Comparative Analysis of Irrigation Techniques for Cleaning Efficiency in Isthmus Structures.

INTRODUCTION: This study aimed to evaluate the removal of a biofilm-mimicking hydrogel from isthmus structures in a simulated complex root canal system consisting of 2 curved root canals by Laser-activated irrigation (LAI, AdvErl Evo, Morita) and mechanical activation techniques. METHODS: A 3D-printed root canal model with 2 parallel root canals (60°-curvature, radius 5 mm, dimension 25/.06) with a total length of 20 mm connected via isthmuses (2.5 × 0.4 × 0.2 mm) at 5 mm and 8 mm from the apical endpoint and with lateral canals (diameter 0.2 mm) in all directions at 2, 5, and 8 mm from the apex was filled with a colored biofilm-mimicking hydrogel. Irrigation protocols under continuous irrigation with distilled water (3 × 20s per root canal; 3 ml/20s; n = 20) included conventional needle irrigation (=NI); manual agitation (=MA, gutta-percha point 25/.06); EndoActivator (=SAI-EA, 25/.04); EDDY (=SAI-E, 25/.04); ultrasonically-activated irrigation (=UAI) and LAI (Er:YAG-laser; P400FL tip at canal entrance; 25pps, 50 mJ, 300µs). Removal of the hydrogel was determined as a percentage via standardized photos through a microscope. Statistical analysis was performed using Kruskal-Wallis and Conover tests (P = .05). RESULTS: Laser-activated irrigation (LAI) was associated with the greatest removal of hydrogel from the entire root canal system (P < .05), followed by SAI-E. No significant differences were reported for the coronal isthmus between LAI, SAI-E, NI, and MA (P > .05), but inferior results for SAI-EA and UAI (P < .05). In the apical isthmus, all techniques outperformed UAI (P < .05), with LAI, SAI-E, and NI showing the best results (P < .05). CONCLUSIONS: Laser-activated irrigation (LAI) was superior to other irrigation techniques in the entire root canal system. SAI-E and NI performed comparable to LAI in the isthmuses.

The effect of root canal preparation tapers on planktonic bacteria and biofilm reduction in the apical third: A correlative microtomography and microbiological laboratory study.

AIM: To evaluate the influence of different preparation tapers on the reduction in planktonic bacteria and biofilms of Enterococcus faecalis and Candida albicans in the apical third (4 mm) of the mesial roots of mandibular molars, correlating decontamination with canal shape. METHODOLOGY: After microtomography analysis for morphological standardization of the canals, 48 mandibular molar roots, each containing two canals (96 canals), were contaminated with E. faecalis and C. albicans and divided into four groups (n = 11) for canal instrumentation using ProDesign Logic 2 files with different tapers G (.03): # 25.03; G (.04): # 25.04; G (.05): # 25.05; and G (.06): # 25.06 and irrigation with 2.5% sodium hypochlorite. Four roots were examined under a scanning electron microscope (SEM) to qualitatively assess biofilm formation. Eight roots were used as the negative control group (samples were not contaminated). Bacteriological samples were taken exclusively from the apical third of the roots before and after chemical-mechanical preparation and bacterial counts were determined (CFU/mL). The final micro-CT scan was used to quantify the volume variation and unprepared canal area in the apical third. Statistical analysis was performed using the Kruskal-Wallis, Student-Newman-Keuls and Wilcoxon tests for analysis of microbiological data. anova and the Tukey or Games-Howell test were used for analysis of micro-CT data and Spearman's test for correlations (α = 5%). RESULTS: All groups showed a significant reduction in bacteria (p < .05), with no statistically significant difference between groups. There was no significant difference in per cent volume increase between groups. The unprepared area (Δ%) was affected by the file used (p = .026) and was significantly lower for G (.06) compared to G (.03). There was no statistically significant correlation among bacterial reduction, volume and unprepared area (p > .05). CONCLUSION: The different preparation tapers influenced root canal shaping in the apical third but did not improve decontamination in this region.

Antimicrobial Effect of Calcium Hydroxide Combined with Electrolyzed Superoxidized Solution at Neutral pH on Enterococcus faecalis Growth.

OBJECTIVE: To evaluate the effect of the combination of calcium hydroxide (Ca(OH)2) and a novel electrolyzed superoxidized solution at neutral pH, known as OxOral® on Enterococcus faecalis growth in root canals. METHODS: Sixty human teeth were used, from which root canals were infected and randomly divided into the following treatment groups: saline solution, saline solution plus Ca(OH)2, OxOral®, and OxOral® plus Ca(OH)2. RESULTS: A permanent reduction in bacterial growth was observed at days 1, 6, 12, and 18 after OxOral® plus Ca(OH)2 treatment from 4.4 ± 0.074 log10 CFU/mL to 0.0 ± 0.001 log10 CFU/mL. In addition, alkaline conditions maintenance was observed from application time (pH = 12.2 ± 0.033) to 18 d posttreatment (pH = 12.6 ± 0.083). CONCLUSION: The combination of OxOral® and Ca(OH)2 provides an alkaline pH and inhibits E. faecalis growth into the root canals. Our study opens the possibility for further research on the use of OxOral® in endodontic therapy.

Evaluation of the anti-biofilm effect of poloxamer-based thermoreversible gel of silver nanoparticles as a potential medication for root canal therapy.

The purpose of this study was to design silver nanoparticles (AgNPs) poloxamer thermoreversible gel (AgNPs-PL) and investigate whether this gel could provide sustained antibacterial activity against Enterococcus faecalis (E. faecalis) in the root canal. The gels fabricated were characterized in terms of gelatin temperature, particle size, in-vitro Ag+ release, and elemental content. Cytotoxicity of AgNPs-PL on primary human periodontal ligament fibroblasts (HPDLFs) was examined by CCK-8 assay. Characterization of AgNPs-PL gel revealed that it contained particles existing as large clumps/fused aggregates of different shapes, with a mean diameter of 21.624 ± 14.689 nm, exhibited sustained release of Ag+ for 9 days, and non-toxic to HPDLFs at a low dose (4-32 µg/mL) through 24, 48, and 72 h exposures. The antibacterial effect of 16 and 32 µg/mL concentrations of AgNPs-PL was compared with blank poloxamer gel (PL) and calcium hydroxide (CH) using three methods: (I) agar counting plate, (II) scanning electron microscope (SEM) observations, and (III) confocal laser scanning microscope (CLSM) analysis. AgNPs-PL at the two doses above was more effective than PL and CH in removing E. faecalis biofilm at 1, 3, 9 days. Thus, AgNPs-PL exhibits strong activity against E. faecalis and is easy to produce, with a continuous release profile of Ag+. AgNPs-PL gel may be a candidate for a new root canal disinfection.

Efficacy of continuous apical negative ultrasonic irrigation (CANUI) in penetration of simulated lateral canals in extracted teeth.

The aim of this study was to evaluate the efficacy of continuous apical negative ultrasonic irrigation into simulated lateral canals and the apical third in straight and curved root canals. Two simulated lateral canals were created 2, 4 and 6 mm from the working length in 120 single-rooted teeth (6 canals/tooth, n = 360 straight, n = 360 curved). The teeth were randomly divided into 3 experimental groups: positive pressure irrigation (PPI) (n = 20); passive ultrasonic irrigation (PUI) (n = 20); continuous apical negative ultrasonic irrigation (CANUI) (n = 20). 20% Chinese ink was added to a 5% sodium hypochlorite solution and delivered into the root canals. The results showed a significantly higher (P < 0.05) penetration of irrigant into the lateral canals and up to working length in the CANUI group for straight and curved roots. CANUI improves penetration into the lateral canals and up to the working length of the cleared teeth in straight and curved roots.

Effects of different irrigation protocols on dentin surfaces as revealed through quantitative 3D surface texture analysis.

The combination of ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) has been advocated as an effective irrigation methodology to remove organic and inorganic matter in root canal therapy. Yet, it was suggested that both solutions might lead to structural changes of the dentinal wall surface, depending on the order of application which might affect sealer mechanical retention. This study aims to evaluate the effect of different irrigating protocols on dentin surface roughness using quantitative 3D surface texture analysis. Data stems from 150 human root dentin sections, divided into five groups, each prepared according to one of the following protocols: Negative control; 17% EDTA; 17% EDTA followed by 5.25% NaOCl; 5.25% NaOCl; and 5.25% NaOCl followed by 17% EDTA. Each dentin sample was examined for its three-dimensional surface texture using a high-resolution confocal disc-scanning measuring system. EDTA 17% and the combined EDTA 17% with NaOCl 5.25% showed considerably higher roughness properties compared to the control and to NaOCl 5.25% alone. However, the irrigation sequence did not affect the dentin roughness properties. Therefore, mechanical retention is probably not dependent upon the selection of irrigation protocol sequence.

Development of Chlorhexidine Digluconate and Lippia sidoides Essential Oil Loaded in Microemulsion for Disinfection of Dental Root Canals: Substantivity Profile and Antimicrobial Activity.

The dental intracanal disinfection is crucial to achieve the success of endodontic treatment, avoiding the maintenance of endodontic infections. Chlorhexidine digluconate can act as an irrigating agent for it. However, it can cause tissue irritation in high concentrations. Therefore, combinations with other antimicrobial agents and more efficient therapeutic alternatives are studied, which make it possible to administer drugs more safely and with minimal adverse effects. Thus, the objective of this study was the development of a microemulsion containing chlorhexidine digluconate and essential oil of Lippia sidoides to be used for disinfection of dental root canals and to evaluate its profile of substantivity and antimicrobial activity. The microemulsions were obtained through phase diagrams, using the spontaneous formation method. We completed a physical-chemical characterization and evaluate the stability of the microemulsions, in addition to the substantivity profile in a bovine root dentin model, and in vitro antibacterial effect on Enterococcus faecalis. A method for quantifying chlorhexidine was developed using UV-Vis spectroscopy. The microemulsions showed acid pH, conductivity above 1.3 µScm-1, and dispersion index similar to water. The microemulsions showed antimicrobial inhibition halos similar to the commercial gel conventionally used, but with four times more substantivity to dentinal tissues. Microemulsions were obtained as a therapeutic alternative to formulations available on the market, presenting themselves as a system with great potential for the administration of drugs for disinfection of root canals.

Efficacy of Endoactivator, CanalBrush, and passive ultrasonic irrigation in the removal of calcium hydroxide paste with iodoform and p-chlorophenol from root canals.

AIMS: We evaluated and compared EndoActivator, CanalBrush, and passive ultrasonic irrigation (PUI) in the removal of calcium hydroxide and calcium hydroxide with iodoform and p-chlorophenol paste (Calcipast Forte) from artificial standardized grooves in the apical third of root canals. MATERIALS AND METHODS: A total of 34 mandibular premolars were prepared and then split longitudinally. A standardized groove was prepared in the apical part of both segments. The grooves were filled with either calcium hydroxide or Calcipast Forte, and the segments were reassembled. CanalBrush, EndoActivator, or PUI were used. The amount of remaining medicament was evaluated using a four-grade scoring system. RESULTS: None of the irrigation methods could completely remove the pastes from the grooves. More Calcipast Forte paste was detected compared with calcium hydroxide (P < 0.01). PUI was the least effective method in removing Calcipast Forte. CONCLUSIONS: It was more difficult to remove Calcipast Forte than a water-based calcium hydroxide paste.

Post preparation: cleanness achieved by different irrigating protocols.

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.

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.

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.

Current Trends in the Use of Irrigant Activation Techniques Among Endodontists & Post-Graduate Dental Students in India -A Knowledge, Attitude and Practice Based Survey.

Objective: The aim of this survey was to examine the practice/use of Irrigant Activation Techniques (IAT) among Endodontists and post-graduate dental students in India. Methods: An invitation to participate in this survey was sent by electronic mail to 902 members of Indian Endodontic society. A total of 32 questions were finalized for the survey after validation by five endodontic experts. Survey contained 2 demographic questions, 7 knowledge based questions, 11 questions on attitude and 12 questions on practice of IAT. The reliability was checked by randomly asking 10 participants to fill the survey forms again after 15 days. The data was analyzed using chi-square test (P<0.05). Results: The overall response rate for the survey was 30.5%. The content validity ratio for the questionnaire was 0.972 & the reliability calculated using Kappa scores was 0.978. Most of the respondents (87.3%) use IAT, while 4.7% do not use IAT. Most commonly used IAT was Manual dynamic agitation (MDA) used by 28.7%, followed by Ultrasonics in 17.2%. Sonic & negative pressure (EndoVac) was used by less than 10% of respondents. Combination of IAT was used by 39%. In 23 (5 on knowledge, 9 on attitude & 9 on practice) out of the 32 questions in this survey, there was a statistically significant difference (P<0.05) in the answers between the groups, with post-graduate dental students opting the correct choices. Sodium hypochlorite (NaOCl) is the preferred choice of irrigant for IAT according to 48.6%, Chlorhexidine (CHX) is used by 4.2% & Ethylene diamine tetra acetic acid (EDTA) by 2.4%. Combination of two irrigants is used by 28.7% and 6% use all the three irrigants. Conclusion: Vast majority of the Endodontist in India use some form of IAT to improve the efficacy of irrigation. MDA is the most commonly used IAT.

Decontamination of Gutta-percha Cones employed in Endodontics.

The gutta-percha 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 gutta-percha 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, gutta-percha 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 gutta-percha cones to the decontaminating agent should not be reduced.

Os cones de guta-percha utilizados no tratamento endodôntico são produzidos em condições assépticas e possuem óxido de zinco em sua composição, responsável pela atividade antibac-teriana. 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 protocolo de desinfecção a ser usado. Nosso objetivo foi avaliar a descontaminação de cones de guta-percha 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 guta-percha 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, observou-se 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 guta-percha ao agente de descontaminação não deve ser reduzido para evitar a possibilidade de falhas nesse estágio.

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.

Effect of Chinese Propolis as an Intracanal Medicament on Post-Operative Endodontic Pain: A Double-Blind Randomized Controlled Trial.

Propolis is a potent anti-microbial and natural anti-inflammatory by-product obtained from the beehive. Studies have demonstrated the superior biocompatibility and anti-microbial properties of propolis as compared to calcium hydroxide. However, its effect on postoperative endodontic pain is unknown. Therefore, this study aimed to investigate the impact of Chinese propolis paste as an intracanal medicament on postoperative endodontic pain intensities compared with calcium hydroxide (control) at different time intervals in necrotic teeth with periapical radiolucency. Eighty patients with single-rooted necrotic teeth with visible periapical radiolucency were recruited and randomly allocated to either the calcium hydroxide or propolis groups. After chemo-mechanical preparation and intracanal medicament insertion, patients were given the VAS (visual analogue scale) to record pain scores. Inter-group data were compared and analyzed using two-way repeated measure ANOVA (Bonferroni test). A p-value of < 0.025 was considered significant. In total, >78% of the patients experienced no or only mild post-operative pain in both the groups at all time intervals, without any significant difference in pain scores between the two groups (p > 0.025). An overall flare-up rate of 14.8% was found. The results suggest that either of these medicaments can be used as an inter-appointment medication for the prevention of postoperative pain in necrotic cases.

The effects of various irrigation protocols on root canal wall adaptation and apical microleakage in primary teeth.

Objective: The objective of this study is to evaluate the wall adaptation and apical microleakage values following the application of various irrigation protocols in primary teeth.Material and methods: For the two parts of the study, extracted upper incisor primary teeth were randomly included to the 1% sodium hypochlorite (NaOCl), 10% ethylenediaminetetraacetic acid (EDTA)+1% NaOCl, 6% citric acid (CA)+1% NaOCl and 0.9% physiological saline (PS) groups. Canal wall adaptation and apical microleakage were assessed by scanning electron microscopy (SEM) and stereomicroscope, respectively.Results: 6% CA + 1% NaOCl group was found to be the most successful irrigation protocol in providing strong canal wall adaptation and less apical microleakage, followed by 10% EDTA +1% NaOCl. 6% CA +1% NaOCl was significantly superior regarding apical microleakage (p < .05).Conclusions: Due to the ability to provide appropriate changes in the root canal walls to make a well-adapted and leak-proof canal filling, 6% CA + 1% NaOCl can be recommended as an irrigation protocol in primary teeth.

Er,Cr:YSGG Laser-Activated Irrigation and Passive Ultrasonic Irrigation: Comparison of Two Strategies for Root Canal Disinfection.

Objective: To compare the antibacterial effectiveness of 0.5% sodium hypochlorite (NaOCl) activated by the Er,Cr:YSGG laser-activated irrigation (LAI) and passive ultrasonic irrigation (PUI) against a 10-day-old intracanal Enterococcus faecalis biofilm. Background: LAI and PUI are regarded as alternative methods to release the irrigant in the inner regions of the root canal system achieving enhanced cleaning ability. Nevertheless, little evidence regarding the activation of low concentrations of NaOCl has been reported. Materials and methods: Seventy-two single-rooted teeth were instrumented, inoculated (E. faecalis ATCC 29212), and incubated for 10 days to allow biofilm formation. Specimens were randomly divided into six groups (n = 12 each): (1) 0.5% NaOCl+Er,Cr:YSGG LAI, (2) saline+Er,Cr:YSGG LAI, (3) 0.5% NaOCl+PUI, (4) saline+PUI, (5) positive control (no treatment), and (6) negative control (no bacteria). The activation time was distributed as follows: 30 sec of activation, followed by a rest phase of 30 sec, and ending with 30 sec of activation. The number of bacterial survivors was determined by plate counting. Results: Both irrigation regimens LAI and PUI reduced the number of colony-forming unit. Moreover, LAI +0.5% NaOCl and the rest of groups significantly differ (p < 0.001 for all comparisons). Conclusions: Er,Cr:YSGG LAI proved to be more effective than PUI in enhancing the antimicrobial activity of 0.5% NaOCl against 10-day-old intracanal E. faecalis biofilms.

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.

Do separated instruments affect pH levels when using calcium hydroxide as intracanal dressing?

BACKGROUND: The aim of this study was to evaluate the effect of intracanal separated instruments with different lenghts on periapical pH levels using calcium hydroxide (CH) as an intracanal medicament. MATERIALS AND METHODS: In total, 60 teeth were used. Following root canal preparation, teeth were divided into four groups (n = 15). In Group 1, 2 mm and in Group 2, 4 mm weakened from the tip of Revo-S NiTi SC2 (Micro-Mega, Besancon, France) instruments were separated in the apical portion of root canals. In Group 3, there was no separated instrument. CH paste was placed in the first three groups. In Group 4, there was no separated instrument or CH paste. Teeth were placed in containers with deionized distilled water. After 1 h and 1, 2, 7, 15, and 30 days, the pH of the solution was measured. RESULTS: At 1 h, Group 3 showed a significantly higher pH than Groups 1 (2 mm) and 2 (4 mm; P < 0.05). At the same time point, Group 1 (2 mm) showed a higher pH than Group 2 (4 mm) without significance. At 1, 2, 7, 15, and 30 days, Group 2 (4 mm) showed a significantly lower pH than Groups 1 (2 mm) and 3 (P < 0.05). At the same time points, Group 1 (2 mm) showed a lower pH than Group 3 without significance. CONCLUSIONS: Separated instrument may affect the rise in periapical pH level when using CH as the intracanal dressing. Therefore, 4 mm of separated instrument in the apical third showed a significant effect.

Allium sativum extract as an irrigant in pulpectomy of primary molars: A 12-month short-term evaluation.

This study indented to assess the clinical and radiographic assessment of Allium sativum extract as an intracanal irrigant for pulpectomy of primary molars. Ninety children with 110 teeth submitted were categorized into two groups. Clinical and radiographic success rates were checked at 3, 6, and 12 months. Qui-square test at a level of significance was ˂0.05. There was no statistically significant difference (p Ë‚ .05) between the two groups that has not been detected clinically or radiographically. Clinical and radiographic success rates of garlic extract at 3 months were (80% and 72.7%), which declined at 6 and 12 months to be 76.4% 6 and 74.5% respectively. For NaOCl group, clinical and radiographic success rates were 87.3% and 85.5% at 3 months, 87.3% and 87.3% at 6 months and 89.1% and 87.3% at 12 months. A. sativum extract can be used efficiently as an irrigant for pulpectomy of primary molar root canals.

Chemical aspect of sodium hypochlorite activation in obtaining favorable outcomes of endodontic treatment: An in-vitro study.

BACKGROUND: Endodontic treatment is one of the most widely performed procedures in a dental office. New techniques for enhancing the effectiveness of irrigants are being introduced into the dental market. It is crucial to choose a proper method to obtain the highest possible long-term success of performed endodontic treatment. Sodium hypochlorite (NaOCl) appears to be one of the most common and profitable solutions for root canal irrigation. The activation of a solution may be analyzed in 2 fields, physical - turbulence of flow, and chemical - disintegration of irrigant molecules into very active radicals that improve its activity. While the physical alternations of irrigant flow with different techniques are widely studied, there are not many attempts to approach the subject in chemical terms. OBJECTIVES: The aim of the study was to compare the chemical effectiveness of 2 methods of NaOCl activation: ultrasonics vs the Self-Adjusting File system (SAF) as an adjunct to increase the efficacy of the irrigant. MATERIAL AND METHODS: The level of activation was evaluated via a reaction of the activated NaOCl samples, with 9-fluorenol as the starting organic material. The model reaction is based on the oxidation of 9-fluorenol to 9-fluorenon. The evaluation was performed using 1H nuclear magnetic resonance (NMR) spectroscopy, comparing the spectra obtained for the examined mixtures. RESULTS: Nuclear magnetic resonance studies show that the use of ultrasonics resulted in increased chemical degradation of NaOCl as compared to the SAF system and non-agitated samples. The prevalence of chemical activation in the ultrasonic group over the SAF group was almost 3 times higher, 3.11 to 1.20, respectively. The Kruskal-Wallis rank sum test revealed there is a statistically significant difference in distributions between the groups. CONCLUSIONS: Both SAF and ultrasonics activate NaOCl. Ultrasonic agitation provided higher chemical activation of NaOCl solution than the SAF. The use of ultrasonic agitation of NaOCl in endodontic treatment will allow us to obtain better long-term clinical results.