Clinical Study of Sodium Hypochlorite, Polymyxin B And Limewater Effect on MMP-3,-8,-9 In Apical Periodontitis.

This study aimed to evaluate sodium hypochlorite (NaOCl), limewater (LW), and Polymyxin B (PMB) as irrigants over MMP-3, MMP-8 and MMP-9. Thirty-three patients with apical periodontitis of single-rooted teeth were treated according to three-experimental groups (n=11): group-1: 2.5% NaOCl was used as irrigant; group-2: 2.5% NaOCl for the first two files and LW: [0.14% Ca(OH)2] for the last two files; group-3: 2.5% NaOCl for the first two files and PMB for the last two files. The association of Ca(OH)2 and CHX was used as an intracanal medication in all groups. Four root canal samplings (S) were collected: S1) immediately after access cavity; S2) after biomechanical preparation; S3) after EDTA application; and S4) after removal of the intracanal medication. After quantification of MMP-3, MMP-8, and MMP-9, the data were analyzed by Friedman and Kruskal-Wallis tests and completed by Dunn test (5%). Regardless the used irrigant, there was no difference in reducing MMP-3 or MMP-8 (P=0,5273, P=0,7048 respectively). However, in reducing MMP-9 (P=0,0246) the NaOCl group was the most effective followed by NaOCl+LW group and NaOCl+PMB group respectively. The intracanal medication [Ca(OH)2 + CHX] with the NaOCl and NaOCl+LW was effective in reducing MMP-8 (P<0,0001, P=0,0025) and MMP-9 (P=0,0007, P=0,0047) respectively, but not for the group of NaOCl+PMB which was not effective in reducing MMP-8 or MMP-9 (P=0,1718, P=0,1953) respectively. NaOCl and NaOCl+LW were effective in reducing MMP-9 levels, and this effectivity could be improved by the use of the intracanal medication [Ca(OH)2 + CHX] in reducing MMP-8 and MMP-9 levels.

Limewater and Polymyxin B Associated with NaOCl for Endotoxin Detoxification in Root Canal with Necrotic Pulp.

This clinical study investigated the effects of endodontic treatment by using different irrigants (limewater + NaOCl and polymyxin B + NaOCl) and intracanal medication on endotoxins in teeth with primary endodontic infection and radiographically visible apical periodontitis. Thirty-three teeth with necrotic pulp and periapical lesions from different patients were selected for this study. Samples were collected after the coronal opening (S1) and after instrumentation (S2). Root canals were divided in 3 groups (n = 11) according to the irrigant combination used: NaOCl + LW: 2.5% NaOCl + calcium hydroxide solution (0.14%, limewater); NaOCl + PmB: 2.5% NaOCl + 10.000 UI/mL polymyxin B; 2.5% NaOCl (control). The third sampling (S3) was performed after ethylenediaminetetraacetic acid and the fourth (S4) after samples got 14 days with intracanal medication with 2% chlorhexidine gel + calcium hydroxide. Endotoxins (lipopolysaccharide) were quantified by chromogenic Limulus amebocyte lysate (LAL). Endotoxins were detected in all root canals after the coronal opening (S1). NaOCl + PmB group presented the greatest endotoxin reduction after instrumentation (76.17%), similar to NaOCl + LW group (67.64%, p<0.05) and different from NaOCl group (42.17%, p<0.05). After intracanal medication period (S4), there was significant increase of endotoxins neutralization. It was concluded that NaOCl + PmB promoted the greatest reduction of endotoxin levels, followed by NaOCl + LW. Intracanal medications had no significant complementary role in the reduction of endotoxins at the end of the treatment.

Limewater and Polymyxin B Associated with NaOCl for Endotoxin Detoxification in Root Canal with Necrotic Pulp

Abstract This clinical study investigated the effects of endodontic treatment by using different irrigants (limewater + NaOCl and polymyxin B + NaOCl) and intracanal medication on endotoxins in teeth with primary endodontic infection and radiographically visible apical periodontitis. Thirty-three teeth with necrotic pulp and periapical lesions from different patients were selected for this study. Samples were collected after the coronal opening (S1) and after instrumentation (S2). Root canals were divided in 3 groups (n = 11) according to the irrigant combination used: NaOCl + LW: 2.5% NaOCl + calcium hydroxide solution (0.14%, limewater); NaOCl + PmB: 2.5% NaOCl + 10.000 UI/mL polymyxin B; 2.5% NaOCl (control). The third sampling (S3) was performed after ethylenediaminetetraacetic acid and the fourth (S4) after samples got 14 days with intracanal medication with 2% chlorhexidine gel + calcium hydroxide. Endotoxins (lipopolysaccharide) were quantified by chromogenic Limulus amebocyte lysate (LAL). Endotoxins were detected in all root canals after the coronal opening (S1). NaOCl + PmB group presented the greatest endotoxin reduction after instrumentation (76.17%), similar to NaOCl + LW group (67.64%, p<0.05) and different from NaOCl group (42.17%, p<0.05). After intracanal medication period (S4), there was significant increase of endotoxins neutralization. It was concluded that NaOCl + PmB promoted the greatest reduction of endotoxin levels, followed by NaOCl + LW. Intracanal medications had no significant complementary role in the reduction of endotoxins at the end of the treatment

Resumo Este estudo clínico investigou os efeitos do tratamento endodôntico com uso de diferentes irrigantes (NaOCl + água de cal e NaOCl + polimixina B) e medicação intracanal sobre endotoxinas em dentes com infecção endodôntica primária e presença de lesão periapical visível radiograficamente. Foram selecionados para o estudo trinta e três dentes de pacientes que apresentavam necrose pulpar e presença de lesão periapical. As amostras foram coletadas após a abertura coronária (S1) e após a instrumentação (S2). Os canais radiculares foram divididos em 3 grupos (n = 11) de acordo com a combinação de irrigantes utilizada: NaOCl + LW:- hipoclorito de sódio 2,5% + solução de hidróxido de cálcio (água de cal 0,14%); NaOCl + PmB: hipoclorito de sódio a 2,5% + polimixina B 10.000 UI/mL; NaOCl (controle): hipoclorito de sódio a 2,5%. A terceira coleta (S3) foi realizada após aplicação do ácido etilenodiamino tetra acético (EDTA) e a quarta coleta (S4) após 14 dias de medicação intracanal de hidróxido de cálcio + clorexidina gel 2%. Endotoxinas (lipopolissacarídeos) foram quantificadas pelo ensaio cromogênico do lisado de amebócitos de Limulus (LAL). Endotoxinas foram detectadas em todos os canais radiculares após abertura coronária (S1). Grupo NaOCl + PmB apresentou a maior redução de endotoxinas após a instrumentação (76,17%), sendo similar ao grupo NaOCl + LW (67,64%, P >.05) e diferente do grupo NaOCl (42,17%, P <.05). Após o período de medicação intracanal, houve aumento significativo da neutralização de endotoxinas. Concluiu-se que NaOCl + PmB promoveu a maior redução dos níveis de endotoxinas, seguido de NaOCl + LW. A medicação intracanal não teve um papel complementar significativo na redução de endotoxinas no final do tratamento.

EDS analysis of gutta-percha cones disinfected by 1% and 2.5% sodium hypochlorite solutions / Análises de EDS dos cones de guta percha desinfetados por soluções de hipoclorito de sódio 1% e 2.5%

To evaluate the effects of 1% and 2.5% sodium hypochlorite (NaOCl) solutionsat different periods on the composition of gutta-percha cones using Energy Dispersive Spectroscopy (EDS). Material and Methods: 110 master gutta-percha points were dividedin to 3 control groups and 8 experimental groups.Cones were immersed in 1% and 2.5% NaOClfor 30 min, 6, 12, 24 h. Then, composition of the samples was analyzed by EDS. Statistical analysis was performed using the ANOVA and Tukey tests (p < 0.05). Results: There was an increase of oxygen in experimental groups, and decrease of zinc when NaOCl was used, concentration and time dependent (Critical comparison value: Oxygen = 9.21;Zinc = 15.19). Conclusion: The disinfection with NaOCl solution causes alterations in the composition of gutta-percha, which were concentration and time-dependent...

Objetivo: Avaliar o efeito das soluções de hipoclorito de sódio (NaOCl) 1% e 2,5% em diferentes períodos de tempos na composição dos cones de guta percha usando estereomiscroscopio de energia dispersiva (EDS). Material and Metodos: Cento e dez cones principais de guta percha foram divididos em 3 grupos controles e 8 grupos experimentais. Os cones foram imersos em solução de NaOCl 1% e 2,5% por 30 min, 6 h, 12h e 24 h. Depois do tempo de imersão, a composição química das amostras foram analisadas por EDS. A análise estatística foi realizada utilizando ANOVA, eos testes de Tukey e Dunnett (p < 0,05). Resultados: Um aumento de peso (%) do oxigênio e diminuição do peso (%) de zinco foram observados nos grupos experimentais dependendo da concentração e tempo de NaOCl utilizados (Valor crítico de comparação: Oxigênio= 9,21; Zinco = 15,19). Conclusão: A desinfecção com soluções de NaOCl causam alterações na composição dos cones de guta percha, sendo tais alterações concentração e tempo dependentes...

Remocão manual ou automatizada do material obturador do canal radicular: Guta-percha x Real Seal / Removal manual ar mechanized of fílling material Root Canal: Gutta-percha x Real Seal

O objetivo deste trabalho foi comparar a qualidade e o tempo de desobturação de canais obturados com guta-percha e cimento AH Plus ou Real Seal e cimento Epiphany, utilizando-se duas técnicas de retratamento: limas Hedstrbem e limas rotatórias ProTaper® Retratamento, associadas ao Eucaliptol. Sessenta dentes unirradiculares foram divididos em quatro grupos de 15 cada. Os canais dos grupos 1 e 2 foram obturados com guta-percha/AH Plus e dos grupos 3 e 4 com Sistema Real Seal. Foram realizadas radiografias antes e após a desobturação as quais foram avaliadas pelo Software Image Tool quanto à porcentagem de material obturador remanescente. O tempo de desobturação também foi avaliado. A remoção foi mais eficaz nos espécimes obturados com Real Seal e desobturados com Limas ProTaper® Retratamento. O tempo de desobturação do sistema Real Seal foi menor que o da guta-percha. Relevância Clínica: Conhecer comportamento de novo material obturador (Real Seal) em situações de retratamento com remoção manual ou com instrumentos rotatórios

This study compared the remaining filling material and working time removing gutta-perchafAH Plus and Real Seal/Epiphanv from root filled. The root fillings were removed using two methods: ProTaper® Retreatment and Hedstrbem files. Sixty extrated single-rooted teeth were divided into four groups of 15 specimens each. The canais were obturated using Real Seal and Epiphany sealer and gutta-percha and AH Plus. Radiographs were taken before and after the retreatment and the amount of remaining material was quantified using the software Image Tool. No significant differences were found for retreatment between gutta-percha filled groups. Retreatment of specimens filled with Real Seal using ProTaper® Retreatment files showed less remaining filling material. The Real Seal/Epiphanv removal using Hedstrbem files was faster than the other groups. Clinical relevance: Understanding the new filling material behavior (Real Seal) in retreatment cases using manual removal or rotary instruments

Efficacy of endodontic treatment for endotoxin reduction in primarily infected root canals and evaluation of cytotoxic effects.

INTRODUCTION: Endotoxins are one of the etiologic agents involved in the pathogenesis of apical periodontitis. The objectives of this clinical study were to investigate the effects of endodontic treatment by using different irrigants on endotoxins in root canals with pulp necrosis and apical periodontitis and to evaluate the cytotoxic effects. METHODS: Thirty-six root canals were selected. Samples were collected before (S1) and after instrumentation (S2). The root canals were divided into 3 groups (n = 12) according to the irrigant combination used: CLX + LW, 2% chlorhexidine gel + calcium hydroxide (0.14%, limewater); CLX + PmB, chlorhexidine + polymyxin B; CLX (control), chlorhexidine + saline. The third sampling (S3) was performed after ethylenediaminetetraacetic acid and S4 after intracanal medication (CLX + calcium hydroxide for 14 days). Endotoxins were quantified by the chromogenic Limulus amebocyte lysate assay, and cytotoxic effects were evaluated by the production of cytokines (interleukin-1ß, tumor necrosis factor α) in macrophages (RAW 264.7) stimulated with the root canal content. RESULTS: Endotoxins were detected in all root canals before instrumentation (S1). Group CLX + LW presented the greatest endotoxin reduction after instrumentation (99.18%), which was similar to group CLX + PmB (96.42%, P > .05) and different from group CLX (90.78%, P < .05). The intracanal medication promoted important endotoxin neutralization, with a reduction of 99.2% to 100%. The root canal content induced a higher production of tumor necrosis factor α and interleukin-1ß in S1 samples compared with samples obtained after treatment. CONCLUSIONS: The combination of CLX and limewater as irrigant was the most effective in reducing endotoxins in root canals, and intracanal medication was important to neutralize the cytotoxic effects.

Estudo in vivo da ação do tratamento endodôntico sobre endotoxinas bacterianas em canais radiculares com polpa necrosada e avaliação dos efeitos citotóxicos / In vivo action of endodontic treatment on bacterial endotoxins in necrotic root canals and evaluation of cytokines

Em canais radiculares com polpa necrosada, a infecção é causada por diferentes bactérias, principalmente Gram-negativas anaeróbias facultativas e estritas, que, consequentemente, liberam diferentes endotoxinas durante sua duplicação ou morte celular. Os objetivos deste estudo foram: a) avaliar in vivo as quantidades de endotoxinas em canais radiculares com polpa necrosada, antes da realização do tratamento endodôntico; b) avaliar a efetividade do preparo biomecânico utilizando diferentes associações de agentes irrigantes [hipoclorito de sódio (NaOCl)2,5%; NaOCl 2,5% + hidróxido de cálcio 0,14% e NaOCl 2,5% +polimixina B] sobre endotoxinas em canais radiculares; c) avaliar a ação da medicação intracanal (clorexidina gel 2% + hidróxido de cálcio) sobre endotoxinas; d) avaliar, durante todo o tratamento endodôntico, a produção de citocinas por macrófagos estimulados pelas amostras coletadas dos canais radiculares. Foram selecionados 33 dentes com necrose pulpar e lesão periapical visível radiograficamente e,imediatamente após o isolamento absoluto e acesso ao canal radicular foi realizada a primeira coleta. Os terços cervical e médio dos canais foram preparados com instrumentação oscilatória utilizando-se como solução irrigadora o hipoclorito de sódio 2,5% e para o preparo manual do terço apical os canais foram divididos em 3 grupos (n=11): G1) NaOCl 2,5%;G2) NaOCl 2,5% + água de cal (0,14%); G3) NaOCl 2,5% + polimixina B. Após o preparo biomecânico foi realizada a segunda coleta e, após a aplicação do EDTA, a terceira coleta. A quarta coleta foi realizada após 14dias de medicação intracanal com pasta de clorexidina gel 2% + hidróxidode cálcio. Para todas as coletas foi realizada a quantificação de endotoxinas pelo teste cinético cromogênico do lisado de amebócitos de Limulus (LAL) e avaliação dos efeitos citotóxicos pela produção de citocinas (IL-1, TNF-) em cultura de macrófagos. Para a quantificação de endotoxinas...

In radicular canals with necrotic pulp, infection is caused by several bacterium, mainly by the facultative anaerobic and strict Gram-negative,which, after wards, release various endotoxins through out its duplication or cellular death. This analysis aims at: a) evaluate in vivo the endotoxina mount in radicular canals with necrotic pulp, prior to endodontic treatment; b) evaluate the effects of biomechanical preparation using various associations of irrigating agents (sodium hypochlorite 2.5% +polymyxin B; sodium hypochlorite 2.5% + calcium hydroxide (0.14%) and sodium hypochlorite 2.5% on endotoxins in radicular canals; c)evaluate the intracanal gauge (2% chlorhexidine gel + calcium hydroxide) on endotoxins; d)evaluate, through out the entire endodontic treatment, the macrophages cytokine out put stimulated by the collected samples inradicular canals. 33 teeth, from various patients with necrotic pulp and periapical lesion visible on x-ray, were selected. The first sampling was performed immediately after the complete isolation and access into radicular canal. The cervical e medium thirds of the canals were preparedby using sodium hypochlorite 2.5% irrigating solution, and for the manual preparation of the apical third, the canals were divided into 3 groups(n=11): G1) sodium hypochlorite 2.5%; G2) sodium hypochlorite 2.5% +lime water (0.14%); G3) sodium hypochlorite 2.5% + polymyxin B. These cond sampling was performed after the biomechanical preparation, and the third was performed 3 minutes after the EDTA was applied. The fourth sampling was performed after 14 days on intracanal medication of chlorhexidine gel 2% paste + calcium hydroxide. To all the samplings,endotoxin quantification was performed, using the Limulus amebocytelysate (LAL) chromogenic kinetic test, and evaluating citotoxic effects dueto the production of cytokines (IL-1, TNF-) in macrophage cultures. A significant estatistical difference...

Ação do laser Nd: YAG sobre selamento retroapical de cavidades preparadas com ultrassom ou broca e retro-obturadas com MTA ou polímero da mamona / The effect of an Nd: YAG laser on the retro-apical sealing of cavities prepared with ultrasound or bur using MTA or castor oil bean polymer as the root-end filling

O objetivo deste trabalho foi avaliar in vitro a ação do laser de Nd:YAG no selamento apical da dentina radicular preparada retroapicalmente com ultrassom ou broca convencional e retro-obturada com MTA ou polímero derivado do óleo da mamona. Foram utilizados 80 dentes humanos unirradiculados cujas coroas foram removidas e o terço radicular apical seccionado em 3 mm. As raízes foram divididas em 8 grupos (n=10): G1: preparo retroapical com ultrassom, aplicação do laser e retro-obturação com MTA; G2: preparo retroapical com ultrassom, aplicação do laser e retro-obturação com cimento à base do polímero da mamona; G3: preparo retroapical com brocas diamantadas, aplicação do laser e retro-obturação com MTA; G4: preparo retroapical com brocas, aplicação do laser e retro-obturação com cimento de mamona; G5: preparo retroapical com ultrassom, retro-obturação com MTA, sem irradiação prévia pelo laser; G6: preparo retroapical com ultrassom, retro-obturação com cimento de mamona, sem irradiação prévia pelo laser; G7: preparo retroapical com o uso de brocas e retro-obturação com MTA, sem irradiação prévia pelo laser; G8: preparo retroapical com brocas e retro-obturação com cimento de mamona, sem irradiação prévia pelo laser. Os espécimes foram imersos em corante, clivados e levados à leitura da infiltração máxima para cada espécime. Os dados foram submetidos à análise de variância ANOVA e teste de Tukey (5%). Os menores valores de infiltração foram verificados nos grupos G2, G4, G5, G6 e G8, com diferença significante em relação aos grupos G1, G3 e G7 (p<0,05), que apresentaram maiores valores de infiltração. Pôde-se concluir que o uso do laser só apresentou bons resultados quando associado ao polímero da mamona. O melhor material retro-obturador foi o polímero da mamona, em todos os grupos (preparo retroapical com broca ou ultrassom, com ou sem laser). O MTA só apresentou bons resultados quando associado ao ultrassom e sem irradiação pelo laser.

The aim of this study was to evaluate in vitro the effect of an Nd:YAG laser on the apical sealing of roots retroapically prepared with ultrasound or conventional bur and using MTA or castor oil bean (COB) polymer as the retrofilling materials. Eighty single-rooted human teeth had their crowns sectioned, and the apical thirds of the roots were cut into 3 mm sectionsand divided into 8 groups (n = 10): G1, retroapical preparation with ultrasound and cavities irradiated by an Nd:YAG laser and MTA as the retrofilling; G2, retroapical preparation using ultrasound with the cavities irradiated by an Nd:YAG laser and retrofilled with COB polymer; G3, retroapical preparation with diamond drills and the cavities irradiated byan Nd:YAG laser and retrofilled with MTA; G4, preparation with retroapical burs, the cavities irradiated by an Nd:YAG laser and COB polymer used as the retrofilling; G5, retroapical preparation with ultrasound, retrofilling with MTA and without laser irradiation; G6, retroapical preparation with ultrasound, retrofilling with COB and without laser irradiation; G7,retroapical preparation with burs, retrofilling with MTA and without previous irradiation; and G8, retroapical preparationwith burs, retrofilling with COB and no laser irradiation. The specimens were immersed in dye and cleaved, and the maximum infiltration for each specimen was read. The values were analyzed using an ANOVA model and the Tukey test. The lowest infiltration values were found in the G2, G4, G5, G6 and G8 groups, significantly different from the G1, G3 and G7 groups (p <0.05), which had higher infiltration values. The laser produced better results only when associated with the COB polymer. The COB polymer was the best material in all of the groups (retroapical preparation with bur or ultrasound, with or without the laser). The MTA produced favorable results only when combined with ultrasound and not with laser irradiation

Avaliação da variação da temperatura intrapulpar após o uso de agentes clareadores e ativação por fontes de luz / Evaluation of the variation of intrapulpal temperature after the use of bleaching agents and activation by light sources

Introdução e objetivo: Buscou-se avaliar in vitro o grau de aquecimento promovido no interior da câmara pulpar após o uso de diferentes agentes clareadores, com ou sem ativação por fontes de luz. Material e métodos: Foram utilizados 60 dentes incisivos bovinos, que receberam acesso ao canal radicular pela face lingual, com a parede vestibular padronizada em 2 mm. Os espécimes foram divididos em 6 grupos (n = 10), de acordo com o agente clareador e a fonte de ativação utilizada: G1 - ausência de agente clareador e aplicação de luz halógena; G2 - ausência de agente clareador e aplicação de LED; G3 - aplicação do agente clareador Whiteness HP Maxx (peróxido de hidrogênio 35%) e ativação com luz halógena; G4 - aplicação do agente clareador Whiteness HP Maxx (peróxido de hidrogênio 35%) e ativação com LED; G5 - aplicação do agente clareador Opalescence Xtra Boost (peróxido de hidrogênio 38%) e ativação com fotopolimerizador; G6 - aplicação do agente clareador Opalescence Xtra Boost (peróxido de hidrogênio 38%) e ativação com LED. A variação da temperatura na câmara pulpar foi mensurada com um aparelho termopar. Resultados: Os valores de temperatura foram medidos pelo aparelho durante 10 minutos, com alguns intervalos selecionados: t1 - temperatura inicial; t2 - após 25 segundos de aplicação do gel e 20 segundos de ativação; t3 - após 10 minutos. Os valores obtidos foram registrados pela máquina no software, e os dados foram submetidos à análise estatística pelo teste Anova. Verificou-se que o aumento da temperatura não foi significante em todos os grupos testados. Conclusão: Não foram encontradas diferenças estatisticamente significantes entre os grupos com e sem ativação por fontes de luz ou entre os diferentes clareadores.

Introduction and objective: To evaluate in vitro the degree of warming promoted within the pulp chamber, after the use of bleaching agents, with or without activation by light sources. Material and methods: Sixty bovine teeth were used, which had received access to the root canal by the side lingual, with the wall vestibular standardized at 2 mm. The specimens were divided into 6 groups (n = 10), according to the bleaching agent and the source of activation used: G1 - absence of bleaching agent and application of halogen light; G2 - absence of bleaching agent and application of LED; G3 - application of the Whiteness HP Maxx (35% hydrogen peroxide) and activation with halogen light; G4 - application of Whiteness HP Maxx (35% hydrogen peroxide) and activation with LED; G5 - application of the Opalescence Xtra Boost (38% hydrogen peroxide) and activation with photopolymerizer; G6 - application of the Opalescence Xtra Boost (38% hydrogen peroxide) and activation with LED. The change of temperature in the pulp chamber was measured using a Termopar apparatus. Results: The values of temperature were measured by the device during an interval of 10 minutes, with some selected intervals: t1 - initial temperature; t2 - after 25 seconds of application of the gel and 20 seconds of activation; t3 - after 10 minutes. The values were registered by the machine in the software and the data were subjected to statistical analysis using the Anova test. Conclusion: There were no statistically significant differences between groups with and without activation or between different bleaching.

Sealing ability of castor oil polymer as a root-end filling material

OBJECTIVE: The purpose of this study was to evaluate the sealing ability of castor oil polymer (COP), mineral trioxide aggregate (MTA) and glass ionomer cement (GIC) as root-end filling materials. Forty-five single-rooted human teeth were cleaned and prepared using a step-back technique. The apical third of each root was resected perpendicularly to the long axis direction. All teeth were obturated with gutta-percha and an endodontic sealer. After, a root-end cavity with 1.25-mm depth was prepared using a diamond bur. The specimens were randomly divided into three experimental groups (n=15), according to the root-end filling material used: G1) COP; G2) MTA; G3) GIC. The external surfaces of the specimens were covered with epoxy adhesive, except the root-end filling. The teeth were immersed in rhodamine B dye for 24 hours. Then, the roots were sectioned longitudinally and the linear dye penetration at the dentin/material interface was determined using a stereomicroscope. ANOVA and Tukey's tests were used to compare the three groups. The G1 group (COP) presented smaller dye penetration, statistically different than the G2 (MTA) and G3 (GIC) groups (p<0.05). No statistically significant difference in microleakage was observed between G2 and G3 groups (p>0.05). The results of this study indicate that the COP presented efficient sealing ability when used as a root-end filling material showing results significantly better than MTA and GIC.

Sealing ability of castor oil polymer as a root-end filling material.

OBJECTIVE: The purpose of this study was to evaluate the sealing ability of castor oil polymer (COP), mineral trioxide aggregate (MTA) and glass ionomer cement (GIC) as root-end filling materials. Forty-five single-rooted human teeth were cleaned and prepared using a step-back technique. The apical third of each root was resected perpendicularly to the long axis direction. All teeth were obturated with gutta-percha and an endodontic sealer. After, a root-end cavity with 1.25-mm depth was prepared using a diamond bur. The specimens were randomly divided into three experimental groups (n=15), according to the root-end filling material used: G1) COP; G2) MTA; G3) GIC. The external surfaces of the specimens were covered with epoxy adhesive, except the root-end filling. The teeth were immersed in rhodamine B dye for 24 hours. Then, the roots were sectioned longitudinally and the linear dye penetration at the dentin/material interface was determined using a stereomicroscope. ANOVA and Tukey's tests were used to compare the three groups. The G1 group (COP) presented smaller dye penetration, statistically different than the G2 (MTA) and G3 (GIC) groups (p<0.05). No statistically significant difference in microleakage was observed between G2 and G3 groups (p>0.05). The results of this study indicate that the COP presented efficient sealing ability when used as a root-end filling material showing results significantly better than MTA and GIC.

Atividade antimicrobiana de um EDTA gel associado a peróxido de hidrogênio sobre cepas clínicas de Candida albicans / Antimicrobial activity of gel EDTA associated with hydrogen peroxide on clinical isolates of Candida albicans

O presente trabalho teve como objetivo analisar a atividade antimicrobiana de um produto composto por EDTA gel associado a peróxido de hidrogênio (Canal Plus®) sobre amostras clínicas de Candida albicans, utilizando o método de diluição em caldo. Foram incluídos no estudo isolados bucais e amostra padrão de Candida albicans (ATTC 18804). O Canal Plus foi diluído em caldo BHI em placas de microtitulação, obtendo-se as concentrações finais de 50% a 0,02%. O hipoclorito de sódio 2,5% foi utilizado como controle positivo. Após, foi adicionado suspensão padronizada de Candida albicans e as placas foram incubadas a 37ºC por 24 horas. Foram determinadas diluição inibitória mínima(DIM) e diluição fungicida mínima (DIF). O Canal Plus® foi capaz de inibir todas as cepas clínicas a partir da diluição 0,75%. Considerando os resultados obtidos, os dados sugerem que o Canal Plus tem eficiente atividade antimicrobiana sobre cepas clínicas de Candida albicans.

The purpose of this study was to analyze the antimicrobial activity of a composed product for EDTA gel associated with hydrogen peroxide (Plus® Canal) on clinical isolates of Candida albicans, using the method of dilution in broth. They had been enclosed in the study clinical isolates and reference strain of Candida albicans (ATTC 18804). The Plus Canal was diluted in broth BHI in microtitulation plates, obtaining the final concentrations of 50% to 0.02%. The sodium hypochlorite 2.5% was used as positive control. After, standardized suspension of Candida albicans was added and the plates had been stored in an oven at 37º C for 24 hours. Minimal inhibitory dilution and minimal fungicidal dilution had been determined. The Plus® Canal was capable to inhibit all clinical isolates from dilution 0.75%. Considering the results, the data suggest that the Canal Plus has efficient antimicrobial activity on clinical isolates of Candida albicans.

Smear layer removal by auxiliary chemical substances in biomechanical preparation: a scanning electron microscope study.

The aim of this study was to assess, by scanning electron microscopy analysis, the cleaning ability of irrigants and auxiliary chemical substances in biomechanical preparation. Thirty-two single-rooted human teeth were subjected to standardized root canal instrumentation with different irrigants (n = 8): group 1, 2.5% NaOCl + 17% ethylenediaminetetraacetic acid (EDTA); group 2, 2% chlorhexidine gel + 17% EDTA; group 3, Canal Plus + 2.5% NaOCl; group 4, saline + 17% EDTA. After instrumentation, the teeth were prepared for scanning electron microscopy analysis (2000x) to evaluate the cleaning of cervical, middle, and apical thirds. The area analyzed was quantified according to the percentage of open tubules, and data were statistically analyzed by analysis of variance and Tukey tests (P = .05). The results showed statistically significant difference with higher quantity of open tubules in groups 1 and 3. In all groups, the cleaning obtained on the cervical third was better than that obtained on the middle and apical thirds, with statistically significant difference in the chlorhexidine group. Irrigation with Canal Plus in combination with NaOCl and NaOCl followed by EDTA produced greater cleaning of the root canal walls.

Influência do cianoacrilato pós-tratamento endodôntico no selamento de restaurações de resina composta e de ionômero de vidro / Influence of the cianoacrilato posttreatment endodontic in the sealing of restorations of composit resin and of glass ionomer

Introdução: O objetivo deste trabalho é avaliar o selamento marginal de restaurações adesivas realizadas após o uso do cianoacrilato pós-tratamento endodôntico. Métodos: Foram utilizados 72 incisivos bovinos tratados endodonticamente e obturados com cones de guta-percha e cimento Sealapex. O corte da guta-percha foi realizado 2mm abaixo do limite cervical e metade dos dentes recebeu uma camada de cianoacrilato sob a superfície do material obturador e nas paredes da cavidade de acesso. Os dentes foram mantidos a 37ºC e umidade 100% por 24 horas. Os espécimes foram divididos em 6 grupos de 12 dentes cada, sendo 10 experimentais e dois controles (positivo e negativo): G1ûimpermeabilização com cianoacrilato + restauração com cimento de ionômero de vidro (CIV); G2ûsem cianoacrilato + CIV; G3-com impermeabilização, restaurado com resina composta convencional Z100; G4-sem impermeabilização, restaurado com Z100; G5ûcom impermeabilização e restaurado com resina composta condensável P60; G6ûsem impermeabilização e restaurado com P60. Os dentes permaneceram em saliva artificial 24 h a 37ºC e umidade 100%, foram levados a termociclagem e permaneceram em saliva artificial por 60 dias. Foram então imersos em solução de Rhodamina B 2% durante 24 horas para posterior avaliação das infiltrações, que foram submetidas ao teste de comparação múltipla de Dunn. Resultados: Os resultados mostraram mais infiltração com diferença significativa para dentes restaurados com CIV e impermeabilizados com cianoacrilato em relação às demais condições. Entre os grupos restaurados com resina composta não houve diferença estatística significante (p<0,05). Conclusão: Conclui-se que o cianoacrilato, utilizado para selamento pós-tratamento endodôntico, não interfere no selamento marginal das restaurações de resina composta, mas prejudica a adesão de restaurações de cimento de ionômero de vidro.

Introduction: The objective of this study is to evaluate the marginal sealing ability of adhesive restorations using a sealing with cyanoacrylate after endodontic therapy. Methods: Seventy- two bovine incisive teeth were endodontically treated and filled with guta-percha and Sealapex. The cervical cut of the guta-percha was performed 2mm under the cement enamel junction. Half of the teeth received a cyanoacrylate layer in contact with the filling material and in the coronary access. The teeth were maintained at 37ºC and 100% humidity for 24 hrs. The specimens were divided into 6 groups of 12 teeth each, where 10 were experimental and 2 were control (positive and negative): G1- cover with cyanoacrylate + restoration with CIV; G2- without cyanoacrylate + CIV; G3- cover with cyanoacrylate and restored with composite resin Z100; G4- without cyanoacrylate and restored with Z100; G5- cover with cyanoacrylate and restored with composite resin P60; G6- without cyanoacrylate and restored with P60. The teeth were kept in artificial saliva for 24hrs at 37ºC and 100% humidity. They were thermocycled and returned to artificial saliva for 60 days. The teeth received external waterproof sealing, except in the restoration, and 1mm next to their margins, and were immersed in Rhodamine B solution at 2% for 24 hrs for subsequent dye penetrations. The leakage was submitted to statistical analysis. Results: The results showed more leakage with statistically difference for the teeth restored by CIV with cyanoacrylate, in the other groups no statistically significant difference was observed (p>0.05). Conclusion: It was concluded that cyanoacrylate, used after endodontic therapy, does not influence the marginal sealing of the restorations in composite resin, but influences the marginal sealing of glass ionomer restorations.

In vitro evaluation of apical microleakage using different root-end filling materials

Objetivo deste trabalho foi avaliar o selamento marginal de cavidades retroapicais obturadas com os cimentos Portland (Concrebrás S/A-MG-Brasil), MTATM (Dentsply International, Johnson City, TN, EUA) e SealapexTM (Kerr Corporation, Orange, California, EUA) acrescido de óxido de zinco (Odahcam Herpo Produtos Dentários Ltda, Rio de Janeiro, RJ, Brasil). Foram utilizados 42 dentes unirradiculados humanos extraídos que, após a remoção de suas coroas, tiveram seus canais preparados a 1mm aquém do ápice radicular até o instrumento nº 60. Os canais foram obturados com cones de guta-percha e cimento SealapexTM e, em seguida, foi realizado o seccionamento de 3mm do ápice radicular em ângulo de 90º em relação ao longo eixo do dente. Foram preparadas cavidades retroapicais com ponta diamantada em ultrasom, a uma profundidade de 3mm, e as raízes foram divididas aleatoriamente em 3 grupos de acordo com o material retrobturador: G1- Portland, G2 - MTA, G3 – Sealapex acrescido de óxido de zinco. As raízes foram impermeabilizadas externamente e imersas em fluido tissular simulado por 30 dias. Em cada grupo, 2 dentes serviram como controle positivo (não impermeabilização) e negativo (total impermeabilização). Os espécimes foram imersos em corante Rhodamina B 0,2% por 24 horas para avaliação da infiltração marginal. Os cimentos Portland, SealapexTM + óxido de zinco e MTA apresentaram média de infiltração de 0,75; 0,35 e 0,35mm respectivamente, não havendo diferenças estatísticas significantes entre eles (p>0,05).

In vitro evaluation of apical microleakage using different root-end filling materials%Avaliação in vitro da microinfiltração marginal usando diferentes materiais restauradores

Objetivo deste trabalho foi avaliar o selamento marginal de cavidades retroapicais obturadas com os cimentos Portland (Concrebrás S/A-MG-Brasil), MTATM (Dentsply International, Johnson City, TN, EUA) e SealapexTM (Kerr Corporation, Orange, California, EUA) acrescido de óxido de zinco (Odahcam Herpo Produtos Dentários Ltda, Rio de Janeiro, RJ, Brasil). Foram utilizados 42 dentes unirradiculados humanos extraídos que, após a remoção de suas coroas, tiveram seus canais preparados a 1mm aquém do ápice radicular até o instrumento nº 60. Os canais foram obturados com cones de guta-percha e cimento SealapexTM e, em seguida, foi realizado o seccionamento de 3mm do ápice radicular em ângulo de 90º em relação ao longo eixo do dente. Foram preparadas cavidades retroapicais com ponta diamantada em ultrasom, a uma profundidade de 3mm, e as raízes foram divididas aleatoriamente em 3 grupos de acordo com o material retrobturador: G1- Portland, G2 - MTA, G3 û Sealapex acrescido de óxido de zinco. As raízes foram impermeabilizadas externamente e imersas em fluido tissular simulado por 30 dias. Em cada grupo, 2 dentes serviram como controle positivo (não impermeabilização) e negativo (total impermeabilização). Os espécimes foram imersos em corante Rhodamina B 0,2% por 24 horas para avaliação da infiltração marginal. Os cimentos Portland, SealapexTM + óxido de zinco e MTA apresentaram média de infiltração de 0,75; 0,35 e 0,35mm respectivamente, não havendo diferenças estatísticas significantes entre eles (p>0,05)

In vitro evaluation of apical microleakage using different root-end filling materials.

The objective of this study was to evaluate the apical leakage of retrograde cavities filled with Portland Cement (Concrebrás S/A-MG-Brazil), ProRoot MTA (Dentsply International, Johnson City, TN, USA) and Sealapex (Kerr Corporation, Orange, California, USA) with addition of zinc oxide (Odahcam Herpo Produtos Dentários Ltda, Rio de Janeiro, RJ, Brazil). Forty-two extracted single-rooted human teeth were decoronated and used for this study. The root canals were instrumented at 1.0mm short of the apical foramen using the step-back technique to an apical ISO size 60. The roots were obturated with gutta-percha points and sealer Sealapex (Kerr Corporation-USA) and then 3mm of each root apex was sectioned at a 90 degrees angle. Ultrasonic retrograde preparation was performed with a diamond tip to 3mm depth and the roots were randomly divided into 3 groups according to the filling material: G1-Portland, G2-ProRoot MTA, G3- Sealapex zinc oxide-added cement. The root surfaces were covered with nail varnish up to 2mm from the apical foramen, immersed in simulated tissue fluid for 30 days, and then immersed in 0.2% Rhodamine B solution for 24 hours for evaluation of marginal leakage. The results showed mean leakage of 0.75, 0.35 and 0.35 for groups 1, 2 and 3, respectively; however, Kruskal-Wallis test revealed that there was no statistically significant difference among the results (p>0.05).