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).

Comparison of genotypes, antimicrobial resistance and virulence profiles of oral and non oral Enterococcus faecalis from Brazil, Japan and the United Kingdom.

OBJECTIVES: To determine whether phenotypic and genotypic differences amongst isolates ofEnterococcus faecalis relate to geographical and clinical origin. METHODS: E. faecalis from primary endodontic infections in Brazilian patients (n = 20), oral infections in UK patients (n = 10), and non-oral infections in Japanese patients (n = 9) were studied. In addition, 20 environmental vancomycin resistant Enterococcus faecalis (VRE) isolates from a UK hospital were analysed. For all isolates, polymerase chain reaction (PCR) was used to detect genes associated with antibiotic resistance and virulence, whilst randomly amplified polymorphic DNA-PCR (RAPD-PCR) was used to produce molecular profiles. RESULTS: Gelatinase gene (gelE) was prevalent amongst isolates (77-100%) and for oral isolates, genes of aggregation substances (agg), immune evasion protein (esp), cytolysin (cylB), tetracycline resistance (tetM; tetL) and erythromycin resistance (ermB) were detected to varying extent. Japanese non-oral isolates had a similar genetic profile to oral isolates, but with higher prevalence of ermB and cylB. All VRE isolates were positive for gelE, esp, agg, vanA, ermB and tetM, 95% were positive for cylB and 17% positive for tetL. All isolates were negative for ermA, asa373 vanB, vanC1 and vanC2/3. RAPD-PCR revealed clustering of VRE isolates. CONCLUSIONS: RAPD-PCR analysis revealed extensive genetic variability among the tested isolates. Oral isolates carried antibiotic resistance genes for tetracycline and whilst they possessed genes that could contribute to pathogenicity, these were detected at lower incidence compared with non-oral and VRE isolates. RAPD-PCR proved to be a useful approach to elucidate relatedness of disparate isolates.

Effect of final irrigation protocols on push-out bond strength of an epoxy resin root canal sealer to dentin.

The purpose of the present study was to evaluate the effect of different final irrigation protocols on push-out bond strength of an epoxy resin root canal sealer to dentin. Eighty single-rooted anterior teeth were used. The root canals were partially prepared using a rotary system and the final diameter was standardised using a #5 Gates-Glidden drill prior to the push-out bond test. During chemomechanical preparation, 5.25% NaOCl or 2% CHX gel was used. For smear layer removal, 17% ethylenediaminetetraacetic acid (EDTA) or QMix 2 in 1 was applied for 3 min. As final irrigant, 1 mL of NaOCl, CHX solution or distilled water was used. On conclusion of preparation, canals were filled with gutta-percha/AH Plus sealer. Bond strength was measured by the push-out test. Data were statistically analysed by Kruskal-Wallis and Mann-Whitney U-tests. The group NaOCl/EDTA/NaOCl showed significantly higher bond strength values than other groups. In all groups, there were mainly mixed failure patterns. It can be concluded that 5.25% NaOCl proved to be the best solution for the final irrigation when combined with EDTA. The final irrigation protocols affect the push-out bond strength of AH Plus to dentin.

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.

Antimicrobial resistance and virulence traits of Enterococcus faecalis from primary endodontic infections.

OBJECTIVES: To determine the phenotypic and molecular characteristics of Enterococcus faecalis recovered from primary endodontic infections in Brazilian patients. METHODS: Twenty isolates of E. faecalis recovered from 43 Brazilian patients with primary endodontic infections were identified by biochemical profiling (API20Strep) and 16S rDNA sequencing. Antimicrobial susceptibility was ascertained by agar dilution, using the recommended protocol of the Clinical and Laboratory Standards Institute (CLSI). PCR with validated primers was used to detect genes associated with antibiotic resistance and specific virulence factors. RESULTS: All isolates were deemed susceptible to penicillin G, erythromycin and vancomycin. However, nine isolates had a minimum inhibitory concentration of 4µg/mL to vancomycin (the resistance breakpoint). Fourteen isolates (70% of isolates) were also resistant to tetracycline with MICs of >64µg/mL. PCR products for tetracycline resistance genes were detected in test isolates, while erythromycin and vancomycin resistance genes were not evident. Gelatinase, aggregation substance and enteroccocal surface protein genes were detected in 20, 18 and 12 isolates, respectively. CONCLUSIONS: Endodontic E. faecalis isolates exhibit high level of resistance to tetracycline, an antibiotic that has use in local treatment of dental infections. This opens up a much-needed debate on the role and efficacy of this antibiotic for oral infections. Furthermore, these isolates were shown to possess genes that could contribute to pathogenicity in the pulp cavity.

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.

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.

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.

Interfacial adaptation of the Epiphany self-adhesive sealer to root dentin.

OBJECTIVE: The present study was designed to investigate interfacial quality between both Epiphany and Epiphany SE and the surrounding dentin having conventional gutta-percha/AH plus root filling as reference for comparison. STUDY DESIGN: A sample of 36 human maxillary canines was prepared and assigned to experimental groups of 12 teeth each, designated as G1, Resilon/Epiphany; G2, Resilon/Epiphany SE; and G3, gutta-percha/AH Plus. After the filling procedures, each specimen was horizontally sectioned at 3, 6, and 8 mm from the apex and a metallographic preparation was performed to enable the evaluation under Confocal Laser Scanning Microscopy (CLSM). The integrity of the interface was determined by calculating the ratio between the total sealer/dentin interface and the sealer/dentin interface that presented gap-containing regions. Additionally, the width of each gap was measured and pooled per each specimen for comparison. Statistical analysis was performed using nonparametric methods. RESULTS: Nonbonding AH Plus/gutta-percha root fillings showed a significantly higher amount of gap-free regions (P < .05). In the same way, nonbonding AH plus root fillings displayed significantly narrower gaps compared with the 2 adhesive root-filling groups (P < .05). CONCLUSIONS: Under the present in vitro conditions, the quality of the interfacial adaptation of the current adhesive root fillings is compromised even when teeth with simple anatomic features were obturated under well-monitored laboratory conditions.

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.

Suboptimal debridement quality produced by the single-file F2 ProTaper technique in oval-shaped canals.

INTRODUCTION: The aim of this study was to determine whether the debridement quality of the single-file F2 ProTaper instrumentation technique is comparable to a full conventional ProTaper sequence in both round and oval-shaped root canals. METHODS: Fifty-four recently extracted vital lower incisors were instrumented with either a full range of ProTaper Universal instruments in rotary motion (group 1) or with the single-file F2 ProTaper technique in reciprocating motion (group 2). Teeth were previously classified as round or oval-shaped by means of bidirectional radiographs, resulting in 24 round canals, 24 oval canals, and 12 controls. After instrumentation, the roots were demineralized, and the apical 3 mm was multi-sliced and processed for histologic examination. The percentage of residual pulp tissue (PRPT) was calculated with the aid of image analysis software. Univariate analysis of variance was used to verify the variables influencing PRPT. RESULTS: Both canal shape and technique significantly influenced PRPT (P < .05). Oval-shaped canals displayed much more PRPT than round canals in both techniques (P < .05). The difference in PRPT between the techniques depended on the root canal shape, since a significant interaction between canal shape and technique was observed (P < .05). Group 1 displayed considerably less PRPT in oval canals than group 2 (P < .05), whereas in round canals no significant difference was found between the 2 techniques (P > .05). CONCLUSIONS: The single-file F2 ProTaper technique displayed similar PRPT to the full range of ProTaper instruments in round canals. However, the debridement quality of the single-file F2 ProTaper technique was suboptimal in oval canals.