Efeito de diferentes protocolos de irrigação final na remoção da smear layer / Effect of different protocols of final irrigation on smear layer removal

Objetivo: esse estudo avaliou o efeito de protocolos de irrigação final, associados ao uso de EDTA e QMix, na remoção de smear layer. Métodos: foram utilizados 40 dentes humanos com canal único. Os canais foram instrumentados com sistema ProTaper Universal SX-F3. As substâncias químicas utilizadas durante o preparo foram hipoclorito de sódio a 5,25% (NaOCl) ou clorexidina a 2% (CHX) gel. Terminado o preparo, os dentes foram divididos em oito grupos, de acordo com os irrigantes: G1) NaOCl 5,25% + EDTA 17% + NaOCl 5,25%; G2) NaOCl 5,25% + EDTA 17% + água destilada (AD); G3) NaOCl 5,25% + QMix + NaOCl 5,25%; G4) NaOCl 5,25% + QMix + AD; G5) CHX 2% gel + EDTA 17% + CHX 2% solução; G6) CHX 2% gel + EDTA 17% + AD; G7) CHX 2% gel + QMix + CHX 2% solução e G8) CHX 2% gel + QMix + AD. As amostras foram avaliadas por microscopia eletrônica de varredura ambiental, antes e após os protocolos de irrigação final. As imagens foram classificadas por escores, em relação à presença de smear layer, e os dados foram analisados pelos testes de Kruskal-Wallis e de Mann-Whitney. Resultados: o G1 mostrou os melhores resultados em relação à remoção de smear layer (p < 0,05). A CHX gel 2% mostrou menor formação de smear layer, quando comparada ao NaOCl, após o preparo biomecânico; e o NaOCl apresentou melhor limpeza como irrigante final (p < 0,05). Conclusões: o NaOCl como irrigante final, combinado ao EDTA, mostrou melhor capacidade de remoção da smear layer (AU).

Introduction: This study evaluated the effect of different final irrigation protocols using EDTA and QMix on smear layer removal. Methods: The root canals of 40 single-rooted human teeth were prepared with ProTaper Universal SX - F3. The substances used were 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine gel (chlorhexidine), 2% chlorhexidine solution and distilled water. The teeth were divided into 8 groups, according to the irrigant used: G1: 5.25% NaOCl + 17% EDTA + 5.25% NaOCl; G2: 5.25% NaOCl + 17% EDTA + distilled water; G3: 5.25% NaOCl + QMix + 5.25% NaOCl; G4: 5.25% NaOCl + QMix + DW; G5: 2% chlorhexidine gel + 17% EDTA + 2% chlorhexidine solution; G6: 2% chlorhexidine gel + 17% EDTA + distilled water; G7: 2% chlorhexidine gel + QMix + 2% chlorhexidine solution; and G8: 2% chlorhexidine gel + QMix + distilled water. Samples were evaluated under environmental scanning electron microscopy (ESEM) before and after irrigation. ESEM images were classified according to smear layer scores, and the Kruskal-Wallis and Mann-Whitney tests were used for statistical analyses. Results: Group 1 had the best results for smear layer removal (p<0.05). Smear layer formation was lower when 2% chlorhexidine gel was used after cleaning and shaping than when the irrigant was 5.25% NaOCl, and 5.25% NaOCl had the best cleaning ability as a final irrigant. Conclusion: 5.25% NaOCl combined with EDTA was the best final irrigant for smear layer removal (AU).

Refinement influence in the cleaning efficacy of rotary nickel-titanium Mtwo ® instruments in oval-shaped canals by means of optical microscopy.

Objective: This study evaluated the cleaning efficacy of the rotary nickel–titanium Mtwo® by means of optical microscopy in oval‑shaped root canals and compared refinement influence using ultrasonic files or Hedströem files. Materials and Methods: Twenty mandibular incisors were accessed, included in epoxy resin blocks, and cut transversely at 3, 6, and 9 mm from the apex. Teeth were instrumented using rotary nickel–titanium Mtwo. Digital images of the root cross sections were obtained before and after instrumentation with a digital camera attached to an optical microscope. Subsequently, samples were randomly divided into two groups for refinement. Group I was refined using ultrasonic files #30 and group II with Hedströem files #30. Final digital images of cross sections after refinement were captured and analyzed. The boundaries for the uninstrumented perimeter were measured by the software ImageTool 3.0. The data obtained were statistically analyzed by analysis of variance (ANOVA) and t‑test. Results: Mtwo instrumentation produced 41.48% of the uninstrumented perimeter. The final refinement using Hedströem and ultrasonic files decreased the uninstrumented perimeter. Significant differences (t‑test, P = 0.00) were found at the three thirds after the final refinement, except for the apical third that was enhanced by Hedströem file. However, there was no statistical difference between the two refinement techniques used (P > 0.05). Mtwo instrumentation was not capable of cleaning and shaping the entire perimeter of the root canals walls. Conclusions: The final refinement, either with ultrasonic files or with Hedströem files, resulted in significantly less uninstrumented perimeter.

Histological evaluation of refinement influence in the cleaning efficacy of rotary nickel-titanium ProTaper® instruments in oval-shaped root canals

Introduction and objective: The aim of this in vitro study was to evaluate the cleaning and shaping efficacy of rotary nickel-titanium ProTaper® instrumentation in oval canals and the influence of ultrasonic irrigation on the final refinement. Material and methods: Twenty mandibular molars were accessed and divided in two groups. Only distal roots with oval canals were used. Group I was instrumented using only rotary nickel-titanium ProTaper® instruments. Group II received the same preparation followed by refinement with 3 minutes of ultrasonic passive irrigation. After preparation, the distal roots were sectioned for histological processing. Coronal, middle and apical thirds were analyzed. Uninstrumented perimeter in each third was measured by the software Image tool 3.0. Results: The percentage of uninstrumented perimeter was calculated for each third of each root and average percentage was calculated for each third in both groups. Statistical analysis was performed with t-test through the software SPSS 11.0.1 for Windows. The level of significance was set at 1%. Group I showed higher percentage of uninstrumented perimeter in all thirds. Group II, which received ultrasonic irrigation showed better results in all thirds (p < 0.01). Comparing the three thirds in the same group, no statistically significant differences were found (p > 0.05). Conclusion: Under the conditions of this ex vivo study, the three minutes use of ultrasonic irrigation after rotary instrumentation resulted in significantly more instrumented walls in the distal roots of mandibular molars.

Cytotoxicity of root canal sealers on endothelial cell cultures

This study evaluated, in vitro, the cytotoxicity of six root canal sealers after 12, 24 and 72 h of contact time, using an endothelial ECV-304 cell line. The MTT assay was used for analysis of cell viability. Twelve specimens of each sealer were prepared and randomly assigned to 6 groups according to the commercial brands (n=4/time). A control group was also formed, which was not subjected to the contact with sealers. To assess the effects of sealers on endothelial cells, the specimens were placed in culture plate wells and incubated at 37°C with 5% CO2 and 100% humidity. MTT assays were performed in quadruplicate after 12, 24 and 72 h of contact of the sealer specimens with monolayers. Statistical analysis was performed by two-way ANOVA with Bonferroni post-hoc test at a significance level of 5%. Analysis of absorbance in the experimental groups showed that GuttaFlow presented the lowest cytotoxicity, with a mean absorbance of 0.048, followed by Pulp Canal Sealer (0.038), Sealer 26 (0.038), Endo Densell (0.036) and Pulp Fill (0.035). The control group had a mean absorbance of 0.098. Based on the results, Endofill and GuttaFlow were the most and the least cytotoxic sealers, respectively.

Este estudo avaliou, in vitro, a citotoxicidade de 6 cimentos endodônticos após 12, 24 e 72 h de tempo de contato, utilizando-se uma linhagem de células endoteliais ECV-304. Para a avaliação da viabilidade celular, utilizou-se o teste de citotoxicidade MTT. Para cada cimento foram preparados 12 corpos de prova que foram distribuídos em 6 grupos experimentais de acordo com as marcas comerciais, sendo 4 para cada tempo. Foi criado um grupo controle que não foi submetido à ação de cimento. Para avaliação do efeito dos cimentos sobre as células endoteliais, os corpos de prova foram inseridos nos poços da placa cultura, incubados a 37°C em presença de 5% de CO2 e 100% de umidade. Os testes MTT foram realizados em quadruplicata, após 12, 24 e 72 h de contato das amostras com o tapete celular. Foi utilizada a prova two-way Anova com o teste post hoc de Bonferroni com nível de significância de 5%. Quando analisadas as médias gerais de absorbância dos grupos analisados observou-se que o cimento GuttaFlow se apresentou como o cimento com menor índice de citotoxicidade, apresentando média de absorbência de 0,048. Logo após, apresentando médias de absorbância iguais (0,038) encontraram-se os cimentos Pulp Canal Sealer e Sealer 26; seguidos do Densell Endo e do Pulp Fill, com 0,036 e 0,035, respectivamente. O grupo controle apresentou média de absorbância de 0,098. Portanto, tendo como base os resultados obtidos, pôde-se concluir que o cimento Endofill foi o que apresentou maior citotoxicidade e o cimento GuttaFlow, o menos citotóxico.

A barodontalgia em voo e o diagnóstico diferencial de dor odontogênica: relato de caso / In flight barodontalgia and the differential diagnosis of odontogenic pain: a case report

Introdução: A barodontalgia é uma condição aguda que ocorre pela diferença de pressão atmosférica e que afeta a saúde e o bem-estar dos pilotos durante o voo. Os pilotos militares estão mais suscetíveis às diferenças de pressão em razão das manobras rápidas e situações extremas que enfrentam ou por não haver cabine pressurizada na aeronave. Tal ocorrência pode levar a vertigem, incapacitação do profissional e finalização prematura do voo. Sua origem pode estar no dente, relacionada a alguma patologia pré-existente ou não, e ainda em outras estruturas da face, principalmente no seio maxilar. Dos casos relatados na literatura, 70% decorreram de pulpite relacionada a restaurações profundas e a maior parte (81%) ocorreu na decolagem da aeronave. Objetivo: Apresentar um caso clínico de um piloto de T-29 da Força Aérea Brasileira, atendido na Odontoclínica de Aeronáutica Santos-Dumont, imediatamente após o pouso. Relato de caso: A anamnese apontou a diferença de pressão como fator desencadeador da dor dentária aguda. Após o diagnóstico de necrose pulpar, o dente foi submetido ao tratamento endodôntico em sessão única, pelo uso de sistema rotatório Protaper Universal® e obturação com técnica termoplastificada Híbrida de Tagger. Na consulta de reavaliação, o paciente não relatou qualquer outro episódio de dor dentária em voo. Conclusão: Torna-se evidente a relevância do conhecimento desta condição por cirurgiões-dentistas civis e militares, para a correta condução do diagnóstico e do tratamento de aeronavegantes.

Introduction: The barodontalgia is an acute condition due to the air pressure difference that affects the health and the well being of pilots during flight. Military pilots are more susceptible to pressure differences due to quick maneuvering, the extreme situations in flight, or due the lack of pressure into aircraft cabin. Such occurrence can lead to dizziness and premature end of the flight. Its origin may be in the tooth, related to some pre-existing condition or not, and also in other structures of the face, especially in the maxillary sinus. Of the cases reported, 70% came from pulpitis related to deep restorations, and most cases (81%) appeared in the aircraft taking off. Aim: To report a clinical case of a T-29 Brazilian Air Force pilot, who came to Santos-Dumont Air Force Dental Clinic, immediately after landing. The patient interview pointed out barodontalgia as a cause of his acute toothache. After the diagnosis of necrotic pulp, the tooth was endodontically treated in single session by using the Protaper Universal rotary system, and filling with Hybrid Tagger thermoplasticized technique. In the query of reevaluation, the patient reported no further episodes of dental pain in flight. Conclusion: It is evident the relevance of knowledge of this condition by military and civilian dentists, to conduct proper diagnosis and treatment of airmen.

Antimicrobial activity of sodium hypochlorite, chlorhexidine and MTAD® against Enterococcus faecalis biofilm on human dentin matrix in vitro

Objective: This study evaluated the antimicrobial efficacy of 2.5% and 5.25% NaOCl, 2% gel and liquid CHX and MTAD® against Enterococcus faecalis biofilms on human dentin. Material and methods: E. faecalis biofilms grown on dentin matrix of 216 root sections were submerged in test irrigants for 1, 5, 15 and 30 minutes. The antimicrobial activity of the test irrigants were assessed through CFU counts. Biofilm formation over the dentin surface was ensured by SEM analysis.Results: Results showed no statistic difference among CHX gel, 2.5% and 5.25% NaOCl. However, the CHX liquid and MTAD were less effective than 2.5% and 5.25% NaOCl. Only CHX liquid and MTAD had differences in its efficacy depending on the time.Conclusion: The most effective irrigants in eliminating E. faecalis biofilms were 2.5% and 5.25% NaOCl and 2% CHX gel, at all the tested time intervals, in comparison to CHX liquid and MTAD.

Effectiveness of an electronic apex locator used after preflaring of cervical and middle third

Introduction: The electronic method has been studied and improved aiming to add precision, speed and reliability of the measurement technique to determine the exact location of the working length. Currently, the root canal preparation recommends prior to determine the tooth length and consequent perform instrumentation of the apical portion, a previous preflaring of the cervical and middle thirds in various techniques. This procedure may provide a reduction in system impedance, leading to read errors by the apex locators. Objective: Investigate the influence of preflaring of the cervical and middle thirds on the accuracy of measuring the working length by apex locators. Material and methods: Twenty-five mesial roots of molars were used and had their crowns cut at the cemento-enamel junction. The actual measure of each root canal was performed and then the samples were embedded into a mixture of alginate, used as a conducting medium, where electronic measurements were taken with apex locator before and after preflaring of the canals with Gates-Glidden drills in descending order (#4, #3, #2). Measurements obtained by electronic method were then compared with the actual measurement of the root canal. The results were tabulated and submitted to the Student t test. Results: The results show that there was no statistical significance (p<0.05) between the readings before and after preflaring. Readings closer to the foraminal ending occurred in the group after preflaring with Gates Glidden. Conclusion: It was concluded that preflaring with Gates Glidden drills were not able to influence significantly the accuracy of apex locator in determining the exact working length.

Atividade antimicrobiana de materiais reparadores de uso endodôntico pelos testes de difusão em ágar e por contato direto / Antimicrobial activity of repair materials of endodontic use by the agar diffusion test and the direct contact

O presente trabalho teve como objetivo avaliar a atividade antimicrobiana dos materiais reparadores de uso endodôntico: MTA/Bio Angelus®, cimento Portland branco, MTA Angelus® branco e MTA ProRoot® branco sobre os micro-organismos Enterococcus faecalis, Escherichia coli e Staphylococcus aureus, pelos os testes de difusão em ágar e por contato direto. Os dados experimentais foram obtidos através da mensuração do halo de inibição formado e pela contagem de unidades formadoras de colônia, respectivamente. De posse dos resultados, foi possível verificar que o MTA/Bio Angelus® apresentou atividade antimicrobiana superior para todas as espécies bacterianas testadas tanto no teste de difusão em ágar quanto no teste por contato direto e que este último teste demonstrou ser uma metodologia segura, reproduzível e confiável.

The aim of this study was to evaluate the antimicrobial activity of repair materials of endodontic use MTA/Bio Angelus®, white Portland cement, white MTA Angelus® and white MTA ProRoot® on Enterococcus faecalis, Escherichia coli and Staphylococcus aureus by the agar diffusion test and the direct contact test. Data was retrieved by measuring the zones of inhibition and by counting colony-forming units, respectively. The results showed that MTA/Bio Angelus® presented superior antimicrobial activity against all bacteria in the agar diffusion test and in the direct contact test. In addition, our results suggest that the use of the direct contact test is a safe, reproducible and trustable method.

A remodelação óssea de extensa lesão periapical apósuso de PRP e hidróxido de cálcio - relato de caso clínico / The remodeling of extensive periapical lesion after use of PRP and calcium hydroxide- case report

Durante o preparo do canal radicular, em algunscasos, se faz necessário o uso de medicação intracanal(MIC) com o objetivo de continuar asanificação do sistema de canais radiculares.Dentre o arsenal de medicamentos do endodontista,encontra-se o PRP (paramonoclorofenol2%, Rinossoro e polietilenoglicol), umacombinação de antissépticos que pode, ainda,ser associada ao hidróxido de cálcio, por suaspropriedades antimicrobianas e capacidade deindução da reparação tecidual. Este trabalhoteve por objetivo apresentar um caso clínicoda paciente F.G.M., 19 anos, leucoderma, quecompareceu à Odontoclínica de AeronáuticaSantos-Dumont, queixando-se de dor intensanos dentes anteriores. Ao exame clínico-radiográficofoi observado edema no palato, percussãovertical positiva e extensa lesão periapical doincisivo lateral superior direito. Após anestesia eisolamento absoluto, procedeu-se acesso, penetraçãodesinfetante, preparo químico-mecânicoe aplicação de pasta de PRP e hidróxido de cálcio,como MIC. Foram realizadas trocas mensaisdesta MIC por seis meses, até que se observassea regressão da lesão. A observação clínica e radiográficademonstrou que a associação dessesmedicamentos parece induzir boa resposta tecidual,culminando com a remodelação óssea dostecidos periapicais.

During root canal preparation, in some cases,it is necessary the use of intracanal medication(ICM) in order to continue the sanitation of theroot canal system. Among the variety of endodonticmaterials, there is PRP (paramonochlorophenol2%, Rinossoro and polyethylene glycol),a combination of antiseptics, which can also beassociated with calcium hydroxide because ofits antimicrobial properties and induction of tissuerepair ability. This study aimed to present aclinical case of FGM patient, 19 years old, Caucasian,who attended the Santos-Dumont AirForce Dental Clinic, reporting intense pain in the maxillary anterior teeth. After physical and radiographicexamination, an edema was observed onthe palate region, presenting positive vertical percussionand an extensive periapical lesion of upperright lateral incisor. After anesthesia and rubberdam isolation were carried out the access, chemical-mechanical preparation and application of PRPpaste and calcium hydroxide as MIC. Exchangesof MIC were conducted on a monthly basis for sixmonths until was observed the regression of thelesion. The clinical and radiographic observationshowed that the combination of these drugs seemto induce good tissue response, culminating in therepair of periapical tissues.

Clinical management of a complicated crown-root fracture: a case report

This report describes the clinical procedures involved in the treatment of a complicated crown-root fracture in the maxillary left central incisor with a wide open apex of a 10-year-old male patient, due to fall from his own height. Post-trauma treatment comprised cervical pulpotomy and adhesive tooth fragment reattachment. After 1 year, clinical and radiograph examinations showed pulp necrosis and an associated periapical lesion. Endodontic therapy with calcium hydroxide-base intracanal dressing, root canal filling and orthodontic extrusion were performed. Extrusion was completed within approximately 16 weeks and the tooth was restored with a post-core system and a prosthetic crown. After a 3 years of follow-up, there was no evidence of apical periodontitis and the tooth was satisfactory both esthetically and functionally.

Este relato de caso apresenta os procedimentos clínicos envolvidos no tratamento de um caso de fratura corono-radicular complicada de um incisivo superior esquerdo com ápice aberto de um paciente de 10 anos de idade devido à queda da própria altura. O tratamento envolveu pulpotomia cervical e fixação do fragmento. Após 1 ano, os exames clínicos e radiográficos demonstraram necrose pulpar e lesão perirradicular associada. O tratamento endodôntico foi realizado com a utilização de pasta de hidróxido de cálcio, obturação endodôntica e extrusão ortodôntica. Após aproximadamente 16 semanas, o processo de extrusão foi finalizado e o dente restaurado com pino e coroa protética. Após acompanhamento de 3 anos, não havia evidência de lesão perirradicular e o dente estava estética e funcionalmente satisfatório.

Efficacy of five rotary systems versus manual instrumentation during endodontic retreatment

The purpose of this study was to evaluate the efficiency of ProFile, GT, ProTaper, Race and K3 rotary instruments compared with hand K-files for removal of gutta-percha during retreatment. Sixty mandibular premolars were instrumented with GT rotary files and filled by thermomechanical compaction of gutta-percha and AH Plus sealer. The teeth are randomly divided into 6 groups of 10 specimens each. The roots were split longitudinally, digital images were created using a flatbed scanner, and the areas with remaining filling material were demarcated using Image Tool 1.21 software. The results indicate that GT left significantly less (p<0.05) remaining filling material (1.18 ± 1.47) than hand (3.70 ± 3.16) and Hero instruments (2.99 ± 2.58). There was no statistically significant difference (p<0.05) among the others techniques: ProFile (1.99 ± 2.66), ProTaper (2.00 ± 1.99) and K3 (2.71 ± 2.87) when compared with GT. In conclusion, GT, ProFile, ProTaper and K3 were more effective in removing gutta-percha than manual and Hero instruments.

O propósito deste estudo foi avaliar a eficiência dos instrumentos rotatórios ProFile, GT, ProTaper, Race e K3 comparados com limas K para a remoção do material obturador durante o retratamento. Sessenta pré-molares inferiores foram instrumentados com o sistema rotatório GT e obturados usando a técnica de compactação termomecânica de guta-percha com cimento AH Plus. Os dentes foram divididos aleatoriamente em seis grupos de dez espécimes cada. As raízes foram seccionadas longitudinalmente, imagens digitais foram criadas através de um scanner, e as áreas de remanescentes de material foram medidas usando o programa Image Tool 1.21. Os resultados indicaram que o GT deixou significantemente menos material remanescente (1,18 ± 1,47) do que os instrumentos manuais (3,70 ± 3,16) e os instrumentos Hero (2,99 ± 2,58) (p<0,05). Não houve diferença estatisticamente significante entre as outras técnicas ProFile (1,99 ± 2,66), ProTaper (2,00 ± 1,99) e K3 (2,71 ± 2,87) quando comparadas com o GT. Como conclusão, GT, ProFile, ProTaper e K3 foram revelados como mais efetivos em remover a guta-percha do que os instrumentos manuais e os instrumentos Hero.

Influência da conicidade de instrumentos endodônticos de NiTi mecanizados na falha por torção / The influence of taper on rotatory endodontic NiTi instruments related to torsion failure

O objetivo deste trabalho foi comparar a deflexão angular até a fratura e o torque máximo em torção de instrumentos endodônticos de NiTi mecanizados de um mesmo número, de um mesmo fabricante de diferentes conicidades. Os instrumentos foram submetidos ao ensaio mecânico de torção à direita. Os valores obtidos foram submetidos à análise estatística e os resultados revelaram que a conicidade das hastes helicoidais dos instrumentos ensaiados influenciaram na deflexão angular até a fratura e no torque máximo suportado pelo instrumento antes da fratura. A deflexão angular aumentou com a redução da conicidade, enquanto o torque máximo diminuiu com a redução desta.

The aim of this work was to compare the angular deflection at failure and the maximum torque of NiTi rotatory instruments with the same size, same trademark and different tapers. The instruments were submitted to clockwise torsional mechanical tests. The values were submitted to statistical analisys and the results showed that the taper of helical shaft influenced theangular deflection and the maximum torque at failure. The angular deflection increased with the taper reduction,although the maximum torque at failure decreased with the taper reduction.

Tratamento endodôntico com laserterapia de lesão cística de grande volume na mandíbula - relato de caso / Endodontic treatment with laser therapy of large cystic lesion on the mandible - case report

Introdução e objetivo: Este trabalho teve como objetivo mostrar a possibilidade de tratamento não-cirúrgico de grandes cistos. Relato de caso: Realizou-se tratamento endodôntico de lesão perirradicular com aproximadamente 4,5 cm de diâmetro máximo, envolvendo as raízes dos dentes 36 e 37. Indicou-se tratamento de canal dos dentes antes do procedimento cirúrgico da lesão. Observou-se melhora clínica em 20 dias do início do tratamento endodôntico, com diminuição do edema e regressão cística. Optou-se por consultas de manipulação dos canais, colocação de pasta de hidróxido de cálcio e laserterapia. Após seis meses do início do tratamento verificou-se regressão clínica da lesão; procedeu-se à obturação endodôntica dos dentes e fez-se controle clínico radiográfico de 1 e 2 anos. Observaram-se desaparecimento do cisto e consequente reparação óssea. Conclusão: Com a utilização dos avanços tecnológicos, como microscópios e laserterapia, atualmente é possível, em casos de lesão perirradicular em que se recomendava cirurgia, efetuar tratamento não-cirúrgico com sucesso.

Introduction and objective: This study aimed to show the possibility of non-surgical treatment of large cysts. Case report: Endodontic treatment of periradicular lesion with approximately 4.5 cm in maximum diameter regarding the roots of teeth 36 and 37 was performed. Root canal treatment of teeth before the lesion surgical procedure was indicated. After twenty days from the endodontic treatment beginning, an improvement in the clinical condition was observed, with reduction of edema and cystic regression. Thus, the option was for sessions of canal manipulation, placement of calcium hydroxide paste and laser therapy. After six months from the treatment beginning, clinical regression of the lesion was observed; endodontic obturation of the teeth was performed, and clinical radiographic control was carried out for 1 and 2 years. Disappearance of cyst was observed and consequent bone repair. Conclusion: By using technological advances, such as microscopes and laser therapy, nowadays it becomes possible to perform successful non-surgical treatment in cases of periradicular lesion, to which surgery used to be the regular recommendation.

Influência de dois irrigantes na infiltração bacteriana em perfurações de furca obturados com MTA e cimento Portland / Influence of two irrigants in bacterial microleakage of furcal perforation sealed with MTA and Portland cement

O objetivo deste estudo foi avaliar a influência de duas soluções irrigadoras antibacterianas na capacidade de vedamento do MTA e do cimento Portland brancos utilizados como material obturador de perfurações de furca, em quarenta e seis molares humanos extraídos. Após a realização das perfurações na furca realizadas com brocas esféricas # 2, os dentes foram divididos em quatro grupos de dez dentes, sendo os seis dentes restantes divididos em grupos controle positivo e negativo. Os grupos 1 e 2 foram irrigados com hipoclorito de sódio 5,25% e obturados com MTA e cimento Portland respectivamente. Os grupos 3 e 4 foram irrigados com clorexidina gel 2% e também obturados com MTA e cimento Portland respectivamente. Após a obturação das perfurações, os espécimes foram montados em aparatos e inoculados com uma suspensão de Enterococcus faecalis por 61 dias. Os resultados foram submetidos ao teste de Log-rank que demonstrou não haver diferença estatística significativa entre os quatro grupos (p < 0,05). Sob as condições experimentais deste trabalho, a clorexidina gel 2% e o hipoclorito de sódio 5,25% não prejudicaram a capacidade de vedamento do MTA assim como do cimento Portland.

The aim of this study was to evaluate the effect of two endodontic irrigation solutions on the ability of white mineral trioxide aggregate (MTA), compared to Portland cement, to seal furcal perforations in 46 extracted human mandibular molars. Furcal perforations were made in the center of the pulp chamber floor using a high-speed round bur #2. The teeth were randomly divided into four experimental groups of 10, with the remaining six teeth used as positive and negative groups. Experimental groups 1 and 2 were irrigated with 5,25% sodium hypoclorite, and then repaired with MTA and Portland cement, respectively. Experimental groups 3 and 4 were irrigated with 2% chlorhexidine gluconate gel, and then repaired with MTA and Portland cement respectively. After placing the repair materiais into the perforations, the specimens were mounted in an apparatus and inoculated with a suspension of Enterococcus faecalis for 61 days. The leakage data were analysed statistically by a log-rank test (p < 0,05). There was no statistically significant difference among the four groups. Under the conditions of this study, 2% chlorhexidine gluconate gel and 5,25% sodium hypoclorite did not adversely affect the sealing ability of MTA. Portland cement and MTA demonstrated similar ability to seal furcal perforations.

Comparação ex vivo da extrusão de restos dentinários sobduas técnicas de instrumentação dos canais radiculares / An ex vivo comparison of apically-extruded dentinedebris using two instrumentation techniques

O presente estudo teve como objetivo avaliar, ex vivo, a quantidade de dentina extruída após o preparo químico-mecânico de canais radiculares, quando do emprego de duas técnicas de instrumentação. Quarenta canais mésio-vestibulares de raízes de molares inferiores queapresentavam comprimento aproximado de 15 mm foram selecionados, divididos aleatoriamente em dois grupos experimentais de 20 raízes cada e instrumentados, utilizando-se duas técnicas distintas, porém ambas baseadas no princípio coroa-ápice (Técnica de Oregon atualizada e Profile Série 29 Taper.04). Para a coleta do material extruído foi confeccionado um dispositivo em plástico PVC, apresentando na sua porção inferior um filtro de papel que, com auxílio de uma balança de precisão, era pesado antes e após a instrumentação. Mediante a obtenção dos valores de peso inicial e final do filtro, foi possível calcular o peso do material extruído. O peso das raspas de dentina dos canais instrumentados pela técnica de Oregon atualizada variou entre 0,0000 g e 0,0040 g, commédia de 0,0009 g; e nos canais instrumentados com Profile Série 29 Taper.04, a variação foi de 0,0000 a 0,0060 g, com média de 0,0017 g. Os dados foram tratados estatisticamente pelo teste t-Student, que revelou diferenças significantes (p< 0,05). Diante dos resultados obtidos pode-se concluir que a técnica de Oregon atualizada demonstrou maior quantidade de dentina extruída em relação à técnica Profile Série 29 Taper.04.

The present study aimed to compare ex vivo, the amount of extruded dentin after chemico-mechanical preparation of the root canal system, using two instrumentation techniques. Forty mesio-buccal roots of mandibular molars, having 15 mm in length were selected and randomlydivided into 2 experimental groups with 20 samples each. Teeth were instrumented using two crown-down distinct techniques (actualized Oregon Technique and Profile Series 29 Taper.04). Extruded material was collected through a PVC plastic apparatus, with a paper filter in its lowerportion, which was weighted before and after the instrumentation. The extruded material weight was calculated assessing the initial weight and the post-instrumentation weight. Dentin debris form root canals instrumented by Oregon technique showed weight varying from 0,0000 g to 0,0040 g, with a mean of 0,0009 g; and the root canals instrumented with Profile Série 29 Taper.04, the variation was from 0,0000 to 0,0060 g, with a mean of 0,0017 g. Data were statistically treated with t-Student test, that revealed significant differences (p < 0,05). From the results obtained it may be concluded that the Oregon technique demonstrated higher amount of extruded dentin than the Profile Series 29 Taper.04 technique.

Avaliação da infiltração marginal observada em cinco cimentos utilizados como seladores temporários / Microleakage evaluation of five temporary endodontic restorations

Introdução e objetivo:: O objetivo deste estudo foi avaliar a infiltração marginal, através da passagem de íons níquel, em cinco tipos de materiais utilizados na clínica de Endodontia como seladores temporários: Coltosol, Tempore plus® (DFL), Cimento de Zinco® (Lee Smith), Vitro-Fill® (DFL) e New Bond®(Technew). Material e métodos: Neste estudo foram usados 56 dentes unirradiculares, conservados em solução de timol 0,1%. Os espécimes foram divididos em: grupo I – Coltosol®; grupo II – Tempore plus®; grupo III – Cimento de Zinco®; grupo IV – Vitro-Fill®; grupo V – New Bond®. Uma bolinha de algodão impregnada com solução de dimetilglioxima a 1% foi colocada na câmara pulpar, e o selamento das cavidades de acesso foi realizado com os materiais a serem testados. Os dentes foram então imersos em solução de sulfato de níquel a 5% a 37°C por 7 dias. A área infiltrada foi medida em mm2 com o auxílio do software ImageTool. Resultados: Os grupos I, II e V apresentaram valores de infiltração significativamente menores que os grupos III e IV. No entanto não houve diferença estatística entre os grupos III e IV e entre os grupos I, II e V. Conclusão: Os grupos I, II e V (Coltosol®, Tempore plus® e New Bond®) demonstraram os melhores resultados, embora todos os materiais tenham permitido percolação do corante utilizado.

Introduction and objecttiivvee:: The aim of this study was to evaluate microleakage, through the crossing of íons nickel, in five types of materials used in the clinic of Endodontics, as temporary endodontics restorations: Coltosol®; Tempore plus® (DFL); Cimento de Zinco® (Lee Smith); Vitro-Fill® (DFL); New Bond® (Technew). Material and methods: In this study 56 uniradicular teeth had been used conserved in solution of timol 0,1%. The specimens had been divided in: group I – Coltosol®; group II – Tempore plus®; group III – Cimento de Zinco®; group IV – Vitro-Fill®; group V – New Bond®. A cotton pellet moistened with solution of 1% dimethylglyoxime was put into the pulp chamber and the sealing of the access cavities was made with the materials to be tested.The specimens were then immersed in 5% NiSO4 for 7 days. The infiltrated area was measured in mm2 with aid of ImageTool software. Results: Groups I, II and V had presented significantly lesser values of infiltration than groups III and IV. However, there wasn’t statistics difference between groups III and IV and among groups I, II and V. Conclusion: The groups I, II e V (Coltosol®,Tempore plus® and New Bond®) showed the best results, although every restoration had allowed dye leakage.

Tempo de endurecimento de alguns cimentos endodônticos à base de óxido de zinco eeugenol / Setting times of some zinc oxide and eugenol based endodontic sealers

Objetivo: Procurou-se analisar ex vivo o tempo de endurecimento dos cimentos endodônticos nacionais à base de óxido de zinco e eugenol: Endofill®, Intrafill®, cimento de Rickert (LenzaFarm®), Pulp Fill® e Target®. Material e métodos: O tempo de endurecimento dos cimentos endodônticos foi obtido de acordo com a especificação n. 57 da American Dental Association. Resultados: A análise das médias indicou a existência de diferença altamente significante entre os tempos de endurecimento dos cimentos. Conclusão: Considerando a propriedade avaliada, os cimentos Target® e Intrafill® mostraram valores mais compatíveis com a atividade clínica.

Objective: To analyse ex-vivo setting times of national zinc oxide and eugenol based root canal sealers: Endofill®, Intrafill®, Rickert’s sealer (LenzaFarm®), Pulp Fill® and Target®. Material and methods: The setting times was obtained in accordance with the specification n. 57 of the Dental American Association. Results: The analysis of the averages indicated the existence of highly significant difference between the setting times of the sealers. Conclusion: Considering the evaluated property, the cement Target® and Intrafill® have shown values more compatible with the clinical activity.

Avaliação radiográfica da eficiência dediferentes instrumentos rotatórios no retratamento endodôntico / Assessment of the effectiveness of differentrotary instruments in endodontic retreatment

Objetivo: O objetivo deste estudo foi comparar in vitro a eficiência da remoção da guta-percha dos canais radiculares por meio de diferentes instrumentos rotatórios. Material e métodos: Foram utilizados 60 prémolares inferiores humanos extraídos, os quais foram manejados com os instrumentos GT até o #30 taper .04 e obturados pela técnica híbrida de Tagger. O retratamento foi realizado de acordo com os seguintes instrumentos: ProFile (grupo I), ProTaper (grupo II), GT (grupo III), manual controle (grupo IV), K3 (grupo V) e Hero (grupo VI). Radiografias no sentido vestibulolingual foram realizadas, escaneadas a uma resolução de 480 DPI e analisadas em computador de acordo com o remanescente de material obturador após o retratamento. As raízes foram divididas em terço cervical, médio e apical, e atribuíram-se escores numa escala de: 0 (sem material remanescente), 1 (até 25%), 2 (até 50%) e 3 (mais de 50%). Os escores de remanescente de material obturador para os diferentes instrumentos testados foram analisados estatisticamente por meio do teste Kruskal- Wallis. Resultados: Existiu diferença estatística entre os instrumentos (p < 0,01). O grupo instrumentado com o sistema Hero e K3 diferiram dos demais grupos, que obtiveram os melhores resultados. O grupo controle (manual), apesar de ter baixos valores juntamente com os demais, quando avaliado por terços, apresentou a maior quantidade de remanescente de material no terço apical. Conclusão: Os grupos ProFile, ProTaper, GT e manual alcançaram os melhores resultados, porém não houve diferença estatística significante entre eles.

Objective: The purpose of this study was to compare in vitro the effectiveness of removing guta-percha from root canals using differents rotatory instruments. Material and methods: Sixty human inferior premolars have been used, which were instrumented with GT hand files up to #30 taper .04 and obturated using Tagger’s hybrid technique. The retreatment has been based in the following instruments: ProFile (group I), ProTaper (group II), GT (group III), Manual-Control (group IV), K3 (group V), and Hero (group VI). Radiographies were taken in vestibular orientation, scanned at resolution 480DPI and analyzed by computer for the observation of the remnant parts of obturation materials after retreatment. The roots have been divided in 1/3 cervical, medium and apical, and scores were attributed as per the following scale: 0 (absence of remnant materials), 1 (up to 25%), 2 (up to 50%), and 3 (over 50%). The scores of obturation remnant materials for the differents tested instruments were statistically assessed by means of the Krusckal-Wallis’ method. Results: There was statistical difference among the instruments (p < 0.01). The group instrumented using Hero and K3 differed from the remaining groups, which presented best results. The control group (manual), in spite of presenting low values, as well as the remaining groups, when appraised by thirds has shown a greater quantity of remaining material at the apical third. Conclusion: The ProFile, ProTaper, GT, and Manual groups have presented more outstanding results, notwithstanding the absence of meaningful statistical difference among them.