Análise da superfície de instrumentos de diferentes ligas metálicas após preparo mecanizado / Surface analysis instruments of different metal alloys after mechanical preparation

Este estudo teve como objetivo avaliar, através da microscopia eletrônica de varredura (MEV), a ocorrência de fratura e perda de metal na superfície de instrumentos endodônticos de NiTi do sistema Profile® e de aço inoxidável tipo FlexoFile após o uso no preparo mecanizado. Para isso, foram preparados canais mesiais de molares extraídos com instrumentos FlexoFile, através do sistema de rotação alternada M4, e instrumentos ProFile®, com o sistema de rotação contínua. Os instrumentos nº. 25 e 30 de ambos os sistemas foram analisados em MEV em relação à perda de metal e presença ou não de fratura. As imagens obtidas foram analisadas por um observador calibrado. Os dados obtidos foram submetidos ao teste não paramétrico de Friedman, teste não paramétrico Kruskal-Wallis, complementada pelo teste de comparações múltiplas, com nível de significância de 5%. Através dos resultados, observou-se que os instrumentos de aço inoxidável apresentaram, na média, maior perda de metal em sua superfície a partir do 2º uso, porém sem diferença estatística significativa. Já os instrumentos de níquel titânio mantiveram sua superfície inalterada durante os usos. A partir do 3º uso, houve diferença estatística entre os tipos de instrumentos, em relação à perda de metal. Não houve fratura dos instrumentos analisados (AU).

The aim of this study was to evaluate, by scanning electron microscopy (SEM), the occurrence of fracture and loss of metal on the surface of NiTi endodontic instruments of the system and ProFile® stainless steel type FlexoFile after use in preparing mechanized. For this, channels were prepared mesial molar extracted with FlexoFile instruments through the system alternating rotation M4, and ProFile® instruments, with the continuous rotation system. The instruments 25 and 30, both systems were analyzed by SEM with respect to metal loss and presence or absence of tracture. The images were analyzed by a calibrated observer. The data were subjected to nonparametric Friedman test, test non-parametric Kruskal-Wallis and test complemented by multiple comparisons, with a significance level of 5%. Through the results, it can be observed that the stainless steel instruments had, on average, greater loss of metal on its surface from the 2nd use, though not statistically significant. Already, the nickel- -titanium instruments remained unchanged during its surface uses. From the 3rd use, there was statistical difference between the types of instruments in relation to metal loss. There was no fracture of the instruments analyzed (AU).

Bovine Pulp Tissue Dissolution Ability of Irrigants Associated or Not to Ultrasonic Agitation.

The aim of this study was to evaluate the tissue dissolution ability of different irrigating solutions associated or not to ultrasonic agitation. Ninety bovine pulp fragments (n=10 per group) were weighed and then placed individually in Eppendorf test tubes containing the following irrigants: G1- 2.5% sodium hypochlorite (NaOCl); G2- 2.5% NaOCl + ultrasonic agitation (US); G3- 2.5% NaOCl + 0.2% cetrimide (CTR); G4- 2.5% NaOCl + 0.2% CTR + US; G5- 400 ppm Sterilox (SX); G6- SX + US; G7- 0.2% CTR; G8- 0.2% CTR + US; G9- saline solution. Two blinded observers assessed the samples continuously for the first 4 h, and then every hour for the next 12 h. Dissolution speed was calculated by dividing the initial pulp weight (mg) by the period of time until complete dissolution (min). Data were compared by ANOVA and Tukey post hoc test with a 5% significance level. G1 to G4 dissolved pulp fragments completely and G2 was significantly faster than the other groups. G5 to G9 did not exhibit dissolving activity. In conclusion, only groups containing NaOCl were capable of pulp tissue dissolution, which was enhanced by ultrasonic agitation, but did not alter when 0.2% cetrimide was associated. This isolated solution and Sterilox showed no dissolving capacity, regardless the use of ultrasound.

Bovine Pulp Tissue Dissolution Ability of Irrigants Associated or Not to Ultrasonic Agitation

Abstract: The aim of this study was to evaluate the tissue dissolution ability of different irrigating solutions associated or not to ultrasonic agitation. Ninety bovine pulp fragments (n=10 per group) were weighed and then placed individually in Eppendorf test tubes containing the following irrigants: G1- 2.5% sodium hypochlorite (NaOCl); G2- 2.5% NaOCl + ultrasonic agitation (US); G3- 2.5% NaOCl + 0.2% cetrimide (CTR); G4- 2.5% NaOCl + 0.2% CTR + US; G5- 400 ppm Sterilox (SX); G6- SX + US; G7- 0.2% CTR; G8- 0.2% CTR + US; G9- saline solution. Two blinded observers assessed the samples continuously for the first 4 h, and then every hour for the next 12 h. Dissolution speed was calculated by dividing the initial pulp weight (mg) by the period of time until complete dissolution (min). Data were compared by ANOVA and Tukey post hoc test with a 5% significance level. G1 to G4 dissolved pulp fragments completely and G2 was significantly faster than the other groups. G5 to G9 did not exhibit dissolving activity. In conclusion, only groups containing NaOCl were capable of pulp tissue dissolution, which was enhanced by ultrasonic agitation, but did not alter when 0.2% cetrimide was associated. This isolated solution and Sterilox showed no dissolving capacity, regardless the use of ultrasound.

Resumo: O objetivo deste estudo foi avaliar a capacidade de dissolução tecidual de diferentes soluções irrigadoras associadas ou não à agitação ultrassônica. Noventa fragmentos de polpa bovina (n=10 por grupo) foram pesados e em seguida colocados individualmente em tubos tipo Eppendorf contendo os seguintes irrigantes: G1- hipoclorito de sódio (NaOCl) a 2,5%; G2- NaOCl a 2,5% + agitação ultrassônica (US); G3- NaOCl a 2,5% + cetramida (CTR) a 0,2%; G4- NaOCl a 2,5% + CTR a 0,2% + US; G5- 400 ppm Sterilox (SX); G6- SX + US; G7- CTR a 0,2%; G8- CTR a 0,2% + US; G9- solução salina. Dois observadores cegados em relação aos grupos experimentais avaliaram as amostras continuamente durante as primeiras 4 h e depois a cada hora pelas próximas 12 h. A velocidade de dissolução foi calculada dividindo o peso inicial da polpa (mg) pelo período de tempo até sua dissolução completa (min). Os dados foram comparados por ANOVA e teste post hoc de Tukey com nível de significância de 5%. Os grupos G1 a G4 dissolveram os fragmentos de polpa completamente e G2 foi significativamente mais rápido do que os outros. Os grupos G5 a G9 não apresentaram atividade de dissolução. Em conclusão, apenas grupos contendo NaOCl foram capazes de dissolver tecido pulpar, o que foi melhorado pela agitação ultrassônica, mas não alterado quando CTR a 0,2% foi associada. Esta solução isolada e o Sterilox não mostraram nenhuma capacidade de dissolução, independentemente da utilização do ultrassom.

Effect of superoxidized water and sodium hypochlorite, associated or not with EDTA, on organic and inorganic components of bovine root dentin.

INTRODUCTION: This study aimed to evaluate the effects of Sterilox (Sx), a superoxidized water, 5% and 2% sodium hypochlorite (5NaOCl and 2NaOCl), and 17% EDTA (E) on the organic and inorganic components of bovine dentin. METHODS: Eighty bovine incisors were randomly divided into 8 groups (n = 10): 5NaOCl, 5NaOCl + E, 2NaOCl, 2NaOCl + E, Sx, Sx + E, E alone, and distilled water (H2O). Root canal instrumentation was performed by using the corresponding irrigant. The apical 15 mm was longitudinally sectioned into 2 fragments, one for light microscopy analysis in slides stained with picrosirius red (organic component) and the other for scanning electron microscopy analysis (inorganic component). Scores data obtained in the light microscopy analysis were submitted to the Kruskal-Wallis test, followed by multiple comparisons test (P < .05). Scanning electron microscopy images were analyzed descriptively. RESULTS: The chemical solution 5NaOCl had a greater effect on the organic component of dentin in area and depth than 2NaOCl. The chemical solutions 5NaOCl + E, 5NaOCl and 2NaOCl + E caused the greatest change in the collagenous organic matrix near the root canal lumen. The chemical solution 2NaOCl showed similar behavior to Sx, associated or not with E, promoting more superficial disorganization of collagen in a smaller area. Demineralization was observed in all groups in which E was used. However, areas of erosion and open dentinal tubules were detected only when it was combined with NaOCl. CONCLUSIONS: Five percent NaOCl promoted the most extensive damage to the organic component of dentin, and when associated to EDTA, dentinal erosion could be seen. Considering these specific aspects, 2% NaOCl and Sx had milder effects on bovine root dentin.

Effect of super-oxidized water, sodium hypochlorite and EDTA on dentin microhardness.

The present study aimed to evaluate the influence of the following irrigating solutions on the microhardness of root canal dentin: 2% sodium hypochlorite (2NaOCl), 5% sodium hypochlorite (5NaOCl), super-oxidized water (400 ppm Sterilox - Sx) and 17% EDTA (E). Eighty roots from bovine incisors were randomly divided into 8 groups (n=10): 2NaOCl, 5NaOCl, Sx, and 2NaOCl + E, 5NaOCl + E, Sx + E (associated with E as final irrigant for 5 min), E solely and distilled water (dH2O) as the negative control. Root canal preparation was performed by hand instruments, using one of the irrigation protocols for 30 min. Then, 5 mm of the cervical root third were cut out from each sample and subjected to the Vickers microhardness test, at two points, one at approximately 500-1000 µm from the root canal lumen (distance 1), and the other at approximately 500-1000 µm from the external root surface (distance 2). Data were analyzed by Wilcoxon and Kruskal-Wallis tests at 5% significance level. Microhardness values at distance 1 were significantly lower than those at distance 2 for all groups, except 5NaOCl and 5NaOCl + E groups (p>0.05). EDTA showed the lowest microhardness values. However, no statistically significant difference was detected among groups at distance 1 and EDTA was significantly different only from Sx at distance 2. In conclusion, all tested solutions showed lower microhardness at the most superficial root canal dentin layer compared to the one found near the external root surface, except 5NaOCl and 5NaOCl + E; EDTA promoted lower microhardness values in comparison to Sterilox at this site.

Effect of Super-Oxidized Water, Sodium Hypochlorite and EDTA on Dentin Microhardness

The present study aimed to evaluate the influence of the following irrigating solutions on the microhardness of root canal dentin: 2% sodium hypochlorite (2NaOCl), 5% sodium hypochlorite (5NaOCl), super-oxidized water (400 ppm Sterilox - Sx) and 17% EDTA (E). Eighty roots from bovine incisors were randomly divided into 8 groups (n=10): 2NaOCl, 5NaOCl, Sx, and 2NaOCl + E, 5NaOCl + E, Sx + E (associated with E as final irrigant for 5 min), E solely and distilled water (dH2O) as the negative control. Root canal preparation was performed by hand instruments, using one of the irrigation protocols for 30 min. Then, 5 mm of the cervical root third were cut out from each sample and subjected to the Vickers microhardness test, at two points, one at approximately 500-1000 µm from the root canal lumen (distance 1), and the other at approximately 500-1000 µm from the external root surface (distance 2). Data were analyzed by Wilcoxon and Kruskal-Wallis tests at 5% significance level. Microhardness values at distance 1 were significantly lower than those at distance 2 for all groups, except 5NaOCl and 5NaOCl + E groups (p>0.05). EDTA showed the lowest microhardness values. However, no statistically significant difference was detected among groups at distance 1 and EDTA was significantly different only from Sx at distance 2. In conclusion, all tested solutions showed lower microhardness at the most superficial root canal dentin layer compared to the one found near the external root surface, except 5NaOCl and 5NaOCl + E; EDTA promoted lower microhardness values in comparison to Sterilox at this site.

O presente estudo teve como objetivo avaliar a influência das seguintes soluções irrigadoras na microdureza da dentina do canal radicular: hipoclorito de sódio a 2% (NaOCl2), hipoclorito de sódio a 5% (NaOCl5), água superoxidada (Sterilox(r) 400 ppm - Sx) e EDTA a 17% (E). Oitenta raízes de incisivos bovinos foram divididas aleatoriamente em 8 grupos (n=10): NaOCl2, NaOCl5, Sx e NaOCl2 + E, NaOCl5 + E, Sx + E (associados ao E como irrigante final por 5 min), E isolado e água destilada (H2Od), como controle negativo. O preparo dos canais radiculares foi realizado com instrumentos manuais, usando um dos protocolos de irrigação por 30 min. A seguir, 5 mm do terço cervical de cada amostra foram cortados perpendicularmente e submetidos ao teste de microdureza de Vickers, em dois pontos, um aproximadamente 500-1000 µm da luz do canal radicular (distância 1), e o outro aproximadamente 500-1000 µm da superfície externa da raiz (distância 2). Os dados foram analisados pelos testes de Wilcoxon e Kruskal-Wallis com um nível de significância de 5%. Os valores de microdureza na distância 1 foram significativamente menores do que na distância 2 para todos os grupos, exceto NaOCl5 e NaOCl5 +E (p>0,05). O EDTA mostrou os menores valores de microdureza. No entanto, não foi detectada diferença estatisticamente significativa entre os grupos na distância 1 e o EDTA foi significativamente diferente apenas do Sx na distância 2. Pode-se concluir que todas as soluções testadas mostraram menor microdureza na camada de dentina mais superficial do canal radicular em comparação aos valores encontrados próximo à superfície radicular externa, exceto NaOCl5 e NaOCl5 + E; o EDTA promoveu menor microdureza em comparação ao Sterilox(r) neste ponto.

Management of type III dens invaginatus in a mandibular premolar: a case report.

Dens invaginatus is a well-known malformation of teeth, which probably results from an invagination of enamel organ into dental papilla during tooth development. The endodontic treatment of invaginated teeth may be challenging due to difficulties in accessing the root canals and also due to complex variations of internal morphology. This article presents the endodontic management and follow-up in a rare case of right mandibular second premolar with Oehlers' type III dens invaginatus. The result of cold pulp testing was positive for this tooth but it was associated to a sinus tract and periapical lesion. Herein, it is described the root canal therapy of this tooth combined with periapical surgery, emphasizing the importance of proper diagnosis and planning by using cone beam computed tomography (CBCT). This case report presents the proper periapical healing 6 months after the combination of nonsurgical and surgical treatments. It also shows that CBCT is an important auxiliary examination to avoid errors in diagnosis and subsequent treatment of dental anomalies.

Management of Type III Dens Invaginatus in a Mandibular Premolar: A Case Report

Dens invaginatus is a well-known malformation of teeth, which probably results from an invagination of enamel organ into dental papilla during tooth development. The endodontic treatment of invaginated teeth may be challenging due to difficulties in accessing the root canals and also due to complex variations of internal morphology. This article presents the endodontic management and follow-up in a rare case of right mandibular second premolar with Oehlers' type III dens invaginatus. The result of cold pulp testing was positive for this tooth but it was associated to a sinus tract and periapical lesion. Herein, it is described the root canal therapy of this tooth combined with periapical surgery, emphasizing the importance of proper diagnosis and planning by using cone beam computed tomography (CBCT). This case report presents the proper periapical healing 6 months after the combination of nonsurgical and surgical treatments. It also shows that CBCT is an important auxiliary examination to avoid errors in diagnosis and subsequent treatment of dental anomalies.

Dens invaginatus é uma malformação dentária já bem reconhecida, que provavelmente resulta de uma invaginação do órgão do esmalte para dentro da papila dentária durante o desenvolvimento do dente em questão. O tratamento endodôntico de dentes invaginados pode ser um desafio devido às dificuldades de acesso aos canais radiculares e também devido à complexidade da morfologia interna. Este artigo apresenta o manejo endodôntico e o acompanhamento de um caso raro de segundo pré-molar inferior direito com dens invaginatus Tipo III de Oehlers. O resultado do teste de sensibilidade pulpar ao frio foi positivo para este dente, mas o mesmo estava associado a uma fístula e lesão periapical. Relata-se o tratamento de canal deste dente associado à cirurgia periapical, enfatizando a importância de um correto diagnóstico e plano de tratamento, utilizando a tomografia computadorizada de feixe cônico (TCFC). Este relato de caso mostra reparo periapical adequado 6 meses após a combinação dos tratamentos não-cirúrgico e cirúrgico. Mostra também que a TCFC é um importante exame auxiliar para evitar erros no diagnóstico e posterior tratamento de anomalias dentárias.

In vitro evaluation of filling of lateral root canals with different filling materials by using digital radiography / Avaliação in vitro da obturação de canais laterais com diferentes materiais obturadores utilizando radiografia digital

PURPOSE: To evaluate the ability of different endodontic systems to fill simulated lateral canals using resources of digital radiography. METHODS: Seventy extracted single-rooted human teeth were selected, the coronal access was performed, and the working length was established 1 mm short of the foramen. Two lateral canals were created, one in the middle third and one at the apical third, in each root canal. After chemo-mechanical preparation the teeth were divided into 7 groups (n=10) according to the filling material used: G1 Epiphany, G2 AH Plus, G3 EndoRez, G4 EndoFill, G5 Endomethasone, G6 Sealapex and G7 Sealer 26. In the G1 Epiphany system, Resilon cones were used. In all other groups gutta-percha cones were used. After seven days of storage, digital radiographs were taken to assess the results. The program DBSWIN measured the total length, in mm, of each lateral canal and the length, in mm, that each filling system was able to obturate the canals. Data were analyzed by ANOVA and Tukey's test at the 5% significance level. RESULTS: The filling system Sealer 26/gutta-percha showed less capacity to fill lateral canals than the other filling systems tested (P<0.05); statistical analysis revealed no statistically significant difference in the ability to fill lateral canals between the other groups (P>0.05). CONCLUSION: The system Sealer 26/gutta-percha was less effective in the filling of simulated lateral canals.

OBJETIVO: Avaliar a capacidade de obturação de canais laterais de diferentes sistemas obturadores endodônticos por meio de radiografia digital. METODOLOGIA: Setenta dentes humanos unirradiculares extraídos foram selecionados, a abertura coronária foi feita e o comprimento de trabalho foi determinado 1 mm aquém do forame apical. Foram confeccionados dois canais laterais, um no terço médio e outro no terço apical, em cada canal radicular. Após o preparo químico-mecânico os dentes foram divididos em 7 grupos (n=10) de acordo com o material obturador utilizado: G1, Epiphany; G2, AH Plus; G3, EndoRez; G4, EndoFill; G5, Endomethasone; G6, Sealapex; G7, Sealer 26. No G1 foram utilizados cones de Resilon e nos demais grupos cones de guta-percha. Sete dias após a obturação foram feitas radiografias digitais e as imagens foram introduzidas num software para a leitura dos resultados. Para avaliar a obturação dos canais laterais, o software mensurou em mm a extensão total de cada canal lateral e o quanto em mm cada sistema obturador conseguiu preencher em cada um deles. Os dados foram analisados estaticamente por ANOVA e teste de Tukey ao nível de significância de 5%. RESULTADOS: O sistema obturador Sealer 26/guta-percha obturou uma menor quantidade de canais laterais comparado aos demais sistemas obturadores em uma diferença estatisticamente significante (P<0,05); não houve diferença estatisticamente significante entre os demais grupos (P>0,05). CONCLUSÃO: O sistema obturador Sealer 26/guta-percha apresentou uma menor efetividade na obturação de canais laterais simulados.

Estudo in vitro da microinfiltraçäo coronária em materiais restauradores temporários usados em endodontia / Coronal microleakage of temporary restorative materials used in endodontics - an in vitro study

Este trabalho avaliou, in vitro, a microinfiltraçäo coronária em três materiais restauradores temporários usados em endodontia, um cimento de óxido de zinco e eugenol reforçado, o IRM (Dentsply); um cimento destinado especificamente para uso endodôntico, Cimpat Blanc (Septodont) e um material temporário fotopolimerizável, Bioplic (Biodinâmica). Foram realizadas cavidades de acesso endodôntico nos 45 dentes e divididos em 3 grupos de 15. As restauraçöes temporárias foram realizadas utilizando os materiais de acordo com as recomendaçöes do fabricante. Em seguida, os dentes foram impermeabilizados. Os corpos de prova foram submetidos à ciclagem térmica com 500 ciclos nas temperaturas de 5§C e 55§C. Após este período, os dentes foram imersos em fucsina básica a 0,5 por cento em estufa a 37§C, por 24 horas. Os dentes foram seccionados no sentido mésio-distal, obtendo-se 4 faces para avaliaçäo. A extensäo da penetraçäo do corante foi observada, em microscopia estereoscópica com 20 vezes de aumento. Os graus de penetraçäo do corante foram estabelecidos de 0 a 3. Os resultados obtidos foram submetidos à análise estatística através do teste Kruskal Wallis ao nível de significância de 1 por cento. Os resultados mostraram que o IRM (Dentsply) apresentou a maior microinfiltraçäo coronária sendo estatisticamente diferente dos demais materiais. Os materiais temporários Cimpat Blanc (Septodont) e Bioplic (Biodinâmica) demostraram capacidades de selamento semelhantes entre si, com comportamento estatisticamente superior ao IRM (Dentsply)