Post preparation: cleanness achieved by different irrigating protocols / Preparación para poste: limpieza lograda por diferentes protocolos de irrigación

ABSTRACT The aim of this study was to evaluate the ability of different irrigation protocols to remove from the walls of the root canal and entrance to dentinal tubules the smear layer produced during preparation for a fiber post. Fifty decoronated human lower premolars were treated endodontically and the apical third of the canal was filled with a single gutta-percha point using warm vertical compaction. Ten millimeters were left free for post preparation, which was done by sequential use of a Largo #1 drill and Exacto #3 pilot drill (Angelus, Brazil), with irrigation with distilled water upon each instrument change. Samples were distributed randomly into 5 groups (n=10). G 1: No irrigation after post preparation. G 2: Distilled water activated for 60 s + distilled water. G 3: 5.25% NaOCl 15 s+ distilled water. G 4: 17% EDTA (Farmadental, Argentina) 60 s + 5.25% NaOCl 15 s + distilled water. G 5: 10% polyacrylic acid (Densell) 15 s + distilled water. Irrigant was activated mechanically with a low-speed conical brush. Roots were then split longitudinally in vestibular-lingual direction. Each surface was observed under SEM in its different thirds. Microphotographs were taken at 150X and 600X magnification and results analyzed statistically using Kruskall Wallis and Friedman tests (p<0.05). The results [mean (standard deviation)] were: for 150X: G1 11.00 (1.33), G2 7.50 (3.13), G3 6.30 (2.58), G4 2.20 (2.80), G5 4.30 (1.50), and for 600X G1 11.40 (0.84), G2 10.00 (1.94), G3 7.70 (3.33), G4 5.80 (3.70), G5 7.20 (2.65). The statistical analysis showed significant differences between irrigants (p<0.05) but not between root thirds (p>>0.05). The EDTA+NaOCl combination and polyacrylic acid showed greater capacity to remove the smear layer created during post preparation.

RESUMEN El objetivo del presente trabajo fue evaluar la capacidad de diferentes protocolos de irrigación para remover el barro dentinario de las paredes del conducto y entrada de los túbulos dentinarios, producido durante la preparación para anclaje intarradicular. Se utilizaron 50 premolares inferiores humanos a los cuales se les cortó la corona clínica. Luego se les realizó tratamiento endodóntico y obturación del tercio apical con cono único de conicidad aumentada y compactación vertical caliente. Se dejaron libres 10 mm para la preparación para poste que se realizó utilizando secuencialmente fresa de Largo # 1y fresa piloto Exacto #1(Angelus, Brasil), irrigando a cada cambio de instrumento con agua destilada. Las muestras fueron distribuidas aleatoriamente en 5 grupos (n=10). G 1: No se efectuó ningún lavaje. Los irrigantes fueron activados con cepillo mecánico cónico a baja velocidad. G 2: Agua destilada activada 60 s+ agua destilada G 3: NaOCl al 5,25%, 15 s+ agua destilada. G 4: EDTA al 17% (Farmadental, Argentina) 60 s +NaOCl al 5,25% 15 s , + agua destilada. G 5 : Ácido poliacrílico al 10% ( Densell) 15 s + agua destilada. Posteriormente, las raíces fueron seccionadas longitudinalmente en sentido vestíbulo lingual. Cada superficie fue observada al MEB en sus diferentes tercios. Las micrografías se realizaron a 150 y 600 X y los resultados analizados estadísticamente mediante test de Kruskall Wallis y Friedman (p<0,05), Los resultados [Medias (desviaciones estándar)] fueron: para 150X G1 11,00(1,33), G2 7,50 (3,13), G3 6,30 (2,58), G4 2,20 (2,80), G5 4,30 (1,50) y para 600X G1 11,40 (0,84), G2 10,00 (1,94), G3 7,70 (3,33), G4 5,80 (3,70), G5 7,20 (2,65). El análisis estadístico mostró diferencia significativa entre irrigantes (p<0,05) pero no entre tercios radiculares (p>0,05). La combinación de EDTA+NaOCl y el ácido poliacrílico tendrían mayor capacidad de remoción del barro dentinario creado durante la preparación para poste.

Decontamination of Gutta-percha Cones employed in Endodontics / Descontaminação de cones de guta-percha empregados em endodontia

ABSTRACT The guttapercha cones used in endodontic treatment are produced in aseptic conditions and their composition includes zinc oxide, which is responsible for antibacterial activity. However, there is the possibility of microbial contamination by manipulation, aerosol or during storage. Although several chemical agents have been tested for their decontamination, there is no consensus on the best disinfection protocol to be used. The aim of this study was to evaluate the decontamination of guttapercha cones contaminated with the bacteria Enterococcus faecalis, by using chlorhexidine digluconate (CHX) and sodium hypochlorite (NaClO) at different concentrations for short exposure times. For this purpose, guttapercha cones (size 40) were selected at random from a sealed box and immersed for 1 min in a microbial suspension. Then they were immersed in specific Petri dishes for different groups containing: CHX 2%, NaClO 1% or NaClO 2.5% for 30 s or 1 min, and subsequently placed in tubes containing BHI broth. After incubating the tubes for 48 h, it was observed that 1% and 2.5% NaClO and 2% CHX were effective for decontaminating the cones at those exposure time intervals. Microbial growth was detected in one of the replicates of the group with CHX applied for 30 s. To prevent the possibility of failures at this stage, the exposure time of guttapercha cones to the decontaminating agent should not be reduced.

RESUMO Os cones de gutapercha utilizados no tratamento endodôntico são produzidos em condições assépticas e possuem óxido de zinco em sua composição, responsável pela atividade antibac te riana. No entanto, existe a possibilidade de contaminação microbiana por manipulação, aerossol ou seu armazenamento. Embora vários agentes químicos já tenham sido testados para sua descontaminação, não há consenso sobre o melhor proto colo de desinfecção a ser usado. Nosso objetivo foi avaliar a descontaminação de cones de gutapercha contaminados com a bactéria Enterococcus faecalis, utilizando digluconato de clorexidina (CHX) e hipoclorito de sódio (NaClO) em diferentes concentrações e tempos de exposição curtos. Para esse fim, 40 cones de gutapercha foram selecionados aleatoriamente, de uma caixa selada e imersos por 1 min em uma suspensão microbiana. Em seguida, foram imersos em placas de Petri específicas para diferentes grupos contendo: CHX 2%, NaClO 1% ou 2,5%, nos tempos de exposição de 30s e 1min e subseqüentemente imersos em tubos contendo caldo BHI. Após incubação dos tubos por 48 h, observouse que NaClO 1% e 2,5% e CHX 2% foram eficazes para a descontaminação dos cones nesses intervalos de tempo de exposição. Em uma das réplicas do grupo com CHX aplicado por 30s foi detectado crescimento microbiano. O tempo de exposição dos cones de gutapercha ao agente de desconta minação não deve ser reduzido para evitar a possibilidade de falhas nesse estágio.

Extrusion of Endodontic Material to the Maxillary Sinus: Avoidable Intercurrence? / Extrusión de Material Endodóntico al Seno Maxilar: ¿Intercurrencia Evitable?

ABSTRACT: The objective of this study is to discuss and analyze whether extrusion of endodontic material constitutes avoidable intercurrence, discussing the clinical, ethical and legal implications. Patient LSR, 31 years old, female, attended a dental consultation complaining of pain in the second left maxillary premolar (tooth 25). Radiographically, a single root canal and thickening of the periodontal ligament associated with extravasation of 8 mm of gutta percha to the maxillary sinus were observed. The first endodontic session aimed to performing the desobturation, root canal preparation and intracanal medication placement. The root canal obturation was performed in the second session. Was carried out an apical surgery that removed 2 mm from the root apex and also performed the covered with a collagen membrane. A 22 months follow-up revealed a tooth function, absence of painful symptomatology or infection, and radiographically normal periodontal ligament and bone neoformation. The second single-root premolar is the type of premolar with less distance with the floor of the maxillary sinus. In this case, the extrusion of the obturator material occurred due to the superinstrumentation of the root canal associated with the proximity of the root with the membrane of the maxillary sinus. From the ethical and legal point of view, the patient has the right to be informed about any intercurrences that may arise during or after the treatment, and the informed consent form is essencial. This document will allow the patient to make a decision about performing an endodontic treatment in which the risk of an accident or complication is imminent or that treatment failure is already expected. It is important that professionals make appropriate diagnosis and treatment plan for each case, since this conduct may avoid clinical intercurrences. In addition, if the intercurrences occur, the patient should be advised of how to proceed.

RESUMEN: El objetivo de este estudio fue discutir y analizar si la extrusión de material endodóntico constituye una intercurrencia evitable, discutiendo las implicaciones clínicas, éticas y legales. Paciente LSR, de 31 años de edad, mujer, asistió a una consulta dental quejándose de dolor en el segundo premolar maxilar izquierdo (diente 25). Radiográficamente, se observó un solo conducto radicular y engrosamiento del ligamento periodontal asociado con la extravasación de 8 mm de gutapercha al seno maxilar. La primera sesión de endodoncia tuvo como objetivo realizar la desobturación, la preparación del conducto radicular y la colocación de medicación intracanal. La obturación del conducto radicular se realizó en la segunda sesión. Se llevó a cabo una cirugía apical que extrajo 2 mm del ápice de la raíz y también se realizó el recubrimiento con una membrana de colágeno. Un seguimiento de 22 meses reveló función dental, ausencia de sintomatología dolorosa o infección y ligamento periodontal radiográficamente normal y neoformación ósea. El segundo premolar de una sola raíz es el tipo de premolar con menos distancia con el piso del seno maxilar. En este caso, la extrusión del material obturador se produjo debido a la superinstrumentación del conducto radicular asociada con la proximidad de la raíz con la membrana del seno maxilar. Desde el punto de vista ético y legal, el paciente tiene derecho a ser informado acerca de cualquier inter-ocurrencia que pueda surgir durante o después del tratamiento, y el formulario de consentimiento informado es esencial. Este documento le permitirá al paciente tomar una decisión sobre la realización de un tratamiento de endodoncia en el que el riesgo de un accidente o complicación sea inminente o de que ya se espera un fracaso del tratamiento. Es importante que los profesionales realicen un diagnóstico y un plan de tratamiento adecuados para cada caso, ya que esta conducta puede evitar las intercurrencias clínicas. Además, si se producen intercurrencias, se debe informar al paciente sobre cómo proceder.

Evaluation of apically extruded debris using positive and negative pressure irrigation systems in association with different irrigants

Abstract This study evaluated the amount of apically extruded debris after chemo-mechanical preparation (CMP) using positive and negative pressure irrigation systems [Conventional irrigation (CI) and EndoVac (EV)] in association with different irrigants [6% Sodium Hypochlorite (NaOCl), 2% Chlorhexidine gel + saline solution (CHXg + SS), 2% Chlorhexidine solution (CHXs) or Saline solution (SS)]. Eighty mandibular premolars with single root canals were selected and randomly assigned into 8 groups (n = 10) according to the irrigation system and the irrigant used during CMP: G1 (EV + NaOCl), G2 (EV + CHXg + SS), G3 (EV + CHXs), G4 (EV + SS), G5 (CI + NaOCl), G6 (CI + CHXg + SS), G7 (CI + CHXs) and G8 (CI + SS). Reciproc® R25 files (25/.08) were used during the CMP and the extruded debris from each tooth was collected in pre-weighted Eppendorf tubes and dried. The average weight of debris was assessed using a microbalance, and the data were statistically analyzed using ANOVA and the post hoc Tukey's test (a = 0.05). All groups were associated with debris extrusion. EV was the irrigation system with less extruded debris (p < 0.05). No differences were observed regarding the irrigant when EV was used. When CI was used, CHXg + SS were associated with lower debris extrusion (p < 0.05). It was concluded that no irrigation protocol succeeded in preventing debris extrusion. EV resulted in lower levels of debris extrusion than CI. The use of CHXg + SS resulted in lower debris extrusion.

Resumo Este estudo avaliou a quantidade de debris extruídos apicalmente após o preparo químico-mecânico (PQM) utilizando sistemas de irrigação com pressão positiva e negativa [irrigação convencional (IC) e EndoVac (EV)] em associação com diferentes irrigantes [hipoclorito de sódio 6% (NaOCl), clorexidina gel + solução salina (CLXg + SS), solução de clorexidina 2% (CLXs) ou solução salina (SS)]. Oitenta pré-molares inferiores com único canal radicular foram selecionados e aleatoriamente alocados em 8 grupos (n=10) de acordo com o sistema de irrigação e irrigante utilizado durante o PQM: G1 (EV + NaOCl), G2 (EV + CLXg + SS), G3 (EV + CLXs), G4 (EV + SS), G5 (IC + NaOCl), G6 (IC + CLXg + SS), G7 (IC + CLXs) e G8 (IC + SS). Limas Reciproc® R25 foram utilizadas durante o PQM e os debris extruídos de cada dente foi coletado em tubos pré-pesados e secos. O peso médio de debris foi avaliado por meio de microbalança, e os dados foram analisados estatisticamente utilizando ANOVA e teste de Tukey (a = 0.05). Todos os grupos foram associados com extrusão de debris. EV foi o sistema de irrigação com menos debris extruídos (p<0.05). Não foram observadas diferenças entre os irrigantes quando o EV foi utilizado. Quando foi utilizada IC, CLXg + SS foram associados a menor extrusão de debris (p<0.05). Concluiu-se que nenhum protocolo de irrigação conseguiu prevenir extrusão de debris. EV resultou em menores níveis de extrusão de debris que a IC. A utilização da CLXg + SS resultou em menor extrusão de debris.

Effect of sonic versus ultrasonic activation on aqueous solution penetration in root canal dentin

The aim of this study was to observe the penetration of an aqueous solution into the root canal dentin under sonic activation and ultrasonic activation. Materials and Method: this study consisted of experimental in vitro research. In order to achieve a closed system, the apex of 45 single-rooted teeth was sealed with wax. The step-back technique was manually performed using a K50 apical master file and 3 groups were organized according to the protocol of the final irrigant activation: group I: non-activated chinese ink for 30 seconds, group II: chinese ink sonically activated with EndoActivator for 30 seconds, and group III: chinese ink ultrasonically activated with Varios 350 equipment for 30 seconds. Teeth were sectioned longitudinally, and the samples obtained were observed under a stereomicroscope at 1X magnification in order to be photographed and scanned to calculate the penetration area using the Image J software. The tinted radicular area was evaluated in relation to the total area of the root dentin. The tukey's post-hoc test and ANOVA were used for the statistical analysis (p<0.05). Results: group I and II obtained 9.13 percent and 9.42 percent penetration respectively, while in group III the highest degree of dye infiltration was achieved (13.9 percent), being statistically significant (p<0.001). Conclusions: ultrasonic activation produced a significantly higher penetration of the dye when compared to conventional activation and sonic activation.

Determination of residual parachloroaniline produced by endodontic treatment after the use of 5% sodium hypochlorite and 2% chlorhexidine combined: an ex-vivo study

ABSTRACT: Aim: The objective of this work was to determine the concentrations of irrigating solutions and the residual content of parachloroaniline (PCA) formed after endodontic irrigation, using 5% NaOCl, 0.9% NaCl, 10% EDTA and 2% CHX 2%. Methodology Twenty premolars were used and 13 samples were collected per tooth from each of the treatment phases. Samples of: NaOCl, EDTA, CHX and PCA were quantified by UV and visible spectrophotometry. Results: Sodium hypochlorite decreased its concentration from 3.8% to 3.4% in phases 1 to 4. In phases 5, 6 and 7, residual NaOCl was measured with concentrations of 0.007%, 0.003% and 0.001% %. The concentration of EDTA decreased to 8.85% in phase 8. In phases 9, 10 and 11, irrigated with serum, EDTA was quantified with concentrations of 0.013% to 0.002% and NaOCl values of 0.0011% to 0, 0006%. In phases 12 and 13, CHX concentrations were 1.850% and 1.812% and PCA values were 0.0005% and 0.0007%. PCA formation occurred in presence of 2% CHX and residual NaClO and was detected colorimetrically in phases 12 and 13. Conclusions. During endodontic irrigation the concentration of 5% NaOCl decreases significantly in the first four phases and the concentrations of EDTA and CHX also decrease. There is PCA training in the last stages of the procedure.

Penetración Dentinaria in vitro del Hipoclorito de Sodio a Diferentes Concentraciones con las Técnicas de Irrigación Convencional y Ultrasónica Pasiva / In vitro Dentinary Penetration of Sodium Hypochlorite at Different Concentrations with the Conventional and Ultrasonic Passive Irrigation Techniques

RESUMEN: El objetivo del presente trabajo fue comparar la penetración dentinaria in vitro entre las concentraciones de hipoclorito de sodio (NaClO) al 5 % y al 2,5 % con técnicas de irrigación convencional e irrigación ultrasónica pasiva. Este fue un estudio transversal, prospectivo y experimental. Se trabajó con 40 segmentos radiculares (especímenes) de 5 mm de longitud, divididos en 4 grupos. Todos los especímenes se sumergieron en violeta cristal durante 24 horas. Se realizó la preparación biomecánica con sistema rotatorio Pro Taper. Al primer grupo se irrigó con NaClO al 2,5 % con irrigación convencional, al segundo grupo con NaClO al 2,5 % con irrigación convencional más irrigación ultrasónica pasiva por 30 segundos, al tercer grupo con NaClO al 5 % con irrigación convencional y al cuarto grupo con NaClO al 5 % con irrigación convencional más irrigación ultrasónica pasiva por 30 segundos. Al final de la preparación a todos los especímenes se les realizó un corte mesio distal. La profundidad de la penetración del NaClO fue deterrminado por el blanqueamiento de la mancha y medido con un microscopio de luz con una magnificación de 40 X. La prueba estadística usada fue ANOVA con un nivel de significancia de 5 %. El NaClO al 5 % con técnica de irrigación ultrasónica pasiva presentó la mayor penetración dentinaria in vitro.

ABSTRACT: The objective of the present study was to compare in vitro dentin penetration between 5 % and 2.5 % sodium hypochlorite (NaClO) concentrations using conventional irrigation and passive ultrasonic irrigation techniques. This was a cross-sectional, prospective and experimental study. It was worked with 40 root segments (specimen) of 5 mm length, divided into 4 groups. All specimens were immersed in crystal violet for 24 hours. The biomechanical preparation was performed with Pro Taper rotary system. The first group was irrigated with 2.5 % NaClO with conventional irrigation, the second group with 2.5 % NaClO with conventional irrigation plus ulrasonic passive irrigation for 30 seconds, the third group with 5 % NaClO with conventional irrigation and the fourth with 5 % NaClO with conventional irrigation plus ultrasonic passive irrigation for 30 seconds. At the end of the preparation, all specimens had a distal mesio cut. The depth of NaClO penetration was determined by bleaching of the stain and measured with a light microscope at a magnification of 40 X. The statistical test used was ANOVA with a significance level of 5 %. The 5 % NaClO with passive ultrasonic irrigation showed the highest dentin penetration in vitro.

Intracanal Irrigating Solutions Prior to Calcium Hydroxide Medication and Its Effects on Root Dentin Strength

Abstract The aim of this study was to assess the effects of intracanal irrigation with sodium hypochlorite (NaOCl) and ethylenediaminetetracetic acid (EDTA) prior to calcium hydroxide medication on the compressive strength of root dentin. Forty-eight roots with single and straight canals were instrumented with a crown-down technique using Flexofile files and Gates Glidden burs, under 0.9% sodium chloride (NaCl) irrigation. Root canals were randomly separated into 4 groups (n=12), according to the irrigating solution: Control Group, 0.9% NaCl; GroupNaOCl, 1% NaOCl; GroupEDTA, 17% EDTA; and GroupEDTA+NaOCl, 17% EDTA and 1% NaOCl. Solutions remained for 40 min, renewed every 10 min, except for GroupEDTA+NaOCl, where the solutions were alternated every 10 min. Canals were dried and filled with calcium hydroxide paste, and radiographed. Each canal was sealed and stored at 37 °C for 30 days. After this period, the roots were cut 1 mm below the cementoenamel junction and 6 mm apically from this point in order to obtain 6 mm-long cylinders. The compressive test was conducted with a crosshead speed of 1 mm/min. The means (±SD) (MPa) of compressive strength were: Control Group, 151.23±94.36; GroupNaOCl, 167.50±57.25; GroupEDTA, 108.79±99.88; GroupEDTA+NaOCl, 60.12±92.10. Significant statistical differences among groups were found (ANOVA and Tukey, a=5%, p=0.02). Control Group and GroupNaOCl showed higher means of compressive strength than GroupEDTA+NaOCl. Intracanal irrigation with 17% EDTA and 1% NaOCl produced a significant reduction of dentin compressive strength 30 days after medication with calcium hydroxide.

Resumo O objetivo desse estudo foi avaliar o efeito da irrigação intracanal com hipoclorito de sódio (NaOCl) e ácido etilenodiamino tetracético (EDTA) previamente à medicação de hidróxido de cálcio na resistência à compressão da dentina radicular. Quarenta e oito raízes com canais únicos e retos tiveram os canais instrumentados pela técnica coroa-ápice com limas Flexofile e brocas Gates Glidden sob irrigação com solução salina (NaCl) a 0,9%. Os canais radiculares foram separados em 4 grupos (n=12), de acordo com a solução irrigadora: Grupo Controle, NaCl 0,9%; GrupoNaOCl, NaOCl 1%; GrupoEDTA, EDTA 17%; e GrupoEDTA+NaOCl, NaOCl 1% e EDTA 17%. As soluções permaneceram por 40 min, sendo renovadas a cada 10 min, exceto para o GrupoEDTA+NaOCl, onde as soluções foram alternadas a cada 10 min. Os canais foram secos, preenchidos com pasta de hidróxido de cálcio e radiografados. Cada canal foi selado e mantido a 37 °C por 30 dias. Após esse período, as raízes foram cortadas 1 mm abaixo da junção cemento-esmalte e 6 mm apicalmente a este corte, a fim de obter cilindros de 6 mm de comprimento. O teste de compressão foi realizado com velocidade de cruzeta de 1 mm/min. As médias (±SD) da resistência à compressão em MPa foram: Grupo Controle, 151.23±94.36; GrupoNaOCl, 167.50±57.25; GrupoEDTA, 108.79±99.88; GrupoEDTA+NaOCl, 60.12±92.10. Diferenças estatisticamente significativas foram encontradas entre os grupos (ANOVA e Tukey; a=0,05; p=0,02). O Grupo Controle e o GrupoNaOCl obtiveram maiores médias de resistência à compressão em relação ao GrupoEDTA+NaOCl. A irrigação intracanal com EDTA 17% e NaOCl 1% promoveu redução significativa da resistência à compressão da dentina, após 30 dias de medicação intracanal com hidróxido de cálcio.

Effectiveness of NaviTip FX on intracanal calcium hydroxide removal / Efectividad de NaviTip FX para la remoción intracanal de hidróxido de cálcio

Remnants of calcium hydroxide (Ca(OH)2) post-irrigation can compromise cleansing and permeability of dentinal walls in endodontic therapy. The aim of this study was to evaluate effectiveness of irrigation needle NaviTip FX on intracanal Calcium Hydroxide removal. Twenty-two single-rooted human teeth were randomly assigned according to irrigation needle used after calcium hydroxide removal: G1- NaviTip; G2- NaviTip FX, both with n= 9; as well as negative and positive control groups, with n= 2. The samples were analyzed in scanning electron microscopy, with 500x magnification. The difference between groups were analysed by Student t test, for p 0.01. In apical third, G2 group presents better cleaning in comparison with G1 (p= 0.0007). In middle third, no differences between groups were observed. NaviTip FX irrigation needle shows greater effectiveness in removing calcium hydroxide medication than NaviTip needle in the apical third of the canal.

La presencia de hidróxido de calcio post-irrigación compromete la limpieza y la permeabilidad de la pared de la dentina durante el tratamiento endodóntico. El objetivo deste estudio fue evaluar la eficacia de la cánula de irrigación Navitip Fx en la eliminación de hidróxido de cálcio intracanalicular. Veintidós dientes unirradiculares humanos fueron divididos aleatoriamente de acuerdo con la cánula de irrigación, después de la eliminación del hidróxido de calcio, en grupos: G1- Navitip; G2- Navitip FX, ambos con n= 9; así como los grupos de control positivos y negativos, con n= 2. Las muestras fueron analizadas bajo microscopía electrónica de barrido, con magnificación de 500x. La diferencia entre los grupos fue analizada con la prueba t de Student (p 0,01). En el tercio apical, el grupo G2 presentó mejor limpieza en comparación con el grupo G1 (p= 0,0007). En el tercio medio, no se observaron diferencias entre los grupos. La cánula de irrigación Navitip FX muestra una mayor eficiencia en la eliminación de la medicación hidróxido de calcio en comparación con Navitip cánula en el tercio apical del canal.

New Technologies to Improve Root Canal Disinfection

Abstract Effective irrigant delivery and agitation are prerequisites to promote root canal disinfection and debris removal and improve successful endodontic treatment. This paper presents an overview of the currently available technologies to improve the cleaning of the endodontic space and their debridement efficacy. A PubMed electronic search was conducted with appropriate key words to identify the relevant literature on this topic. After retrieving the full-text articles, all the articles were reviewed and the most appropriate were included in this review. Several different systems of mechanical activation of irrigants to improve endodontic disinfection were analysed: manual agitation with gutta-percha cones, endodontic instruments or special brushes, vibrating systems activated by low-speed hand-pieces or by sonic or subsonic energy, use of ultrasonic or laser energy to mechanically activate the irrigants and apical negative pressure irrigation systems. Furthermore, this review aims to describe systems designed to improve the intracanal bacterial decontamination by a specific chemical action, such as ozone, direct laser action or light-activated disinfection. The ultrasonic activation of root canal irrigants and of sodium hypochlorite in particular still remains the gold standard to which all other systems of mechanical agitation analyzed in this article were compared. From this overview, it is evident that the use of different irrigation systems can provide several advantages in the clinical endodontic outcome and that integration of new technologies, coupled with enhanced techniques and materials, may help everyday clinical practice.

Resumo A irrigação do canal radicular é coadjuvante na desinfecção e remoção de debris, contribuindo para o sucesso do tratamento endodôntico. Este artigo apresenta uma visão geral das tecnologias atuais indicadas para melhorar a limpeza e desbridamento do canal radicular. Foi realizado um levantamento bibliográfico eletrônico no site Pubmed utilizando palavras-chave específicas ao tema a fim de abordar literatura relevante. Após busca eletrônica, artigos completos foram revisados e os mais apropriados ao tema foram incluídos nesta revisão. Diferentes sistemas de ativação mecânica foram considerados: agitação manual com cone de guta-percha, instrumentos e escovas endodônticas, sistemas de vibração ativados por peças manuais em baixa rotação ou por energia sônica e subsônica, ultrassom, laser, assim como sistemas de irrigação que utilizam pressão apical negativa. Além disso, esta revisão descreve outros meios indicados para ampliar a descontaminação endodôntica por meio de agentes químicos como ozônio e desinfeção por meio de luz. A ativação ultrassônica do hipoclorito de sódio ainda permanece o padrão ouro e nos estudos é usada como controle na comparação aos demais sistemas que empregam agitação mecânica. A presente revisão mostra vantagens de diversos sistema de irrigação e associações entre eles, podendo aumentar a efetividade da irrigação endodôntica.

Efficacy of four irrigation needles in cleaning the apical third of root canals

This study aimed to evaluate the influence of irrigation needle gauge and design, and the final root canal diameter on the apical cleaning efficacy. Twelve human mandibular incisors were used. At different stages of root canal widening (sizes 20, 30 and 40 K-files), root canals were filled with radiopaque contrast medium. Four different needles were evaluated: 23G with side opening, 22G with apical opening, 30G with side opening and 30G with apical opening. Irrigation was carried out with 2 mL distilled water. The same tooth was radiographed with a digital system several times to assess the four types of needle in those three stages of canal widening. Pre-irrigation (canals filled with contrast) and post-irrigation (canals with remaining contrast) images were submitted to digital subtraction using the Adobe Photoshop CS4 program. Pre-irrigation (filled with contrast) and subtracted (cleaned by irrigation) areas were outlined by a trained and blinded operator using the Image Tool 3.0 software. Their ratio was calculated to express the percentage of apical cleaning in each stage of canal widening (sizes 20, 30 and 40 K-files) with each of the four needles. Data obtained were subjected to one-way ANOVA and Tukey's tests. The 30G needles with side and apical opening promoted better apical cleaning at all stages of root canal widening (p<0.05). In conclusion, smaller diameter needles were more efficacious in cleaning the apical third of the root canals, regardless of their design.

Este estudo teve como objetivo avaliar a influência do diâmetro e design da agulha de irrigação e do diâmetro do canal radicular na eficácia de limpeza apical. Doze incisivos mandibulares humanos foram utilizados. Em diferentes fases de alargamento do canal radicular (limas tipo K #20, 30 e 40), os canais foram preenchidos com meio de contraste radiopaco. Quatro agulhas diferentes foram avaliadas: 23G com abertura lateral, 22G com abertura apical, 30G com abertura lateral e 30G com abertura apical. A irrigação foi realizada com 2 mL de água destilada. O mesmo dente foi radiografado por um sistema digital, repetidas vezes, para avaliar os quatro diferentes tipos de agulha nas três fases de alargamento do canal. As imagens pré-irrigação (preenchidas por contraste) e pós-irrigação (com contraste restante) foram submetidas à subtração digital por meio do programa Adobe Photoshop CS4. As áreas pré-irrigação (preenchidas por contraste) e subtraídas (limpas pelo irrigante) foram demarcadas por um operador treinado e cego em relação aos grupos experimentais, usando o programa Image Tool 3.0. A proporção dessas duas medidas foi calculada para expressar a porcentagem de limpeza apical em cada estágio de dilatação (20, 30 e 40) com cada agulha. Os dados obtidos foram submetidos aos testes ANOVA a um critério e Tukey com nível de significância de 5%. As agulhas 30G com abertura lateral e apical promoveram melhor limpeza apical em todas as fases de ampliação do canal radicular (p<0,05). Em conclusão, as agulhas de menor diâmetro foram mais eficazes na limpeza do terço apical dos canais radiculares, independentemente do seu design.

Carisolv as an endodontic irrigant in deciduous teeth: An SEM study.

Aim: Root canal irrigation plays an important role in the debridement and disinfection of the root canal system. "The purpose of this study was to evaluate the efficacy of Carisolv TM , 1% sodium hypochlorite (NaOCl) gel, and 1% NaOCl solution as root canal irrigants in deciduous anterior teeth." Materials and Methods: Thirty-six extracted deciduous anterior teeth were used. Root canals were flooded with NaOCl solution in Group A, NaOCl gel in Group B and Carisolv TM in Group C and incubated for 30 min. Scanning electron microscope photomicrographs of canal wall debris in the apical, middle and coronal thirds were scored. Results: The results showed that regardless of irrigation regime, canals were consistently cleaner in the coronal and middle thirds than in the apical thirds. NaOCl solution, NaOCl gel, and Carisolv TM had comparable activity at coronal third and middle third of root canals. At the apical third, NaOCl solution cleaned canals better than NaOCl gel and Carisolv TM . Carisolv TM cleaned debris better than NaOCl gel at the apical third. Conclusion: Carisolv TM can be used as an adjunct to root canal preparation.

Cleaning the apical third of curved canals after different irrigation protocols

This study evaluated the protocols of sonic and vacuum irrigation regarding the capacity of debris removal from root canal systems. Canal preparations were carried out on 30 mandibular first molars using the ProTaper Universal System. Teeth were divided into two experimental groups (n=15): Group 1: sonic irrigation and Group 2: vacuum irrigation protocol. Subsequently, the mesial roots were sectioned and observed by stereomicroscopy and scanning electron microscopy. Three independent examiners evaluated images of the apical thirds according to the following scores: 1= small presence of debris, 2= moderate presence of debris, and 3= dense presence of debris. Data were analyzed with ANOVA and Kruskal-Wallis tests (α=0.05). Comparison among the groups revealed that at the apical third, the root halves of Group 1 had significantly less surface debris (p=0.002) than those of Group 2. However, at 2 mm from the working length, Group 2's specimens showed less remaining debris in approximately 75% of the analyzed root canals. At the whole apical third, the sonic irrigation protocol removed significantly more debris than the vacuum protocol. However, in the region at 2 mm from the working length, the second irrigation method demonstrated a better performance.

Este estudo avaliou protocolos de irrigação sônica e a vácuo em relação à capacidade de remoção de debris do sistema de canais radiculares. Trinta primeiros molares mandibulares tiveram seus canais radiculares preparados pela utilização do Sistema ProTaper Universal. Os dentes foram divididos em dois grupos experimentais (n=15): Grupo 1: protocolo de irrigação sônica, e Grupo 2: protocolo de irrigação a vácuo. Posteriormente, as raízes mesiais foram seccionadas e observadas em lupa estereoscópica e microscopia eletrônica de varredura. Três examinadores independentes avaliaram as imagens do terço apical de acordo com as seguintes pontuações: 1. pequena presença de debris; 2: moderada presença de debris; e 3. densa presença de debris. Os dados foram analisados pelos testes estatísticos ANOVA e Kruskal-Wallis (α=0,05). A comparação entre os grupos revelou que, no terço apical, as hemissecções radiculares do Grupo 1 apresentaram debris remanescentes de forma significativamente menor (p=0,002) do que as do Grupo 2. No entanto, a 2 mm do comprimento de trabalho, as amostras do Grupo 2 mostraram menos debris remanescentes em aproximadamente 75% dos canais radiculares analisados. Considerando todo o terço apical, o protocolo de irrigação sônica removeu significativamente mais debris do que o protocolo de irrigação a vácuo. No entanto, na região a 2 mm do comprimento de trabalho, o segundo método de irrigação demonstrou um melhor desempenho.

Time-dependent effects of chitosan on dentin structures

Complete debridement with smear layer removal are essential measures for achieving a successful outcome of root canal treatment. The aim of this study was to evaluate the effects of chitosan at different concentrations on the removal of the smear layer and on dentin structure after 3 and 5 min of application. Twelve recently extracted maxillary canine teeth were instrumented using the crown-down technique and irrigated with 1% sodium hypochlorite. The specimens were distributed according to the time and concentration of the final irrigating solution: G1: 0.1% chitosan for 3 min; G2: 0.2% chitosan for 3 min; G3: 0.37% chitosan for 3 min; G4: 0.1% chitosan for 5 min; G5: 0.2% chitosan for 5 min; G6: 0.37% chitosan for 5 min. All samples were prepared for SEM analysis. G1 exhibited removal of the smear layer, but not the smear plugs. G2 showed visible and open tubules with slight erosion of the peritubular dentin. Cleaning in G3 was similar to that in G2, however, the erosive effect was greater. There was expansion of the diameter of the tubules in G4; and in G5 and G6, there was severe erosion with deterioration of dentin surface. In conclusion, 0.2% chitosan for 3 min appeared to be efficient for removing the smear layer, causing little erosion of dentin.

Completo debridamento dos canais radiculares com a remoção da smear layer são medidas essenciais no sucesso do tratamento endodôntico. O objetivo deste estudo foi avaliar os efeitos da quitosana, em diferentes concentrações, na remoção da smear layer e na estrutura da dentina, após 3 e 5 min de aplicação. Doze dentes caninos superiores, recém extraídos, foram instrumentados pela técnica crown-down e irrigados com hipoclorito de sódio 1%. Os espécimes foram distribuídos em seis grupos conforme o tempo e a concentração da solução irrigante final: G1: quitosana 0,1% por 3 min; G2: quitosana 0,2% por 3 min; G3: quitosana 0,37% por 3 min; G4: quitosana 0,1% por 5 min; G5: quitosana 0,2% por 5 min; G6: quitosana 0,37% por 5 min. Todas as amostras foram preparadas para avaliação em MEV. Os resultados mostraram que o G1 apresentou remoção da smear layer, mas não da smear plug. O G2 mostrou túbulos visíveis e abertos com ligeira erosão da dentina peritubular. A limpeza no G3 foi semelhante à do G2, no entanto, o efeito erosivo foi maior. No G4 houve ampliação do diâmetro dos túbulos e no G5 e G6, severa erosão com deterioração da superfície dentinária. Concluiu-se que a quitosana 0,2% por 3 min foi eficiente na remoção da smear layer, ocasionando pequena erosão.

Efeitos do hidróxido de cálcio e da clorexidina sobre a expressão de citocinas em infecções endodônticas / Effects of calcium hydroxide and chlorhexidine on cytokine expression in endodontic infections

Introdução: A eliminação de microorganismos do sistema de canais radiculares infectados é uma etapa crucial que envolve o complexo debridamento mecânico-químico e a utilização de uma medicação intracanal. O hidróxido de cálcio vem sendo indicado nestes casos por ser estável por longos períodos, por possuir boa biocompatibilidade, ser bactericida em uma área limitada, além de induzir a formação de tecido mineralizado e ser efetivo contra a formação de exsudados inflamatórios. A Clorexidina (CHX) é uma molécula hidrofóbica e lipofílica positivamente carregada, que vem sendo utilizada como solução irrigadora e medicação intracanal...

Root canal debris removal using different irrigating needles: An SEM study.

Aim: This study was carried out to compare the efficacy of three irrigating needle designs in removal of debris from different parts of the root canal. Materials and Methods: Thirty human maxillary canines were prepared using HERO Shaper rotary system and irrigated with 1 ml of 5.25% sodium hypochlorite (NaOCl) after each instrument change. Three 25-gauge irrigation needle designs - brush-covered Navi Tip FX (Group I), side-vented needle RC Twents (Group II) and single-beveled (Group III) irrigating needles - were tested for their efficiency in debris removal in three different parts of the root canal (n=10 canals per group). Following instrumentation, the roots were vertically sectioned and divided into coronal, middle and apical thirds for observation under scanning electron microscope (×200 magnification). Debris on the canal wall was evaluated by using a four-scale scoring system described by Paque and his co-workers. Results: The canals irrigated with brush-covered needle Navi Tip FX (Group I) showed lower average debris score, indicating greater removal of debris in coronal third as compared to middle and apical thirds, whereas the canals irrigated with side-vented needle (Group II) and single-beveled needle (Group III) exhibited lower average score in the middle third than coronal and apical thirds. All the three needle designs exhibited higher debris score in apical third of the root canal. Tukey multiple comparisons test was applied at a significance level of P>0.05. A statistically significant difference (P<0.05) was observed in the debris removal in the coronal and middle thirds of root canals irrigated with brush-covered Navi Tip FX (Group I) and side-vented (Group II) needles, respectively, when compared with other needle design groups. Conclusion: Within the limitations of this study, it can be concluded that all the needle designs tested were effective in certain regions of the root canal with apical third uncleaned. Side-vented needle by creating turbulence removed debris effectively in coronal and middle thirds.

A comparative evaluation of smear layer removal using two rotary instrument systems with ethylenediaminetetraacetic acid in different states: A SEM study.

Aim: The aim of the study was to evaluate the ability of 17% ethylenediaminetetraacetic acid (EDTA) solution and 19% EDTA gel to remove debris, and smear layer produced during root canal preparation with two NiTi files systems, Mtwo and Protaper. Materials and Methods: Twenty freshly extracted human anterior teeth with single root canal were collected. The crowns were sectioned at the cemento-enamel junction, and working length was measured. These samples were randomly divided into four groups of five samples each. In each group, 2ml of 3 % sodium hypochlorite solution was used with first instrument. The groupings were as follows. Group 1: 2 ml of 17% EDTA solution and 2 ml of 3% NaOCl were used alternatively each time a new file was employed. This group was prepared with Mtwo rotary files. Group 2: The samples in this group was prepared with Mtwo rotary files. EDTA gel (19%) was used and the samples were irrigated with 2 ml of 3% NaOCl. NaOCl and EDTA gel were used alternatively. Group 3: Five samples were prepared with Protaper file. Irrigation regime was the same as in Group 1. Group 4: Five samples were prepared with Protaper files and irrigation regime was the same as in Group 2. SEM study was done and the collected data were submitted for statistical analysis. Results: There was no statistically significant difference with the varied instruments used (Mtwo and Protaper files), and 17% EDTA solution and 19% EDTA gel. Conclusion: Both the NITI instruments produced a similar dentin surface on root canal wall when used with EDTA gel and EDTA solution.

Influence of apical enlargement in cleaning and extrusion in canals with mild and moderate curvatures

Optical microscopy and morphometric analysis were used in this study to evaluate, in vitro, the cleaning of the apical region in root canals with mild or moderate curvatures subjected to biomechanical preparation with a rotary system, as well as to assess the amount of extruded material to the periapical area. Lateral incisors (n = 32), 16 with curvature angles smaller or equal to 10º (GI) and 16 between 11º and 25º angles (GII) were submitted to Hero 642 rotary instrumentation with different surgical diameters: (A) 30.02 and (B) 45.02. Irrigation was performed at each change of instrument with 5 mL of ultrapure Milli-Q water and the extruded material through the apical foramen was collected. Root cross-sections were subjected to histological analysis by optical microscopy (×40) and the images were evaluated morphometrically using the Image Tool software. Quantification of the extruded material was performed by weighing after liquid evaporation. ANOVA showed no statistically significant differences (p>0.05) among the groups with respect to the procedures used to clean the apical region. Considering the amount of extruded material, the Tukey's HSD showed that canals with mild curvature prepared with the 45.02 surgical diameter showed significantly higher values (p<0.05) that those of the other groups, which were similar between themselves (p>0.05). In conclusion, the effect of cleaning the apical region did not differ in the groups, considering root curvature and the surgical diameter of instruments used for apical preparation. The amount of extruded material was greater in canals with mild curvature that were prepared with the 45.02 surgical instrument diameter.

Este estudo avaliou, in vitro, por meio de microscopia óptica e morfometria, a limpeza da região apical em canais radiculares com curvatura leve e moderada submetidos ao preparo biomecânico com sistema rotatório, bem como avaliou a quantidade de material extruído para a área apical. Incisivos laterais (n = 32), sendo 16 com ângulo de curvatura igual ou inferior a 10º (GI) e 16 entre 11º e 25º (GII), foram submetidos à instrumentação rotatória com o sistema Hero 642 com diferentes diâmetros cirúrgicos: (A) 30,02 e (B) 45,02. A irrigação, a cada troca de instrumento, foi realizada com água ultra-pura de Milli Q (5 mL), e o material extruído através do forame apical foi coletado. As raízes foram submetidas a análise histológica sob microscopia óptica (40×) e as imagens foram submetidas à análise morfométrica utilizando o software Image Tool. A quantificação do material extruído foi realizada por pesagem, após a evaporação do líquido. A análise de variância não mostrou diferença estatística significante em relação à limpeza da região apical nos diferentes grupos testados (p>0,05). Considerando a quantidade de material extruído, o teste de T6ukey mostrou que os canais com curvatura leve preparados com o diâmetro cirúrgico 45,02 apresentaram os maiores valores, sendo estatisticamente diferente dos demais grupos (p<0,05) que foram semelhantes entre si (p>0,05). Pode-se concluir que a limpeza da região apical não diferiu entre os diferentes grupos, considerando a curvatura radicular e o diâmetro cirúrgico. A quantidade de material extruído foi maior nos canais preparados com curvatura leve que foram preparados com diâmetro cirúrgico 45,02.

An in vitro study of antibacterial effect of calcium hydroxide and chlorhexidine on Enterococcus faecalis.

Aim: To evaluate and compare the antibacterial effects of chlorhexidine and calcium hydroxide on Enterococcus faecalis. Materials and Methods: Root canal treatment involves a number of steps. In spite of all the steps done thoroughly, root canal treatment might fail due to the remnant microbes. Of all such bacteria, E. faecalis is found in failed root canals. The study tests the antibacterial activity of various intracanal medicaments. Agar diffusion test was used to evaluate the antibacterial effects of the following antibacterial agents: i. hexidine:0.2% chlorhexidine gluconate; ii. periogard:0.12% chlorhexidine gluconate; iii. calcium hydroxide powder plus sterile water; iv. metapaste plus sterile water; v. calcium hydroxide plus hexidine; vi. calcium hydroxide plus periogard; vii. metapaste plus hexidine; viii. metapaste plus periogard. The size of zones of inhibition was measured. Results: The average size of zones of inhibition after 72 hours were hexidine: 5 mm; periogard: 4.25 mm; calcium hydroxide plus sterile water: 0.5 mm; metapaste plus sterile water: 0.5 mm; calcium hydroxide plus hexidine: 4.7 mm; calcium hydroxide plus periogard: 4 mm; metapaste plus hexidine: 4.65 mm; metapaste plus periogard: 4 mm. Results were subjected to statistical analysis using one way analysis of variance and Tukey tests. Conclusion: Chlorhexidine and its preparations are more potent antibacterial agents againstE. faecalis in comparison to calcium hydroxide.

Dissolution of bovine pulp tissue in solutions consisting of varying NaOCl concentrations and combined with EDTA

This in vitro study evaluated (1) the dissolution of bovine pulp tissue in solutions consisting of varying NaOCl concentrations and combined with EDTA; and (2) the pH of these solutions before and after the experiment. The independent variables were the concentration and the volume of the solution. Thirty bovine pulps were divided in equal fragments, resulting in 90 fragments of pulp tissue. Each fragment was immersed in one of the following solutions: 1 percent NaOCl (4 ml), 2.5 percent NaOCl (4 ml), 1 percent NaOCl + 17 percent EDTA (2 ml : 2 ml), 1 percent NaOCl + 17 percent EDTA (1 ml : 3 ml), 2.5 percent NaOCl + 17 percent EDTA (2 ml : 2 ml), and 2.5 percent NaOCl + 17 percent EDTA (1 ml : 3 ml). The test solutions were dichotomized as either able or not able to dissolve the tissue, the latter being attributed when the dissolution of the pulp tissue was not complete within 48 hours. When the samples were able to dissolve the tissue, the time required for complete tissue dissolution was submitted to statistical analysis. The pH of the solutions was measured before and after the experiment. The pH variable was dichotomized as either changed or unchanged. The results demonstrated that the NaOCl solutions combined with 17 percent EDTA were not able to dissolve the tissue. The t-test revealed that the 2.5 percent NaOCl solution presented a lower mean dissolution time than the 1 percent NaOCl solution (p < 0.001). The pH of the solutions with equal volumes of NaOCl and EDTA decreased in 48 hours.