DOES THE ACTIVATION OF ROOT CANAL DRESSINGS IMPROVE THEIR FILLING QUALITY ON TEETH WITH SIMULATED INTERNAL ROOT RESORPTION?

This study aims to evaluate, by micro-computed tomography, the filling capacity of two root canal dressings (RCD) - Bio-C Temp and Ultracal - after different activation protocols in teeth with simulated internal root resorption. Eighty single-rooted bovine teeth were sectioned in the cervical portion, standardizing the roots at 16 mm. Then, the canals were prepared by the apex-crown technique until instrument #80 using 2mL of 2.5% sodium hypochlorite solution at each instrument change. Afterward, the roots were sectioned longitudinally, and internal root resorptions were simulated using a diamond bur 1016 at 5 mm from the root apex. Hemiroots were joined and fixed with cyanoacrylate, scanned in micro-computed tomography (micro-CT) to assess total canal volume and simulated internal resorption, and then divided by stratified randomization into experimental groups according to RCD and method of activation (n = 10): Ultracal/Syringe; Ultracal/PUI, Ultracal/XP Endo Finisher, Ultracal Easy Clean, Bio-C Temp/Syringe, Bio-C Temp/PUI, Bio-C Temp/XP Endo Finisher and Bio-C/Easy Clean. Another scanning was performed to assess the volume of voids after RCD activation methods. The ANOVA and Tukey tests compared the activation methods. Student's T-test compared the RCDs within each activation method. Initial root canal volume values were similar for all groups (P > 0.05). There was no difference between activation protocols (P > 0.05). Higher volumes of void spaces were observed for Bio-C Temp compared to Ultracal after all activation methods (P < 0.05), except for Easy Clean (P > 0.05). Due to this, it can be concluded that the agitation methods tested for the Bio-C Temp and Ultracal pastes did not improve the filling of bovine teeth with simulated internal root resorption.

DOES THE ACTIVATION OF ROOT CANAL DRESSINGS IMPROVE THEIR FILLING QUALITY ON TEETH WITH SIMULATED INTERNAL ROOT RESORPTION?

Aims: This study aims to evaluate, by micro-computed tomography, the filling capacity of two root canal dressings (RCD) -Bio-C Temp and Ultracal -after different activation protocols in teeth with simulated internal root resorption.Materials and methods: Eighty single-rooted bovine teeth were sectioned in the cervical portion, standardizing the roots at 16 mm. Then, the canals were prepared by the apex-crown technique until instrument #80 using 2mL of 2.5% sodium hypochlorite solution at each instrument change. Afterward, the roots were sectioned longitudinally, and internal root resorptions were simulated using a diamond bur 1016 at 5 mm from the root apex. Hemiroots were joined and fixed with cyanoacrylate, scanned in micro-computed tomography (micro-CT) to assess total canal volume and simulated internal resorption, and then divided by stratified randomization into experimental groups according to RCD and method of activation (n = 10): Ultracal/Syringe; Ultracal/PUI, Ultracal/XP Endo Finisher, Ultracal Easy Clean, Bio-C Temp/Syringe, Bio-C Temp/PUI, Bio-C Temp/XP Endo Finisher and Bio-C/Easy Clean. Another scanning was performed to assess the volume of voids after RCD activation methods. The ANOVA and Tukey tests compared the activation methods. Student's T-test compared the RCDs within each activation method. Initial root canal volume values were similar for all groups (P > 0.05).Results:There was no difference between activation protocols (P > 0.05). Higher volumes of void spaces were observed for Bio-C Temp compared to Ultracal after all activation methods (P < 0.05), except for Easy Clean (P > 0.05).Conclusion:It can be concluded that the agitation methods tested for the Bio-C Temp and Ultracal pastes did not improve the filling of bovine teeth with simulated internal root resorption.

DOES THE ACTIVATION OF ROOT CANAL DRESSINGS IMPROVE THEIR FILLING QUALITY ON TEETH WITH SIMULATED INTERNAL ROOT RESORPTION?

Aims: This study aims to evaluate, by micro-computed tomography, the filling capacity of two root canal dressings (RCD) -Bio-C Temp and Ultracal -after different activation protocols in teeth with simulated internal root resorption.Materials and methods: Eighty single-rooted bovine teeth were sectioned in the cervical portion, standardizing the roots at 16 mm. Then, the canals were prepared by the apex-crown technique until instrument #80 using 2mL of 2.5% sodium hypochlorite solution at each instrument change. Afterward, the roots were sectioned longitudinally, and internal root resorptions were simulated using a diamond bur 1016 at 5 mm from the root apex. Hemiroots were joined and fixed with cyanoacrylate, scanned in micro-computed tomography (micro-CT) to assess total canal volume and simulated internal resorption, and then divided by stratified randomization into experimental groups according to RCD and method of activation (n = 10): Ultracal/Syringe; Ultracal/PUI, Ultracal/XP Endo Finisher, Ultracal Easy Clean, Bio-C Temp/Syringe, Bio-C Temp/PUI, Bio-C Temp/XP Endo Finisher and Bio-C/Easy Clean. Another scanning was performed to assess the volume of voids after RCD activation methods. The ANOVA and Tukey tests compared the activation methods. Student's T-test compared the RCDs within each activation method. Initial root canal volume values were similar for all groups (P > 0.05).Results:There was no difference between activation protocols (P > 0.05). Higher volumes of void spaces were observed for Bio-C Temp compared to Ultracal after all activation methods (P < 0.05), except for Easy Clean (P > 0.05).Conclusion:It can be concluded that the agitation methods tested for the Bio-C Temp and Ultracal pastes did not improve the filling of bovine teeth with simulated internal root resorption

The penetration effect of ultrasound and Er:YAG laser irrigation activation techniques on dentine of infected human root canals / 口腔疾病防治

Objective@#This ex vivo study evaluated the effect of ultrasound and Er:YAG laser irrigation activation techniques on the penetration of sodium hypochlorite solution into infected human root canal dentin, providing a reference for clinical infection control of infected root canals.@*Methods @#Thirty-six cases of infected root canals were collected and randomly divided into three groups according to the irrigation technique: 12 cases in the conventional syringe irrigation (CSI) group, 12 cases in the passive ultrasonic irrigation (PUI) group, 12 cases in the Er:YAG laser and photon-induced photoacoustic streaming (PIPS) group and 36 cases of clean root canals (12 cases in the CSI group, 12 cases in the PUI group, 12 cases in the PIPS group). All of the selected root canals were straight root canals of posterior teeth. After standardizing the root length, all canals were subjected to instrumentation and dynamic irrigation. 2% methylene blue solution was used to visualize the penetration of the irrigant. EXAKT cutting and grinding equipment was used to take transverse sections of 100-150 μm at the coronal, middle and apical thirds of the root canals. The data (maximum penetration depth, average penetration depth, and penetration percentage) were observed under a light microscope to evaluate the effect of dye penetration. @*Results @# With the three irrigation techniques, the maximum penetration depth, average penetration depth and penetration percentage of the infected root canals were significantly lower than those of clean root canals in the full length of the root canal (P<0.05). The penetration percentage, average penetration depth and maximum penetration depth of the PIPS group were significantly higher than those of the CSI group in the coronal, middle and apical thirds of the infected root canal, respectively (P<0.05). There was no significant difference in the maximum penetration depth, average penetration depth or penetration percentage between the PUI and CSI groups (P>0.05). There was also no significant difference in the maximum penetration depth, average penetration depth or penetration percentage between the PIPS and PUI groups (P>0.05). @*Conclusion @# The dentine permeability of infected root canals was weaker than that of clean root canals. Er:YAG laser-assisted irrigation activation technology could significantly improve the penetration of sodium hypochlorite solution into infected dentin, but passive ultrasonic irrigation did not significantly improve the penetration.

In vitro study of different methods in the removal of calcium hydroxide from root canals / 口腔疾病防治

Objective@#To compare the efficacy of different methods in the removal of calcium hydroxide from root canals and to provide a reference for clinical treatment. @*Methods@# A total of 160 extracted single-rooted mandibular premolars were instrumented up to ProTaper Universal F4. The roots were split longitudinally, and standardized groove and depression models were prepared and filled with calcium hydroxide. The samples were randomly divided into 4 groups (n=40) according to different irrigation methods: syringe needle irrigation, passive ultrasonic irrigation, XP-endo finisher (XPF) irrigation, and M3-Max irrigation. Each group was then divided into 2 subgroups (n=20) according to the irrigation protocol: NaOCl and NaOCl+EDTA. Photos of grooves and depressions were taken under a microscope after irrigation, and the residual calcium hydroxide was scored to compare the removal effects of different irritation methods and solutions.@*Results@#In the groove and depression model, when sodium hypochlorite is used as the irrigation fluid, ultrasound irrigation, XPF and M3-Max are better than syringe needle irrigation in removing calcium hydroxide (P < 0.05); when sodium hypochlorite combined with EDTA flushing, the effect of removing calcium hydroxide with ultrasound irrigation, XPF and M3-Max is better than that of syringe needle irrigation (P < 0.05); but there is no statistically significant difference between ultrasound, XPF and M3-Max (P > 0.05); when compared with the use of sodium hypochlorite, the combined use of EDTA irrigation could enhance the effect of ultrasonic irrigation, XPF and M3 Max on the removal of calcium hydroxide (P < 0.05), but there was no significant improvement in the syringe needle irrigation group (P > 0.05). @*Conclusion @#Sodium hypochlorite combined with EDTA can enhance the effect of ultrasonic irrigation, XPF and M3 Max on the removal of calcium hydroxide, and there is no significant difference among these approaches, which are more effective than syringe needle irrigation.

Effect of edta and qmix ultrasonic activation on the reduction of microorganisms and endotoxins in ex vivo human root canals

Abstract The present study aimed to compare the effectiveness of QMiX and 17% EDTA associated to passive ultrasonic irrigation (PUI) or manual agitation (MA) on the reduction of E. faecalis, E. coli and LPS from root canals. Forty single rooted human teeth were randomly divided into four groups (n=10), according to the final irrigation protocol: EDTA+MA, QMiX+MA, EDTA+PUI, QMiX+PUI. Sample collections were obtained from the root canal content immediately before preparation (baseline-S1), after instrumentation (S2), after final irrigation protocol (S3) and 7 days after instrumentation and final irrigation (S4). The antimicrobial effectivity and on endotoxin content were analyzed by culture procedure (CFU/mL) and LAL assay (EU/mL), respectively. The results were statistically analyzed by Kruskal-Wallis and Friedman test (α=5%). QMiX+MA and QMiX+PUI reduced 100% of E. coli and E. faecalis bacteria and also prevented E. faecalisregrowth at S4. EDTA significantly reduced E. coli, but it was not effective in reducing E. faecalis. All protocols reduced EU/mL when compared to S1, however at S4 there was a significant reduction of EU/mL only in the QMiX+MA and QMiX+PUI groups in relation to S3 and S2, respectively. Final irrigation with QMiX associated with MA or PUI had superior antibacterial efficacy compared to EDTA, eliminating 100% of E. coli and E. faecalis strains. In addition, QMiX+PUI reduced 97.61% of the initial content of LPS.

Resumo O presente estudo objetivou comparar a eficácia do QMiX e do EDTA 17% associado à irrigação ultrassônica passiva (PUI) ou agitação manual (MA) na redução de E. faecalis, E. coli e LPS de canais radiculares. Quarenta dentes humanos unirradiculares foram divididos aleatoriamente em quatro grupos (n = 10), de acordo com o protocolo final de irrigação: EDTA+MA, QMiX+MA, EDTA+PUI, QMiX+PUI. Coletas das amostras foram obtidas a partir do conteúdo do canal radicular imediatamente antes do preparo (inicial-S1), após a instrumentação (S2), após o protocolo final de irrigação (S3) e 7 dias após a instrumentação e irrigação final (S4). A eficácia antimicrobiana e o conteúdo de endotoxina foram analisados ​​por procedimento de cultura (UFC/mL) e ensaio LAL (EU/mL), respectivamente. Os resultados foram analisados estatisticamente pelo teste de Kruskal-Wallis e Friedman (α = 5%). QMiX+MA e QMiX+PUI reduziram 100% das bactérias E. coli e E. faecalis e também preveniram a recolonização de E. faecalis em S4. O EDTA reduziu significativamente E. coli, mas não foi eficaz na redução de E. faecalis. Todos os protocolos reduziram EU/mL quando comparados com S1, no entanto, no S4 houve uma redução significativa de EU/mL apenas nos grupos QMiX+MA e QMiX+PUI em relação a S3 e S2, respectivamente. A irrigação final com QMiX associada a MA ou PUI apresentou eficácia antibacteriana superior em relação ao EDTA, eliminando 100% das cepas de E. coli e E. faecalis. Além disso, QMiX+PUI reduziu 97,61% do conteúdo inicial de LPS.

Radiographic and immunohistochemical evaluation of root canal treatment using different irrigation systems

Abstract The aim of this study was to evaluate the radiographic periapical repair and the synthesis of inflammatory mediators after endodontic treatment in a single session, using different irrigation protocols, in teeth with apical periodontitis. Experimental apical periodontitis were induced in dog's teeth randomly assigned into 4 groups: G1 - Irrigation by Negative Apical Pressure (n= 20); G2 - Passive Ultrasonic Irrigation (n= 20), G3 - Positive Pressure Irrigation (n= 20); G4 - apical periodontitis without treatment (n= 20). After 180 days, the animals were euthanized, the tissues removed and submitted to histotechnical processing for immunohistochemical analysis of osteopontin (OPN), tumor necrosis factor-a (TNF-a) and interleukin 1-a (IL-1a). Radiographic analysis was performed using the Periapical Index (PAI), obtained prior to and 180 days following endodontic treatment. Data were analyzed using Wilcoxon signed-rank test, Fisher's Exact test or Kruskal-Wallis test and Dunn's post-test (a = 5%). Radiographically, after endodontic treatment, apical periodontitis persisted in 35% of G1 specimens, 40% of G2 and 40% of G3 (p>0.05), although a PAI reduction was observed (p<0.05). By immunohistochemical evaluation, endodontic treatment resulted in lower synthesis of TNF-a and OPN in periapical region, compared to apical periodontitis without treatment (p<0.05). Production of IL-1 was not modulated by endodontic treatment (p>0.05). Periapical healing was observed in approximately 60% of the cases after endodontic treatment performed in a single session with lower synthesis of TNF-a and OPN in the periapical region, regardless of the irrigation protocol used.

Resumo O objetivo deste estudo foi avaliar o reparo periapical e a síntese de mediadores inflamatórios após tratamento endodôntico em dentes de cães com lesão periapical, em sessão única, utilizando diferentes protocolos de irrigação. Lesões periapicais foram induzidas experimentalmente em dentes de cães e aleatoriamente divididas em 4 grupos: G1 - Irrigação por Pressão Apical Negativa (n = 20); G2 - Irrigação Ultrassônica Passiva (n = 20), G3 - Irrigação por Pressão Positiva (n = 20); G4 - Lesão periapical sem tratamento (n = 20). Após 180 dias, os animais foram eutanasiados, as peças removidas e submetidas ao processamento histotécnico para análise imunohistoquímica para osteopontina (OPN), fator de necrose tumoral-a (TNF-a) e interleucina 1-a (IL-1a). A análise radiográfica do reparo das lesões periapicais foi realizada por meio do Índice Periapical, obtido antes e 180 dias após o tratamento endodôntico. Os resultados obtidos foram submetidos à análise estatística por meio dos testes de sinais de Wilcoxon, Exato de Fisher ou Kruskal-Wallis seguido pelo pós-teste de Dunn (a = 5%). O exame radiográfico após o tratamento endodôntico, mostrou a persistência de áreas radiolúcidas periapicais e descontinuidade da lâmina dura em 35% dos espécimes do G1, 40% do G2 e 40% do G3, embora uma redução no PAI tenha sido observada (p<0,05). Pela análise imuno-histoquímica, o tratamento endodôntico resultou na menor síntese de TNF-a e de OPN na região periapical, comparativamente à lesão periapical sem tratamento (p<0,05). A produção de IL-1a não foi modulada pelo tratamento endodôntico (p>0,05). Reparo da lesão periapical foi observado em cerca de 60% dos casos após tratamento endodôntico realizado em sessão única e menor síntese de TNF-a e de OPN na região periapical, independente do protocolo de irrigação utilizado.

Avaliação de protocolos de irrigação ultrassônica passiva na remoção de detritos do canal radicular / Evaluation of passive ultrasonic irrigation protocols in the removal of root canal debris

Introdução: O objetivo deste estudo foi avaliar a eficácia de diferentes protocolos de Irrigação Ultrassônica Passiva (PUI) por meio de microscopia eletrônica de varredura (MEV). Métodos: Seis cavidades foram confeccionadas ao longo da seção vestibular de 20 canais radiculares de pré-molares inferiores humanos e preenchidas com detritos. 10 grupos foram criados de acordo com o protocolo final de irrigação: Grupo 1- controle positivo (sem detritos); Grupo 2- controle negativo (com detritos); Grupo 3 - irrigação convencional com hipoclorito de sódio a 2,5% (NaOCl); Grupo 4 - irrigação convencional com 17% de ácido etilenodiaminotetracético (EDTA) seguido de NaOCl; Grupo 5- PUI com 3 ciclos de 20 segundos (NaOCl-NaOCl-NaOCl); Grupo 6- PUI com 3 ciclos de 20 segundos (NaOCl-EDTA-NaOCl); Grupo 7- PUI com um ciclo de 60 segundos (NaOCl); Grupo 8 - PUI com ciclo de 180 segundos (NaOCl); Grupo 9 - PUI com 2 ciclos de 60 segundos (EDTA-NaOCl); Grupo 10 - PUI com 2 ciclos de 60 segundos (NaOCl-EDTA). Os espécimes foram observados em MEV para a análise da remoção dos detritos (scores 1 a 5) e exposição dos túbulos dentinários (score 1 ou 2) dentro das cavidades. O teste de Kruskal-Wallis foi realizado para a análise estatística, com significância de 5%. Resultados: Os grupos PUI apresentaram melhores resultados na limpeza de detritos do que os grupos de irrigação convencionais nas cavidades 1, 2 e 3. As cavidades 4, 5 e 6 foram limpas em todos os grupos experimentais. Em relação à exposição dos túbulos dentinários, os grupos PUI foram capazes de alcançar um resultado melhor do que os grupos de irrigação convencional. Conclusões: A PUI mostrou-se mais eficaz na remoção de detritos do que a irrigação convencional nas cavidades localizadas na região apical do canal radicular, e os grupos PUI promoveram maior exposição dos túbulos dentinários independentemente do uso de EDTA como agente quelante para tecidos inorgânicos(AU)

Introduction: The aim of this study was to evaluate the effectiveness of different Passive Ultrasonic Irrigation (PUI) protocols by means of scanning electron microscopy. Methods: Six hemispherical cavities were made along the buccal section of 20 root canals of human lower premolars and filled with debris. 10 groups was created according to the final irrigation protocol: Group 1- positive control (no debris); Group 2- negative control (with debris); Group 3- conventional irrigation with 2.5% sodium hypochlorite (NaOCl); Group 4- conventional irrigation with 17% ethylenediamine tetracetic acid (EDTA) followed by NaOCl; Group 5- PUI with 3 cycles of 20 seconds (NaOCl-NaOCl-NaOCl); Group 6- PUI with 3 cycles of 20 seconds (NaOCl-EDTANaOCl); Group 7- PUI with a 60 seconds cycle (NaOCl); Group 8- PUI with a 180 seconds cycle (NaOCl); Group 9- PUI with 2 cycles of 60 seconds (EDTA-NaOCl); Group 10- PUI with 2 cycles of 60 seconds (NaOCl-EDTA). Scores were given for the analysis of debris removal in SEM, as well as for the exposure of dentinal tubules within the cavities. Kruskal-Wallis test was performed for statistical analysis. Results: The PUI groups presented better results in cleaning of debris than the conventional irrigation groups in cavities 1, 2 and 3. Cavities 4, 5 and 6 were well cleansed in all experimental groups. Regarding the exposure of the dentinal tubules, the PUI groups were able to achieve a better result than the conventional irrigation groups. Conclusions: Passive ultrasonic irrigation proved to be more effective in the removal of debris than conventional irrigation in the cavities located in the apical region of the root canal, and the PUI groups promoted greater exposure of the dentinal tubules independently of the use of EDTA as a chelating agent for inorganic tissues(AU)

Efeito da irrigação ultrassônica e da medicação intracanal com hidróxido de cálcio na quantidade e no metabolismo de bactérias que persistiram após o preparo dos canais radiculares de dentes com periodontite apical / Effect of ultrasonic irrigation and calcium hydroxide intracanal medication on the levels and metabolism of bacteria that persisted after root canal preparation of teeth with apical periodontitis

Estudos moleculares ressaltam as limitações do protocolo endodôntico tradicional em eliminar bactérias dos canais radiculares. Apesar do preparo químico-cirúrgico (PQC) promover uma drástica redução bacteriana, muitos canais continuam infectados após essa etapa do tratamento. Dessa forma, estudos apontam para a necessidade de complementação técnica para potencializar a desinfecção dos canais radiculares após o PQC. Assim, o objetivo deste estudo clínico foi avaliar, por métodos moleculares baseados em DNA e RNA, o efeito dos métodos complementares ao preparo na desinfecção dos canais radiculares. Coletas microbiológicas dos canais de 20 dentes unirradiculares com periodontite apical foram feitas em diferentes etapas do tratamento endodôntico: previamente ao preparo (S1); após o PQC realizado com sistema Reciproc associado à irrigação com NaOCl 2,5% (S2); após a irrigação ultrassônica passiva, denominada PUI (S3); e após a medicação intracanal à base de hidróxido de cálcio (S4). As amostras foram submetidas à extração de DNA e RNA. O RNA foi submetido à reação de transcrição reversa (RT-PCR) para confecção da fita dupla de DNA complementar (cDNA). DNA e cDNA foram submetidos a reações de qPCR, com iniciadores universais para a região 16S rRNA do domínio Bacteria. A atividade metabólica das bactérias foi verificada através da relação entre os níveis de rRNA e rDNA determinados pelos ensaios de qPCR. Os dados foram analisados pelo teste de Wilcoxon para amostras pareadas (p < 0,05). As amostras S1 dos 20 casos apresentaram altos níveis de rDNA (mediana: 1,25 x 105, intervalo 1,83 x 104 - 9,2 x 106) e rRNA bacteriano (mediana: 5,47 x 105, intervalo 7,8 x 104 - 5,95 x 107). Dezessete canais (85%) apresentaram reações qPCR positivas para rDNA nas amostras pós-preparo (S2). A redução de rDNA após o preparo foi estatisticamente significativa (p = 0,0003), com mediana de 2,5 x 104 (intervalo 2,26 x 103 - 9,52 x 104) cópias de rDNA em S2. Por sua vez, os níveis de rRNA (mediana: 7,84 x 104, intervalo 2,91 x 103 - 1,09 x 106) foram maiores que os níveis de rDNA (p = 0,01), sugerindo que essas bactérias estavam metabolicamente ativas em S2. Após a PUI, o número de amostras S3 com resultados positivos para rDNA caiu para 12, representando uma redução significativa em relação às amostras S2 (p = 0,008). Além disso, a PUI promoveu uma redução significativa dos níveis de rDNA (mediana 2,94 x 103, intervalo 2,70 x 103 - 1,09 x 105) em relação à amostras S2 (p = 0,01). Na análise baseada em rRNA, os níveis em S3 (mediana: 03 x 104, intervalo 1,82 x 103 - 1,39 x 105) não apresentaram diferença significativa em comparação aos níveis de rDNA (p = 0,07), sugerindo que houve uma redução do metabolismo bacteriano após a PUI. Em S4, o número de casos positivos para rDNA bacteriano (n = 13) e os níveis de rDNA (mediana: 3,73 x 104, intervalo 1,98 x 103 - 3,21 x 105) foram ligeiramente maiores quando comparados aos valores das amostras S3, porém sem diferenças significativas. Entretanto, os níveis de rRNA (mediana: 1,08 x 105, intervalo 3,41 x 103 - 1,60 x 106) foram maiores que os de rDNA (p = 0,02) nas amostras S4, sugerindo que as bactérias retomaram sua atividade metabólica apesar do uso da medicação intracanal. Portanto, foi possível concluir que a irrigação ultrassônica passiva contribuiu para a desinfecção dos canais radiculares, promovendo uma redução do número e do metabolismo de bactérias. Por outro lado, as bactérias persistiram ativas nos canais radiculares após o uso do hidróxido de cálcio como medicação intracanal em dentes com periodontite apical.

A comparison of the effect of different nickel-titanium instruments combined with ultrasonic irrigation on root canal preparation / 口腔疾病防治

Objective @#To compare the removal efficiency and the amounts of apically extruded debris using Twisted File (TF), Twisted File Adaptive (TFA), ProTaper, and ProTaper Next combined with ultrasonic irrigation and to provide an experimental basis for the selection of root canal instrumentation in the clinic.@*Methods@#Forty mandibular premolars were randomly divided into 4 groups (n=10 teeth per group). The canals were cut using a Twisted File, Twisted File Adaptive, ProTaper, or ProTaper Next nickel-titanium instrument. The canals were irrigated with ultrasonic irrigation. The apically extruded debris were collected in preweighted Eppendorf tubes. The amount of dental tissue removed and extruded debris were assessed with an electronic balance.@*Results @#The amount of tooth tissue removed in groups A, B, C and D was 20.5 ± 2.0 mg, 17.8 ± 4.2 mg, 20.8 ± 3.9 mg and 16.5 ± 2.2 mg, respectively. Combined with ultrasonic irrigation, the Twisted File and ProTaper had a better removal efficiency than the ProTaper Next(P < 0.05). There was no significant difference in the amount of extruded debris (χ2=4.057, P=0.255) among four groups.@*Conclusion@#The Twisted File and ProTaper had a better removal efficiency than the ProTaper Next combined with ultrasonic irrigation. There was no significant difference in the amount of extruded debris using four Nickel-titanium instruments combined with ultrasonic irrigation.

In vitro evaluation of the effectiveness of XP-endo Finisher file on smear layer removal after root canal instrumentation / 华西口腔医学杂志

OBJECTIVE@#This study aimed to evaluate the effectiveness of XP-endo Finisher (XPF) file and passive ultrasonic irrigation (PUI) in the smear layer removal of the root canal.@*METHODS@#A total of 60 human single-rooted premolars were selected and decoronated to standardize their canal length to 16 mm. Tooth samples were prepared using a S3 rotary system to prepare root canal with the file size of 3S and then randomly divided into 6 groups according to the final irrigation protocol, as follows: XPF 3 mL of 3% NaOCl for 1 min (group A); XPF 3 mL of 3% NaOCl for 1 min, followed by 4 mL of 17% ethylene diamine tetraacetic acid (EDTA) for 1 min (group B); PUI of 3 mL of 3% NaOCl for 1 min (group C); PUI of 3 mL of 3% NaOCl for 1 min, followed by 4 mL of 17% EDTA for 1 min (group D); 3 mL of 3% NaOCl for 1 min by using a syringe and a 30 G side-vented needle (group E); and 3 mL of 3% NaOCl for 1 min by using a syringe and a 30 G side-vented needle, followed by 4 mL of 17% EDTA for 1 min (group F). After the completion of the root canal preparation, the teeth were split into two longitudinally. The mean numbers of the visible open dentinal tubules in the apical and middle thirds of the root canals were evaluated via scanning electron microscope.@*RESULTS@#The whole surfaces of the root canals in groups A, C, and E were covered by a smear layer. Groups A and C possessed significantly higher number of visible open dentinal tubules than in group E (P0.05). The apical third of the samples in groups B and D and in the middle thirds of canals in group F exhibited a small amount of smear layer, and the dentinal tubules were open or semi-open. The root canal surfaces in the apical third of the samples in group F were covered by a smear layer, and the dentinal tubules were sealed or semisealed. The smear layers in the middle third of the samples in groups B and D were removed, and the dentinal tubules were more visibly open than those of the four other groups (P0.05).@*CONCLUSIONS@#The difference between XPF and PUI in terms of the smear layer removal of the root canals was insignificant. Hence, XPF, as a new irrigation agitation technique, can aid in improving smear layer removal.

Comparación de tres técnicas de irrigación en la remoción de hidróxido de calcio / Comparison of three irrigation techniques in the removal of calcium hydroxide

Objetivos: Comparar la eficacia de tres de protocolos de irrigación en la remoción de hidróxido de calcio (Ca(OH)2) Material y Métodos: Mediante un diseño de estudio comparativo in vitro, se instrumentaron 106 conductos radiculares de incisivos bovinos hasta una lima de diámetro 60, la raíces se fraccionaron en dos mitades siguiendo el eje mayor del diente y se creó un surco estandarizado a 2 mm del agujero apical que fue rellenado con una pasta de hidróxido de calcio, luego se reensamblaron las mitades, se incubaron por 7 días y se realizaron los protocolos de irrigación: ultrasónica pasiva (PUI), sónica con Endo Activator (EA) y activación dinámica manual (MDA), donde se usó como irrigante hipoclorito de sodio (NaOCl) al 5%. Se utilizó un control negativo y positivo. Con un estereomicroscópio se observó la cantidad de residuo, las imágenes se examinaron y se les asignó una puntación de acuerdo a la escala de van der Sluis, finalmente los datos se analizaron con la prueba estadística del Chi Cuadrado. Resultados: Los porcentajes de eficacia para los protocolos de irrigación PUI, EA y MDA fueron del 87,5%; 46,9% y 28,1% respectivamente, la técnica PUI fue superior a EA y MDA y obtuvo diferencias estadísticamente significativas (p<0,001). Conclusiones: PUI fue el método más efectivo en la remoción de Ca(OH)2 de los surcos simulados en los conductos radiculares.

Objectives: To compare efficacy of three irrigation protocols in the removal of calcium hydroxide (Ca(OH)2). Materials and Methods: Through an in vitro comparative study design, 106 root canals of bovine incisors were instrumented up to a file of diameter 60, the roots were fractioned into two halves following the major axis of the tooth and a standardized groove was created 2mm from the apical foramen that was filled with a paste of calcium hydroxide, then the halves were reassembled, incubated for 7 days and the irrigation protocols were carried out: passive ultrasonic (PUI), sonic with Endo Activator (EA) and manual dynamic activation (MDA), where 5% sodium hypochlorite (NaOCl) was used as irrigant. A negative and positive control was used. With a stereomicroscope the amount of residue was observed, the images were examined and assigned a score according to the van der Sluis scale, finally the data were analyzed with the statistical test of Chi-square. Results: The percentages of efficacy for PUI, EA and MDA irrigation protocols were 87.5%; 46.9% and 28.1% respectively, the PUI technique was superior to EA and MDA and obtained statistically significant differences (p <0.001). Conclusions: PUI was the most effective method in the removal of Ca(OH)2 from the simulated grooves in the root canals.

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.

Comparison of different final irrigant agitation techniques for the removal of Enterococcus faecalis biofilms from root canals: an in vitro study / Comparação de diferentes técnicas finais de agitação de irrigantes para a remoção de biofilmes de Enterococcus faecalis de canais radiculares: estudo in vitro

Objective: The aim of this in vitro study was to compare the effectiveness of different final irrigant agitation techniques in the removal of Enterococcus faecalis biofilms from root canals. Material and Methods: In total, the root canals of 85 extracted single-rooted human maxillary incisors teeth were prepared using the Revo-S system to a 40/06 size. The apical foramen of each tooth was sealed by light-cured resin composite material to obstruct bacterial leakage. The specimens were sterilized in an autoclave at 121°C for 15 min and stored until further use. All teeth except five (negative control group) were inoculated with Enterococcus faecalis and incubated in a CO2 chamber at 37°C for 7 days; the trypticase soy broth was changed every 2 days. For the determination of possible biofilm formation, five of the 80 teeth were randomly selected as a positive control group; one tooth of positive control group was analysed for biofilm development by scanning electron microscope (SEM) and these teeth received no final irrigant agitation procedure. Then, the remaining 75 teeth were randomly divided into five test groups (n=15 each) and were sequentially irrigated with 5% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid and 5% NaOCl. Following each irrigant application, different final irrigant agitation techniques were introduced for 60 s (3×20-s sessions). Group 1 received manual­ dynamic agitation, group 2 received passive ultrasonic agitation (PUI), group 3 received EndoActivator agitation, group 4 received photoninitiated photoacoustic streaming (PIPS) with the Er:YAG laser and group 5 received conventional syringe irrigation. Colony-forming units (CFUs) were counted in samples from the positive control and test groups. Data were analysed using Kruskal­ Wallis and post-hoc Mann­Whitney U multiple comparison tests. Results: E. faecalis elimination was significantly better in the experimental groups than in the positive control groups (p < 0.001). Manual­dynamic agitation and conventional syringe irrigation, with no significant differences between the two groups. Conclusion: Essentially, CFU reduction was significantly greater in the PUI, EndoActivator and PIPS groups than in the manual­dynamic agitation and conventional syringe irrigation groups (p <0.001) , with no significant differences among the former three groups. (AU)

Objetivo: O objetivo deste estudo in vitro foi comparar a eficácia de diferentes técnicas finais de agitação de irrigantes na remoção de biofilmes de Enterococcus faecalis de canais radiculares. Material e Métodos: No total, os canais radiculares de 85 dentes incisivos superiores unirradiculares humanos extraídos foram preparados usando o sistema Revo-S para um tamanho 40/06. O forame apical de cada dente foi selado por material compósito de resina fotopolimerizável para obstruir o vazamento bacteriano. Os espécimes foram esterilizados em autoclave a 121 ° C por 15 min e armazenados até uso posterior. Todos os dentes, exceto cinco (grupo controle negativo), foram inoculados com Enterococcus faecalis e incubados em câmara de CO2 a 37 ° C por 7 dias; o caldo de soja tripticase foi trocado a cada 2 dias. Para a determinação da possível formação de biofilme, cinco dos 80 dentes foram selecionados aleatoriamente como grupo controle positivo; um dos dentes do grupo controle positivo foi analisado para o desenvolvimento do biofilme por microscopia eletrônica de varredura (MEV) e estes dentes não receberam nenhum procedimento final de agitação irrigante. Em seguida, os 75 dentes restantes foram aleatoriamente divididos em cinco gruposteste (n = 15 cada) e irrigados sequencialmente com hipoclorito de sódio a 5% (NaOCl), ácido etilenodiaminotetracético a 17% e NaOCl a 5%. Após cada aplicação de irrigantes, diferentes técnicas finais de agitação foram introduzidas por 60 s (3 x 20 s sessões). Grupo 1 recebeu agitação manual-dinâmica, grupo 2 recebeu agitação ultra-sônica passiva (PUI), grupo 3 recebeu agitação EndoActivator, grupo 4 recebeu fotoacústica iniciada por fóton (PIPS) com o laser Er: YAG e grupo 5 recebeu irrigação convencional com seringa. As unidades formadoras de colônia (CFUs) foram contadas em amostras dos grupos controle positivo e teste. Os dados foram analisados utilizando testes de comparação múltipla Kruskal-Wallis e post-hoc Mann-Whitney U. Resultados: A eliminação de E. faecalis foi significativamente melhor nos grupos experimentais do que nos grupos de controle positivo (p < 0,001). Agitação manual-dinâmica e irrigação com seringa convencional, sem diferenças significativas entre os dois grupos. Conclusão: Essencialmente, a redução de UFC foi significativamente maior nos grupos PUI, EndoActivator e PIPS do que nos grupos de agitação manual-dinâmica e de seringa convencional (p < 0,001), sem diferenças significativas entre os três grupos anteriores (AU)

The efficacy of ultrasonic irrigation technique on debris removal during root canal treatment

PURPOSE: The purpose of this study was comparing the efficacy of passive irrigation (PI) and passive ultrasonic irrigation (PUI) for ability to remove debriment of canals. MATERIALS AND METHODS: Mandibular premolars were decoronated and standardized to 16 mm length. After root canal enlargement and half separating longitudinally, standardized groove of 4 mm length, 0.2 mm width and 0.5 mm depth were formed on the dentin wall of one half. Three depressions in the canal wall of the opposite half, 0.3 mm in diameter and 0.5 mm in depth, were formed. After each groove and depression was filled with dentin debris, two sections of each half were reassembled using impression putty material. In group 1 the canals were irrigated with 2.5% NaOCl by PI. In group 2 the canals were irrigated with 2.5% NaOCl by PUI. Before and after root canal irrigation, the root canal wall of the section was taken with a microscope and a digital camera as images. The amount of dentin debris remaining in grooves and depressions was assessed using a scoring system. RESULTS: There was no significant difference between PI and PUI except for the middle 1/3 of the root canal (P = 0.004). CONCLUSION: At the middle 1/3 of the root canal, PUI removed more dentine debris than PI. But the removal efficiency of dentin debris is not significantly different between the PUI and PI at the apical area of root canal in mandibular premolars.

Evaluation of Different Passive Ultrasonic Irrigation Protocols on the Removal of Dentinal Debris from Artificial Grooves

Abstract The aim of this study was to evaluate the influence of different passive ultrasonic irrigation protocols on the removal of debris in artificially created grooves in the cervical, middle and apical root thirds. Forty extracted bovine incisor roots were instrumented to 1 mm of the root apex with a R50 Reciproc instrument and irrigated with 2.5% sodium hypochlorite. The roots were then inserted in a muffle and cleaved into two hemisections. Grooves (3-mm long) were done at 2, 7 and 12 mm from the root apex in one hemisection and filled with dentinal debris. The hemisections were regrouped into the muffle and divided into 4 groups (n=10) according to the final irrigation protocol: Control group: 3x20 s using a #30 gauge needle without agitation of the irrigating solution; Group PUI-s (static passive ultrasonic irrigation): 3x20 s of passive ultrasonic irrigation with the tip of the insert maintained static on the apical third; Group PUI-t (passive ultrasonic irrigation per third): 20 s of PUI in each third; Group PUI-d (passive dynamic ultrasonic irrigation): 3x20 s of PUI dynamically moving the insert in the whole extent of the root canal. In all groups, was used a total of 6 mL of 2.5% sodium hypochlorite as irrigant. After these procedures, the grooves were analyzed with a stereomicroscope and assigned scores as regards removal of the debris. The data were analyzed statistically (a=0.05). The results showed a better cleaning in all the groups where the irrigating solution was agitated with ultrasonic device than in the control group (p<0.05). In the apical third, the PUI-d and PUI-s showed similar performance (p>0.05) and a better cleanness than PUI-t (p<0.05). The dynamic and static methods of agitation of the irrigating solution provided more effective cleaning. PUI-d provided the most completely clean grooves suggesting that its use is the most adequate in cases of teeth with complex canal anatomy.

Resumo O objetivo deste estudo foi avaliar a influência de diferentes protocolos de irrigação ultrassônica passiva na remoção de detritos em sulcos artificialmente criados nos terços radiculares cervical, médio e apical. Quarenta raízes de incisivos bovinos extraídos foram instrumentadas a 1 mm do ápice radicular com um instrumento R50 Reciproc e irrigadas com hipoclorito de sódio a 2,5%. As raízes foram então inseridas numa mufla e clivadas em duas hemisecções. Sulcos (3 mm de comprimento) foram feitos a 2, 7 e 12 mm do ápice radicular em uma hemisecção e preenchidos com detritos dentinários. As hemisecções foram reagrupadas na mufla e divididas em 4 grupos (n = 10) de acordo com o protocolo de irrigação final: Grupo controle: 3x20 s usando agulha de calibre #30 sem agitação da solução irrigadora; Grupo PUI-s (static passive ultrasonic irrigation): 3x20 s de irrigação ultra-sônica passiva com a ponta do inserto mantida estática no terço apical; Grupo PUI-t (Irrigação ultrassônica passiva por terço): 20 s de PUI em cada terço; Grupo PUI-d (Irrigação ultrassônica dinâmica): 3x20 s de PUI movendo dinamicamente o inserto em toda extensão do canal radicular. Em todos os grupos, foi utilizado um total de 6 mL de hipoclorito de sódio a 2,5% como irrigante. Após estes procedimentos, os sulcos foram analisadas com um estereomicroscópio e pontuações foram atribuídas quanto à remoção dos detritos. Os dados foram analisados estatisticamente (a=0.05). Os resultados mostraram uma melhor limpeza em todos os grupos onde a solução de irrigação foi agitada com dispositivo ultrassônico do que no grupo controle (p<0,05). No terço apical, o PUI-d e o PUI-s apresentaram performance semelhantes (p>0,05) e melhor limpeza do que o PUI-t (p<0,05). Os métodos dinâmico e estático de agitação da solução de irrigação proporcionaram uma limpeza mais eficaz. O PUID promoveu os sulcos mais completamente limpos sugerindo que seu uso é o mais adequado em casos de dentes com anatomia de canal complexa.

Endodontic Management of Variants of C-Shaped Canal: Case Series

A thorough knowledge of the root canal morphology is required for successful endodontic therapy. One of the most important anatomic variations is the C-shaped configuration of the root canal system. The presence of high incidence of transverse anastomoses, lateral canals, and apical deltas makes it difficult to clean and seal the root canal system in these teeth and may complicate endodontic interventions. Meticulous mechanical and chemical debridement of the canal space with additional efforts is essential for complete elimination of pulpal pathology in the anatomical irregularities. Obturation of the canal space also requires special attention as obtaining a three dimensional fill of a C-shaped canal may prove to be a problem due to the various intricacies present within the root canal system. Hence, this case series presents various types of C-shaped canal morphologies of mandibular second molars and their management.

Influência da agitação do hipoclorito de sódio como protocolo de irrigação final quanto à atividade antibacteriana no sistema de canais radiculares / Influence of sodium hypochlorite agitation as a final irrigation protocol on antibacterial activity in the root canal system

Diferentes manobras para promover agitação do hipoclorito de sódio têm sido propostas para incrementar a desinfecção do sistema de canais radiculares (SCR). O objetivo deste trabalho foi comparar, ex vivo, diferentes formas de agitação do NaOCl usado na irrigação final do SCR, avaliando a mais eficaz na redução de UFC/ml, a partir de biofilme de Enterococcus faecalis. Oitenta e cinco incisivos inferiores humanos extraídos, com canais ovais e obtidos do banco de dentes da UERJ foram acessados, contaminados com uma suspensão de E. faecalis (ATCC 29212) e incubados por 30 dias possibilitando crescimento bacteriano em biofilme. Os espécimes foram preparados com o instrumento Primary (25/08) do sistema Wave One TM. Foram formados cinco grupos contendo 15 dentes cada um, que foram irrigados com hipoclorito de sódio a 2,5% e, posteriormente, submetidos à agitação do irrigante como protocolo de irrigação final com o auxílio de diferentes instrumentos/ equipamentos, como a seguir: o EndoActivator ® (EA), o Easy Clean® (EC), a espiral de Lentulo (EL), a lima manual tipo K número 10 (LM) e o inserto ultrassônico Irrisonic - E1 (US). Foi formado o grupo controle positivo (n=5) o qual foi contaminado, sem a realização de nenhum procedimento. Foi formado também o grupo controle negativo (n=5) que não foi contaminado, mas seus espécimes foram irrigados com o NaOCl e submetidos a cada um dos protocolos de agitação da substância química auxiliar. As amostras microbiológicas foram coletadas usando cone de papel estéril antes da instrumentação (S1), após a instrumentação (S2) e após o protocolo final de irrigação (S3). Tais cones foram transferidos para tubos contendo meio BHI e incubados durante 48 horas. O crescimento bacteriano foi contado em unidades formadoras de colônia (UFC/ml). Os resultados foram submetidos aos testes Shapiro-Wilks, Wilcoxon e Kruskall-Wallis, para análise estatística ( P< 0.05) e demostraram que não houve diferença estatística significativa entre os grupos EA e EC, o grupo US quando comparado aos grupos EL e LM, foi significantemente mais eficiente na redução bacteriana. De acordo com os resultados do presente estudo, é possível afirmar que a agitação do NaOCl tem influência na atividade antibacteriana no SCR, e que o uso de ultrassom é mais eficiente quando comparado ao uso da espiral de lentulo e da lima manual.

Different maneuvers to promote agitation of sodium hypochlorite have been proposed to increase the disinfection of the root canal system. The objective of this study was to compare, ex vivo, different forms of agitation of chemical substance used in irrigation of the root canal system, evaluating the most effective in reducing or eliminating biofilms of Enterococcus faecalis. Eighty-five human mandibular incisors extracted with oval shape and obtained from UERJ teeth bank were accessed, contaminated with a suspension of E. faecalis (ATCC 29212) and incubated for 30 days allowing bacterial growth in biofilms. The specimens were prepared with the instrument Primary (25 / 0.08) Wave One TM system. Five groups were formed containing 15 teeth each, which were irrigated with sodium hypochlorite to 2.5% and then subjected to agitation of the irrigator as the final irrigation protocol with the help of different instruments / equipment, as follows: the EndoActivator ® (EA), Easy Clean® (EC), the Lentulo spiral (EL), the manual K file number 10 (LM) and the ultrasonic insert Irrisonic -E1 (US). The positive control group was formed (n=5), which was contaminated, without performing any procedure. It has also formed the negative control group containing (n=5), which was not infected but was irrigated with NaOCl and subjected to each of the agitation protocols of the irrigator. Microbiological samples were collected using sterile paper points before instrumentation (S1) after instrumentation (S2) and after the end of the irrigation protocol (S3). These points were transferred to Eppendorf containing BHI and incubated for 48 hours. Bacterial growth was counted in colony forming units (CFU / ml). The results were submitted to the Shapiro-Wilks test, Wilcoxon and Kruskal-Wallis test for statistical analysis and demonstrated a significant difference between the groups. US group compared to EL and LM groups was significantly more efficient in bacterial reduction. According to the results of this study it is clear that the agitation of NaOCl influences the antibacterial activity in the root canal system and that the use of ultrasonic is more efficient when compared to the use of lentullo and manual file.

Effect of Passive Ultrasonic Irrigation on Enterococcus faecalis from Root Canals: An Ex Vivo Study

Endodontic irrigation aims to clean and disinfect the root canal system. Passive ultrasonic irrigation (PUI) is based on the use of an ultrasound-activated instrument into the root canal filled with irrigant. The aim of this study was to evaluate, ex vivo, the effectiveness of PUI in eliminating Enterococcus faecalis from root canals. Seventy-five extracted human single-root teeth were used. After root canal preparation, specimens were inoculated with E. faecalis and incubated at 37 °C for 21 days. Specimens were distributed into five groups (n=15), according to the irrigation method: PUI + saline solution (PUI/SS); PUI + 1% NaOCl (PUI/NaOCl); conventional needle irrigation (CNI) + saline solution (CNI/SS); CNI + 1% NaOCl (CNI/NaOCl); No irrigation (control). Microbiological samples were collected at three time points: initial (21 days after inoculation), post-irrigation (immediately after irrigation), and final (7 days after irrigation). Data were obtained in CFU mL^-1 and subjected to analysis by ANOVA and Tukey's tests at 5% significance level. The post-irrigation samples did not demonstrate statistical difference between PUI/SS and CNI/SS nor between PUI/NaOCl and CNI/NaOCl (p>0.05), but PUI/NaOCl and CNI/NaOCl had lower CFU mL^-1 number than the other groups (p>0.05). Statistically significant difference was observed between the initial and post-irrigation samples and between the post-irrigation and final samples (p<0.05) in all groups, except in the control. The final samples of all groups presented bacterial counts similar to the initial samples. PUI or CNI with 1% NaOCl contribute to disinfection, but are unable to eradicate E. faecalis from the root canal system.

A irrigação endodôntica visa à limpeza e desinfecção do sistema de canais radiculares. A irrigação ultrassônica passiva (IUP) baseia-se na utilização de um instrumento ultrassônico ativado no interior do canal radicular preenchido com a solução irrigadora. O objetivo deste estudo foi avaliar, ex vivo, a eficácia da IUP na eliminação de Enterococcus faecalis dos canais radiculares. Foram usados 75 dentes humanos unirradiculares extraídos. Após o preparo biomecânico dos canais radiculares, foram inoculados com E. faecalis e incubados a 37 °C por 21 dias. Os espécimes foram distribuídos em cinco grupos (n=15), de acordo com o método de irrigação: IUP + solução salina (IUP/SS); IUP + NaOCl a 1% (IUP/NaOCl); irrigação manual convencional (IMC) + solução salina (IMC/sol); IMC + NaOCl a 1% (IMC/NaOCl); Sem irrigação (controle). Foram realizadas três coletas microbiológicas: inicial (21 dias após a inoculação), pós-irrigação (imediatamente após a irrigação), e final (7 dias após a irrigação). Os dados foram obtidos em UFC mL^-1 e submetidos aos testes de ANOVA e Tukey. A coleta pós-irrigação não demonstrou diferença estatisticamente significante entre IUP/SS e IMC/SS nem entre IUP/NaOCl e IMC/NaOCl (p>0,05), mas IUP/NaOCl e IMC/NaOCl apresentaram menor número de UFC mL^-1 comparado aos outros grupos (p>0,05). Diferença estatisticamente significante foi observada entre as coletas iniciais e pós-irrigação e entre a pós-irrigação e a coleta final (p<0,05) em todos os grupos, exceto no controle. Na coleta final, todos os grupos apresentaram contagem bacteriana similar à coleta inicial. IUP ou IMC com NaOCl a 1% contribuem para a desinfecção, mas não eliminam E. faecalis do sistema de canais radiculares.

Passive ultrasonic irrigation in calcium hydroxide removal from root canals: a sem/ eds analysis

AIM: The aim of this study was to evaluate the efficacy of different lengths of time of passive ultrasonic irrigation (PUI) in removing calcium hydroxide (CH) paste from root canal, using scanning electron microscopy and energy dispersive spectrometry (SEM/EDS). MATERIAL AND METHODS: Fifty-four human premolars were used. After coronal access, a size #15 K-file was used to obtain apical patency. Root canal preparation was performed using WaveOne 40.08 instruments. CH paste was placed into the root canal. Specimens were stored in a humid environment, and after seven days, they were divided into five groups (n=12) according to the irrigation protocols: Manual­ a size #40 K-file; PUI/1­ 1 min; PUI/2­ 2 min; PUI/3­ 3 min; and Control­ without CH paste. An elementary chemical microanalysis (SEM/EDS) was performed to quantify the presence of calcium on the dentinal walls. RESULTS: The percentage of calcium was higher in all experimental groups when compared to the control group (P < 0.05); but no differences among them were found (P > 0.05). CONCLUSION: The amount of calcium hydroxide paste on the dentinal walls was not dependent on length of time of ultrasonic activation. SEM/EDS analysis seems to be a reliable method to assess CH paste removal from the root canals.