Ex vivo Analysis of Three Electronic Apex Locators Accuracy with Different Settings.

Aims: The correct determination of a root canal length is a fundamental step for an adequate chemical-mechanical preparation and consequently, for a successful endodontic treatment. Electronic apex locators (EAL) were developed to provide fast and reliable working lengths. The aim of the present study was to analyze the accuracy of the Root ZX II, RomiApex A-15, and SmarPex EAL’s to determine the location of apical constriction, with and without the instructions recommended by the manufacturers. Methodology: Fifteen mandibular premolars were randomly selected and root canals were accessed. The real canal length was determined by introducing a #15 K-file until the tip was visualized in the apical foramen, using 40x magnification of an operative microscope. In the sequence, the teeth were inserted in plastic flasks containing floral foam soaked in 0.9% saline solution. The root canals were filled with 1% sodium hypochlorite and the electronic measures were obtained with the selected devices until the “0.0” or the last green bar mark, as showed in devices display, and as per the manufacturers settings recommendation. The data were submitted to statistical analysis with the Friedman and Wilcoxon tests with a 0.05% significance level (p < 0.05). Results: All devices were similar (p > 0.05) and showed precise and acceptable measurements at both times. Without manufacturers setting recommendation, the Root ZX II was the EAL that presented the greater percentage of coincidences with the real teeth length measures (73.33%), followed by the RomiApex A-15 (66.66%) and the SmarPex (40%). After performing the recommended settings the Root ZX II and the SmarPex presented 86.66% of coincidence with the real length, however, only the SmarPex device enhanced the mean precision with the real length (p < 0.05). Conclusion: Considering a clinically acceptable average error of ±0.5 mm, all devices were effective in determining the measurement until the apical constriction. Although, there were no statistical significant difference with and without manufacturers instruction, for Root ZX II, the performance was better when manufacturer instructions were followed.

Evaluation of cutting ability and plastic deformation of reciprocating files

Abstract This in vitro study evaluated the cutting ability of reciprocating files and the deformations caused by their multiple use. Five Reciproc® R25 files were divided into five groups for 10 simulated root canal preparations each. The resin blocks were weighed and photographed (12.5X and 20X) before and after preparation. The canals were prepared according to the manufacturer’s instructions. Enlargement of the root canals was evaluated by comparison of pre- and post-preparation images using a computer software. The preoperative and postoperative weight differences determined the cutting ability of repeatedly used instruments. The data were analyzed using Lilliefors and Friedman statistical tests. The cutting ability and enlargement of the canals gradually decreased after each use, with significant differences observed at the 8th and 9th repetitions, respectively. There was no evidence of file deformation. The cutting ability and enlargement of the simulated canals gradually decreased when a reciprocating file was used up to 10 times.

Influence of calcium hydroxide dressing and two irrigants on the filling of artificial lateral canals.

Context: This study was carried out on the assumption that calcium hydroxide [Ca(OH)2] dressing and irrigants may influence the obturation of lateral canals. Aims: To evaluate the influence of 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) gel and Ca(OH)2 on the filling of artificial lateral canals. Settings and Design: Ex vivo quantitative laboratory study. Materials and Methods: Forty‑two human mandibular premolars were selected. After cavity access, six lateral canals were performed, two in each root section, one mesial and one on the distal root surface. After preparation, the specimens were randomly divided into four groups: Group I: Under irrigation with 2% CHX and saline solution and with intracanal dressing Ca(OH)2 paste; Group II: The same preparation as Group I, but without Ca(OH)2; Group III: Under irrigation with 2.5% NaOCl without Ca(OH)2; and Group IV: The same preparation as Group III, but with Ca(OH)2. Two teeth without intracanal dressing were used as negative controls. Lateral condensation technique was performed. Then, digital radiographic images were obtained. Statistical Analysis Used: Data were analyzed using SPSS 17.0, submitted to Kappa (reliability between examiners) and Kruskal–Wallis test. Results: No statistical difference was registered between Groups II and III in all root sections (P > 0.05), but it was observed between Groups I and IV (P < 0.05), except on the apical section (P > 0.05). In all sections, the Group I filled more artificial lateral canals than in Group IV. Conclusions: The irrigants tested had no influence on the filling of artificial lateral canals. Nevertheless, intracanal dressing of Ca(OH)2 influenced this filling.

Applying liquid chromatography-tandem mass spectrometry to assess endodontic sealer microleakage

The objective of this study was to describe a new method for the quantitative analysis of a microleakage of endodontic filling materials. Forty extracted single-rooted teeth were randomly divided into three experimental groups. After root canal shaping, the experimental groups were filled using the lateral condensation technique with the Epiphany system (G1), with gutta-percha + Sealapex (G2), and with gutta-percha + AH Plus (G3). Each root was mounted on a modified leakage testing device, and caffeine solution was used as a tracer (2000 ng mL-1, pH 6.0), applied in the coronal direction towards the tooth apex, creating a hydrostatic pressure of 2.55 kPa. Presence of caffeine in the receiving solution was measured after 10, 30, and 60 days, using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). None of the groups presented microleakage at 10 days. At 30 days, G2 and G3 showed similar infiltration patterns (means: 16.0 and 13.9 ng mL-1, respectively), whereas G1 showed significantly higher values (mean: 105.2 ng mL-1). At 60 days, leakage values were 182.6 ng mL-1for G1, 139.0 ng mL-1 for G2, and 53.5 ng mL-1 for G3. AH Plus showed the best sealing ability and HPLC-MS/MS showed high sensitivity and specificity for tracer quantification.

Penetration of a resin-based filling material into lateral root canals and quality of obturation by different techniques

The aim of this study was to evaluate the penetration of a resin/polyester polymer-based material (Resilon Real Seal; SybronEndo Corp., Orange, USA) into simulated lateral canals, and the quality of obturations by different techniques. A total of 30 standardized simulated canals were divided into three groups according to the technique of obturation used: MS (McSpadden), SB (SystemB/Obtura II), and LC (Lateral Condensation). To analyze the penetration of the filling material, the simulated canals were digitalized and the images were analyzed using the Leica QWIN Pro v2.3 software. The data of the middle and apical thirds were separately submitted to analysis of variance (ANOVA), followed by the Tukey’s test for the comparison of the techniques. Results showed a significant difference (p < 0.05) between groups (LC < SB) in the middle third, and a significant difference (p < 0.05) between groups (LC < SB and MS < SB) in the apical third. To analyze the quality of the obturations, the canals were radiographed and evaluated by three examiners. The Kappa test on interexaminer agreement and the nonparametric Kruskal-Wallis test indicated no significant difference between filling techniques. It was concluded that Resilon achieves greater levels of penetration when associated with thermoplastic obturation techniques.

Influence of Apical Patency and Cleaning of the Apical Foramen on Periapical Extrusion in Retreatment

This study evaluated the influence of apical patency, root filling removal technique and cleaning of the apical foramen, concerning the amount of debris extruded during root canal retreatment. Forty mandibular incisors were randomly assigned to 4 groups - GIM (n=10), GIIM (n=10), GIPT (n=10) and GIIPT (n=10), which were named according to leaving (I) or not (II) apical patency during canal preparation and filling removal technique (manual - M or ProTaper system - PT). After filling material removal, each specimen of each group had the apical foramen cleaned by sizes 15, 20 and 25 instruments, generating 12 subgroups: GIM15, GIM20, GIM25, GIIM15, GIIM20, GIIM25, GIPT15, GIPT20, GIPT25, GIIPT15, GIIPT20 and GIIPT25. Extruded filling debris was collected by a Milipore filtration system, an HV-durapore, 0.45 µm pore filter with a 25 mm diameter. The filters were weighed before and after the collection on an analytical scale (10–5 g), and the difference was calculated. The mean weight of extruded filling debris was analyzed statistically by Kruskal-Wallis and Friedman ANOVA tests (α=0.05). The mean values found in the groups (in mg) were: GIM (0.95±0.94), GIIM (0.47±0.62), GIPT (0.30±0.31) and GIIPT (0.32±0.44). There was no statistically significant difference among any of the groups or subgroups (p>0.05). ProTaper provided the smallest amount of extruded filling material, regardless of presence or absence of apical patency, followed by manual technique, without and with apical patency. Additional amounts of debris were collected during cleaning of the apical foramen, regardless of the instrument, presence/absence of patency or root filling removal technique.

Este estudo verificou a influência da patência apical, técnica de desobturação e limpeza foraminal na quantidade de material sólido extruído, durante retratamento endodôntico. Quarenta incisivos inferiores foram divididos aleatoriamente em quatro grupos - GIM (n=10), GIIM (n=10), GIPT (n=10) e GIIPT (n=10) - nomeados de acordo com a realização (I) ou não (II) de patência apical durante o preparo de canais e a técnica de desobturação - manual (M) ou sistema ProTaper (PT). Após a desobturação, realizou-se a limpeza foraminal em cada espécime de todos os grupos com instrumentos #15, #20 e #25, gerando 12 subgrupos: GIM15, GIM20, GIM25, GIIM15, GIIM20, GIIM25, GIPT15, GIPT20, GIPT25, GIIPT15, GIIPT20 e GIIPT25. O material sólido extruído foi coletado pelo sistema de filtração Millipore®, com filtros de 0,45 µm de poro e 25 mm de diâmetro. Os filtros foram pesados antes e após a coleta, em balança analítica de precisão (10–5g), e as diferenças foram calculadas. Os valores médios encontrados (em mg) foram: GIM (0,95±0,94), GIIM (0,47±0,62), GIPT (0,30±0,31) e GIIPT (0,32±0,44), sem diferença estatística entre quaisquer dos grupos ou subgrupos (p>0,05). O sistema Protaper proporcionou a menor quantidade de material sólido extruído, independente da presença ou não de patência apical seguidos da técnica manual sem e com patência apical. Quantidades adicionais foram coletadas durante a limpeza foraminal, independente do instrumento utilizado, da presença ou não da patência apical ou da técnica de desobturação.

Performance of RaCe Instrumentation System in Curved Root Canals: A Comprehensive Analysis by Three Study Methods

In this study, curved maxillary molar root canals were instrumented with RaCe rotary system to evaluate: 1. the occurrence of canal transportation using a radiographic platform; 2. the action of the instruments on the dentin walls, centering ability and canal enlargement by analysis of digital images; and the percentage of regular dentin surfaces and debris within the canal by histological analysis. Ten mesiobuccal roots of extracted human maxillary molars were embedded in acrylic resin and sectioned at the middle and apical thirds. Root canal shaping was performed using the RaCe rotary system at 250 rpm and 1 Ncm torque. Each instrument set was used five times according to a crown-down technique in the following sequence: 40/0.10, 35/0.08, 25/0.06, 25/0.04, 25/0.02 (working length - WL), 30/0.02 (WL) and 35/0.02 (WL). Each instrument was inserted until resistance was felt and then pulled back, followed by brushing movements towards all canal walls. Each specimen was assessed by three study methods: radiographic platform, digitized image assessment and histological analysis. The radiographic platform showed lack of apical transportation. No statistically significant difference (Wilcoxon test, p>0.05) was found between the middle and apical thirds regarding instrument action on dentin walls, centering ability, area of root canal enlargement, percentage of regular dentin surfaces and debris within the root canal. It may be concluded that RaCe system is a suitable method for the preparation of curved root canals, regarding the maintenance of root canal original path, action on dentin walls, canal enlargement and removal of debris from the root canal lumen.

O objetivo do presente estudo foi verificar a presença de desvio apical por meio da plataforma radiográfica, avaliar a ação dos instrumentos, centralização do preparo e ampliação por meio de imagens digitais do canal e calcular a porcentagem de superfícies regulares e presença de debris por meio da análise histológica. Dez raízes mésiovestibulares de molares superiores extraídos foram incluídos em blocos de resina e seccionados no terço médio e apical. O preparo do canal foi feito empregando o sistema RaCe, a 250 rpm e torque de 1 Ncm. Cada sistema rotatório foi usado 5 vezes no sentido coroa-ápice na seguinte sequência: 40/0.10, 35/0.08, 25/0.06, 25/0.04, 25/0.02 (comprimento de trabalho - CT), 30/0/02 (CT) e 35/0/02 (CT). Cada amostra foi avaliada por 3 métodos de estudo: plataforma radiográfica, imagem digital e análise histológica. A plataforma radiográfica mostrou ausência de transporte apical. Em relação à ação dos instrumentos sobre as paredes dentinárias, centralização do preparo, ampliação, porcentagem de superfícies regulares e presença de debris, o teste estatístico de Wilcoxon não mostrou diferença significativa entre os terços apical e médio. O sistema RaCe se mostrou adequado para o preparo de canais radiculares curvos em relação à manutenção do trajeto original do canal, ação sobre as paredes dentinárias, ampliação e remoção de debris da luz do canal radicular.

Preenchimento de canais radiculares com pastade hidróxido de cálcio, utilizando-se propulsor de Lentulo, em diferentes velocidades / Root canal filling with calcium hydroxide paste using lentullo spiral at different speeds

Objetivo: este estudo analisou a efetividade do preenchimento do canal radicular com pasta de hidróxido empregando o propulsor de Lentulo, acionado em diferentes velocidades.Métodos: trinta pré-molares inferiores tiveram seus canais radiculares preparados até o instrumento #50 e divididos aleatoriamente em três grupos. Pasta de hidróxido de cálcio preparada com solução fisiológica foi inserida nos canais radiculares empregando-se um propulsor de Lentulo, acionado com velocidades de 5.000 rpm (G1), 10.080 rpm(G2) e 15.000 rpm (G3). A densidade óptica foi determinada utilizando-se o sistema de radiografia digital (Kodak Dental RGV-5000). Resultados: a maior densidade óptica obtida no terço apical foi no G3, e nos terços médio e cervical no G1. Por meio do teste Kruskal-Wallis-Anova, observou--se diferença estatística (p<0,05) entre o G1 e G3 no terço apical, e G1 e G2 no terço médio, mas nenhuma diferença estatística foi observada no terço cervical (p>0,05).Conclusão: velocidades diferentes são necessárias para o correto preenchimento de canais radiculares com pasta de hidróxido de cálcio. A velocidade de 15.000 rpm foi mais efetiva no preenchimento do terço apical e a velocidade de 5.000 rpm foi mais efetiva no preenchimento dos terços médio e cervical.

Objective: This study analyzed the effectiveness of fillingthe root canal with calcium hydroxide paste using the Lentulospiral at different speeds. Methods: Thirty mandibularpremolars after root canal preparation were divided in threegroups. Calcium hydroxide paste was inserted in the rootcanals with a Lentulo spiral at 5,000 rpm (G1), 10,000 rpm(G2) and 15,000 rpm (G3). The optical density was determinedby the use of the digital radiography system KodakDental RGV-5000. Results: The highest optical densityobtained in the apical third was in G3 and in the middle andcervical third in G1. Statistical difference (Kruskal-Wallis -Anova) was observed (p<0.05) between G1 and G3 in theapical third and G1 and G2 in the middle third. No differencewas observed in the cervical third (p>0.05). Conclusion:Different speeds are necessary for the correct fillingof the root canal with calcium hydroxide paste. The 15,000rpm speed was more effective in filling the apical third and5,000 rpm speed was more effective in filling the cervicaland middle thirds.

Capacidade de selamento marginal apical propiciado por alguns materiais retrobturadores / Apical sealing ability of some retrograde filling materials

OBJETIVO: Analisar a microinfiltração marginal através da penetração linear de corante Rodamina B em obturações retrógradas utilizando diferentes materiais. MÉTODOS: Sessenta e um dentes permanentes extraídos e tratados endodonticamente tiveram seus 3 mm apicais amputados transversalmente e retrocavidades com 3 mm de profundidade foram preparadas com pontas de ultrasson. Os espécimes foram divididos em grupos experimentais onde os materiais retrobturadores foram inseridos e submersos em corante por 24 horas. Os grupos continham Super EBA, MTA, Histoacryl além dos controles positivo e negativo. RESULTADOS: A microinfiltração marginal analisada com auxílio de computador, utilizando o programa Image J e aplicando-se o teste de comparação múltipla de Kruskal Wallis, mostraram diferença entre os materiais testados. Em ordem decrescente de capacidade de selamento marginal aparece o Histoacryl com o melhor desempenho, não apresentando nenhum espécime com microinfiltração, seguidos do Super EBA e MTA com comportamentos estatisticamente semelhantes. CONCLUSÃO: O grupo do histoacryl foi o que apresentou o melhor vedamento entre os três materiais comparados.

OBJECTIVE: Assess marginal leakage by linear penetration of rhodamine B dye in retrograde fillings filled with different materials. METHODS: Sixty-one permanent teeth extracted and treated endodontically had their 3 apical millimeters amputated cross-sectionally and 3 mm deep retro-cavities were prepared with ultrasonic tips. The specimens were divided into experimental groups where the retrofilled materials were inserted and submerged in a dye for 24 hours. The groups consisted of Super EBA, MTA and Histoacryl, in addition to the positive and negative controls. RESULTS: Marginal leakage was analyzed by the Image J software and multiple comparisons with the Kruskal-Wallis test revealed differences among the materials. The material with the best marginal sealing capacity was Histoacryl. None of the specimens sealed with this product presented leakage. Super EBA was next in terms of sealing capacity followed by MTA, but their performances were similar. CONCLUSION: Histoacryl presented the best sealing capacity of the three studied materials.

In vitro analysis of thermocompaction time and gutta-percha type on quality of main canal and lateral canals filling

The aim of this study was to evaluate the quality of filling in main and lateral root canals performed with the McSpadden technique, regarding the time spent on the procedure and the type of gutta-percha employed. Fifty simulated root canals, made with six lateral canals placed two apiece in the cervical, middle and apical thirds of the root, were divided into 5 groups. Group A: McSpadden technique with conventional gutta-percha, performed with sufficient time for canal filling; Group B: McSpadden technique with conventional gutta-percha, performed in twice the mean time used in Group A; Group C: McSpadden technique with TP gutta-percha, performed with sufficient time for canal filling; Group D: McSpadden technique with TP gutta-percha, performed in twice the mean time used in Group C; Group E: lateral condensation technique. Images of the filled root canals were taken using a stereomicroscope and analyzed using the Leica QWIN Pro software for filling material flow, gutta-percha filling extension and sealer flow. Data were analyzed by analysis of variance (ANOVA) and Tukey test (p < 0.05). The best values of penetration in lateral canals in the middle third occurred in the groups where TP gutta-percha was used. However, in the apical third, group B showed the best values. Although a longer time of compactor use allows greater penetration of the filling material into the lateral canals, the presence of voids resulted in bad quality radiographic images, suggesting porosity. The best quality of filling material was observed in Group A (McSpadden technique with conventional Gutta-Percha, performed with sufficient time for root canal filling).

Sistema BioRace: segurança e eficiência / The BioRace system: safe and efficiency

A eficácia do processo de sanificação do sistema de canais radiculares está em função direta de suaampliação. Quanto maior a ampliação melhor é a qualidade de limpeza e sanificação uma vez que a substânciaquímica atua com mais efetividade e, quando da necessidade de uma medicação intracanal, esta atuacom toda a sua potencialidade. Os sistemas rotatórios de NiTi tem se revelado uma inovação importante,mas os kits desenvolvidos pelos fabricantes tem se limitado a uma ampliação reduzida da crítica zona apical.O sistema BioRace da FKG Dentaire, Switzerland, foi desenvolvido atendendo os princípios de segurança,efetividade e contemplando os princípios biológicos que permitem maior ampliação do terço apical, áreacrítica para o controle da infecção endodôntica. No presente artigo os autores apresentam, analisam e apresentamo protocolo clínico para a sua utilização.

The efficacy of the sanitization process in root canal preparation is dependent on its enlargement.With greater enlargement of the root canal, the irrigating solution activity is higher and intracanal dressingacts on its total potential. The development of NiTi rotary systems is a revolution in endodontic therapy, butthe kits available in the market are limited in enlarging the apical third. The BioRace system by FKG Dentairewas developed attending to efficient, safe and biological based sequence files. The authors present the systemand establish a protocol for its clinical application.

A model system to study antimicrobial strategies in endodontic biofilms

The purpose of this work was to develop a model system to study antimicrobial strategies in endodontic biofilms. Enterococcus faecalis suspension was colonized in 10 human root canals. Five milliliters of Brain Heart Infusion (BHI) were mixed with 5 mL of the bacterial inoculums (E. faecalis) and inoculated with sufficient volume to fill the root canal during 60 days. This procedure was repeated every 72 h, always using 24-h pure culture prepared and adjusted to No. 1 MacFarland turbidity standard. Biofilm formation was analyzed by scanning electron microscopy (SEM). E. faecalis consistently adhered to collagen structure, colonized dentin surface, progressed towards the dentinal tubules and formed a biofilm. The proposed biofilm model seems to be viable for studies on antimicrobial strategies, and allows for a satisfactory colonization time of selected bacterial species with virulence and adherence properties.

Antibacterial efficacy of intracanal medicaments on bacterial biofilm: a critical review

The purpose of this paper is to discuss critically the antibacterial efficacy of intracanal medicaments on bacterial biofilm. Longitudinal studies were evaluated by a systematic review of English-language articles retrieved from electronic biomedical journal databases (MEDLINE, EMBASE, CENTRAL) and handsearching records, using different matches of keywords for root canal biofilm, between 1966 and August 1st, 2007. The selected articles were identified from titles, abstracts and full-text articles by two independent reviewers, considering the tabulated inclusion and exclusion criteria. Disagreements were resolved by consensus. The search retrieved 91 related articles, of which 8.8 percent referred to in vivo studies demonstrating the lack of efficacy of endodontic therapy on bacterial biofilm. Intracanal medicaments were found to have a limited action against bacterial biofilm.

Análise do perfil de escoamento de seis cimentos endodônticos / Analysis of the flow profile of six endodontic cements

Objetivo: Avaliar o perfil de escoamento de seis cimentos obturadores endodônticos, por meio do teste de escoamento vertical: N-Rickert (Fórmula e Ação, São Paulo, Brasil), Endofill (Dentsply, Petrópolis, Brasil), Óxido de Zinco e Eugenol (SS White, Rio de Janeiro, Brasil), AHPlus (Dentsply, Petrópolis, Brasil), EndoRez (Ultradent, South Jordan, UT, USA) e Intra-Fill (SS White, Rio de Janeiro, Brasil). Métodos: O teste de escoamento foi realizado utilizando placas duplas de vidro polidas de 30 x 26 cm, para abrigar as amostras de 0,1 ml dos cimentos. As amostras foram depositadas na parte superior com o auxílio de seringa para insulina. As placas foram levadas para a estufa a 37° e umidade relativa de 100%. O escoamento foi medido por meio de uma folha de papel milimetrado entre as placas de vidro, nos tempos de 10 minutos, 20 minutos, 30 minutos, uma hora, duas horas, três horas, quatro horas, cinco horas, seis horas, 12 horas, 24 horas e 48 horas. Resultados: Endofill (Dentsply, Petrópolis, Brasil) apresentou escoamento de 69,3mm, seguido do N-Rickert (Fórmula e Ação, São Paulo, Brasil) (43,0mm) e do AH-Plus (Dentsply, Petrópolis, Brasil) (29,3mm). Os cimentos Intrafill (SS White, Rio de Janeiro, Brasil), Óxido de Zinco e Eugenol (SS White, Rio de Janeiro, Brasil) e EndoRez (Ultradent, South Jordan, UT, USA) não apresentaram escoamento. N-Rickert (Fórmula e Ação, São Paulo, Brasil) e Endofill (Dentsply, Petrópolis, Brasil) tiveram comportamentos semelhantes, não necessitando de força inicial para se deslocar. O cimento N-Rickert (Fórmula e Ação, São Paulo, Brasil) escoou até trinta minutos e o Endofill (Dentsply, Petrópolis, Brasil) até a segunda hora de observação. O escoamento inicial do AH-Plus (Dentsply, Petrópolis, Brasil) foi de 0,8mm até três horas, permanecendo estável a partir da quinta hora. Conclusão: Os cimentos Óxido de Zinco e Eugenol (SS White, Rio de Janeiro, Brasil), Intrafill (SS White, Rio de Janeiro, Brasil)...

Objective: To assess the flow characteristic of six endodontic filling cements by means of the vertical flow test: N-Rickert (Fórmula e Ação, São Paulo, Brazil), Endofill (Dentsply, Petrópolis, Brazil), Zinc Oxide and Eugenol (SS White, Rio de Janeiro, Brazil), AH-Plus (Dentsply, Petrópolis,Brazil), EndoRez (Ultradent, South Jordan, UT, USA) and Intra-Fill (SS White, Rio de Janeiro, Brazil). Methods: Flow test was performed by placing the 0.1 ml samples of cements between two plates of polished glass measuring 30 x 26 cm. The samples were deposited on the top part with aid of a insulin syringe. The plates were taken to an oven at 37° and relative humidity of 100%. Flow was measured by means of a sheet of millimetric paper placed between the glass plates, at time intervals of 10 minutes, 20 minutes, 30 minutes, one hour, two hours, three hours, four hours, five hours, six hours, 12 hours, 24 hours and 48 hours. Results: Endofill (Dentsply, Petrópolis, Brazil) showed flow of 69.3mm, followed by N-Rickert (Fórmula e Ação, São Paulo, Brazil) (43.0mm) and AH-Plus (Dentsply, Petrópolis, Brazil) (29.3mm). The cements Intrafill (SS White, Rio de Janeiro, Brazil), Zinc Oxide and Eugenol (SS White,Rio de Janeiro, Brazil) and Endo Rez (Ultradent, South Jordan, UT, USA) presented no flow. N-Rickert (Fórmula e Ação, São Paulo, Brazil) and Endofill (Dentsply, Petrópolis, Brazil) behaved similarly, and needed no initial force to become displaced. The cement N-Rickert (Fórmula eAção, São Paulo, Brazil) flowed for up to thirty minutes and Endofill (Dentsply, Petrópolis, Brazil) up to the second hour of observation. Initial flow of AH-Plus (Dentsply, Petrópolis, Brazil) was 0.8mm up to three hours, remaining stable after the fifth hour. Conclusion: The cements Zinc Oxide and Eugenol (SS White, Rio de Janeiro, Brazil), Intrafill (SS White, Rio de Janeiro, Brazil) and EndoRez (Ultradent, South Jordan, UT, USA) did not present any flow during the experiment. The greatest flow was...

Retratamento: protaper para retratamento X técnica híbrida manual / Retreatment: protaper x hibrid manual technique

O objetivo do presente estudo foi avaliar a capacidade de remoção do material obturador nos retratamentoscom o sistema Protaper Universal-Retratamento e com técnica híbrida manual auxiliada pelos instrumentosPré-Race. Foram selecionados vinte e quatro dentes humanos incisivos inferiores com comprimentos entre19 e 21mm os quais foram preparados e obturados, e armazenados em ambiente de umidade relativa de100% por 180 dias. Completado este período, os dentes foram radiografados individualmente no sentidomesio-distal e vestíbulo-lingual e divididos aleatoriamente em dois grupos. Os dentes do Grupo 1 foramdesobturados empregando-se os instrumentos Protaper Universal - Retratamento, D1, D2 e D3 seguindoseo preparo com instrumentos F1 e F2; no Grupo 2 os dentes foram desobturados empregando-se técnicahíbrida manual com auxilio dos instrumentos Pré-Race. Os dentes foram novamente radiografados em ambosos sentidos, as imagens digitalizadas e a medição linear das paredes foram realizados pelo softwareImage Tool 3.0. Os resultados mostraram diferenças estatisticamente significantes no remanescente quandoProtaper Universal - Retratamento foi empregado e com o uso de F1 e F2 em ambos os sentidos. A técnicahíbrida manual apresentou melhores resultados.

The aim of this study was to evaluate the ability of the Protaper Retreatment and a hybrid manualtechnique on removing the root canal filling during retreatment. Twenty-four human incisors teeth were selected,prepared and filled with gutta-percha and Endo Fill cement in a lateral condensation technique andstored for 180 days. The teeth were radiographed mesio-distally and bucco-lingually , and digitalized. Theteeth were divided into two groups. In Group 1 retreatment were performed with the Protaper Universal - RetreatmentD1, D2 and D3. An x-ray showed the remaining of endodontic filling material. A Protaper F1 andF2 were used to complete the removal. In group 2 hybrid manual techniques with Pré-Race instruments forthe radicular access were performed. Before and after retreatment the x-rays were digitalized and the linearrate determined with the Image Tool 3.0 software. The results showed statistically difference between theremaining filling material when Protaper Universal - Retreatment was employed and when Protaper F1 andF2 in both view. Hybrid manual technique showed the best results when compared with the use of PT-R F1and F2 but showed similar results when compared to Protaper Universal Retreatment.

Análise da radiopacidade de cimentos endodônticos por meio de radiografia digital / Analysis of the radiopacity of endodontic sealers using a digital radiograph system

Objetivo: O presente estudo teve por finalidade analisar a radiopacidade de alguns cimentos endodônticos utilizando um sistema de radiografia digital. Metodologia: Foram testados os cimentos endodônticos AH-Plus, N-Rickert, Endofill, Óxido de zinco e eugenol (OZE) e Intrafill. Seis corpos-de-prova cilídricos (1x0,5cm) para cada cimento foram confeccionados e armazenados a 37ºC e umidade relativa de 100%, durante 72h. Os corpos-de-prova foram posicionados na região central do sensor do sistema digital Kodak RVG 5000 e o cilindro do aparelho radiográfico foi posicionado perpendicularmente a uma distância focal de 5cm, com tempo de exposição de 0,05 segundos. A partir da imagem digital obtiveram-se os valores da densidade óptica em pixels da região central e pontos eqüidistantes à direita e à esquerda de cada corpo-de-prova. Os dados foram analisados por ANOVA e teste de Tukey (α=0,05). Resultados: Houve diferença estatística entre todos os cimentos, com exceção da comparação entre o Intrafill e o Endofill. A radiopacidade dos cimentos em ordem crescente foi: ZOE < Endofill = Intrafill < N-Rickert < AH-Plus. Conclusão: O método de radiografia digital foi sensível para detectar diferenças de radiopacidade entre os cimentos endodônticos analisados.

Purpose: This study aimed to evaluate the radiopacity of some endodontic sealers using a digital radiograph system. Methods: The endodontic sealers tested were: AH-Plus, N-Rickert, Endofill, Óxido de zinco e eugenol (OZE), and Intrafill. Six cylindrical-shaped specimens (1x0.5cm) were fabricated with each material and stored at 37ºC and 100% relative humidity for 72h. Each specimen was placed at the central area of the sensor of the digital system Kodak RVG 5000, and the X-ray cylinder was positioned perpendicularly at a 5cm-focal distance with time of exposure of 0.05s. The digital image software was used to measure optical density in pixels of the specimens at their central area and at the right and left sides. Data were analyzed by ANOVA and Tukey test (α=0.05). Results: There was a statistically significant difference of radiopacity among the tested materials, except for the comparison between Intrafill and Endofill. The level of radiopacity in ascending order was: ZOE < Endofill = Intrafill < N-Rickert < AH-Plus. Conclusion: The digital radiograph method was sensitive to detect differences of radiopacity among the tested endodontic sealers.

Acesso radicular / Radicular access

As grandes dificuldades durante o preparo estão em função direta de aspectos anatômicos presentescomo curvaturas e atresias, tornando-se o grande desafio a ser vencido. Canais de diâmetros reduzidosdevido a calcificações dificultam a progressão dos instrumentos no alargamento, e canais com curvaturasacentuadas tornam a sua manutenção crítica. O conceito de acesso radicular introduzido por Goering em1982 é um passo extremamente importante, independente da técnica de preparo a ser empregada, visandoa eliminação de depósitos dentinários na entrada dos canais radiculares e propiciando um acesso diretoaos terços médio e apical. As brocas de Gates-Glidden tem sido o instrumento mais utilizado para este fim.Recentemente, instrumentos com diferentes conicidades têm sido introduzidos para serem empregadoscom contra-ângulo convencional: a Coronal Preparation Drill - CP Drill (Injecta), os instrumentos LA Axxess(Sybron-Kerr) e os instrumentos Pré-Race (FKG). No presente artigo os autores discutem e analisam aeficiência clínica destes instrumentos apontando para o seguinte resultado em ordem decrescente: Pré-Race, CP Drill e LA Axxess.

Difficulties during root canal preparation are related to anatomic aspects as curvatures and atresias,which are a challenge to overcome. Calcifications at the entrance and atresic root canals make the instrumentsaction difficult and great curvatures are not easy to be maintained. The radicular access introduced by Goeringin 1982 is an extremely important step to any root canal preparation technique, eliminating dentin from theentrance and getting a straight access to the middle and apical third. Gates-Glidden bur has been the mostemployed instrument to the radicular access. Recently, instruments showing different conicities have beenintroduced to be used with the normal angle: CP Drill, LA Axxess and Pre-Race. This paper discussed andanalyzed the clinical efficiency of these instruments and observed the following result, in decreasing order:Pre-Race, CP Drill and LA Axxess.

Clorexidina na terapia endodôntica / Chlorhexidine in endodontic therapy

Introdução e objetivo: Este trabalho buscou realizar uma revisão de literatura sobre o emprego da clorexidina no tratamento endodôntico. Revisão da literatura e conclusão: Foram estudadas as propriedades antimicrobianas, de substantividade, biocompatibilidade, capacidadede limpeza e de dissolução tecidual da clorexidina. Em virtude de sua eficácia antimicrobiana, essa droga pode ser empregada como substância irrigadora durante o preparo químico-mecânico, assim como na fase medicamentosa, em casos de polpa morta. Por não possuir capacidade de dissolução tecidual, sua indicação torna-se limitada.Quando comparada às demais concentrações, a clorexidina na concentração de 2% tem apresentado maior efetividade bactericida,com baixa toxicidade. Parece-nos claro que sua efetividade é muito maior como irrigante do que como substância auxiliar na forma de gel. Entretanto recentes estudos sobre a sua genotoxicidade conduzem aum alerta sobre sua indicação segura na terapia endodôntica.

Introduction and objective: The objective of this work was to make a review about the use of chlorhexidine in the endodontic therapy. Literature review and conclusion: Its properties of substantivity, antimicrobial, biocompatibility, cleanliness and tissue dissolution were analyzed. Widely used as an endodontic irrigant during root canal preparation and as an intracanal dressing the inability on tissue dissolution establishes a limitation. In 2% concentration it has show nits better antimicrobial effectiveness and low toxicity, but recent studies about its potential genotoxicity and tissue damage when extruded into the periradicular tissue require new researches to answer important questions.

Efficacy of calcium hydroxide dressing in endodontic infection treatment: a systematic review / Eficácia da pasta de hidróxido de cálcio no tratamento de infecção endodôntica: uma revisão sistemática

Pupose: To perform a systematic review of the efficacy of calcium hydroxide (CH) dressing prepared with different vehicles on the treatment of teeth with endodontic infection. Methods: Search strategies included electronic search in databases (MEDLINE, EMBASE, CENTRAL) from 1966 to January 2007 and manual search in endodontic journals and references of previously selected studies. The following terms were used: calcium hydroxide, chlorhexidine, root canal infection, faecalis, intracanal dressing, endodontic infection, intracanal medicament, paramonochlorophenol, para monochlorophenol, and p-monochlorophenol. Results: From the 71 in vivo studies retrieved, five clinical studies met the inclusion criteria. Saline solution was the vehicle of CH dressing in all five included studies, and only one study compared saline versus chlorhexidine as vehicles of CH dressing. From a total of 130 teeth with endodontic infection, 39 teeth (30%) had remaining microorganisms after sanitation and CH dressing with saline. Conclusion: Adequate sanitation and CH dressing with saline vehicle reduce microorganisms in teeth with endodontic infection.

Objetivo: Realizar uma revisão sistemática sobre a eficácia de pastas de hidróxido de cálcio preparadas com diferentes veículos no tratamento de dentes com infecções endodônticas. Metodologia: As estratégias de busca incluíram buscas eletrônicas em bases de dados (MEDLINE, EMBASE, CENTRAL) de 1966 a janeiro de 2007 e busca manual em periódicos especializados e referências de estudos selecionados. Os seguintes unitermos foram utilizados: calcium hydroxide (CH), chlorhexidine, root canal infection, faecalis, intracanal dressing, endodontic infection, intracanal medicament, paramonochlorophenol, para monochlorophenol e p-monochlorophenol. Resultados: Dos 71 trabalhos in vivo obtidos, cinco estudos clínicos satisfizeram os critérios de inclusão. Solução salina foi o veículo na pasta de hidróxido de cálcio em todos os cinco estudos incluídos na revisão, e apenas um estudo comparou solução salina versus clorexidina como veículo da pasta de hidróxido de cálcio. De um total de 130 dentes com infecção endodôntica, 39 dentes (30%) apresentaram microrganismos após o procedimento de sanificação combinado com pasta de hidróxido de cálcio associada à solução fisiológica. Conclusão: O adequado procedimento de sanificação do canala associado à pasta de hidróxido de cálcio com veículo de solução fisiológica reduzem a quantidade de microrganismos em dentes com infecção endodôntica.

Análise in vitro da viabilidade do uso do MTA e do hidróxido de cálcio como plug apical em dentes com rizogêneze incompleta / An in vitro analysys of the viability of mta and calcium hydroxide paste as an apical plug in teeth withimature apexes

O objetivo deste trabalho foi avaliar a capacidade do MTA e o do hidróxido de cálcio de evitar asobre-obturação de guta-percha e cimento quando empregados como plug apical em dentes com ápiceincompletamente formado. Foram selecionados 24 dentes monoradiculares, incisivos centrais superiores epré-molares inferiores com ápice completo, que através de desgastes com brocas apropriadas, simulou-sea anatomia apical de dente imaturo. Os dentes foram inseridos em alvéolos artificiais e plugs apicais foramrealizados com MTA ou com hidróxido de cálcio e os canais obturados com cones moldados. Radiografiasnos sentidos mésio-distal e vestíbulo-lingual foram realizados e analisadas quanto à capacidade dos plugsde evitar extravasamento da obturação. Os resultados mostraram que o plug apical com MTA foi mais efetivoque o do hidróxido de cálcio, não ocorrendo extravasamento em nenhum caso, ao passo que no grupo doplug apical com o hidróxido de cálcio, houve o rompimento do plug em quatro casos, porém sem extrusãoda obturação.

The aim of this study was to evaluate the ability of the MTA and calcium hydroxide to avoid overextension of theguta-percha and sealer when used as an apical plug in teeth with imature apexes. Twenty-four monoradicularteeth with complete root formation were selected, and an incomplete apex was created through a specificconical bur. The teeth were placed in a artificial socket an the apical plug created with both materials. Rootcanals were filled with guta-percha and cement and the teeth radiographed in the mesial-distal and bucolingualview. The x-rays were analysed about the ability to avoid overextension of the filling materials. Theresults showed that MTA was more efficient on avoiding overextension than calcium hidroxide.