Das Ziel der hier durchgeführten Studie war es, die Möglichkeiten der zerstörungsfreien Untersuchungsmethode, 3-D-Röntgenmikrotomographie, bei der Bewertung von Wurzelkanalfüllungen anhand der modifizierten lateralen Kondensation, der lateralen Kondensation und bei Thermafil zu untersuchen. Es sollte gezeigt werden, dass die einzelnen Bestandteile der Wurzelkanalfüllung zu differenzieren und im Anschluss auch zu quantifizieren sind. Die ersten 21 mit dieser zerstörungsfreien Methode untersuchten Proben wurden im Anschluss nochmals mit einer klassischen Untersuchungsmethode, der Lichtmikroskopie, beurteilt. Die hier erzielten Ergebnisse wurden bei einem Methodenvergleich mit den Ergebnissen der 3-D-Röntgenmikrotomographie verglichen und auf eine mögliche Korrelation überprüft. Ziel war es zu überprüfen, ob verschiedene Methoden zur Qualitätsprüfung von Wurzelkanalfüllungen als gleichwertig angenommen werden können. Im Rahmen dieser Untersuchung wurde eine neue modifizierte laterale Kondensation eingeführt, die hinsichtlich ihrer Qualität anhand der bereits genannten Parameter mit zwei bereits eingeführten Wurzelkanalfüllmethoden verglichen werden sollte. Die 3-D-Röntgenmikrotomographie ermöglichte eine selektive Darstellung der einzelnen Komponenten in 400 bis 750 Ebenen, welche ebenfalls quantifizierbar waren. Es wurden Füllgrade zwischen 71 % und 92 % erzielt. Das Thermafil-System schien den auf lateraler Kondensation basierenden Systemen bezüglich der bestimmten Volumen vereinzelt signifikant überlegen. Bei der lichtmikroskopischen Auswertung ergaben sich diesbezüglich ähnliche Ergebnisse. Die Farbstoffpenetrationstiefen zeigten weder tendenzielle noch signifikante Unterschiede zwischen den einzelnen Fülltechniken. Beim Vergleich der Methoden zur Bewertung der Obturation bezüglich der erhobenen Volumen konnte keine Korrelation nachgewiesen werden. Auch beim Vergleich der Farbstoffpenetrationstiefen und der bestimmten Volumen bei der 3-D-Röntgenmikrotomographie konnten keine Korrelationen ermittelt werden. Unter Berücksichtigung der Grenzen dieser Untersuchung lässt sich festhalten, dass die Methode der 3-D-Röntgenmikrotomographie zur Bewertung und zum Vergleich von Wurzelkanalfüllungen geeignet ist. Die Ergebnisse korrelieren jedoch nicht mit denen der Lichtmikroskopie.

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.

The purpose of this study was to compare the density of gutta percha following three different obturation techniques using two split-tooth models. One split-tooth model was constructed with a straight rooted maxillary incisor and the other with the curved palatal root of a maxillary molar. Each tooth was obturated using single cone, cold lateral, and warm vertical obturation techniques without sealer. Each obturation technique was performed 20 times for each of the root systems. The weights of the gutta percha were recorded for each root type and obturation technique by subtracting the post-fill weight from the pre-fill weight of the two split-tooth models. Results show that in the straight canal, the three obturation techniques are significantly different (p < 0.0001). The warm vertical technique had the largest weight of gutta percha, followed by the single cone, and lastly by the cold lateral condensation group. In the curved canal, the three fill types were also significantly different (p < 0.0001). The warm vertical and single cone obturation techniques were not significantly different from one another but were significantly greater in gutta percha weight than the cold lateral technique. In conclusion, within curved canals, warm vertical and single cone techniques were more dense than cold lateral condensation. In the straight canal, the warm vertical was more dense than the single cone which was more dense than the cold lateral technique.

Analisou-se a influência da aplicação do ácido cítrico em três concentrações, EDTA-T e EDTA-C no vedamento marginal apical de canais radiculares em 90 caninos humanos extraídos. O preparo químico-cirúrgico dos canais radiculares foi realizado pela técnica de Paiva & Antoniazzi, sendo esses dentes posteriormente distribuídos aleatoriamente em seis grupos. Cada grupo de dentes recebeu um tratamento químico específico efetuado pela repleção do canal radicular por 3 minutos com uma das seguintes substâncias: soro fisiológico, ácido cítrico a 10%, ácido cítrico a 15%, ácido cítrico a 20%, EDTA-T a 17% e EDTA-C a 17%. Posteriormente, todos os canais radiculares foram obturados com cones de guta-percha e cimento N-Rickert pela técnica de cones múltiplos com condensação vertical. Foi observado um aumento crescente de infiltração do corante azul-de-metileno nos canais tratados com ácido cítrico correspondente ao aumento da concentração do ácido. A maior média de infiltração verificada ocorreu nos canais radiculares tratados com EDTA-C e as menores registradas naqueles tratados com soro fisiológico ou EDTA-T. As diferenças entre as médias de infiltração apical nos seis grupos experimentais, analisadas conjuntamente, não foram estatisticamente significantes. Em comparações individualizadas, houve diferença significante (p < 0,05) entre o grupo G6 (EDTA-C) tanto em relação ao grupo G5 (EDTA-T) quanto ao grupo G1 (soro fisiológico). / Ninety extracted human teeth were analysed in this work to verify the influence of citric acid application under three concentrations, EDTA-T and EDTA-C in the apical marginal sealing of root canals. Chemical and surgical root canal preparations were performed by Paiva & Antoniazzi technique, being these teeth randomly distributed in six groups. Each group had specific chemical treatment of filling the root canal for 3 minutes with one of the following substances: saline solution, 10% citric acid, 15% citric acid, 20% citric acid, 17% EDTA-T and 17% EDTA-C. All root canals were filled with gutta-percha cones and N-Rickert cement by the multiple cone technique with vertical condensation. A crescent increase of methylene blue dye penetration could be observed in the root canals treated with citric acid equivalent to the increase in acid concentration. The highest penetration mean was shown in the root canals treated with EDTA-C and the lowest in those treated wint saline solution or EDTA-T. The differences between the apical penetration means in the six experimental groups that had been together analysed showed no statistical significance. When individually compared, there was a significant difference (p<0,05) between group G6 (EDTA-C), group G5 (EDTA-T) and group G1 (saline solution).

O objetivo deste estudo foi avaliar o pH e a liberação de íons cálcio dos cimentos AH Plus, MTA Fillapex e Sealapex, em diferentes períodos, quando empregados em obturações de canais radiculares, bem como, a qualidade das obturações, após 1 ano de realizadas. O pH e a liberação de íons cálcio foram avaliados por meio de um peagômetro e espectrofotômetro de absorção atômica, respectivamente. A qualidade das obturações foi avaliada por meio de um estereomicroscópio. Cento e vinte e quatro pré-molares inferiores humanos extraídos, unirradiculados, foram divididos em 01 grupo controle e 02 grupos experimentais, de acordo com a padronização do diâmetro do forame apical. Em seguida, os 02 grupos experimentais foram divididos em 4 subgrupos, considerando as técnicas de instrumentação e obturação empregadas. Após o preparo dos canais radiculares cada subgrupo teve o número de dentes divididos por dois, formando novos subgrupos, de acordo com os cimentos obturadores utilizados. Imediatamente após a obturação, a raiz de cada dente foi imersa em 15 mL de água ultrapura para avaliação do pH e liberação de íons cálcio nos seguintes períodos: 1 h, 1, 3, 7, 30, 180 e 365 dias, após a obturação. Após o período de 1 ano, os dentes foram seccionados transversalmente a 2, 4, 6 mm do forame apical para análise da qualidade das obturações, analisando-se a porcentagem de cimento, guta-percha e espaços vazios na massa obturadora. Os cimentos apresentaram pH neutro, porém, aos 180 dias, os valores mostraram um ligeiro aumento quando utilizados em canais com forames de diâmetro 0,25 mm. Quando utilizados em canais com forames de diâmetro 0,45 mm, o pH mostrou-se com valores maiores para todos os períodos sem distinção do cimento. Todos os cimentos liberaram íons cálcio, com menores valores para o AH Plus. Na estereomicroscopia, observaram-se variações nas porcentagens de cimento e guta-percha, considerando-se os diâmetros foraminais e técnicas obturadoras, e porcentagem insignificante de espaços vazios. / The objective of this study was to evaluate the pH and calcium ion release of AH Plus, MTA Fillapex and Sealapex cements at different time periods when used in root canal obturations, as well as the quality of the obturations one year after being performed. The pH and calcium ion release were evaluated by means of a pH meter and an atomic absorption spectrophotometer, respectively. The quality of the obturations was evaluated using a stereomicroscope. One hundred and twenty-four extracted human uniradicular mandibular premolars were divided into 1 control and 2 experimental groups, according to the standardization of the apical foramen diameter. Next, the 2 experimental groups were divided into 4 subgroups, considering the instrumentation techniques and obturations employed. After the preparation of the root canals, each subgroup had the number of teeth divided by two, forming new subgroups, according to the sealers used. Immediately after the obturation, the root of each tooth was immersed in 15 mL of ultrapure water for the evaluation of the pH and calcium ion release in the following time periods: 1 hr, 1, 3, 7, 30, 180 and 365 days after the obturation. After the period of one year, the teeth were transversely sectioned at 2, 4 and 6 mm from the root apex to examine the quality of the obturations, analyzing the percentage of cement, gutta-percha and voids in the obturator mass. The cements presented a neutral pH, which showed slightly increase as of 180 days when used in canals with foramens of 0.25 mm diameters. When used in canals with foramens with diameters of 0.45 mm, the pH presented higher values in all periods for all cements. All cements released calcium ions, with lower values for the AH Plus. In the stereomicroscopy, there were variations in the percentages of cement and gutta-percha, considering the foraminal diameters and obturation techniques and an insignificant percentage of voids.

Um material obturador deve apresentar boas propriedades biológicas e físico-químicas, uma vez que ficará em íntimo contato com os tecidos periapicais. Sendo assim, não deve ser irritante aos tecidos adjacentes, possibilitando, ou mesmo favorecendo, o reparo da região periapical, para isso não devem alterar o processo inflamatório. O presente estudo avaliou a citotoxicidade dos cimentos AH Plus, Sealapex, MTA Fillapex e Sealepox em neutrófilos humanos. Neutrófilos humanos cultivados na presença ou ausência de LPS foram tratados com os cimentos em diferentes diluições (1:1, 1:4, 1:8, 1:16 e 1:32) e tempo de presa (24 e 48 horas) durante 24 horas. A viabilidade celular foi analisada por citometria de fluxo, a dosagem de CXCL8 pelo método de ELISA, e Óxido Nítrico na absorvância de 540nm. Os dados foram analisados com o auxílio do programa GraphPad Prism5 por ANOVA a 1 critério seguido pelo teste de Tukey, e os valores considerados significantes quando p<0,05. O cimento AH Plus interferiu apenas na síntese de NO, estimulando-a, tendo a diluição 1:16 melhor comportamento biológico, em ambos períodos experimentais. O Sealapex diminuiu a produção de NO, sendo significante para 1:32 em 48 horas. O MTA Fillapex induziu apoptose, a produção de CXCL8 (1:4 e 1:8 em 48 horas) e diminuiu a síntese de NO (1:32 em 48 horas). Sealepox diminuiu a apoptose (1:16 e 1:32 em 24 horas) e interferiu na produção de CXCL8, diminuindo-a (1:8 em 48 horas, e 1:16 em ambos os períodos). A citotoxicidade em ordem crescente dos cimentos foram: AH Plus, Sealapex, MTA Fillapex e Sealepox. Nosso estudo concluiu que os cimentos AH Plus e Sealapex foram os menos citotóxicos, que menos interferiram na viabilidade celular e na sua função (não indução de CXCL8 e na produção de NO), tanto em 24 horas como em 48 horas. MTA Fillapex e o Sealepox, apesar de causarem mais morte celular e interferirem na produção de NO e CXCL8, seus efeitos podem ser aceitáveis, uma vez que os níveis dessas alterações são, de tal maneira discretos, não agressivos. / A filling material must have good biological and physicochemical, since you\'ll be in close contact with the periapical tissues. Thus it should not be irritating to the surrounding tissues, allowing, or even encouraging, the repair of the periapical region, for it must not alter the inflammatory process. The present study evaluated the cytotoxicity of AH Plus, Sealapex, MTA and Fillapex Sealepox in human neutrophils. Human neutrophils cultured in the presence or absence of LPS cements were treated with different dilutions (1:1, 1:4, 1:8 , 1:16, 1:32) and setting time (24 and 48 hours) for 24 hours. Cell viability was analyzed by flow cytometry, the dosage of CXCL8 by ELISA and nitric oxide in absorbance at 540 nm. Data were analyzed with the aid of GraphPad Prism5 ANOVA for the first criterion followed by Tukey test, and values considered significant when p < 0.05. The AH Plus sealer interfered only in NO synthesis , stimulating it , having a 1:16 dilution better biological behavior , in both experimental periods . The Sealapex decreased production of NO, with 1:32 significant to within 48 hours. The MTA Fillapex induced apoptosis, production of CXCL8 (1:4 to 1:8 within 48 hours) and reduced NO synthesis (1:32 in 48 hours). Sealepox decreased apoptosis (1:16 and 1:32 in 24 hours) and interfere with the production of CXCL8, reducing it (1:8 in 48 hours, and 1:16 in both periods). The cytotoxicity of the cements in ascending order were: AH Plus, Sealapex, MTA and Fillapex Sealepox. We conclude that AH Plus and Sealapex cements were less cytotoxic than less interfered with cell viability and function ( CXCL8 and noninduced NO production ) both in 24 hours and in 48 hours. MTA and Fillapex Sealepox, although most causing cell death and interferes the production of NO and CXCL8, their effects may be acceptable, since the levels of these changes are so mild, non-aggressive.

Avaliou-se presença de espaços vazios, presença de fendas na interface cimento/dentina, o perímetro de penetração do cimento obturador nos canais e nos istmos.e a ação antimicrobiana intra-dentinária do cimento endodôntico (AH Plus) quando submetido ou não a agitação ultrassônica no momento da obturação. Para a avaliação do preenchimento de istmos foram utilizadas 30 raízes mesiais de primeiros molares inferiores, as quais foram divididas em 2 grupos (n=15). A instrumentação foi realizada com o sistema reciprocante Reciproc (R25) e finalizado com instrumento rotatório Mtwo (35.04). Em seguida, o cimento AH Plus foi espatulado com Rodamina B e foi inserido nos canais com espiral de Lentulo no35; o cimento do grupo 1 foi submetido a agitação ultrassônica enquanto o do grupo 2 não foi agitado, sendo que todos os canais foram obturados por meio da técnica do cone único e armazenados em estufa a 37oC durante 7 dias. As raízes foram seccionadas transversalmente a 2, 4 e 6 mm do ápice radicular para análise em esteromicroscópio e microscopia confocal a laser. Para a avaliação da ação antimicrobiana foram utilizados 30 incisivos de bovinos, os quais foram seccionados em cilindros de 6 mm de espessura. Os canais tiveram seu diâmetro padronizado com uma lima tipo K no 80 e então contaminados com Enterococcus faecalis (ATCC 29212) por 4 dias. Após esse período os espécimes foram divididas em 3 grupos (n=30). No grupo 1 o cimento foi agitado com o ultrassom e obturados com a técnica de cone único; no grupo 2 o cimento não foi agitado e o grupo 3 foi o grupo controle. As raízes foram seccionadas longitudinalmente no sentido vestíbulopalatino e coradas com corante LIVE/DEAD para avaliar a viabilidade bacteriana em microscopia confocal a laser. Para análise da agitação ultrassônica do cimento obturador no preenchimento de canais e istmos, foi utilizado o teste não paramétrico de Mann-Whitney (p <0.05) e para a análise da ação antimicrobiana intradentinária, foi utilizado o teste não paramétrico Kruskal-Waliis e o Teste Dunn (p <0.05). Os resultados indicaram que a agitação ultrassônica do cimento AH Plus favoreceu o preenchimento de istmos e a penetração intratubular. A agitação ultrassônica do cimento AH Plus reduziu significantemente a viabilidade bacteriana. Conclui-se que a agitação ultrassônica do cimento AH Plus favoreceu maior penetração intratubular, menor presença de fendas, menos espaços vazios e maior ação antimicrobiana. / In this study it was assessed the presence voids, gaps in the sealer/dentin interface, the intratubular sealer penetration in canals and isthmuses and intratubular antimicrobial effect of the AH Plus sealer when ultrasonic activation was performed during obturation. 30 mesial roots of mandibular first molars were selected and divided into 2 groups (n=15). Root canal instrumentation was performed with the reciprocating system Reciproc (R25) and finished with the Mtwo (35.04) rotary instrument. Then the AH Plus sealer was mixed with Rhodamine B and was inserted into the root canals with a Lentulo spiral #35. In group 1 the ultrasonic activation of the sealer was performed while in group 2 was not activated. Then, the root canal filling was performed using the single cone technique. After 7 days of storage the roots were sectioned at 2, 4 and 6 mm from the apex and analyzed in the stereomicroscope and by confocal laser scanner microscopy. To the antimicrobial test 30 bovine incisors cut into cylinders with 6 mm in thickness were used. The root canals diameter was standardized with a K file # 80 and then contaminated with Enterococcus faecalis (ATCC 29212) for 4 days. After this period the samples were divided into 3 groups (n = 30). In group 1 the ultrasonic activation of the sealer was perfomed and filled with single cone technique; in group 2 the sealer was not ultrasonic activated and in group 3 the canals were not obturated (control group). The roots were sectioned in the buccal-palatal direction and stained with LIVE / DEAD stain to assess the bacterial viability by confocal laser microscopy. For analysis of ultrasonic activation of the sealer on the filling quality of the canals and isthmuses, a non-parametric Mann-Whitney test (p <0.05) was used. For the analysis of the intradentin antimicrobial action, a Kruskal-Waliis nonparametric and Dunn\'s test was used (p <0.05). The results showed that the ultrasonic agitation of the AH Plus sealer favored the isthmus filling and the intratubular penetration. Also, the ultrasonic activation of AH Plus sealer reduced bacterial viability. It was concluded that the ultrasonic agitation of the sealer favored higher intratubular penetration, lower presence of gaps and voids and higher antimicrobial activity.

O objetivo deste estudo ex vivo foi avaliar o preparo biomecânico e a obturação de canais radiculares ovais utilizando os sistemas ProTaper, WaveOne, Reciproc e Self-Adjusting File. Com esta finalidade avaliou-se: 1) área, perímetro, circularidade, diâmetro maior, diâmetro menor, área de superfície, volume e SMI após o preparo biomecânico, por meio de microtomografia computadorizada (&mu;TC); 2) percentual volumétrico de espaços vazios após a obturação do canal, por meio de &mu;TC; 3) resistência de união (RU) e tipo de falha ocorrida após teste de push-out; e 4) a interface dentina/material obturador em microscopia eletrônica de varredura (MEV). Cem caninos inferiores humanos foram escaneados no microtomógrafo SkyScan 1174v.2. Após o preparo do terço cervical dos canais, os dentes foram distribuídos em 4 grupos (n=25), de acordo com o sistema usado no preparo biomecânico: ProTaper; WaveOne; Reciproc; Self-Adjusting File (SAF). Após a segunda &mu;TC, 18 espécimes de cada grupo foram redistribuídos em dois grupos (n=9), de acordo com a técnica de obturação: Técnica Modificada da Onda Contínua de Condensação e técnica recomendada pelo fabricante. Os sete espécimes restantes de cada grupo constituíram os grupos controle negativo e positivo. Após a TC dos espécimes obturados, as raízes foram seccionadas transversalmente em fatias de 1 mm de espessura correspondentes às regiões cervical, média e apical. A RU foi avaliada pelo teste de push-out e as falhas após desunião observadas em microscópio digital. Após preparo para MEV, avaliou-se a interface adesiva de forma qualitativa nominal e ordinal pelo estabelecimento e determinação de escores. No conjunto, a análise dos parâmetros avaliados no preparo biomecânico mostraram que as alterações mais significativas ocorreram nos grupos ProTaper e WaveOne. Os resultados no grupo Reciproc ficaram em um nível intermediário, enquanto as menores alterações foram observadas no grupo SAF (ANOVA, p<0,05). Em relação à obturação, a Técnica Modificada da Onda Contínua de Condensação apresentou menor percentual volumétrico de espaços vazios que a técnica recomendada pelo fabricante apenas no terço cervical (Kruskall-Wallis, p<0,05). Após o teste de push-out, a análise das médias indicou RU (MPa) significativamente maior nos espécimes obturados pela técnica do fabricante em comparação com a Técnica Modificada de Onda Contínua de Condensação (teste t para amostras independentes, p<0,05). Em todos os grupos foi verificado maior percentual de falhas adesivas, com predominância de falhas mistas na técnica do fabricante e de falhas adesiva na dentina na Técnica Modificada de Onda Contínua de Condensação. Em MEV, não houve tags na maioria dos espécimes obturados pela Técnica Modificada da Onda Contínua de Condensação e quando presentes, eram pequenos e irregularmente distribuídos. Nos espécimes obturados pela técnica recomendada pelo fabricante observou-se formação de tags longos e bem distribuídos, principalmente no terço apical (teste de Friedman, p<0,05). Concluiu-se que todos os sistemas resultaram em alterações nos parâmetros bidimensionais e tridimensionais do canal após o preparo biomecânico; a técnica recomendada pelo fabricante resultou em maior volume de espaços vazios no terço cervical e maior RU do material obturador do que a Técnica Modificada de Onda Contínua de Condensação. Obs: tese completa no site: https://rapidshare.com/files/963588082/Tese_Prof._Dr._Marco_Versiani_FORP_USP_2012.pdf (na pagina que abrir, clicar no botao \"download\"). / The purpose of this ex vivo study was to evaluate the biomechanical preparation and obturation of root canals using ProTaper, WaveOne, Reciproc and Self-Adjusting File systems. It was evaluated: 1) area, perimeter, roundness, major diameter, minor diameter, surface area, volume and SMI after biomechanical preparation, using microcomputed tomography (&mu;TC), 2) percentage volume of voids in the obturation material by means of &mu;TC, 3) bond strength (BS) and type of failure after the pushout test, and 4) the analysis of the interface dentin / filling material using scanning electron microscopy (SEM). One-hundred human mandibular canines were scanned in the SkyScan 1174v.2 device. After preparing the coronal third of the canals, the teeth were divided into 4 groups (n=25), according to the biomechanical preparation system used: ProTaper, WaveOne, Reciproc, and Self-Adjusting File (SAF). After the second TC, eigthteen specimens of each group were assigned to two groups (n=9), according to the obturation technique: the Modified Continuous Wave of Condensation Technique and the technique recommended by the manufacturer. The remaining seven specimens of each group were used as negative and positive controls. After scanning, the obturated specimens were sectioned perpendicularly to its long axis into 1-mm slice thickness of the coronal, middle and apical thirds. The bond strength (BS) was performed by the push-out test and, after dislodgments, the failures were observed in a digital microscope. The specimens were processed for SEM analysis to observe bonding interface formation and resin tag density using a four-step scale method. Overall, the analysis of the biomechanical parameters showed that the most significant changes in the root canal occurred in the ProTaper group and WaveOne groups. Reciproc results were in an intermediate level and smaller changes were observed in the SAF group (ANOVA, p<0.05). In the coronal third, the Modified Continuous Wave of Condensation Technique showed a lower percentage volume of voids than the technique recommended by the manufacturer (Kruskal-Wallis test, p<0.05). After the push-out test, the analysis indicated the mean BS (MPa) was significantly higher in specimens filled by the manufacturer\'s technical than the Modified Continuous Wave of Condensation Technique (t test for independent samples, p<0.05). The adhesive failures were frequent in all groups. The Modified Continuous Wave of Condensation Technique showed the highest percentage of adhesive failure in dentin while in the technique recommended by the manufacturer, mixed failure was predominant. Overall, in SEM analysis, no tags were observed in most of the specimens filled by the Modified Continuous Wave of Condensation Technique. When present, they were small and irregularly distributed. The specimens filled by the technique recommended by the manufacturer showed long and well-distributed tags, especially in the apical third (Friedman test, p<0.05). It was concluded that all systems promoted root canal changes after the biomechanical preparation, the obturation technique recommended by the manufacturer resulted in a higher volume of voids in the coronal third and BS of the Modified Continuous Wave of Condensation Technique group.

Este estudo avaliou, in vitro, tempo de endurecimento (TE), alteração dimensional (AD), solubilidade (Sl) e radiopacidade (Rp) dos cimentos AH Plus, GuttaFlow, RoekoSeal, Activ GP, Endofill e um cimento experimental à base de MTA. Para estes testes o cimentos Activ GP foi manipulado na relação pó/líquido de 28 mg para 50 &micro;L de líquido. Para determinar o TE, moldes (10 X 2 mm) foram preenchidos com cimento e, decorridos 150 s, os cimentos foram testados com agulha tipo Gillmore (100 g), a cada 60 s, até que não houvesse marcas na superfície. Para o teste de alteração dimensional, 5 corpos-de-prova cilíndricos (3,58 x 3,0 mm) foram obtidos. Após a mensuração de seus comprimentos por meio de parquímetro digital, foram imersos em 2,24 mL de água destilada e deionizada por 30 dias e mensurados novamente. Para o teste de Sl, foram obtidos 10 corpos-de-prova (1,5 X 7,75 mm). Após serem pesados, dois a dois, foram imersos em 7,5 mL de água destilada por 7 dias e pesados novamente, determinando-se a perda percentual da massa. Os líquidos de imersão foram submetidos à espectrometria para detecção dos íons Ca2+, K+, Ni2+, Pb2+, Zn2+, Ag+. Para a Rp, 5 placas de acrílico com 4 perfurações (5 X 1 mm) foram preenchidas com cimento e, ao lado de escada de alumínio padronizada, foram radiografadas com distância foco-objeto de 30 cm e exposição de 0,2 s. A densidade radiográfica foi determinada por meio do Digora for Windows 1.51. Os resultados mostraram que os cimentos GuttaFlow e RoekoSeal estavam de acordo com a Especificação n° 57 da ANSI/ADA para os testes de TE e Rp. Em relação a ED, somente o Guttaflow estava de acordo com esta Especificação. Em relação à Sl, somente o cimento Activ GP (11,80%) não atendeu os padrões exigidos pela ANSI/ADA. A espectrometria de absorção atômica mostrou que o cimento Activ GP apresentou liberação expressiva de ions Ca2+. A liberação de ions Zn2+ foi evidenciada no cimento Activ GPl. Concluiu-se que somente cimento Guttaflow atendeu às exigências da ANSI/ADA em relação à radiopacidade, estabilidade dimensional e solubilidade. / This study evaluated, in vitro, the setting time (ST), dimensional alteration (DA), solubility (Sl) and radiopacity (Rp) of the sealers AH Plus, GuttaFlow, RoekoSeal, Activ GP, Endofill and a MTA-based experimental sealer. For these tests, the sealer Activ GP was prepared using a powder/liquid mixing ratio of 28 mg to 50 &micro;L of liquid. In order to determine the ST, moulds (10 x 2 mm) were filled with sealer. After 150 s, the sealers were tested with a Gilmore needle (100 g) at 60-s intervals until no marks were visible on the material surface. For the DA test, 5 cylindrical specimens (3.58 x 3.0 mm) were obtained. After having their dimensions checked with a digital caliper, the specimens were stored in 2.24 mL distilled deionized water for 30 days and their dimensions were rechecked. For the Sl test, 10 specimens (1.5 x 7.75 mm) were obtained. After being weighed in pairs, the specimens were stored in 7.5 mL distilled water for 7 days and reweighed to determine the percent mass loss. The liquids in which the specimens were immersed were subjected to spectrometry for detection of ions Ca2+, K+, Na+, Ni2+, Pb2+, Zn2+and Ag+. For the Rp test, 5 acrylic plates with 4 perforations (5 x 1 mm) were filled with sealer and were radiographed near to a graduated aluminum stepwedge with 30-cm focus-object distance and 0.2-s exposure time. The radiographic density was determined using the Digora for Windows 1.51 software. The results showed that GuttaFlow and RoekoSeal were in compliance with the ANSI/ADAs specification no. 57 for the TE and Rp tests. Regarding DA, only GuttaFlow was in accordance with this specification. Regarding Sl, only Activ GP (11.80%) did not meet the ANSI/ADAs requirements. The atomic absorbance spectrometry showed that the sealer Activ GP presented significant release of Ca2+. Release of Zn2+ ions was observed for the sealer Activ GP. In conclusion, only the sealer Guttaflow met the ANSI/ADAs requirements for radiopacity, dimensional stability and solubility.

A proposta deste estudo foi avaliar a infiltração bacteriana em dentes obturados pela técnica de condensação lateral, cone único modificada e termoplastificada por onda contínua de condensação. Quarenta e nove raízes disto-vestibulares de molares superiores padronizados no limite de trabalho de 9 mm foram instrumentados com sistema ProTaper até lima F2, e assim divididos em 3 grupos (n=15) de acordo com a técnica de obturação: G1 cone único modificada, G2 condensação lateral, e G3 - termoplastificada por onda contínua de condensação e injeção de guta percha. O grupo controle positivo foram 2 espécimes sem obturação, e o grupo controle negativo foram 2 espécimes obturados pela técnica de condensação lateral e abertura coronária selada com cianoacrilato. As raízes foram impermeabilizadas deixando 2 mm apicais livre e montadas no aparato de duplo compartimento. Após esterilização com óxido de etileno, 3 ml de TSB estéril foi inoculado no compartimento inferior, e 400 l de caldo contendo Enterococcus faecalis no compartimento superior. A nutrição bacteriana foi realizada a cada 48 h através da retirada de 200 l de caldo bacteriano e adição de 200 l de TSB. O TSB contido no compartimento inferior foi checado a cada 48 h para verificar presença de turvamento num período experimental de 30 dias. O grupo controle positivo infiltrou em 24 h, e nenhum controle negativo apresentou infiltração em 30 dias. No tempo experimental, o grupo do cone único modificado apresentou 73,3% das amostras infiltradas, a condensação lateral apresentou 66,6%, e a termoplastificada 53,3%, não havendo diferença significante entre os grupos aplicando-se os testes do Quiquadrado e Kruskal-Wallis (p>0.05). Pode-se concluir que a técnica de cone único modificada apresenta capacidade de selamento semelhante à técnica de condensação lateral e termoplastificada por onda contínua. / The aim of this study was to evaluate bacterial leakage in root canals obturated with lateral condensation, modified single-cone and continuous wave of condensation techniques. Forty-nine distobuccal root canals of upper molars were standardized with 9 mm of working length. Then the canals were shaped by ProTaper Rotary system up to F2, and divided in three groups (n=15) according to obturation technique: G1 modified single-cone, G2 lateral condensation and G3 continuous wave of condensation. The positive control was two no obturated root canals, and positive control two root canals obturated with lateral condensation technique and coronal opening sealed with cyanoacrylate. The roots external surfaces were sealed, except for the apical 2 mm around the apical foramen, and the bacterial leakage model of two chambers was used. After sterilization by ethylene oxide gas, 3 ml of TSB was poured into the lower chamber, and 400 l of soy broth containing Enterococcus faecalis was inoculated into the upper chamber. Bacterial nutrition was performed each through changing of 200 l of bacterial soy broth to 200 l of TSB. The TSB placed in the lower chamber was checked each 48 h to verify turbidity on the experimental period of 30 days. The positive control leaked within 24 h, and the negative control no leaked on 30 days. In the experimental period, modified single-cone technique showed leakage of 73,3% samples, lateral condensation showed 66,6%, and wave continuous of condensation 53,3%. There were no significant difference between the groups according to Chi-square and Kruskal-Wallis tests (p>0.05). It can be concluded that modified single-cone technique shows sealing ability semelhante to lateral condensation and continuous wave of condensation techniques.