Ultrasonic agitation reduces the time of calcium hydroxide antimicrobial effect and enhances its penetrability.

OBJECTIVES: The objective of the present work was to evaluate the ultrasonic agitation, time and vehicle (propylene glycol or distilled water) on the antimicrobial potential and penetrability of calcium hydroxide pastes on infected dentin by means of Confocal Laser Scanning Microscopy (CLSM) and microbiological culture (MC). MATERIALS AND METHODS: Dentin specimens were infected with Enterococcus faecalis using a new contamination protocol of 5 days. The specimens were divided into eight groups and dressed with the pastes for 7 or 15 days: G1) calcium hydroxide (CH) + propylene glycol (prop)/7 days (d), G2) CH + prop/7d + ultrasonic agitation (U), G3) CH + distilled water (dw)/7d, G4) CH + dw/7d + U, G5) CH + prop/15d, G6) CH + prop/15d + U, G7) CH + dw/15d, G8) CH + dw/15d + U. The ultrasonic activation was made for 1 min in both directions with a plain point insert. After medications removal, the images obtained by CLSM showed the viable (green) and dead (red) bacteria with Live and Dead dye. By the MC, the dentinal wall debris obtained by burs were collected for colony counts. For the penetration test, the Rodamine B dye was added to the CH pastes and analyzed by CLSM. RESULTS: The 7 and 15-days CH + prop+U pastes performed better antimicrobial efficacy, followed by the CH + dw+U/15d paste. CONCLUSIONS: All pastes demonstrated better penetration and antimicrobial activity against E. faecalis when agitated with ultrasound, even in periods of up to seven days. The propylene glycol vehicle showed better results. CLINICAL RELEVANCE: Agitation of the dressing that remains for less time inside the root canal can optimize the decontamination of endodontic treatment.

Penetration of sodium hypochlorite into root canal dentine: effect of surfactants, gel form and passive ultrasonic irrigation.

AIM: To assess the penetration of sodium hypochlorite (NaOCl) gel or NaOCl solutions with surfactants, and the effect of passive ultrasonic irrigation (PUI) on penetration into dentinal tubules. METHODOLOGY: Bovine incisor root canals were instrumented, the roots sectioned and the dentine blocks obtained were stained with crystal violet. Dentine blocks (n = 10 per group) were exposed to 3% NaOCl gel or 3% NaOCl solution for 10 and 20 min. Other dentine blocks (n = 10 per group) were exposed to Chlor-Extra (6% NaOCl + surfactant), 6% NaOCl, 2.5% NaOCl with 0.2% cetrimide and 2.5% NaOCl for 10 and 20 min. The penetration depth of irrigants into dentinal tubules was measured in micrometres by viewing the bleached crystal violet under a stereomicroscope. Additionally, bovine incisor root canals, instrumented and stained with crystal violet, were distributed into two groups (n = 10) and irrigated with 2.5% NaOCl with PUI or conventional syringe irrigation (CSI). The penetration depth of irrigants into dentinal tubules was assessed 3 and 7 mm from the apex. Statistical analysis was performed by ANOVA and Tukey tests (α = 0.05). RESULTS: There was significantly greater penetration of 3% NaOCl solution into dentinal tubules compared with the gel form (P < 0.05). There was no difference (P > 0.05) between 6% NaOCl and Chlor-Extra, and between 2.5% NaOCl and 2.5% NaOCl + cetrimide. PUI significantly increased the penetration depth of NaOCl into dentinal tubules when compared with CSI (P < 0.05). CONCLUSIONS: In extracted bovine incisors, NaOCl gel penetrated less into dentinal tubules than NaOCl solution. The addition of surfactants did not increase the penetration depth. The use of PUI significantly increased NaOCl penetration into dentinal tubules.

Sodium hypochlorite penetration into dentinal tubules after manual dynamic agitation and ultrasonic activation: a histochemical evaluation.

The aim of this study was to compare the effects of Manual Dynamic Agitation and Passive Ultrasonic Irrigation on sodium hypochlorite (NaOCl) penetration into dentinal tubules using its bleaching ability. Thirty-four single-rooted teeth with round-shaped root canals were distributed in two homogeneous groups and one control group, characterized by different NaOCl activation systems: Manual Dynamic Agitation and Passive Ultrasonic Irrigation. After instrumentation, all root canals were stained with 10% copper sulphate solution followed by 1% rubeanic acid alcohol solution under vacuum. Final irrigation was performed with 5 mL of 5.25% NaOCl solution for 1 min and activated with Manual Dynamic Agitation or Passive Ultrasonic Irrigation for another 1 min depending on the treatment group. The teeth were transversely sectioned at the middle portion of the apical, middle, and coronal thirds and observed under light microscope. NaOCl solution penetration was evaluated by measuring the percentage of bleached circumference of the root canal relative to the stained circumference, bleached areas, mean, and maximum penetration depth. No differences in the evaluated parameters were observed between groups (p > 0.05). Within groups, an increase of values was recorded from apical to coronal direction as for percentage of staining, percentage of bleaching and bleached area. NaOCl penetration into dentinal tubules did not significantly vary among the three levels. No significant differences in penetration of sodium hypochlorite into dentinal tubules when activated by means of Manual Dynamic Agitation or Passive Ultrasonic Irrigation were observed in the apical, middle, and coronal thirds of teeth with single straight round root canals.

Effect of Different Irrigation Systems on Sealer Penetration into Dentinal Tubules.

INTRODUCTION: Different irrigation systems have been developed to improve the efficacy and distribution of the irrigants. The aim of this study was to compare the effect of conventional endodontic needle irrigation with other irrigant delivery and/or agitation systems on sealer penetration into dentinal tubules. METHODS: Fifty single-rooted teeth with round-shaped root canals were distributed in 5 homogeneous groups characterized by the different cleansing system used: conventional endodontic needle irrigation, EndoActivator, Irrisafe, Self-Adjusting File, and EndoVac. After instrumentation, all teeth were filled by Thermafil obturators and rhodamine B dye labeled TopSeal sealer. Teeth were transversally sectioned at 2-, 5-, and 7-mm levels from the apex and observed under confocal laser scanning microscope. Maximum, mean, and percentage of sealer penetration inside tubules around the root canal were measured. Moreover, the integrity of the sealer layer perimeter was evaluated. RESULTS: No significant differences both in mean (p > .05) and in maximum penetration depth (p > .05) were observed among groups, whereas both parameters showed an increased trend within each group from the 2- to the 7-mm level from apex. Similarly, the percentage of penetration around the root canal wall did not differ among groups (p > .05) and showed an increasing trend within each group from the apical to the coronal portion of the canal. CONCLUSIONS: Sealer penetration into dentinal tubules is not affected by the irrigant delivery and/or agitation systems studied. Thermafil with TopSeal technique achieves complete sealer perimeter integrity in all groups.

Effect of a Low Surface Tension Vehicle on the Dentinal Tubule Penetration of Calcium Hydroxide and Triple Antibiotic Paste.

INTRODUCTION: The purpose of this study was to evaluate dentinal tubule penetration (DTP) of calcium hydroxide (CH) and triple antibiotic paste (TAP) when performed with distilled water (DW) or a low surface tension liquid (ie, propylene glycol [PG]). METHODS: Root apices of 40 single-rooted premolars were removed to obtain 14-mm roots in length. Root canals were enlarged to simulate immature teeth. After smear layer removal, the roots were randomly divided into 4 groups (n = 10) according to the root canal medicaments and the vehicles used: group 1:TAP + DW, group 2: TAP + PG, group 3: CH + DW, and group 4:CH + PG. Root canal medicaments were labeled with 0.1% rhodamine and applied into the canals using a Lentulo spiral. Specimens were molded into acrylic blocks, and 1-mm-thick sections were obtained from the middle third of each root. Specimens were mounted onto glass slides and scanned under a confocal laser scanning microscope. DTP depth, percentage, and area were measured using imaging software. Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis. The level of significance was set at P < .05. RESULTS: No significant difference was found among the experimental groups in terms of both percentage and depth of DTP (P > .05). CH had a lower penetration area compared with TAP regardless of the vehicle used (P < .05). CONCLUSIONS: A low surface tension vehicle did not alter the penetration of CH and TAP.

Effect of photon-initiated photoacoustic streaming, passive ultrasonic, and sonic irrigation techniques on dentinal tubule penetration of irrigation solution: a confocal microscopic study.

OBJECTIVES: The aim of this in vitro study was to evaluate the efficacy of different irrigation techniques including laser-activated irrigation using an erbium:yttrium-aluminum-garnet (Er:YAG) laser with a novel tip design (photon-induced photoacoustic streaming (PIPS)), Er:YAG laser with Preciso tip, sonic activation, and passive ultrasonic activation on the final irrigation solution penetration into dentinal tubules by using a laser scanning confocal microscope. MATERIAL AND METHODS: In this study, 65 extracted single-rooted human mandibular premolars were instrumented up to size 40 and randomly divided into 5 groups (n = 13) based on the activation technique of the final irrigation solution as follows: conventional irrigation (control group), sonic activation, passive ultrasonic activation, Er:YAG-PIPS tip activation, and Er:YAG-Preciso tip activation. In each group, 5 mL of 5% NaOCl labeled with fluorescent dye was used during the activation as the final irrigation solution. Specimens were sectioned at 2.5 and 8 mm from the apex and then examined under a confocal microscope to calculate the dentinal tubule penetration area. Data were analyzed using two-way analysis of variance (ANOVA) and Tukey's post hoc tests (P = 0.05). RESULTS: Both Er:YAG laser (Preciso/PIPS) activations exhibited a significantly higher penetration area than the other groups (P < 0.05). Additionally, passive ultrasonic activation had significantly higher penetration than the sonic activation group and the control group. Statistically significant differences were also found between each root canal third (coronal > middle > apical) (P < 0.001). CONCLUSIONS: The results from the present study support the use of Er:YAG laser activation (Preciso/PIPS) to improve the effectiveness of the final irrigation procedure by increasing the irrigant penetration area into the dentinal tubules. CLINICAL RELEVANCE: The activation of the irrigant and the creation of the streaming with the Er:YAG laser have a positive effect on the irrigant penetration.

Penetration of hypochlorites with lowered surface tension into dentine tubules.

BACKGROUND: The purpose of the present study was to assess the effect of concentration and temperature of sodium hypochlorite (NaOCl) with added surfactants and time of exposure on its penetration into human dentine. METHODS: Seventy-five extracted permanent maxillary anterior teeth with single canals were shaped by using ProTaper SX hand-operated instruments. Then teeth were sectioned perpendicular to their long axis. The crowns and apical thirds of all the teeth were removed. The remaining roots were processed into 4-mm-long blocks and stained overnight in crystal violet. One hundred fifty stained blocks were further split into halves and treated by six NaOCl-based solutions from different brands: three solutions added with surfactants (Hypoclean, H6, Chlor-Xtra) and their regular counterparts (5.25%, 6%, <%6NaOCl). The dentine blocks were exposed to the solutions for 2, 5, and 20 minutes at 20° C, 37° C, and 45° C, respectively. The depth of penetration of NaOCl was determined by bleaching of the stain and measured by light microscopy at magnifications of 20x and 40x. Statistical analysis was made by using two way ANOVA and by comparing groups two by two with t-test. RESULTS: The shortest penetration (130.80±1.92µm) was measured after incubation with 5.25%NaOCl for 2 minutes at 20° C; the highest penetration (375.40±3.05µm) was obtained with Chlor-Xtra for 20 minutes at 45° C. Temperature and exposure time had a significant direct relationship with penetration of sodium hypochlorites with lowered surface tension into dentinal tubules. CONCLUSIONS: The exposure time and temperature of sodium hypochlorite as well as the addition of surfactants may influence the penetration depth of irrigants into dentinal tubules.

Dentinal Tubule Penetration of Tricalcium Silicate Sealers.

INTRODUCTION: The treatments for which mineral trioxide aggregate (MTA)-based materials can be used in dentistry are expanding. Smaller particle size and easier handling properties have allowed the advent of tricalcium silicate sealers including EndoSequence BC Sealer (Brasseler USA, Savannah, GA), QuickSet2 (Avalon Biomed, Bradenton, FL), NeoMTA Plus (Avalon Biomed), and MTA Fillapex (Angelus, Londrina, Brazil). The objective of this study was to measure the tubule penetration with these sealers using continuous wave (CW) and single-cone (SC) obturation techniques. METHODS: Eighty single-rooted teeth were randomly divided into 8 groups of 10 and obturated with 1 of the previously mentioned sealers mixed with trace amounts of rhodamine using either the CW or SC technique. Teeth were sectioned at 1 mm and 5 mm from the apex and examined under a confocal laser microscope. The percentage of sealer penetration and the maximum sealer penetration were measured. RESULTS: The tricalcium silicate sealers penetrated tubules as deep as 2000 µm (2 mm). The percentage of sealer penetration was much higher 5 mm from the apex, with many specimens having 100% penetration for both SC and warm vertical techniques. MTA Fillapex, a resin-based sealer with less than 20% MTA particles, had significantly greater tubule penetration with a warm vertical technique versus the SC technique at the 1-mm level. CONCLUSIONS: Within the limitations of this study, the CW and SC techniques produced similar tubule penetration at both the 1-mm and the 5-mm level with the tricalcium silicate sealers BC Sealer, QuickSet2, and NeoMTA Plus.

Irrigant flow during photon-induced photoacoustic streaming (PIPS) using Particle Image Velocimetry (PIV).

OBJECTIVES: This study aimed to compare fluid movements generated from photon-induced photoacoustic streaming (PIPS) and passive ultrasonic irrigation (PUI). MATERIALS AND METHODS: Particle Image Velocimetry (PIV) was performed using 6-µm melamine spheres in water. Measurement areas were 3-mm-long sections of the canal in the coronal, midroot and apical regions for PIPS (erbium/yttrium-aluminium garnet (Er:YAG) laser set at 15 Hz with 20 mJ), or passive ultrasonic irrigation (PUI, non-cutting insert at 30% unit power) was performed in simulated root canals prepared to an apical size #30/0.04 taper. Fluid movement was analysed directly subjacent to the apical ends of ultrasonic insert or fiber optic tips as well as at midroot and apically. RESULTS: During PUI, measured average velocities were around 0.03 m/s in the immediate vicinity of the sides and tip of the ultrasonic file. Speeds decayed to non-measureable values at a distance of about 2 mm from the sides and tip. During PIPS, typical average speeds were about ten times higher than those measured for PUI, and they were measured throughout the length of the canal, at distances up to 20 mm away. CONCLUSIONS: PIPS caused higher average fluid speeds when compared to PUI, both close and distant from the instrument. The findings of this study could be relevant to the debriding and disinfecting stage of endodontic therapy. CLINICAL RELEVANCE: Irrigation enhancement beyond needle irrigation is relevant to more effectively eradicate microorganisms from root canal systems. PIPS may be an alternative approach due to its ability to create high streaming velocities further away from the activation source compared to ultrasonic activation.

Importancia de la activación de la irrigación durante el tratamiento de conductos: Una revisión de la literatura / Importance of the activation of irrigation during root canal treatment: A review of the literature

Introducción: La compleja anatomía presente en el sistema de conductos limita nuestra habilidad para limpiar y desinfectar de manera predecible. La remoción de cualquier resto pulpar vital y necrótico, microorganismos y sus toxinas, así como el barrillo dentinario que se produce durante la instrumentación, es esencial para el éxito del tratamiento de conductos. Durante los últimos años se han desarrollado nuevas técnicas de irrigación, empleando sistemas de activación y liberación, con el objetivo de mejorar la técnica convencional y lograr que el irrigante acceda a las zonas más inaccesibles del entramado radicular, como son: áreas no instrumentadas, conductos laterales, deltas apicales,etc. En este estudio se revisará la bibliografía existente acerca de dos de las técnicas de irrigación mecánicas más importantes: la activación sónica y la ultrasónica, para comprobar su eficacia respecto a la técnica convencional, y también para compararlas entre sí. Ambas técnicas se han probado más eficaces que la manual. No obstante, la técnica ultrasónica ha obtenido mejores resultados a la hora de eliminar detritus del conducto, así como al distribuir el irrigante y penetrar en áreas no instrumentadas en comparación con la activación sónica (AU)

The complex anatomy of root canal systems has limited our ability to clean and disinfect it predictably. The removal of any vital and necrotic pulp tissue, microorganisms and their toxins, along with the smear layer is essential for endodontic success. Proper cleaning of the canal system is a necessary goal for endodontic treatment success, and so has been the subject of numerous studies. Recently, new irrigation techniques have been developed, which use mechanical systems in order to improve the manual technique and to help the irrigant get to the most intricated areas of the canal system. This study will review the literature about two important mechanical irrigation techniques: Sonic and ultrasonic irrigation, in order to check its effectiveness over the conventional technique, and to compare them. Both techniques have been proven to be more efficient than the traditional one. however, the use of ultrasonics has been more successful in removing debris from the duct, distributing irrigant and penetrating uninstrumented areas compared to sonic activation (AU)

Antimicrobial effect and transdentinal diffusion of new intracanal formulations containing nitrofurantoin or doxycycline.

The aim of this study was to investigate in vitro the antimicrobial effect and diffusion against E. faecalis of new intracanal medications on the external root surface. The medications tested were a placebo gel (PC); the new formulations with either 3% nitrofurantoin (NIT) or 3% doxycycline hydrochloride (DX) and 2% chlorhexidine (CHX) gel as positive control. The new formulations were tested using the traditional agar diffusion test (ADT) and an adapted agar diffusion method (AADM), where the teeth were filled with the medications and left to diffuse on agar surface seeded with E. faecalis. In the ADT, the larger zones of microbial growth inhibition were seen in DX, followed by CHX and NIT. In the AADM test only DX and CHX showed antimicrobial effect. Statistically significant differences between groups were observed by the Kruskal-Wallis test (2=47.126; p<0.001). The new intracanal formulations with DX and NIT have demonstrated antimicrobial effect against E. faecalis, but only DX was able to diffuse through the dentinal tubules and exert antimicrobial effect outside the roots.

Eliminación de Enterococcus faecalis por medio del uso de hipoclorito de sodio, clorhexidina y MTAD en conductos radiculares / Elimination of Enterococcus faecalis using sodium hypochlorite, chorhexidine and MTAD in root canals

Objetivos: Comparar la efectividad de diferentes soluciones irrigadoras en la eliminación de cepas de Enterococcus faecalis en pacientes con patología periapical crónica, mediante pruebas microbiológicas. Métodos: Se evaluaron 21 dientes con diagnóstico de periodontitis apicales crónicas no supurativas de pacientes que asistieron a consulta en las clínicas odontológicas de la Universidad de Cartagena, previa firma y aprobación del consentimiento informado para participar en el estudio. Los sujetos de estudio se asignaron aleatoriamente en tres grupos usando las siguientes sustancias irrigantes: hipoclorito de sodio al 5%, clorhexidina al 2% e hipoclorito de sodio 2,5% con irrigación final de MTAD. Se identificaron microorganismos por medio de la prueba Reacción en Cadena de la Polimerasa (PCR) y se cuantificaron las unidades formadoras de colonias de Enterococcus faecalisantes y después de ser utilizadas las sustancias irrigadoras. Análisis estadístico: Se realizó el test de Kruskal wallis. Resultados: La investigación demostró que todas las sustancias fueron efectivas en la eliminación de E. faecalisen pacientes con periodontitis apicales crónicas no supurativas. El hipoclorito de sodio al 5% (p= 0,018), hipoclorito de sodio y MTAD (p= 0,021) y clorhexidina al 2% (p= 0,028) fueron igual de efectivas. Conclusiones: El hipoclorito de sodio al 5%, clorhexidina al 2%, hipoclorito de sodio y MTAD pueden ser utilizadas en pacientes con periodontitis apical crónica no supurativa por ser efectivas en la eliminación de E. faecalis (AU)

Objectives: To compare the effectiveness of different irrigating solutions in eliminating of Enterococcus faecalisin patients with chronic periapical pathology by applying microbiological tests. Methods: Twenty one teeth with chronic apical periodontitis of non suppurative diagnosis of patients that attended the dental clinics of the University of Cartagena were evaluated after the patients signed the consent form to participate in the study. The study subjects were randomized into three groups using the following irrigating substances: Sodium hypochlorite at 5%, chlorhexidine 2% and sodium hypochlorite and MTAD. Microorganisms were identified through the Chain Reaction (PCR) and quantified the colony forming units before and after Enteroccocus faecalis be used irrigating substances for cleansing. Statistical analysis: We performed the Kruskal Wallis test. Results: The research showed that all substances were effective in eliminating E. faecalis in patients with chronic apical periodontitis non suppurative. Sodium hypochlorite 5% (p= 0,018), sodium hypochlorite and MTAD (p= 0,021) and chlorhexidine 2% (p= 0,028) were equally effective. Conclusions: Sodium hypochlorite 5% chlorhexidine 2% and sodium hypochlorite and MTAD can be used in patients with chronic apical periodontitis non suppurative after being proven effective in eliminating E. faecalis (AU)

Biofilm en endodoncia y su tratamiento / Biofilm in Endodontics and its treatment

El biofilm es la forma más habitual que utilizan las bacterias para crecer y sobrevivir en la naturaleza. Hoy en día se considera que bajo ciertas condiciones ambientales, todos los microorganismos son capaces de formar biofilms. Por ello y por todos los problemas que causan tanto en el entorno médico como odontológico causando infecciones crónicas difíciles de erradicar con los tratamientos convencionales conocidos, el interés por su estudio ha aumentado en las dos últimas decadas. El objetivo de esta revisión es actualizar los conocimientos de tratamiento para el control y eliminación del biofilm en la terapia endodóntica (AU)

Biofilm is the most common form in nature used by bacteria to grow and survive. Nowadays it is considered that under certain environmental conditions, all organisms are able to create biofilms. Due to this ability and to the potential problem both in Medicine and Dentistry related to chronic infections difficult to eradicate with conventional treatments, the studies about biofilm have increased over the past two decades.I The aim of this review is to update the knowledge of treatment for the control and elimination of the biofilm in endodontic therapy (AU)

Comparison of irrigant penetration up to working length and into simulated lateral canals using various irrigating techniques.

AIM: To evaluate the effect of an apical negative pressure system, a passive ultrasonic irrigation system and a combination of both apical negative pressure and passive ultrasonic irrigation on the penetration of the irrigating contrast solution (ICS) up to working length and into simulated lateral canals. METHODOLOGY: The root canals of 64 single-rooted teeth were instrumented using the ProTaper rotary system. In each sample, three simulated lateral canals were created at 2, 4 and 6 mm levels from the root apex using a 06-size C+ file (Dentsply Maillefer, Ballaigues, Switzerland). Samples were randomly assigned into 4 experimental groups (n = 16): group I - conventional needle irrigation, group II - passive ultrasonic irrigation, group III - apical negative irrigation system and group IV - combination of passive ultrasonic irrigation and apical negative pressure irrigation system. To examine irrigating solution penetration, Indian ink was mixed with 5.25% NaOCl and delivered into the root canals. Samples were then assessed by direct observation of the images taken using Canon EOS rebel T3. The depth of penetration of ICS up to the working length and into the simulated lateral canals was analysed using chi-squared tests. RESULTS: The combination (ANP and PUI) and ANP group had significantly deeper ICS penetration up to the working length (P < 0.001). The combination (ANP and PUI) and the PUI group exhibited significantly greater ICS penetration into lateral canals at the 6 mm level (P < 0.001). At the 4 and 2 mm levels, the combination of ANP and PUI had significantly greater ICS penetration into the lateral canals than the other groups (P < 0.001). CONCLUSIONS: The combination of ANP and PUI was the only group able to achieve irrigating contrast solution penetration both up to the working length and into lateral canals.

Actividad antimicrobiana de la solución de nanopartícula de plata en cultivo de Enterococcus faecalis / Antimicrobial activity of silver nanoparticles solution on culture of Enterococcus faecalis

Objetivo. El objetivo del estudio fue evaluar la actividad antimicrobiana de la solución de nanopartículas de plata en cultivo de Enterococcus faecalis (ATCC 29212) comparándola con diversas soluciones de hipoclorito de sodio (NaOCl). Material y Métodos. Cinco placas de Petri en agar fueron inoculadas con E. faecalis y sobre cada una de ellas se colocó un disco de celulosa saturado de solución de nanopartículas de plata, así como en cada una de las soluciones de hipoclorito de sodio evaluadas (Viarzon, Cloralex, Clorox). El digluconato de clorhexidina al 2% y solución salina estéril fueron utilizados como control. Transcurridas 24 horas de incubación a 37°C, en condiciones de aerobiosis, las zonas de inhibición de crecimiento bacteriano fueron medidas y los resultados sometidos a la prueba “t” entre los grupos experimentales (= 5%). Resultados. El Cloralex presentó la mayor media de inhibición en comparación con las demás substancias (p < 0,05), excepto con digluconato de clorhexidina al 2% (p > 0,05). La solución de nanopartículas de plata proporcionó mayor zona de inhibición que Clorox y Viarzon (p <0,05). El Clorox y el Viarzon no proporcionaron zonas de inhibición y fueron semejantes entre sí (p > 0,05). Conclusiones. La solución de nanopartículas de plata presenta actividad antimicrobiana en cultivo de E. faecalis, incluso mayor que las formas comerciales de hipoclorito de sodio. Futuros estudios deben ser realizados para comprobar su viabilidad como solución de irrigación en endodoncia (AU)

Objective. The objective of this study was to evaluate the antimicrobial activity of the silver nanoparticles solution in enterococcus faecallis cultures (ATCC 29212), compared with various solutions of sodium hypoclorithe (NaOCl). Material and methods. Five Agar Petri plates were inoculated with E. faecallis and each of them was placed a cellulose dish embedded with silver nanoparticles solution, or a solution of sodium hypochlorite evaluated (Viarzon, Cloralex, Clorox). Chlorhexidine digluconate 2% was used as positive control and sterile saline solution was used as negative control. After 24 hours of incubation at 37ºc, under aerobic conditions, the zones of inhibition of bacterial growth were measured and the results subjected to the statistical t test among the experimental groups (= 5%). Results. The Cloralex showed to be the most effective reflected in the extent of inhibition in relation to other substances (p< 0.05), except that the chlorhexidine digluconate 2% (p> 0.05). The solution of silver nanoparticles provided a greater zone of inhibition than the sodium hypochlorite solution (Clorox) and Viarzon (p< 0.05). Clorox and Viarzon didn’t provide zones of inhibition and were similar to each other (p> 0.05). Conclusions. The solution of silver nanoparticles presents antimicrobial activity in cultured E. faecallis, even higher than other commercial forms of sodium hypochlorite. Further studies should be carried out to determine its viability as irrigating solution in endodontics (AU)

Decalcifying effects of antimicrobial irrigating solutions on root canal dentin

Objective: The aim of this study was to determine the decalcifying efficacy of 7% maleic acid (MA), 2% chlorhexidine (CHX), and combinations of 7% MA + 0.2% cetrimide (CTR) and 2% CHX + 0.2% CTR, in four time periods. Study Design: Four specimens per tooth were obtained from a 2-mm thick slice of the cervical third of the root of ten human incisors. At 1, 2, 3 and 5 minutes of immersion, the concentrations of Ca2+ were measured by atomic absorption spectrophotometry. The results were analyzed using the Mann-Whitney U-test. Results: Statistically significant differences were seen for the extracted calcium in all time periods. The amount of calcium extracted by 7% MA was the highest at all four immersion times, followed by 7% MA + 0.2% CTR. Two percent CHX and its combination with 0.2% CTR extracted virtually no calcium. Conclusions: The decalcifying capacity of 7% MA and 2% CHX diminished when combined with 0.2% CTR (AU)

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The effect of surface tension reduction on the clinical performance of sodium hypochlorite in endodontics.

Sodium hypochlorite (NaOCl) is recommended as an endodontic irrigant in view of its broad antimicrobial and tissue dissolution capacities. To enhance its penetration into inaccessible areas of root canals and to improve its overall effect, the addition of surface-active agents has been suggested. The aim of this investigation was to review the effect of the reduction of the surface tension on the performance of NaOCl in endodontics. A search was performed in the Medline electronic database (articles published up to 28 July 2012, in English) with the search terms and combinations as follows: 'sodium hypochlorite AND surface tension or interfacial force or interfacial tension or surface-active agent or amphiphilic agent or surface active agent or surfactant or tenside or detergent'. The purpose of this search was to identify publications that compared NaOCl alone and NaOCl modified with the addition of a surface-active agent in endodontics. A hand search of articles published online ('in-press' and 'early view'), and appearing in the reference list of the articles included, was further performed, using the same search criteria as the electronic search. The search identified 302 publications, of which 11 fulfilled the inclusion/exclusion criteria of the review. The evidence available suggests that surface-active agents improve the penetration of NaOCl in the main canal and have no effect on its pulp tissue dissolution ability. There are, however, insufficient data to enable a sound conclusion to be drawn regarding the effect of modifying NaOCl's surface tension on lubrication, antimicrobial and smear layer or debris removal abilities.

Capacidad de disolución de tejido pulpar vital del hipoclorito de sodio al 5, 25% y clorhexidina al 2% / Dissolution capacity of pulp vital tissue by sodium hypochlorite 5, 25% and 2% chlorhexidine

Objetivo. Comprobar la capacidad de disolución de tejido pulpar vital de hipoclorito de sodio al 5.25% y Clorhexidina al 2% post instrumentación rotatoria. Material y método. Se analizaron treinta y dos primeros premolares superiores con vitalidad pulpar que se obtuvieron post exodoncia. Fueron agrupados en: grupo 1, irrigación con NaOCI 5,25%; grupo, 2, irrigación con CHX 2%; grupo 3 o control irrigación con suero fisiológico, seguidamente las piezas dentarias fueron instrumentadas con sistema de limas rotatorias, irrigadas con las soluciones descritas y posteriormente muestras histológicas fueron teñidas y finalmente observadas en microscopio óptico. Resultados. Mostraron que no hubo diferencia estadística significativa tanto en los grupos irrigados por NaOCI 5.25% y CHX 2% debido a que fueron encontrados tejido pulpar residual en todos los grupos. Los tercios coronarios fueron mayormente desprovisto de tejido pulpar que en los tercios apicales. La anatomía accesoria no fue desprovista de tejido pulpar. Conclusión. Aunque la CHX no tenga capacidad de disolver tejido pulpar y los resultados de este estudio no hayan demostrado diferencia estadística significativa en relación al NaOCI este resultado no se debe al efecto disolutorio de las soluciones irrigadoras sino a que el NaOCI no tuve suficiente tiempo de contacto con tejido pulpar (AU)

Aim. Of this study was to test the ability of vital pulp tissue dissolution of 5.25% sodium hypochlorite and 2% chlorhexidine after rotary instrumentation system. Material and methods. Thrity-two freshly extracted premolar teeth, with pulps vital at the time of extraction were assigned in groups. Group 1, 5.25% NaOCI irrigation, group 2, 2% CHX irrigtation, group 3 with distilled water irrigation as control. After to teeth were instrumented with rotary files system, irrigated with the solutions described and decalcified. Each root was divided in thirds and transverse histological sections were perfomed at four levels, then histological samples were stained and observed in microscope optical. Results. No statistically significant differences were found in both groups irrigated by 5.25% NaOCI and CHX 2% residual pulp tissue were found in all groups. Coronal parts were more frequently devoid of pulp tissue than the apical. The isthmus had residual pulp tissue less frequently in the NaOCI groups. Accessory anatomy was unaffected regardless of irrigant. Conclusions. Although CHX has no ability to dissolve pulp tissue and the results of this study were not statistically significantly compared to NaOCI. This results this is not due to the dissolving effect of irrigating solutions but that NaOCI did not have enough time contact with pulp tissue (AU)

In vitro antimicrobial activity of Sodium hypochlorite, Chlorhexidinegluconate and Octenidine Dihydrochloride in elimination of microorganisms within dentinal tubules of primary and permanent teeth

The aim of this study was to evaluate the effectiveness of different irrigation solutions at different time intervals for the elimination of E.faecalis and C.albicans penetrated into the dentine tubules of primary and permanent teeth in vitro.The 4mm primary and permanent teeth sections were sterilized and contaminated with a mixture of E.faecalis and C.albicans strains. After the apllication of different irrigation solutions (..) (AU)

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Penetration into dentin of sodium hypochlorite associated with acid solutions.

OBJECTIVE: The objective of this study was to evaluate the penetration of 2.5% NaOCl associated with 17.0% EDTA, 1.0% citric acid, and 1.0% peracetic acid into dentin tubules. STUDY DESIGN: The roots of 44 bovine incisors were cross-sectioned and 5-mm-long fragments were produced from their middle thirds. The specimens were instrumented with ProTaper hand files, stained in crystal violet, then sectioned mesiodistally. The buccal fragments were divided into 4 groups (n = 9) and subjected to 2 consecutive 10-minute immersion periods in one of the following acid solutions combined with 2.5% NaOCl: 17.0% EDTA (group 1), 1.0% citric acid (group 2), and 1.0% peracetic acid (group 3). Nine fragments were immersed in 2.5% NaOCl (group 4). The analysis of the penetration of NaOCl solutions into dentin was performed by measuring the depth of crystal violet stain that was bleached using a steromicroscope under ×50 magnification. Statistical comparisons were carried out by Kruskal-Wallis and Dunn's tests at the 5% significance level. RESULTS: Group 1 showed less penetration into dentin than group 4 (P < .05). No statistically significant differences were observed among groups 2, 3, and 4 (P > .05). CONCLUSIONS: Association of NaOCl with acid solutions did not increase its penetration depth into root dentin.