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AIM: This single-arm interventional trial aimed to investigate the efficacy of ultrasonic irrigation as a supplementary disinfection approach after chemomechanical procedures using molecular techniques based on ribosomal RNA (rRNA) and rRNA genes (referred to as DNA). METHODOLOGY: Samples were collected from 35 single-rooted teeth with radiographic evidence of apical periodontitis. Samples were taken after gaining root canal access (S1), chemomechanical procedures (CMP, S2), and ultrasonic irrigation (S3). DNA-targeted qPCR using universal primers was used to estimate total bacterial levels, while rRNA-targeted qPCR was used to assess bacterial activity. Ratios between rRNA and DNA levels were calculated to search for active bacteria in the samples (rRNA/ DNA ≥ 1). Wilcoxon matched-pairs signed-rank test was used to compare the differences in DNA levels between samples and DNA and rRNA levels within samples (P <.05). RESULTS: DNA-based methods revealed a significant decrease in bacterial levels from S1 to S2 and S2 to S3 (both P <.05). Notably, 11 out of 35 (31.4%) root canals did not harbor bacterial DNA after CMP, whereas ultrasonic activation increased DNA-negative samples to 17 (48.6%). However, all DNA-positive samples were also positive for rRNA, with significantly higher rRNA than DNA levels (P <.05), indicating bacterial activity at the sampling time. CONCLUSIONS: Ultrasonic irrigation improved the disinfection of root canals after chemomechanical procedures by reducing bacterial levels. However, persisting bacteria remained active in the root canals after CMP and ultrasonic irrigation.

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This ex vivo study devised an analytical ex vivo method for infection/disinfection of simulated lateral canals located in the middle and apical segments of the root. The antibacterial effects of supplementary approaches were tested in this model. Extracted mandibular premolars had their main root canals enlarged and then two lateral canals (100 µm in diameter) were created in the root, one in the apical and the other in the middle portion. Micro-computed tomography was used for specimen selection and to confirm the quality of the simulated ramifications. The specimens were contaminated with a mixed bacterial culture from subgingival bacterial biofilm added to pure Enterococcus faecalis strain ATCC 29212 grown overnight, using special strategies to facilitate culture medium penetration within the lateral canals. The following procedures were tested for disinfection: NaOCl/passive ultrasonic irrigation (PUI), NaOCl/XP-endo Finisher, ozonated water/continuous ultrasonic irrigation (CUI), and NaOCl/conventional irrigation with 30-G needles (control). Bacteriological samples were taken from the main canal before (S1) and after (S2) each supplementary protocol, and also from each lateral canal after treatment (S3). DNA extracted from the samples was subjected to quantitative real-time polymerase chain reaction. All S1 main canal samples were positive for bacterial presence. Bacterial counts in the main root canal substantially decreased by 99.2% after PUI, 99.1% after ozone/CUI, 99% after XP-endo Finisher, and 96% in the control group (P < 0.01 for all groups). There were no significant differences between groups (P > 0.05). The same was observed when comparing the effects of the supplementary approaches in the apical and middle lateral canals (P > 0.05). Only a few lateral canals showed no detectable bacteria. The method proposed here proved effective for ex vivo infection/disinfection studies. All supplementary approaches induced a substantial bacterial reduction in the main canal, with no significant differences between them. However, in terms of lateral canal disinfection, none of the tested approaches showed significant effects when compared to the control group.

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Introduction: The final step of irrigation has been considered to of increase the bonding strength of filling material to dentin. This study investigated the impact of three final-step irrigation methods on the endodontic sealer bond strength to dentin by using a micro push-out test. Materials and Methods: Palatal roots of human maxillary molars were cleaned and shaped and randomly divided in six groups (n=15) according to the final-step irrigation method and the type of root canal sealer used. The solutions used for the final-step irrigation were 17% ethylenediaminetetraacetic acid and 2.5% sodium hypochlorite, which underwent three methods: 1) syringe-needle irrigation/conventional, 2) passive ultrasonic irrigation, and 3) XP-endo Finisher agitation. The root canal sealers used were: EndoSequence BC Sealer, and AH-Plus sealer. Roots were obturated with the single cone technique and then, cross-sectioned in 2-mm-thick slices (3 slices from each root). Push-out test was performed on the sliced specimens (cervical, middle, and apical thirds) with a universal testing machine. Bond strength values were recorded in megapascal (MPa). Subsequently, each specimen was longitudinally split to verify the type of failure. Data analysis was performed using Johnson transformation, three-way analysis of variance, Tukey's post-hoc tests, and the partial Eta squared test. Results: There were significant differences in bond strength between the sealers [AH: 4.46±2.24 and BC: 3.47±2.19 MPa (P<0.001)]; between final-step irrigation methods [passive ultrasonic irrigation: 4.52±2.25, XP-endo Finisher: 3.93±3.93 and syringe-needle irrigation/conventional: 3.37±2.51 MPa (P<0.001)], and between the root canal thirds represented by the sliced specimens [cervical: 5.45±2.39, middle: 4.14±1.99 and apical: 2.30±1.30 MPa (P<0.001)]. The interaction between the variables had no significance (P>0.05). Conclusion: Agitation of the final irrigating solution may improve the bonding of the sealer to canal walls. AH-Plus sealer had the highest bond strength. The bond strength reduced significantly towards the apical third.

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The objective of the study was to investigate the 5.25% sodium hypochlorite (NaOCl) penetration into the dentinal tubules after different irrigation methods. Seventy canines were stained with 1% crystal violet and divided into groups (n = 20): GEC-EasyClean; GPUI-E1 Irrisonic ultrasonic insert; GXP-XP-Endo finisher; GPC-conventional irrigation and GNC-stained tooth without irrigation. Axial sections (16×) were assessed and irrigant penetration was quantified as a bleaching halo on the surface of the apical, middle and coronal third. In the apical third, GPUI promoted greater NaOCl penetration (p < 0.05). GXP was better than GEC (p < 0.05), as was GPC (p > 0.05). The GPUI and GXP groups were similar in the middle and coronal third (p > 0.05). GPUI and GXP showed better results than GEC (p < 0.05). GPUI was more effective in the apical third and like GXP in the cervical and middle third.

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OBJECTIVES: The study aimed to compare the efficacy of XP-endo Finisher and Passive Ultrasonic Irrigation (PUI) in removing hard tissue debris from curved canals. MATERIALS AND METHODS: Thirty-four mandibular molars with Vertucci's type II mesial canals were scanned in microcomputed tomography before and after preparation with HyFlex EDM, and accumulated hard tissue debris was quantified. Subsequently, the teeth were randomly divided into two groups according to the supplementary procedure: PUI with the Ultra-X insert or XP-endo Finisher. After the intervention, the specimens underwent another scanning. Two separate analyses were conducted, one for the total canal and another for the isthmus area. Unpaired and paired T-tests were used for inter- and intergroup comparisons, with a significance level set at 5%. RESULTS: Both supplementary methods reduced the amount of debris compared to the initial volume. Remarkably, the XP-endo Finisher achieved a significantly higher percentage of debris removal (71% for the total canal and 74% for the isthmus areas) compared to PUI (41% for the total canal and 52% for the isthmus area) (P < 0.05). CONCLUSIONS: Both supplementary approaches reduced the amount of hard tissue debris from canal preparation, still XP-endo Finisher showed a higher reduction compared to PUI (p < 0.05). CLINICAL RELEVANCE: None of the supplementary methods rendered canals completely free of hard tissue debris. However, the supplementary approach with XP-endo Finisher resulted in lower levels of hard tissue debris than PUI in curved canals with isthmuses.

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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.

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Background: The effectiveness of endodontic retreatment essentially depends on the cleaning and/or disinfection processes. In this context, the removal of root canal filling materials plays a crucial role. Aims: To assess the efficacy of passive ultrasonic irrigation (PUI), EndoActivator system (EAS), and XP-endo Finisher R (XPEFR) as additional cleaning techniques to remove the remaining root canal filling materials from flattened root canals. Subjects and Methods: Thirty-six similar flattened distal root canals of extracted human first lower molars were selected by micro-computed tomography (micro-CT) and then instrumented and filled. After the initial retreatment procedures, the residual volume of root canal filling materials was assessed by micro-CT (V1). Then, the specimens were divided into three groups (n. 12), according to the additional cleaning technique and submitted to another micro-CT scan (V2). Statistical Analysis Used: Analysis of variance and Games-Howell tests (P < 0.05). Results: The percentage reduction in the residual volume of root canal filling materials reached by PUI, EAS, and XPEFR was 28.38%, 28.12%, and 43.52%, respectively, considering the total space of the root canal (P > 0.05). In the apical third, these values were 20.05%, 21.54%, and 48.82% (P < 0.05). Conclusions: Additional cleaning techniques enabled removing a greater amount of root canal filling material from flattened distal root canals of extracted human first lower molars. Considering the total space of the root canal, there were no statistically relevant differences among the groups. In the apical third, XPEFR performed better.

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AIM: The aim of the study was to assess biofilm removal efficacy of GentleWave System and passive ultrasonic irrigation (PUI). METHODOLOGY: Twenty-two human mandibular molars with Vertucci's type II configuration in the mesial root were selected. Teeth were autoclaved, inoculated with dental plaque and incubated in a CDC biofilm reactor for two weeks. The mesial roots were instrumented up to 20.06 file (V-Taper) for the GentleWave group and up to 35.04 file (Vortex Blue) for PUI group. Irrigation was performed using GentleWave and PUI irrigation protocols (n = 11). Dentine debris on paper points samples were obtained for quantitative real-time polymerase chain reaction (qPCR) and 16S ribosomal RNA gene sequencing (next-generation aequencing-NGS). For qPCR, a non-parametric test (α = 0.05) was used. Next-generation sequencing data were analysed using mothur, with alpha diversity calculated as the Shannon and Chao1 indices and Bray-Curtis dissimilarities were used for beta diversity. Differences in alpha diversity and abundances of genera were evaluated using Kruskal-Wallis test. Differences in community composition were evaluated using analysis of similarity with Bonferroni correction for multiple comparisons. RESULTS: Quantitative real-time polymerase chain reaction results showed that the reduction estimated in percentages for both groups was equivalent (p > .05). NGS analysis showed that both techniques promoted a significant reduction in reads and OTUs number (p < .05). Shannon alpha diversity and Chao1 index showed no differences between pre- or post-treatment samples for both groups (p > .05). Additionally, pre-treatment communities differed from post-treatment samples in both groups regarding bacterial taxa reduction (ANOSIM R = 0.50 and 0.55, p < .001). CONCLUSIONS: Bacterial reduction in mesial roots of mandibular molars prepared to 35.04 with PUI was similar to those prepared to 20.06 with a multisonic irrigant activation system.

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OBJECTIVE: The objective of this systematic review and meta-analysis (SRM) was to answer the question whether the use of ultrasonic irrigation (UI) results in less postoperative pain (PP) compared to conventional irrigation (CI). METHODS: A literature search was performed within the main scientific databases carried out until May 2021. The eligibility criteria were randomized clinical trials (RCTs). Meta-analysis was conducted using R software with the "META" package, the mean difference (MD) measure of effect was calculated, and the fixed effect model was applied with a 95% confidence interval (CI). The Cochrane collaboration scale was used to assess risk of bias and the GRADE tool to assess the quality of evidence. RESULTS: Six RCTs were included for systematic review and four for meta-analysis. UI resulted in less PP in 3 of 5 periods, at 6 h (MD - 1.40 [CI - 2.38 to - 0.42] p = 0.0052), 24 h (MD - 0.73 [CI - 1.07 to - 0.39] p = 0.0001), and 48 h (MD - 0.36 [CI - 0.59 to - 0.13] p = 0.022). However, PP showed no significant differences between the groups at 72 h and 7 days (p > 0.05). A low risk of bias was observed for most domains, except allocation that was considered unclear. The certainty of evidence was classified as moderate (24 h, 48 h, and 7 days) and low (6 and 72 h). CONCLUSION: Within the limitations of this SRM, UI presented less occurrence of PP than CI. Further randomized clinical trials are needed to corroborate these findings. CLINICAL RELEVANCE: UI should be used by clinicians as it reduces postoperative pain in patients undergoing endodontic treatment.

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The aim was to assess the effect of XP-endo Finisher (XPF) on multispecies biofilm removal, in comparison with passive ultrasonic irrigation (PUI) and conventional syringe irrigation (CSI), by scanning electron microscope (SEM). Fifty mandibular first premolars were instrumented, longitudinally sectioned. The split halves were incubated for 4 days with a broth obtained from three bacteria strains: Enterococcus faecalis, Eikenella corrodens and Streptococcus anginosus. Subsequently, the re-approximated split halves were irrigated with 4% sodium hypochlorite (NaOCl) or water using CSI, and the final irrigation protocols were CSI with 4% NaOCl (CSI+4%NaOCl), PUI+4%NaOCl, XPF+4%NaOCl and CSI+water. The analysis of biofilm removal was performed using SEM images. There were no differences between PUI and XPF (P > 0.05), and both groups promoted higher biofilm removal than CSI+4%NaOCl and CSI+water groups (P < 0.05). It can be concluded the multispecies biofilm removal was significantly improved using XPF and PUI when compared to CSI.

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OBJECTIVE: This study aimed to evaluate the efficacy of passive ultrasonic irrigation (PUI) and the easy clean instrument by micro-computed tomography (CT) for removing remnant filling materials during endodontic retreatment. MATERIALS AND METHODS: Forty mesial roots of mandibular molars were divided into four groups (n = 10) according to the agitation system and sealer used: Group 1: PUI/AH Plus; Group 2: PUI/TotalFill; Group 3: Easy Clean/AH Plus; and Group 4: Easy Clean/TotalFill. The groups were compared by micro-CT analysis according to the volumes of the obturation and the remaining material before and after the agitation systems were used. RESULTS: There was no difference between the groups for total filling volume and initial and final remaining filling volume (P > 0.05). CONCLUSIONS: Both the PUI and easy-clean instrument are effective for removing remnants of filling material with no difference between the groups.

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Background: Sodium hypochlorite (NaOCl) is the most commonly used irrigant in endodontics . The purpose of this study was to evaluate the effect of NaOCl solution (2.5%) and gel (3%) with/without passive ultrasonic irrigation (PUI) on Enterococcus faecalis, Escherichia coli, and their endotoxins, lipopolysaccharide (LPS) and lipoteichoic acid (LTA). Methods: 40 human lower premolars were contaminated with E. coli (ATCC 25922) for 28 days and E. faecalis (ATCC 29212) for 21 days. Specimens were randomly divided into four groups: (1) 2.5% NaOCl irrigating the canals without PUI activation; (2) 2.5% NaOCl with PUI; (3) 3% NaOCl gel irrigating the canals without PUI; and (4) 3% NaOCl gel with PUI. 40 mL of irrigant was used for each group. PUI activation was carried out using E1-Irrisonic stainless-steel tip at 10% frequency. After treatment, all specimens were filled with 3mL of 17% ethylenediaminetetraacetic acid (EDTA) for 3min and then washed with nonpyrogenic saline solution. Three samples were collected from the canals: S1, at baseline to confirm biofilm formation; S2 after treatment; and S3 after EDTA. Samples were assessed for E. coli and E. faecalis colony forming units, and LPS and LTA were assessed using chromogenic kinetic LAL assay and ELISA, respectively. Data were analyzed by Kruskal-Wallis, Friedmann and Dunn tests with α≤0.05. Results: All groups were effective in reducing the microbial load of E. coli and E. faecalis after treatment without a significant difference among the groups. NaOCl and NaOCl gel groups had no significant difference in reducing LPS and LTA. Statistically increased reduction was seen for NaOCL + PUI and NaOCl gel + PUI compared for groups without PUI. Conclusions: NaOCl gel has the same antimicrobial action of NaOCl solution and can partially detoxify endotoxins. PUI improves NaOCl (gel or solution) action over E. faecalis and E. coli and their endotoxins.

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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.

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CONTEXT: The use of chemicals solutions and means of activation is of utmost importance in endodontic treatment. AIMS: This study compared three activation techniques used in the final irrigation of the endodontic treatment. SUBJECTS AND METHODS: Eighty uniradicular teeth were instrumented with the Protaper Universal system up to F4 file. After decalcification, the teeth had artificial lateral canals created at 2, 4.5 and 6 mm from working length (WL). The groups were randomly divided into four groups (n = 20): control group (C), passive ultrasonic irrigation (PUI) group, continuous ultrasonic irrigation (CUI) group, and easy clean (EC) group. The penetration of the irrigant into the samples was evaluated using image observation using the Image J program. STATISTICAL ANALYSIS USED: The level of agreement among the observers was determined by the Cronbach's alpha test. The likelihood ratio test was used to evaluate possible differences between the groups and the Kendall's W statistic test to verify possible differences between the irrigant penetration levels in the lateral canals. The Fisher's exact test was applied to verify differences by the studied group considering the WL variables and lateral canals. RESULTS: The results showed no statistical difference in the penetration of the irrigator in the main canal when compared to the C, PUI, CUI, and EC groups (P > 0.05). CONCLUSIONS: The method using a positive syringe and needle pressure was not able to effectively carry the irrigator to the artificially made lateral canals, whereas PUI, CUI, and EC were equally efficient in this regard (P < 0.01).

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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.

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OBJECTIVES: This study aimed to compare four final irrigation protocols (passive ultrasonic irrigation [PUI], EndoVac, Self-Adjusting File [SAF] and EasyClean) on the removal of accumulated hard-tissue debris (AHTD) from mesial canals of mandibular molars through microcomputed tomographic (micro-CT) analysis. MATERIALS AND METHODS: Forty mesial roots of mandibular molars presenting isthmuses type I or III were scanned in a micro-CT device and instrumented up to Reciproc R40 instrument. After the completion of canal preparations, root canals of each group were submitted to a final rinse using 20 mL of solution (16 mL of 5.25% NaOCl and 4 mL of 17% EDTA) in a total time of 5 min according to one of the four final irrigation protocols (n = 10): PUI, EndoVac, SAF and EasyClean operated at reciprocating motion. The sample was scanned again after canal preparation and after the use of the final irrigation protocols, and the registered data sets were examined to evaluate the percentage of AHTD. Data were statistically compared using the Tukey test with a significance level set at 5%. RESULTS: All groups presented a decrease on the accumulation of hard-tissue debris after the use of the final irrigation protocols (P < 0.05). No significant differences in the removal of AHTD were observed among the final irrigation protocols (P > 0.05). CONCLUSIONS: All final irrigation protocols showed the same effectiveness in the removal of AHTD. None of them was able to render mesial canals of mandibular molars completely free from packed debris. CLINICAL RELEVANCE: This study highlighted that all final irrigation protocols (PUI, EndoVac, SAF, and EasyClean) promoted a similar removal of AHTD. However, none of the final irrigation protocols was able to render mesial canals of mandibular molars completely free from packed debris.

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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.

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OBJECTIVE: To compare the effectiveness of the XP-endo Finisher instrument and passive ultrasonic irrigation (PUI) as final irrigation protocols on the removal of accumulated hard-tissue debris (AHTD) from oval-shaped canals using micro-computed tomographic (micro-CT) analysis. METHODS: Twenty mandibular incisors were anatomically pair-matched based on similar morphological dimensions (length, volume, aspect ratio, and configuration) through micro-CT analysis, prepared with Reciproc R25 instrument, scanned again, and assigned to one of the two experimental groups (n = 10), according to the final irrigation protocol: XP-endo Finisher and PUI. After the final irrigation protocols, the specimens were rescanned and the registered datasets were examined to quantify the amount of AHTD. Data were statistically analyzed using Student's t test with a significance level of 5%. RESULTS: The final irrigation protocols were highly similar in terms of volumetric percentage reduction of AHTD (P = 1.000). CONCLUSIONS: XP-endo Finisher and PUI showed the same effectiveness on the removal of AHTD. None of the tested final irrigation protocols completely removed the AHTD from oval-shaped root canals. CLINICAL RELEVANCE: AHTD may be considered clinically relevant because it could harbor bacterial contents away from the disinfection procedures. Both final irrigation protocols were effective on the removal of AHTD.

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OBJECTIVE: To investigate whether there are differences between the root canal disinfection, comparing the passive ultrasonic irrigation technique with the conventional technique. MATERIALS AND METHODS: The following electronic databases were searched: Pubmed; VHL; Web of Sciences and OVID with no publication date restriction. The study's quality evaluation was carried out using the Handbook by Cochrane. The online research identified 5464 studies. From the nine studies selected for a full reading of the text, five were included in the present systematic review. Meta-analysis was performed in three articles, which evaluated the root canal's cleanness through microbiological analysis. RESULTS: Only one article concluded that the ultrasonic passive irrigation showed a better performance compared with the conventional irrigation. None of the articles analyzed presented a low risk of bias in all domains. According to the results of the meta-analysis, there was no statistical difference between the groups (OR = 0.34, IC 95%: 0.10-1.19). CONCLUSIONS: The level of evidence comparing the two techniques is fragile since in all studies some type of bias was observed which may interfere in the results and conclusions.

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Técnicas de agitação da solução irrigadora melhoram a eficácia da limpeza apical através do aumento do fluxo de fluidos, potencializando a desinfecção do canal radicular. A irrigação ultrassônica passiva (PUI) é a técnica mais utilizada e promove, além de uma melhor limpeza, o aumento da temperatura do hipoclorito de sódio (NaOCl). Já o sistema XP-endo Finisher, tipo especial de instrumento rotatório de NiTi tratado termicamente, tem sua capacidade de alcance e eficácia aumentada através da alteração na sua conformação. Esta, ocorre devido à tranformação reversa da martensita quando o instrumento entra em contato com temperatura corporal no interior do canal radicular. O objetivo deste estudo foi avaliar a variação da temperatura da solução irrigadora no interior da câmara pulpar em três situações clínicas: em repouso e após agitação mecânica com o sistema XP-endo Finisher e PUI. As temperaturas de transformação dos instrumentos XP-Endo Finisher foram determinadas por DSC. Um Termopar digital foi usado para mensurar a temperatura do irrigante, dentro da câmara pulpar. Três mensurações foram realizadas em cada dente (n = 12): com a solução irrigadora em repouso, durante a agitação com XPEndo Finisher e durante o uso de PUI, ambos por 60 segundos, observando a evolução da temperatura por 325 segundos. Os dados foram analisados estatisticamente pelo teste t-student, com nível de confiança de 95%. Os resultados do DSC sugeriram que o instrumento XP-endo Finisher à temperatura ambiente apresenta uma estrutura mista, de austenita e fase R. Para o protocolo realizado com a lima XP-Endo, a temperatura média observada no momento da inserção do instrumento no interior do canal radicular foi de 28,7ºC. Após 60 segundos de agitação a temperatura atingiu 34°C. A estabilização da temperatura da solução dentro do canal a 35,5°C foi observada somente após 211 segundos. A temperatura média máxima da solução irrigadora registrada no interior do canal foi de 35,5°C com o irrigante em repouso e após agitação com XP-endo (p> 0,05). Para o protocolo realizado com PUI após 30 segundos de ativação da solução irrigadora a temperatura do NaOCl atingiu 33,3°C e após 60 segundos 37,8ºC, um aumento de aproximadamente 10°C na temperatura do irrigante foi observado. O sistema XP-endo Finisher não promove o aquecimento da solução irrigadora, mas a expansão do instrumento, que é responsável pela melhor capacidade de limpeza desse sistema, ocorrerá e começará em uma temperatura abaixo da esperada. O protocolo de agitação por 60 segundos com PUI, pode ser considerado uma técnica segura que, além dos benefícios descritos na literatura de aumentar a dinâmica do fluxo de fluidos, não promove um superaquecimento que poderia causar danos aos tecidos periodontais.

Irrigation solution agitation techniques improve the efficacy of apical cleaning by increasing the fluids flow, potentiating disinfection of the root canal. Passive ultrasonic irrigation (PUI) is the most used technique and promotes, besides a better cleaning, the increase of sodium hypochlorite (NaOCl) temperature. The XP-endo Finisher system, a special type of thermally treated NiTi rotary instrument, has its capacity to reach and increase efficiency due to a change in its conformation. This, occurs due to the reverse transformation of martensite when the instrument comes in contact with body temperature inside the root canal. The aim of this study was to evaluate the temperature variation of the irrigation solution inside the pulp chamber in three clinical situations: at resting and after mechanical agitation with the XP-endo Finisher system and PUI. Transformation temperatures of XP-Endo Finisher instruments were determined by DSC. A digital thermocouple was used to measure the irrigant temperature, inside the pulp chamber. Three measurements were performed in each teeth (n = 12): with irrigant at resting, during agitation with XP-Endo Finisher and during the use of PUI, both for 60 seconds, observing the temperature evolution. Data were statistically analyzed using t-student test, with a confidence level of 95%. DSC results suggested that XP-Endo finisher at room temperature will be in a mixed R-phase and austenitic structure. For the protocol performed with the XP-Endo file, the mean temperature observed at the time of instrument insertion inside the root canal was 28,7ºC. After 60 seconds of agitation temperature reached 34°C. The stabilization of the solution temperature inside the canal at 35.5°C was observed only after 211 seconds. The mean maximum irrigation solution temperature recorded inside the canal was 35.5°C with the irrigant at resting and after XP-endo agitation (p>0.05). For the protocol performed with PUI, after 30 seconds of irrigation solution activation the temperature of NaOCl reached 33.3°C and after 60 seconds 37.8°C, an increase of approximately 10°C in the irrigant temperature was observed. The XP-endo Finisher system does not promote heating of the irrigation solution, but the file expansion which is responsible for the instruments better cleaning ability will occur and it starts in a temperature under the expected. The 60 seconds PUI agitation protocol, can be considered a safe technique that besides the benefits described in the literature of increasing fluid flow dynamics, do not promote an overheating that could cause damage to periodontal organic tissues.

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