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[pt] O propósito deste estudo in vitro foi avaliar a qualidade de obturações endodônticas em relação ao selamento apical e marginal, comparando duas técnicas de obturação: Condensação Lateral (CL) e Condensação Vertical (CV) da guta-percha aquecida. Foram utilizadas 40 amostras que foram submetidas à penetração passiva de solução de nitrato de prata a 50% e divididas em dois grupos. Para cada grupo de amostras infiltradas foi utilizada uma metodologia diferente. O grupo 1, com cada metade das amostras obturadas com um tipo de técnica de obturação, foi preparado para microscopia Óptica (MO), processamento digital de imagens (PDI) e espectrometria de absorção atômica (EAA). O grupo 2, com metade das amostras obturadas por cada uma das técnicas, foi preparado para microscopia eletrônica de varredura (MEV). Através da MO e PDI, as amostras foram avaliadas quanto à qualidade das obturações, quantificando o percentual de guta-percha e cimento presentes. Através da utilização da EAA, a massa de prata infiltrada na obturação foi quantificada e finalmente, com o uso da MEV, a adaptação marginal dos materiais obturadores às paredes do canal radicular foi avaliada. Nas condições experimentais em que este trabalho foi conduzido e através da análise estatística, concluiu-se que houve diferença estatisticamente significante em relação ao selamento apical produzido pelas duas técnicas de obturação avaliadas e quanto à qualidade de preenchimento das obturações. Nas observações ao MEV, a CV mostrou uma melhor adaptação do material obturador às paredes dentinárias quando comparada com a CL em algumas regiões do canal radicular. / [en] The aim of this in vitro study was to evaluate the quality of endodontics obturations in relation to apical and marginal sealing comparing two obturation techniques: lateral condensation and vertical condensation of warm gutta-percha. Forty samples were used and submitted to passive penetration of a 50% silver nitrate solution. The samples were divided in two equal-sized groups. For each group a different methodology was used. Group 1, with half of the samples obturated by each different technique, was prepared for optical microscopy (OM), digital image processing (DIP) and atomic absorption spectrometry (AAS). Group 2, again with half of the samples obturated by each technique, was prepared for scanning electron microscope (SEM). Using OM and DIP, the quality of the obturation was evaluated and the percent of gutta-percha and sealer present was quantified. Using AAS, the leakage of silver was quantified. Finally, the marginal adaptation of obturation materials in the root canal walls was evaluated with SEM. Statistical analysis showed significant differences in apical sealing produced by the two obturation techniques and in the quality of obturation fillings. In SEM observations, the vertical condensation method showed a better adaptation to the dentin walls when compared with lateral condensation at some regions of the root canal.

No description available.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esse trabalho teve como objetivo avaliar a qualidade de padronização dos cones acessórios Fine Medium (FM), Medium (M) e Medium Large (ML) de cinco diferentes marcas comerciais de cones de guta-percha e de uma marca de cone Resilon, através do desenvolvimento de um método automático de processamento e análise digital de imagens. Para tal, 21 cones de cada conicidade e marca comercial foram digitalizados em um scanner com 1200 DPI, o que implica em uma precisão de 0.021 mm, e uma rotina de processamento digital das imagens foi desenvolvida para obter medições automáticas dos seguintes parâmetros: diâmetro da ponta (D0), diâmetro a 3 mm da ponta (D3), diâmetro a 16 mm da ponta (D16), comprimento (L) e conicidade (C). As medidas encontradas foram submetidas a análises estatísticas e comparações entre os grupos das médias de cada parâmetro avaliado. As especificações ANSI/ADA números 57 e 78 foram empregadas como referências para a análise da estandardização dos cones testados. De posse dos resultados, foi possível concluir que existe uma ineficaz padronização dos cones obturadores, os quais apresentaram grandes variações entre as diversas marcas testadas e dentro de uma mesma marca. O método desenvolvido para medição dos parâmetros de controle dos cones se mostrou bastante eficaz, gerando resultados confiáveis. / The present study aimed to evaluate the standardization quality of the accessory gutta-percha cones Fine Medium (FM), Medium (M) and Medium Large (ML) of five different commercial brands of gutta-percha cones and a brand of Resilon cone, through the development of an automated method of digital image processing and analysis sequence. Hence, 21 cones of each conicity and commercial brand were digitalized with a scanner with 1200 DPI, which implicates on a precision of 0,021mm and a sequence of digital image processing were developed to obtain automatic measures of the following parameters: D0, D3, D16, length (L) and conicity (C). The measures found were submitted to statistical analysis and comparisons among the groups of the means of each parameter evaluated. Numbers 57 and 78 ANSI/ADA specifications were used as references to the standardization analysis of the tested cones. Based on the results obtained it was possible to conclude that there is an inefficient standardization of obturating cones, which presented large variations among the different tested brands and in a single brand also. The method developed to measure the parameters of the obturating cones control group was very efficient, producing reliable results.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo desse trabalho foi avaliar a biocompatibilidade de um material a base de guta-percha autoadesiva (Bio-Gutta) em tecido subcutâneo de camundongos. A guta-percha convencional foi utilizada como referência para comparação. Para isso, foram utilizados 30 camundongos, os quais foram distribuídos aleatoriamente em dois grupos (Bio-Gutta e guta-percha convencional). Os materiais avaliados foram implantados na região dorsal dos camundongos. Após 7, 21 e 63 dias, os animais foram sacrificados e 5 amostras por grupo por tempo experimental foram obtidas. As amostras histológicas foram seccionadas em 5 m de espessura e coradas convencionalmente com hematoxilina e eosina. Um escore de I-IV foi utilizado para graduar a reação inflamatória. O teste U de Mann-Whitney com correção de Bonferroni foi utilizado para análise estatística (p < 0,05). Os resultados mostraram que, após 7 dias, a Bio-Gutta induziu uma reação tecidual de leve a moderada (II) e a guta-percha convencional apresentou uma resposta inflamatória de moderada a intensa (III). Após 21 dias, a Bio-Gutta induziu uma leve reação tecidual (I), enquanto que a guta-percha convencional ainda apresentava uma resposta inflamatória moderada (III). Uma reação tecidual de leve a ausente (I) foi observada na Bio-Gutta após 63 dias, ao passo que na guta-percha convencional observou-se uma resposta inflamatória de leve a moderada (II). Houve diferença significativa na mediana do grau de inflamação entre os grupos em cada tempo experimental (p = 0,005, aos 7 dias; p = 0,011, aos 21 dias; e p = 0,003, aos 63 dias). Concluiu-se então que a Bio-Gutta foi mais biocompatível que a guta-percha convencional em tecido subcutâneo de camundongos apresentando uma boa resposta tecidual. / The purpose of this study was to evaluate the biocompatibility of a self-adhesive gutta-percha material (Bio-Gutta) in connective tissue of mice. Conventional gutta-percha was used as reference for comparison. Thirty mice were used in this study and they were randomly assigned into two groups (Bio-Gutta and conventional gutta-percha). The tested materials were implanted in the dorsal region of mice. After 7, 21 and 63 days, animals were sacrificed and 5 samples per group per time-point were obtained. Histologic samples were sectioned in 5 m thickness and stained with conventional hematoxylin and eosin. A grade from I-IV was used to graduate the inflammatory reaction. Bonferroni-corrected Mann-Whitney U test was used for statistical analysis (p < 0,05). The results showed that after 7 days Bio-Gutta induced a slight to moderate tissue reaction (II) and conventional gutta-percha presented a moderate to intense inflammatory response (III). After 21 days, Bio-Gutta presented a slight tissue reaction (I), while conventional gutta-percha still showed a moderate inflammatory response (III). A slight to absent tissue reaction (I) was observed in Bio-Gutta after 63 days, whereas conventional gutta-percha showed a slight to moderate inflammatory response (II). There was a significant difference in the median degree of inflammation between the groups at each time-point (p = 0,005, at 7 days; p = 0,011, at 21 days; and p = 0,003, at 63 days). It was concluded that Bio-Gutta was more biocompatible than conventional gutta-percha in subcutaneous tissue of mice showing a good tissue response.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esse trabalho teve como objetivo avaliar a qualidade de padronização dos cones acessórios Fine Medium (FM), Medium (M) e Medium Large (ML) de cinco diferentes marcas comerciais de cones de guta-percha e de uma marca de cone Resilon, através do desenvolvimento de um método automático de processamento e análise digital de imagens. Para tal, 21 cones de cada conicidade e marca comercial foram digitalizados em um scanner com 1200 DPI, o que implica em uma precisão de 0.021 mm, e uma rotina de processamento digital das imagens foi desenvolvida para obter medições automáticas dos seguintes parâmetros: diâmetro da ponta (D0), diâmetro a 3 mm da ponta (D3), diâmetro a 16 mm da ponta (D16), comprimento (L) e conicidade (C). As medidas encontradas foram submetidas a análises estatísticas e comparações entre os grupos das médias de cada parâmetro avaliado. As especificações ANSI/ADA números 57 e 78 foram empregadas como referências para a análise da estandardização dos cones testados. De posse dos resultados, foi possível concluir que existe uma ineficaz padronização dos cones obturadores, os quais apresentaram grandes variações entre as diversas marcas testadas e dentro de uma mesma marca. O método desenvolvido para medição dos parâmetros de controle dos cones se mostrou bastante eficaz, gerando resultados confiáveis. / The present study aimed to evaluate the standardization quality of the accessory gutta-percha cones Fine Medium (FM), Medium (M) and Medium Large (ML) of five different commercial brands of gutta-percha cones and a brand of Resilon cone, through the development of an automated method of digital image processing and analysis sequence. Hence, 21 cones of each conicity and commercial brand were digitalized with a scanner with 1200 DPI, which implicates on a precision of 0,021mm and a sequence of digital image processing were developed to obtain automatic measures of the following parameters: D0, D3, D16, length (L) and conicity (C). The measures found were submitted to statistical analysis and comparisons among the groups of the means of each parameter evaluated. Numbers 57 and 78 ANSI/ADA specifications were used as references to the standardization analysis of the tested cones. Based on the results obtained it was possible to conclude that there is an inefficient standardization of obturating cones, which presented large variations among the different tested brands and in a single brand also. The method developed to measure the parameters of the obturating cones control group was very efficient, producing reliable results.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo desse trabalho foi avaliar a biocompatibilidade de um material a base de guta-percha autoadesiva (Bio-Gutta) em tecido subcutâneo de camundongos. A guta-percha convencional foi utilizada como referência para comparação. Para isso, foram utilizados 30 camundongos, os quais foram distribuídos aleatoriamente em dois grupos (Bio-Gutta e guta-percha convencional). Os materiais avaliados foram implantados na região dorsal dos camundongos. Após 7, 21 e 63 dias, os animais foram sacrificados e 5 amostras por grupo por tempo experimental foram obtidas. As amostras histológicas foram seccionadas em 5 m de espessura e coradas convencionalmente com hematoxilina e eosina. Um escore de I-IV foi utilizado para graduar a reação inflamatória. O teste U de Mann-Whitney com correção de Bonferroni foi utilizado para análise estatística (p < 0,05). Os resultados mostraram que, após 7 dias, a Bio-Gutta induziu uma reação tecidual de leve a moderada (II) e a guta-percha convencional apresentou uma resposta inflamatória de moderada a intensa (III). Após 21 dias, a Bio-Gutta induziu uma leve reação tecidual (I), enquanto que a guta-percha convencional ainda apresentava uma resposta inflamatória moderada (III). Uma reação tecidual de leve a ausente (I) foi observada na Bio-Gutta após 63 dias, ao passo que na guta-percha convencional observou-se uma resposta inflamatória de leve a moderada (II). Houve diferença significativa na mediana do grau de inflamação entre os grupos em cada tempo experimental (p = 0,005, aos 7 dias; p = 0,011, aos 21 dias; e p = 0,003, aos 63 dias). Concluiu-se então que a Bio-Gutta foi mais biocompatível que a guta-percha convencional em tecido subcutâneo de camundongos apresentando uma boa resposta tecidual. / The purpose of this study was to evaluate the biocompatibility of a self-adhesive gutta-percha material (Bio-Gutta) in connective tissue of mice. Conventional gutta-percha was used as reference for comparison. Thirty mice were used in this study and they were randomly assigned into two groups (Bio-Gutta and conventional gutta-percha). The tested materials were implanted in the dorsal region of mice. After 7, 21 and 63 days, animals were sacrificed and 5 samples per group per time-point were obtained. Histologic samples were sectioned in 5 m thickness and stained with conventional hematoxylin and eosin. A grade from I-IV was used to graduate the inflammatory reaction. Bonferroni-corrected Mann-Whitney U test was used for statistical analysis (p < 0,05). The results showed that after 7 days Bio-Gutta induced a slight to moderate tissue reaction (II) and conventional gutta-percha presented a moderate to intense inflammatory response (III). After 21 days, Bio-Gutta presented a slight tissue reaction (I), while conventional gutta-percha still showed a moderate inflammatory response (III). A slight to absent tissue reaction (I) was observed in Bio-Gutta after 63 days, whereas conventional gutta-percha showed a slight to moderate inflammatory response (II). There was a significant difference in the median degree of inflammation between the groups at each time-point (p = 0,005, at 7 days; p = 0,011, at 21 days; and p = 0,003, at 63 days). It was concluded that Bio-Gutta was more biocompatible than conventional gutta-percha in subcutaneous tissue of mice showing a good tissue response.

Objetivo: Evaluar la eficacia disolvente de una sustancia experimental a base de Aceite esencial de Myrciaria dubia en la desobturación de conductos radiculares. Materiales y métodos: Se utilizaron 60 tubos de PLA (ácido poliláctico)que fueron divididos en 5 grupos de 12 especímenes. Estos se rellenaron con un material de restauración temporal (coltosol) el primer tercio y el tercio medio con gutapercha. Se añadió un total de 0,1 ml de disolvente dependiendo del grupo de estudio (Agua destilada,camu camu, xilol,aceite de cascara de naranja y de eucalipto) a la parte superior de los tubos de PLA. Después de 5 minutos, se utilizó la máquina Instron 5566 (Instron, Buckinghamshire, UK) se movió hacia abajo a través de gutapercha con una velocidad de cabecera de 5 mm / min a una profundidad de 5 mm min. La carga(fuerza) utilizada para penetrar el separador en la profundidad de 5 mm se registró en Newton. Para el análisis se realizará la prueba de kruskal Wallis para comparar la medida fuerza de penetración según el tipo de solvente, posterior a comprobarse los supuestos estadísticos. Resultados: Se encontraron diferencias estadísticamente significativas al comparar todos los solventes (p= 0.001), obteniendo 14.02N para la sustancia experimental. Los resultados de la profundidad de disolución superficial y la fuerza utilizada para penetrar el esparcidor a 5 mm revelaron que el Aceite de Myrciaria Dubia ( Camu Camu) fue significativamente el mejor solvente para ablandar la gutapercha (P <0.05), seguido del xilol y el aceite de cascara de naranja, mientras que el disolvente con menos efectividad fue el aceite de eucalipto. Conclusiones: El aceite esencial de Myrciaria Dubia presento mayor poder reblandecedor que las demás soluciones en estudio. / Objective: To evaluate the solvent efficacy of an experimental substance based on Myrciaria dubia essential oil in the desobturation of root canals. Materials and methods: 60 PLA (polylactic acid) tubes were used, which were divided into 5 groups of 12 specimens. These were filled with a temporary restoration material (coltosol) the first third and the middle third with gutta-percha. A total of 0.1 ml of solvent was added depending on the study group (distilled water, camu camu, xylol, oil of orange peel and eucalyptus) to the top of the PLA tubes. After 5 minutes, the Instron 5566 machine (Instron, Buckinghamshire, UK) was used and moved down through gutta-percha with a head speed of 5 mm / min at a depth of 5 mm min. The load (force) used to penetrate the separator to the depth of 5 mm was recorded in Newton. For the analysis, the kruskal Wallis test will be carried out to compare the penetration force measure according to the type of solvent, after checking the statistical assumptions. Results: Statistically significant differences were found when comparing all solvents (p = 0.001), obtaining 14.02N for the experimental substance. The results of the surface dissolution depth and the force used to penetrate the spreader to 5 mm revealed that Myrciaria Dubia Oil (Camu Camu) was significantly the best solvent to soften gutta-percha (P <0.05), followed by xylol and orange peel oil, while the least effective solvent was eucalyptus oil. Conclusions: The essential oil of Myrciaria Dubia presented greater softening power than the other solutions under study. / Tesis

Indiana University-Purdue University Indianapolis (IUPUI) / Root canal therapy requires three important steps accomplished in concert to achieve long-term success: canal shaping, disinfection, and obturation. Traditionally gutta-percha has been used with sealer in a cold lateral condensation technique. Schilder introduced the concept of warm vertical compaction of gutta-percha in 1967 to attempt to obturate more canal irregularities. Johnson presented the use of stainless steel files with thermally plasticized gutta-percha in 1978, and later the metal carrier was changed to plastic and named Thermafil. Thermafil has shortcomings in that it does not always fulfill Grossman’s obturation material properties, such as apical extent of the material (extrusion) and ease of retreatment. A new obturation material by Dentsply Tulsa, the GuttaCore cross-linked gutta-percha core obturator, has been introduced that replaces the plastic core with a cross-linked gutta-percha core. The manufacturer states removal of the obturation material and 89 core is fast and easy. To date, no microleakage studies have been done to test this newer obturation material. Methods used to study microleakage have included the use of dyes, radioisotopes, electrochemicals, fluid filtration, and microorganisms. A microbial leakage model has been constructed using a modified two-chamber apparatus as described by Torabinejad et al. and has been used successfully. Green fluorescent protein (GFP) from the jellyfish Aequorea victoria is useful as a bacterial label because the fluorescent marker can be exhibited in the bacterial host without having to use stains. A plasmid that encodes for a copy of the green fluorescent variant gene was transferred into the E. faecalis. The marker glows green under a standard fluorescence microscope and has been used successfully to evaluate microleakage. The purpose of this investigation was to evaluate the sealing ability of a new obturation material, GuttaCore, to determine if there will be a significant decrease in microleakage of AH Plus with GuttaCore obturator versus AH Plus with gutta-percha. Sixty-two human, single-rooted premolars extracted for periodontal considerations were accessed and instrumented for non-surgical root canal therapy. Hand and rotary instrumentation was accomplished to MAF size 40.04, and irrigation was accomplished with 6.0-percent NaOCl and 17-percent EDTA with use of EndoActivator. Teeth were randomly assigned to two experimental groups of 27 teeth each. Group I (conventional method) teeth were obturated with gutta-percha and AH Plus sealer using warm vertical condensation, and Group II (test method) teeth were obturated with GuttaCore and AH Plus sealer. Two control groups containing four teeth each 90 served as positive and negative controls. The positive and negative control groups ensured that the microleakage model was working correctly. The teeth were evaluated for microbial microleakage of E. faecalis green fluorescent protein (GFP) construct using a dual chamber leakage model. If turbidity is observed in the lower chamber, it will indicate microleakage and an inadequate seal of the obturation method. The teeth were sectioned and viewed with a standard fluorescence microscope to determine the depth of microleakage utilizing the inherent fluorescence of the E. faecalis GFP construct. No microleakage was observed in the negative control groups. Microleakage was observed in both gutta-percha positive control groups and in one of the two GuttaCore positive control groups. One of 27 GuttaCore samples displayed turbidity, which occurred at day 14. None of the 26 gutta-percha samples displayed turbidity at any point. The 95-percent confidence intervals (CI) for the percentage of samples with turbidity were 0.1 percent to 19 percent for GuttaCore and 0.0 percent to 13.2 percent for gutta-percha using a Fisher’s Exact Test. The two groups did not have a significantly different percentage of samples with turbidity (p =1.00). No E. faecalis GFP was visualized under fluorescent microscopy in either the turbid GuttaCore sample or the gutta-percha positive control in the apical, middle or coronal thirds. Both samples that demonstrated microleakage had confirmation that the lower chamber broth contained E. faecalis GFP when cultured on blood agar plates. Within the limitations of this study, there was no significant decrease in microleakage between the GuttaCore obturator and warm vertical condensation with gutta-percha. Turbidity of the broth in samples that leaked was not associated with 91 noticeable bacteria when using fluorescent microscopy, which indicated that leakage may be the result of very few bacteria.