correlation was found between the ability to perform retting and the degradation of sparsely esterified pectin, a substrate of polygalacturonase. This led to the conclusion that polygalacturonase plays a key role in the enzymatic retting of flax. We purified and characterized an extracellular polygalacturonase produced by Rhizopus oryzae, a very potent retting organism. The purified enzyme which appeared to be the single active component in retting, has non-methylated polygalacturonan as its preferred substrate. Peptide sequences indicate that the enzyme, like another polygalacturonase (EC. 3.2.1.15), belongs to glycosyl hydrolase family 28. It contains, however, an N-terminal sequence absent from other fungal pectinases, but present in an enzyme from the phytopathogenic bacterium, Ralstonia solanacearum.</p><p>Our finding that removal of calcium ions from the plant material by pre-incubation in dilute acid in enzymatic retting could reduce enzyme consumption by several orders of magnitude, improves the economical feasibility of the enzymatic retting process. Comparisons with different acids showed that the action was mainly pH dependent.</p><p>Pectinases were employed as analytical tools in a study of stored wood discoloration and, together with cellulases, in a mechanical process for making pulp from flax and hemp in paper production. </p>

Pectinases are a group of enzymes produced by bacteria, fungi, higher plants and animals. Pectinases can modify and degrade pectins, a class of heterogeneous and multifunctional polysaccharides present in middle lamellae and primary cell walls of plants. Pectins have been showed to play diverse roles in cell physiology, growth, adhesion and separation. Pectinases are used technically in the processing of fiber production and fruit juice or wine making. We have studied the mechanisms and applications of pectinases, especially in retting, a microbiological process where bast fibers in flax and other bast fiber cultivars are released from each other and from the woody core. A strong correlation was found between the ability to perform retting and the degradation of sparsely esterified pectin, a substrate of polygalacturonase. This led to the conclusion that polygalacturonase plays a key role in the enzymatic retting of flax. We purified and characterized an extracellular polygalacturonase produced by Rhizopus oryzae, a very potent retting organism. The purified enzyme which appeared to be the single active component in retting, has non-methylated polygalacturonan as its preferred substrate. Peptide sequences indicate that the enzyme, like another polygalacturonase (EC. 3.2.1.15), belongs to glycosyl hydrolase family 28. It contains, however, an N-terminal sequence absent from other fungal pectinases, but present in an enzyme from the phytopathogenic bacterium, Ralstonia solanacearum. Our finding that removal of calcium ions from the plant material by pre-incubation in dilute acid in enzymatic retting could reduce enzyme consumption by several orders of magnitude, improves the economical feasibility of the enzymatic retting process. Comparisons with different acids showed that the action was mainly pH dependent. Pectinases were employed as analytical tools in a study of stored wood discoloration and, together with cellulases, in a mechanical process for making pulp from flax and hemp in paper production.

Firefighters’ coats and pants, referred to as firefighters’ protective clothing in this research, are made of similar fabrics and often include three layers: an outer shell, a moisture barrier, and a thermal liner. Minimum requirements of firefighters’ protective clothing performance have been clearly established by various national and international standards for new clothing to ensure the reasonable safety of firefighters. However, there are no clear guidelines on the requirements for continuing performance of firefighters’ protective clothing. In general, the protection offered by firefighters’ protective clothing is expected to deteriorate over time, but it is still uncertain how destructive different exposures are and how long a piece of firefighters’ protective clothing can continue to protect a firefighter to an acceptable level. Non-destructive techniques are preferable in order to investigate how the performance of protective clothing may change with time since this allows firefighters’ protective clothing to return to service after a test. These non-destructive methods, which could be used to monitor the level of deterioration in firefighters’ protective clothing performance and to make decisions on retirement of individual pieces of protective clothing, would be extremely useful for fire departments in Canada and other countries. Thermal exposure is an important factor in ageing of firefighters’ protective clothing during firefighting operations. Outer shell and moisture barrier specimens made of common fabrics used in construction of firefighters’ protective clothing, and of different colours, were exposed to different levels of thermal exposure simulated using a cone calorimeter in single and multiple stages. Tensile strength of outer shell specimens, and tear strength, water vapour transmission rate, and water penetration pressure of moisture barrier specimens, which are critical aspects of performance of firefighters’ protective clothing, were measured. In order to explain the changes in performance after thermal exposure, the temperature profile of specimens during each thermal exposure was recorded. Furthermore, thermogravimetric analysis for each specimen material was carried out and images of the surface of specimens were obtained using scanning electron microscope. The test results demonstrated that tensile strength of outer shell specimens deteriorated faster than other aspects of performance. Two non-destructive techniques, colour measurement and near infrared spectroscopy, were implemented to correlate tensile strength of outer shell specimens with discoloration and reflectance spectrum. Two types of correlation between tensile strength and colour change were identified among the tested fabrics, depending on the initial fabric colour, which could be a basis to develop numerical models to predict tensile strength of outer shell specimens. Linear predictive equations were developed using a numerical code based on regression analysis, which correlated tensile strength with reflectance of outer shell specimens within the wavelength region of 1500-2500 nm. A three-variable model predicted tensile strength of thermally aged test specimens, the tensile strength of which were 600 N and higher, with a relative error of up to 10%. For test specimens with tensile strength of about 300 N, the relative error was 55%. The difference in error percentage was related to a gap in training data points for the model within the tensile strength range of 300 - 600 N.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2001. / Härtill 4 uppsatser.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo desse estudo foi comparar a capacidade de dois materiais restauradores em prevenir a descoloração coronária causada pela minociclina como medicação intracanal e propor uma técnica de fácil implementação para encorajar o uso da pasta tri-antibiótica para desinfecção do sistema de canais radiculares durante procedimentos de regeneração pulpar sem perda estética. Cem dentes foram selecionados, seus canais radiculares foram instrumentados e divididos em quatro grupos de acordo com o tratamento dentinário utilizado: Grupo OB- Agente adesivo OptiBond All-In-One (KERR); Grupo U200- Cimento resinoso auto-condicionante e auto adesivo RelyX U200 (3M ESPE); Grupo MIN- Sem revestimento; Grupo CN- Sem revestimento (controle negativo). Em todos os grupos, com exceção do CN, foi utilizada pasta de minociclina como medicação intracanal coberta por uma bolinha de algodão e vedados com restauração provisória. As medições de cor foram realizadas com um espectrofotômetro no início do estudo (T0), e 7(T7), 14 (T14), 21 (T21) e 28 dias (T28) pós-minociclina. Os resultados obtidos foram submetidos à análise estatística. As diferenças de cor (&#61508;E*) foram crescentes nos grupos CN, OB, U200 e MIN, respectivamente. A diferença de luminosidade (&#61508;L*) foi também crescente nos grupos CN, OB, U200 e MIN, respectivamente. Houve diferença significante entre os grupos MIN e CN, e entre os grupos MIN e U200 (p<0,05). O eixo amarelo-azul (&#61508;b*) não apresentou alteração de cor significante (p>0,05). Uma alteração de cor significante no eixo vermelho-verde (&#61508;a*) foi observada no grupo MIN em relação ao grupo CN (p<0,05). Portanto, conclui-se que a técnica foi fácil de ser implementada, ambos materiais reduziram a descoloração da coroa causada pela pasta de minociclina mas foram ineficazes em impedi-la completamente. / The aim of this work was to assess the ability of two restorative materials to prevent crown discoloration caused by topic use of minocycline as an intracanal medicament and to propose an easy to implement technique to encourage the use of the tri-antibiotic paste to disinfect the root canal system during pulp regeneration procedures without aesthetic depletion. One hundred teeth were divided into four groups after access and instrumentation by the dentinary treatment: Group OB- Self etching bonding agent OptiBond All-In-One (KERR); Group U200- Self etching resin cement RelyX U200 (3M ESPE); Group MIN- Without restorative material; Group CN- Without restorative material. All groups, except CN, received minocycline as intracanal medicament covered by cotton pellet and sealed with provisional restoration. Color determination were performed with an spectrophotometer at the beginning of the study (T0), 7 days (T7), 14 days (T14), 21 days (T21) and 28 days (T28) after intracanal placement of the minocycline paste. The results were statistically analyzed. Overall color difference (&#61508;E*) increased from Grupo CN, Grupo OB, Grupo U200 and Grupo MIN respectively. There was significant difference between groups MIN and CN, and between groups MIN and U200 (p<0,05). Luminosity difference (&#61508;L*) increased from Groupo CN, Groupo OB, Grupo U200 and Grupo MIN respectively. There was significant difference between groups CN and MIN, between groups MIN and OB, and between groups MIN and U200 (p<0,05). Color variance in the blue-yellow axis (&#61508;b*) showed no statistical difference (p>0,05). Color variance in the red-green axis (&#61508;a*) was significant between groups MIN and CN (p<0,05). We concluded that the technique was indeed easy to implement, both materials reduced the crown discoloration caused by the minocycline paste but were unable to prevent it completely.

Submitted by JULIANA BOA SORTE DE OLIVEIRA null (grc@unesp.br) on 2016-03-16T06:46:22Z No. of bitstreams: 1 Dissertação - Juliana Boa Sorte.pdf: 1304673 bytes, checksum: dde4b206040aaf2ec3e5e04e1bf030eb (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-03-18T12:55:01Z (GMT) No. of bitstreams: 1 oliveira_jbs_me_sjc.pdf: 1304673 bytes, checksum: dde4b206040aaf2ec3e5e04e1bf030eb (MD5) / Made available in DSpace on 2016-03-18T12:55:01Z (GMT). No. of bitstreams: 1 oliveira_jbs_me_sjc.pdf: 1304673 bytes, checksum: dde4b206040aaf2ec3e5e04e1bf030eb (MD5) Previous issue date: 2016-01-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Objetivos: o objetivo deste estudo foi comparar a efetividade de enxaguatórios clareadores sobre dentes, clareados previamente ou não, expostos a corantes alimentícios. Material e Método: Cento e vinte espécimes de esmalte e dentina de 3 mm de diâmetro foram obtidos a partir de incisivos bovinos. Os espécimes foram manchados por 14 dias em caldo de manchamento. Após o manchamento, a leitura inicial da cor foi realizada, por meio do espectrofotômetro CM-2600d (Konica Minolta, Osaka, Japão). Sessenta espécimes (Subgrupos PC) foram submetidos ao clareamento com Peróxido de Carbamida a 10% por 14 dias. Após, foram subdividos em 4 subgrupos, com ciclos de manchamento (5 min) e enxaguatório (2 min) por 12 semanas, sendo PC-LI: Listerine Whitening Pré-escovação; PC-PL: Plax Whitening; PC-BP: Bromelina + Papaína; PC-AG: água deionizada. Os subgrupos LI, PL, BP e AG foram submetidos aos mesmos ciclos citados, porém não foram submetidos ao clareamento prévio. A leitura de cor dos espécimes foi feita após 4, 8 e 12 semanas de tratamento com os enxaguatórios. Os dados foram coletados e submetidos à Análise de variância (ANOVA) de medidas repetidas. A comparação entre os subgrupos para a avaliação das diferenças estatísticas foi realizada pelo Teste de Tukey. Todos os testes empregados admitiram 5% como nível de significância estatística. Os resultados mostraram que os valores de ΔL*, Δa*, Δb* e ΔE* confirmaram o clareamento para os subgrupos PC-LI, PC-PL, PC-BP e PC-AG, após o tratamento com peróxido de carbamida, e para os subgrupos PC-LI, PC-PL, LI e PL, após os ciclos manchamento-enxaguatório. Os subgrupos PC-BP e BP assemelharam-se aos subgrupos controle PC-AG e AG. Conclui-se, desse modo, que o enxaguatório bucal Listerine Whitening apresentou maior efeito clareador, seguido do enxaguatório Plax Whitening. Porém, nenhum desses enxaguatórios foi capaz de produzir clareamento semelhante ao evidenciado pelo Peróxido de Carbamida. O enxaguatório contendo Bromelina e Papaína em sua composição não evidenciou efeito clareador, assemelhando-se aos subgrupos controle. / Objectives: The aim of this study was to compare the effectiveness of whitening mouthrinses on teeth previously whitened or not, exposed to food dyes. Material and Methods: One hundred and twenty specimens of enamel and dentin of 3 mm in diameter were obtained from bovine incisors. The specimens were stained for 14 days in broth staining. After staining, the initial color reading was performed by a spectrophotometer CM-2600d (Konica Minolta, Osaka, Japan). Sixty specimens (Subgroups CP) were submitted to whitening (Carbamide Peroxide 10%) for 14 days. Then they were subdivided into 3 subgroups, and were submitted to cycles of staining (5 min) and mouthrinse (2 min) for 12 weeks, with CP-LI: Listerine Whitening Pré-Escovação; CP-PL: Plax Whitening; CP-BP: Bromelain + Papain; CP-DW: deionized water. LI, LP, BP and DW subgroups were submitted to the same cited cycles, but without bleaching before. The color measurements were performed after 4, 8 and 12 weeks of treatment with mouthrinses. Data were collected and subjected to analysis of variance (ANOVA) for repeated measures. The comparison between the subgroups for the evaluation of statistical differences was performed by Tukey test. All tests admitted statistical significance level of 5%. The results showed that the values ΔL*, Δa*, Δb* and ΔE* confirmed bleaching to PC-LI, PC-PL, PC-BP and PC-DW subgroups, after treatment with carbamide peroxide and to CP-LI, CP-PL, LI and PL subgroups, after the staining-mouthrinse cycles. CP-BP and BP subgroups were similar to CP-DW and DW. We conclude, therefore, that the mouthrinse Listerine Whitening presented the highest bleaching effect, followed by mouthrinse Plax Whitening. Both of them were able to maintain the bleaching effect of CP after 12 weeks of dye-rinse cycles. However, none of these rinses was able to produce whitening similar to that evidenced by the Carbamide Peroxide. The mouthrinse containing Bromelain and Papain in its composition did not show bleaching effect, resembling the control subgroups.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo desse estudo foi comparar a capacidade de dois materiais restauradores em prevenir a descoloração coronária causada pela minociclina como medicação intracanal e propor uma técnica de fácil implementação para encorajar o uso da pasta tri-antibiótica para desinfecção do sistema de canais radiculares durante procedimentos de regeneração pulpar sem perda estética. Cem dentes foram selecionados, seus canais radiculares foram instrumentados e divididos em quatro grupos de acordo com o tratamento dentinário utilizado: Grupo OB- Agente adesivo OptiBond All-In-One (KERR); Grupo U200- Cimento resinoso auto-condicionante e auto adesivo RelyX U200 (3M ESPE); Grupo MIN- Sem revestimento; Grupo CN- Sem revestimento (controle negativo). Em todos os grupos, com exceção do CN, foi utilizada pasta de minociclina como medicação intracanal coberta por uma bolinha de algodão e vedados com restauração provisória. As medições de cor foram realizadas com um espectrofotômetro no início do estudo (T0), e 7(T7), 14 (T14), 21 (T21) e 28 dias (T28) pós-minociclina. Os resultados obtidos foram submetidos à análise estatística. As diferenças de cor (&#61508;E*) foram crescentes nos grupos CN, OB, U200 e MIN, respectivamente. A diferença de luminosidade (&#61508;L*) foi também crescente nos grupos CN, OB, U200 e MIN, respectivamente. Houve diferença significante entre os grupos MIN e CN, e entre os grupos MIN e U200 (p<0,05). O eixo amarelo-azul (&#61508;b*) não apresentou alteração de cor significante (p>0,05). Uma alteração de cor significante no eixo vermelho-verde (&#61508;a*) foi observada no grupo MIN em relação ao grupo CN (p<0,05). Portanto, conclui-se que a técnica foi fácil de ser implementada, ambos materiais reduziram a descoloração da coroa causada pela pasta de minociclina mas foram ineficazes em impedi-la completamente. / The aim of this work was to assess the ability of two restorative materials to prevent crown discoloration caused by topic use of minocycline as an intracanal medicament and to propose an easy to implement technique to encourage the use of the tri-antibiotic paste to disinfect the root canal system during pulp regeneration procedures without aesthetic depletion. One hundred teeth were divided into four groups after access and instrumentation by the dentinary treatment: Group OB- Self etching bonding agent OptiBond All-In-One (KERR); Group U200- Self etching resin cement RelyX U200 (3M ESPE); Group MIN- Without restorative material; Group CN- Without restorative material. All groups, except CN, received minocycline as intracanal medicament covered by cotton pellet and sealed with provisional restoration. Color determination were performed with an spectrophotometer at the beginning of the study (T0), 7 days (T7), 14 days (T14), 21 days (T21) and 28 days (T28) after intracanal placement of the minocycline paste. The results were statistically analyzed. Overall color difference (&#61508;E*) increased from Grupo CN, Grupo OB, Grupo U200 and Grupo MIN respectively. There was significant difference between groups MIN and CN, and between groups MIN and U200 (p<0,05). Luminosity difference (&#61508;L*) increased from Groupo CN, Groupo OB, Grupo U200 and Grupo MIN respectively. There was significant difference between groups CN and MIN, between groups MIN and OB, and between groups MIN and U200 (p<0,05). Color variance in the blue-yellow axis (&#61508;b*) showed no statistical difference (p>0,05). Color variance in the red-green axis (&#61508;a*) was significant between groups MIN and CN (p<0,05). We concluded that the technique was indeed easy to implement, both materials reduced the crown discoloration caused by the minocycline paste but were unable to prevent it completely.