Continuous Ultrasonic Irrigation Research Articles

Can Heated Distilled Water Effectively Prevent Precipitate Formation between NaOCl and CHX?

The present study aimed to investigate the capacity of different irrigation protocols using heated distilled water at 65°C (HDW), in preventing the formation of the brown-orange precipitate observed after the interaction between sodium hypochlorite (NaOCl) and chlorhexidine (CHX). Forty human canines were selected, prepared, and cleaved in two halves. Images of delimited areas in each root canal thirds were obtained through a stereomicroscope (16x and 40x). After reassembly, the teeth were distributed into four groups (n = 10) according to the final irrigation protocol: G1 (no HDW): EDTA + NaOCl + CHX with conventional irrigation (CI); G2 (HDW + CI): EDTA with passive ultrasonic irrigation (PUI) + NaOCl (PUI) + HDW (CI) + CHX (PUI); G3 (HDW + PUI): EDTA + NaOCl + HDW + CHX with PUI; G4 (HDW + CUI): EDTA (PUI) + NaOCl (PUI) + HDW with continuous ultrasonic irrigation (CUI) + CHX (PUI). After irrigation, the teeth were re-separated and images of the same delimited areas were obtained again. Scores were assigned according to the amount of precipitate observed, comparing the initial and final images. The data were submitted to Kruskal-Wallis, Dunn and Friedman statistical tests (α = 5%). G1(no HDW) showed the highest scores in the analysis between groups (p < 0.001), with a greater amount of precipitate in the cervical and medium thirds (p < 0.001). The thirds of the other experimental groups did not differ from each other (p > 0.05). The intermediate irrigation with heated distilled water at 65°C prevented the formation of brown-orange precipitate, regardless of the use of ultrasonic activation (PUI or CUI).

Did in-between rinsing and agitating with distilled water prevents precipitate formation by the interaction between sodium hypochlorite and chlorhexidine canal irrigants?

The interaction of sodium hypochlorite (NaOCl) and chlorhexidine gluconate (CHX) produces an orange-brown precipitate. The present study evaluated the influence of distilled water (H2 O) in different irrigation protocols designed to prevent the formation of precipitate with NaOCl and CHX. Fifty canine teeth were instrumented and split longitudinally. The canal was examined with a stereomicroscope and photographed by canal-thirds. The tooth halves were repositioned and distributed randomly into five groups, according to the final irrigation protocol (n = 10): G1 (control)-Ethylenediaminetetraacetic acid (EDTA) + NaOCl + CHX, conventional irrigation (CI); G2-EDTA + NaOCl + CHX, activated with passive ultrasonic irrigation (PUI); G3-EDTA (PUI) + NaOCl (PUI) + H2 O (CI) + CHX (PUI); G4-EDTA + NaOCl + H2 O + CHX (PUI); G5-EDTA (PUI) + NaOCl (PUI) + H2 O (continuous ultrasonic irrigation [CUI]) + CHX (PUI). The specimens were evaluated with a stereomicroscope and scanning electron microscope (SEM). Energy dispersive x-ray spectroscopy analysis was performed to identify the elemental profile of the irrigated canal walls. The images were scored according to the extensiveness of precipitate. Data were analyzed (Kruskal-Wallis test, α = 5%). Under the stereomicroscope, G1 had significantly higher scores than all the other groups in all canal-thirds (p < .05). All four experimental groups showed similar scores (p > .05). There were no significant differences in precipitate formation among root-thirds in intragroup analysis (p > .05). Upon SEM examination, overall, only G5 had lower scores than G1 (p < .05). Analysis by canal-thirds showed no significant difference among groups and among canal-thirds in the intragroup analysis (p > .05). G1 showed high Cl peaks. In-between irrigation with H2 O activated by CUI is effective in preventing precipitate formation during canal debridement with NaOCl and CHX. RESEARCH HIGHLIGHTS: Continuous ultrasonic irrigation with distilled water was capable to prevent the precipitate formation. The precipitate can be classified as a chemical smear layer.

Effect of Continuous Ultrasonic Irrigation on Postoperative Pain in Cases in Symptomatic Apical Periodontitis After Single Visit Endodontic Treatment

Objective: To examine and evaluate the efficacy of Continuous Ultrasonic Irrigation (CUI) in comparison to Syringe Irrigation (SI) with regards to the reduction of postoperative pain. : The clinical investigation was carried out at the Department of Operative Dentistry, Liaquat University of Medical and Health Sciences, Jamshoro, for a period of six months, starting from January 2021 and ending in June 2021. The study involved a total of 90 patients, and its objective was to assess pain levels experienced by the participants 24 hours and seven days after the surgical procedure. The Heft Parker Visual-Analogue Scale was utilized as the tool for pain measurement. Results: CUI yielded superior outcomes in terms of statistically significant postoperative pain reduction at the 24-hour when compared to syringe irrigation. Nevertheless, it was shown that syringe irrigation demonstrated more efficacy in mitigating postoperative discomfort on the seventh day. The findings also revealed statistically significant disparities in pain intensity between the two cohorts at the 24-hour mark and on the seventh day, with notable variations in pain levels based on gender.Conclusion: The efficacy of continuous ultrasonic irrigation in lowering postoperative pain was shown to be higher at the 24-hour mark, whereas syringe irrigation demonstrated greater effectiveness at the 7-day postoperative period.

Micro- CT evaluation of sealers removal by reciprocal instrumentation followed by continuous ultrasonic irrigation in teeth with oval root canals.

The ability of the Reciproc system (R40) followed by continuous ultrasonic irrigation (CUI) to remove filling material from oval root canals of mandibular premolars filled with gutta-percha and AH Plus or Bio-C Sealer was evaluated by microtomography (micro-CT). The straight and oval root canals of 42 mandibular premolars were prepared with the ProDesign R 35.05 reciprocal file and randomly divided into two groups according to the material used to fill the canals (n=21): Group AH - Master Cone and AH Plus; Group BC - Master Cone and Bio-C Sealer. After filling and provisional sealing, the teeth were stored at 100% relative humidity and a temperature of 37°C for 30 days. The filling material was then removed with an R40 file. The material was considered completely removed when the R40 file reached the working length (WL), and no remaining filling material was visible on the canal walls. CUI was then performed. The teeth were scanned by micro- CT before and after removal of the filling material. The remaining filling material was measured in mm in the last apical 5 mm. The data were analyzed with the nonparametric Friedman test and subsequently with the Dunn test. The Mann-Whitney U test was also performed. Statistical significance was accepted at the 5% level. After instrumentation with the Reciproc R40, the volume of residual filling material was significantly greater in the BC group than in the AH group (P = 0.035). After CUI, there was no difference in the volume of residual material between the two groups (P = 0.705). Bio-C sealer was more difficult to remove with the Reciproc file than AH Plus. CUI improved the removal of residual filling material regardless of sealer type. However, no technique was able to completely clear the canals of filling material. Key words:Bioceramic cement, CUI, micro-CT, reciproc, retreatment.

Comparative evaluation of postoperative pain with continuous ultrasonic irrigation, laser-activated irrigation, and laser irradiation: A randomized clinical trial

ABSTRACT Aims: To compare and evaluate the incidence of postoperative pain using continuous ultrasonic irrigation (CUI), laser-activated irrigation (LAI), and laser irradiation (LI). Methods: Sixty-three patients were asked to record their pain level preoperatively using Visual Analog Scale (VAS) and Numerical Rating Scale (NRS). The teeth were isolated and routine root canal treatment was initiated. After cleaning and shaping, the participants were allotted to three different groups: Group I: CUI (n = 21), Group II: LAI (n = 21), and Group III: LI (n = 21). At the end of the first visit, all patients were instructed to record pain level on the VAS pain scale chart after 24, 48 h, and after 7 days. Statistical Analysis Used: The data were entered and analyzed using the Statistical Package for the Social Sciences (SPSS) for Windows 26.0 (SPSS, Inc., Chicago, IL, USA), confidence intervals were set at 95%, and P ≤0.05 was considered statistically significant. Results: Age and gender had no significant difference between the three groups (P = 0.79). Majority of the patients (41.3%) observed mild pain, 30.2% of the patients observed moderate pain, and 28.6% of the patients observed severe pain according to Numerical Rating Scale. Conclusions: There is no statistical difference between CUI, LAI, and LI on the incidence of interappointment pain.

Effect of continuous ultrasonic irrigation and diode laser activation on apical extrusion of debris: in vitro study

Effect of continuous ultrasonic irrigation and diode laser activation on apical extrusion of debris: in vitro study

Effect of Ultrasonic and Diode Laser Irrigation Activation on Post-operative Pain and Microbial Reduction in Single Visit Endodontic Treatment of Necrotic Mandibular Molars

Aim: To clinically evaluate the effect of continuous ultrasonic and diode laser 810 wave length irrigation activation techniques on postoperative pain and bacterial reduction in single visit endodontic treatment of mandibular molars.&#x0D; Material and methods: Forty patients requiring root canal treatment therapy for necrotic mandibular molars teeth were included in this study with age ranges between 20 and 45 years. In all cases, single visit endodontic treatment was carried out using Revo-S rotary file system in crown down sequence. NaOCl 2.5% irrigation solution was used during treatment. Patients were randomly and equally assigned into two groups according to irrigation technique. Group (1): conventional syringe irrigation and group (2): continuous ultrasonic irrigation. Each group was subdivided into two sub groups (n = 10); subgroup 1A (conventional syringe irrigation with no laser), subgroup 1B (conventional syringe irrigation with diode laser), subgroup 2A (continuous ultrasonic irrigation with no laser) and subgroup 2B (continuous ultrasonic irrigation with diode laser).&#x0D; Postoperative pain evaluation was done using Visual Analogue Scale (VAS) at 6, 12, 24, 36, 48 hours and 7 days postoperatively. Microbiological detection of bacterial reduction was done by taking Samples (S1 and S2) for bacterial cultures. S1 after finishing access cavity and before mechanical preparation and S2 after finishing mechanical preparation and irrigation activation and before obturation. Samples were cultured on blood agar and determined as colony forming units (CFU/mL). Microbiological bacterial reduction was calculated accordingly. Statistical analyses were analyzed using the Mann-Whitney U test. The significance level was set at p &lt; 0.05.&#x0D; Results: In all sub groups, postoperative pain decreased by time in all time intervals but pain was significantly lower in subgroup (2B) (continuous ultrasonic irrigation with diode laser) than subgroup (1A) (conventional syringe irrigation with no laser) in all time interval. Microbiological results showed the highest bacterial reduction was in subgroup (2B) (continuous ultrasonic irrigation with diode laser) and least bacterial reduction was in subgroup (1A) (conventional syringe irrigation with no laser).&#x0D; Conclusion: Using diode laser and continuous ultrasonic irrigation activation techniques as adjunctive methods showed improvement in postoperative pain records and enhanced bacterial reduction in root canal therapy.&#x0D; Keywords: Continuous ultrasonic irrigation, diode laser 810, post-operative pain, bacterial reduction, single visit endodontic treatment.

Effectiveness of Different Irrigant Activation Systems on Smear Layer Removal: A Scanning Electron Microscopic Study.

The aim of this study was to evaluate the effectiveness of smear layer removal after the use of different irrigation methods (passive ultrasonic irrigation (PUI), continuous ultrasonic irrigation (CUI), apical negative pressure irrigation and conventional irrigation) using scanning electron microscopy (SEM) as an analytical tool. A total of 100 single-canal teeth were decoronated and randomly divided into five groups (n = 20) according to the irrigation method used: conventional irrigation with front outlet syringe, conventional irrigation with lateral outlet syringe, apical negative pressure irrigation (EndoVac), PUI with Irrisafe and CUI with ProUltra PiezoFlow ultrasonic irrigation needle. Root canal preparation was performed with the ProTaper Gold system up to the F4 instrument, and 5.25% NaOCl was used as an irrigant. After chemical-mechanical preparation, the roots were split longitudinally, and the coronal, middle and apical thirds were examined. SEM digital photomicrographs were taken at ×1000 magnification to evaluate the amount of smear layer in each root canal third; CUI significantly removed more smear layer than any other irrigant activation protocol (p < 0.05); CUI was more effective in removing the smear layer than the other irrigation protocols. However, none of the irrigation protocols were able to produce root canals completely free from smear layer.

Effect of mechanical cleaning protocols in the fiber post space on the adhesive interface between universal adhesive and root dentin.

The aim of this study was to evaluate the effects of cleaning protocols on the presence of residues, open dentinal tubules, and bond strength of a self-etch adhesive plus a dual-cure resin cement to dentin in the fiber-post space. The methods for cleaning utilized were conventional irrigation (CI), rotary brush with continuous rotary movement (RB), and continuous ultrasonic irrigation (CUI). Sixty bovine incisors were used for fiber-post space preparation. Thirty roots were divided into three groups (n=10) according to the cleaning protocols and submitted to scanning electron microscope to evaluate presence of residues and relative quantity of open dentinal tubules on dentin surface. Similar protocols were performed in the other thirty roots (n=10) using a self-etching adhesive system (Scotchbond Universal) and a dual-cure resin cement (Relyx Unicem 2). After 6months cervical, middle, and apical thirds sections of fiber-post space were submitted to push-out testing. To data ANOVA and Tukey's test were employed (α=5%). RB and CUI showed the lowest presence of residues on dentin surface (p=.015) and the highest bond strength values (p < .001), regardless of the dentin third. CUI presented the highest quantity of open dentinal tubules in middle and apical thirds (p < .001). CI presented the lowest bond strength value of resin cement, regardless of dentin third (p < .001). Mechanical cleaning protocols, such as RB and CUI, presented better surface cleaning capabilities and higher bond strength than CI with dual-cure resin cement employed. The use of a mechanical cleaning protocol seems to cause appropriate condition on the root dentin surface. Mechanical cleaning of root dentin provided greater bond strength of the self-etching system with dual resin cement. Conventional irrigation did not provide adequate root dentin cleaning. RESEARCH HIGHLIGHTS: • The use of a mechanical cleaning protocol seems to cause appropriate condition on the root dentin surface. • Mechanical cleaning of root dentin provided greater bond strength of the self-etching system with dual resin cement. • Conventional irrigation did not provide adequate root dentin cleaning.

Outcomes of the GentleWave system on root canal treatment: a narrative review.

This study aimed to describe the outcomes of the GentleWave system (GW) (Sonendo) on root canal treatment. Published articles were collected from scientific databases (MEDLINE/PubMed platform, Web of Science, Scopus, Science Direct and Embase). A total of 24 studies were collected from August/2014 to July/2021, 20 in vitro and 4 clinical. GW System was not associated with extrusion of the irrigant, promoted faster organic dissolution than conventional syringe irrigation (CSI), passive ultrasonic irrigation (PUI) continuous ultrasonic irrigation (CUI) and EndoVac, reduced more bacterial DNA and biofilm than PUI and CUI, promoted higher penetration of sodium hypochlorite into dentinal tubules than PUI and CUI in vitro, and removed more intracanal medication than CSI and PUI. GW was able to remove pulp tissue and calcifications. Moreover, its ability to remove hard-tissue debris and smear layer was better than that of CSI, and its ability to remove root canal obturation residues was lower or similar to that of PUI, and similar to that of CSI and EndoVac. Regarding root canal obturation of minimally instrumented molar canals, GW was associated with high-quality obturation. Clinically, the success rate of endodontic treatment using GW was 97.3%, and the short-term postoperative pain in the GW group was not different from CSI. Further research, mainly clinical, is needed to establish whether GW has any advantages over other available irrigation methods.

Eliminación de la capa de barro dentinario mediante irrigación ultrasónica pasiva y continua: un estudio de microscopía electrónica de barrido

Background: Due to the anatomical complexity of the root canal system, irrigation plays an essential role in endodontics. This in vitro study was sought to compare the removal of the smear layer (RSL) promoted by conventional irrigation (CI), passive ultrasonic irrigation (PUI) and continuous ultrasonic irrigation (CUI) with 17% EDTA, by using scanning electron microscopy (SEM). Material and Methods: Forty single-rooted human mandibular canines were instrumented and randomly assigned to four groups (n=10), according to the irrigation protocol aiming to the RSL: CG (control group) —conventional irrigation with distilled water; CI— conventional irrigation with 17% EDTA; PUI —passive ultrasonic irrigation with 17% EDTA; CUI— continuous ultrasonic irrigation with 17% EDTA. Hemisections from each sample were obtained, and images of each root canal third (cervical, middle and apical) were captured at 1000 X magnification by SEM. Three previously calibrated and blinded evaluators classified the RSL, according to the criteria proposed by Torabinejad et al.: small or no smear layer (all dentinal tubules were clean and open); 2 = moderate smear layer (no smear layer on the surface of root canal, but dentinal tubules contained debris); 3 = dense smear layer (covering practically all dentinal tubules entrances). Statistical analysis was performed by Kruskal-Wallis and Bonferroni tests (p&lt;0.05). Results: Overall, CUI and cervical thirds showed better RSL rates, compared with the other methods and thirds, respectively (p&lt;0.05). More specifically, the cervical thirds showed better results in the CG, CI and PUI groups (p&lt;0.05), whereas the cervical and middle thirds were not significantly different in the CUI group. Conclusion: CUI was the most effective method for the RSL.

Protocols for Mechanical Cleaning of the Post Space on the Bond Strength Between Root Dentin and Cementation System.

To evaluate the effects of mechanical versus chemical cleaning protocols for cleaning the root dentin surface before cementation of fiberglass posts for their effect on the bond strength, failure mode, and dentinal penetration of the cementing agent using an etch-and-rinse adhesive system on dentin prepared to receive a fiberglass post. Forty roots of bovine teeth were endodontically treated and prepared for fiber post cementation. The specimens were randomized into 4 groups of 10: Control group (CO) - irrigation with 2.5% NaOCl; DW group- irrigation with distilled water; RB group - rotating brush for cleaning root canals, and CUI group - continuous ultrasonic irrigation. The fiberglass posts were cemented, and the specimens were immersed in distilled water for 6 months. A push-out test was performed on the cervical, middle, and apical thirds of the samples. Dentinal penetration of the cementing agent and the fracture pattern were evaluated by laser confocal microscopy. Statistical analysis was performed using analysis of variance (ANOVA) and post hoc Tukey tests (α=0.05). Results: The RB and CUI groups showed significantly higher bond strength values when compared to the Control and DW groups (p<0.05). In addition, in the control and DW groups, the apical third presented lower bond strength values when compared to middle and cervical thirds. While DW showed the highest incidence of adhesive type failure, CUI resulted in the highest dentinal penetration of the cementing agent (p<0.05). RB and CUI resulted in the highest bond strength between cementation system and root dentin. In addition, CUI favored greater dentinal penetration of fiberglass post cementing agent.

The antimicrobial effect of different ozone protocols applied in severe curved canals contaminated with Enterococcus faecalis: ex vivo study

The aim of this study was to evaluate 3 different irrigation protocols using ozone on monoculture biofilm of Enterococcus faecalis. Fifty disto-buccal roots of maxillary first molars were instrumented up to the size 25.08, sterilized and then incubated with Enterococcus faecalis for 21days for biofilm maturation in the root canal walls. After contamination, the initial collection (S1) was performed and the 50 samples were divided in 3 experimental groups (n = 15) and 1 positive control group (n = 5) as follows: Group1: Ozonated water (40µg/ml); Group2: gaseous ozone (40µg/ml); Group3: Ozonated water (40µg/ml) under continuous ultrasonic irrigation (CUI) and, Group 4: 2.5% sodium hypochlorite (positive control). The final collection (S2) was performed using hedstroem files # 25 by scraping the root canal wall and absorbed paper cone. The collected samples were analyzed by CFU/ml count and qPCR. To compare the effect of irrigation methods and to investigate E. faecalis count data, Kruskal-Wallis and Wilcoxon nonparametric tests were used at p < 05. The values of the differences between the S1 values and the S2 values revealed that the groups did not differ significantly for either E. faecalis CFU count data (p = 0.713) or q-PCR (p = 0.185), however, it is observed that for all groups, the CFU count of E. faecalis decreased over 99%. For the q-PCR assay, the reduction was on the order of 74-95%. Only the NaOCl positive control group presented total elimination of CFU/mL bacterial counting. The ozone protocols assessed were similar in regard to Enterococcus faecalis reduction.

Efficacy of Different Irrigating Systems on Debris and Smear Layer Removal: A Scanning Electron Microscopic Study

Background: The goal of this research was to see how effective various irrigation methods were at eliminating smear layer and debris. Study design: Sixty extracted single rooted human mandibular premolar teeth were used in this study. The root canals were shaped with a WaveOne large (040.08) rotary file after decoronating all the teeth to a uniform 16 mm root length. Root canals were rinsed with 6 ml of 2.5 percent sodium hypochlorite solution during instrumentation. After instrumentation, teeth were arbitrarily classified into four categories, each containing 15 specimens according to the technique of activation of final irrigant. Smear Clear solution (6 ml) was employed in all the categories as irrigating solution. In Group1- Rotary canal brush, Group 2 – EndoActivator, Group 3 – Passive ultrasonic irrigation (PUI), Group 4 – Continuous ultrasonic irrigation was employed. After sectioning the roots longitudinally, the apical, middle and coronal thirds of the canals were inspected with the help of scanning electron microscopy. Results: Group 4 was most effective in eliminating debris and smear layer at the coronal, middle, and apical thirds. But Group 4 was not significantly different to Group 3 at the middle third in eliminating debris and at middle third and apical third in elimination of smear layer. Conclusion: Continuous ultrasonic irrigation eliminated debris and smear layer most effectively, followed by PUI, EndoActivator, and Rotary canal brush. Keywords: Smear layer, Passive Ultrasonic Irrigation, Continuous ultrasonic irrigation, EndoActivator, Rotary canal brush

Effect of the several epoxy resin-based sealer compositions on adhesion interface in radicular dentin after calcium hydroxide intracanal medication removal.

BackgroundThis study evaluated the effects of several epoxy resin-based sealer compositions (AHP, AH Plus; ADS, Adseal; SPL, Sealer Plus) on bond strength and intratubular dentin penetration of the endodontic obturation, in root canal previously treated with calcium hydroxide intracanal medication (CH) and removed by continuous ultrasonic irrigation (CUI). Material and MethodsForty-five maxillary canines were prepared up to F5 (ProTaper system), filled with CH, coronally sealed, and stored at 37ºC. After 1 week, CH was removed using 2.5% sodium hypochlorite energized by CUI. The specimens were randomly distributed in three groups (n=15) and root canal obturated, according to epoxy-based resin sealer composition (AHP, ADS or SPL). The roots were transversally sectioned in cervical, middle, and apical thirds. In each radicular third, push out bond strength using universal machine and intratubular dentin using confocal laser scanning microscopy (CLSM) and Image J Program were evaluated. Bond strength and intratubular dentin penetration were statistically evaluated by ANOVA one-way and Tukey tests and Kruskal Wallis test, respectively (α = 0.05). ResultsIn middle and apical thirds, AHP showed higher bond strength values (p<0.05), and ADS and SPL were similar each other (p>0.05). All epoxy resin-based sealers presented similar intratubular dentin penetration, independently of the radicular thirds (p>0.05). Cohesive and mixed failures were predominant in the cervical thirds. In the middle and apical thirds, AHP showed more cohesive type failures, while ADS and SPL showed more adhesive-type failures. ConclusionsAHP has the highest bond strength in middle and apical radicular thirds, after calcium hydroxide intracanal medication removal using continuous ultrasonic irrigation, although intratubular dentin infiltration being similar among epoxy resin-based sealer with several chemical composition. Key words:Continuous ultrasonic irrigation, endodontic sealers, epoxy resin-based sealers, root canal obturation.

Heated distilled water with or without continuous ultrasonic irrigation improves final irrigation efficacy and reduces dentine erosion

ObjectivesThe present study evaluated the effects of using heated distilled water (HDW), with or without continuous ultrasonic irrigation (CUI), on smear layer removal and deterioration of root dentine microstructure. Materials and MethodsAfter chemomechanical preparation, 60 human teeth were longitudinally cleaved into two halves for smear layer quantification at the cervical-third, middle-third and apical root-third of the canal space. After reassembly, the root canals were irrigated with 17 % EDTA, followed by one of the six final irrigation protocols (n = 10) - G1: conventional irrigation (CI)+NaOCl at 25 °C; G2: NaOCl at 25 °C + CUI; G3: CI with DW at 25 °C; G4: DW at 25 °C + CUI; G5: CI + HDW at 65 °C; G6: HDW at 65 °C + CUI. Tooth-halves were processed and examined by scanning electron microscopy. The percentage of opened dentinal tubules in the irrigated areas of the canal space was expressed as a percentage of the total surface area. Dentine erosion was classified by numeric scores. Smear layer removal was analysed with ANOVA and Student-Newman-Keuls tests; dentine erosion was analysed with Cohran-Mantel-Haenstel statistic (α = 0.05). ResultsThe cervical-third had a higher percentage of open dentinal tubules for all groups (p < 0.05). In G2, the middle-third had a lower percentage of open tubules, which was significantly different from the other groups (p < 0.05). Groups that utilised NaOCl as the final irrigant had more extensive erosion when CUI was used. ConclusionHeated distilled water, with or without CUI, was as efficient as 1 % NaOCl in the final cleaning of the instrumented canal space. The use of HDW produces less extensive dentine erosion. Clinical significanceHeated distilled water removes smear layers with less deleterious effects on dentine microstructure and may be considered a final irrigant after mechanical preparation and EDTA chelation.

Evaluation of &lt;i&gt;in vitro&lt;/i&gt; biofilm elimination of &lt;i&gt;Enterococcus faecalis&lt;/i&gt; using a continuous ultrasonic irrigation device

This study sought to evaluate biofilm elimination using the HBW Ultrasonic Ring based on continuous ultrasonic irrigation. Forty-five premolars and molars with complex curvatures were included. An Enterococcus faecalis biofilm was established for 30 days on the extracted teeth. The teeth were then stratified into three experimental groups for instrumentation and irrigation (i.e. HBW Ultrasonic Ring, conventional irrigation, and passive ultrasonic irrigation). Pre- and post-instrumentation samples were collected, and reductions of bacterial load were evaluated by McFarland's scale, counting of colony-forming units, and scanning electronic microscopy. The HBW Ultrasonic Ring promoted a higher reduction in bacterial load relative to conventional irrigation (P < 0.05) and a similar reduction compared with passive ultrasonic irrigation (P > 0.05). These results suggest the HBW Ultrasonic Ring is a promising alternative modality for simultaneous instrumentation and irrigation during root canal treatment, achieving an appropriate level of bacterial reduction and allowing the passage of the irrigating solution throughout the entire working length.

Efficacy of passive ultrasonic irrigation, continuous ultrasonic irrigation versus irrigation with reciprocating activation device in penetration into main and simulated lateral canals.

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).

Activated Irrigation vs. Conventional non-activated Irrigation in Endodontics - A Systematic Review.

Objective:Irrigant activation has been claimed to be beneficial in in vitro and clinical studies. This systematic review aims to investigate the clinical efficiency of mechanically activated irrigants and conventional irrigation.Methods:A literature search (PROSPERO registration number: CRD42018112595) was undertaken in PubMed, Cochrane and hand search. The inclusion criteria were clinical trials, in vivo/ex vivo on adult permanent teeth involving an active irrigation device and a control group of conventional irrigation. The exclusion criteria were studies done in vitro, animals and foreign language. Adult patients requiring endodontic treatment of permanent dentition and irrigant activation during the treatment were chosen as the participants and intervention respectively.Results:After removal of duplicates, 89 articles were obtained, and 72 were excluded as they did not meet the selection criteria. 6 devices (EndoVac, EndoActivator, Ultrasonic, MDA (manual dynamic agitation), CUI (Continuous Ultrasonic Irrigation) and PUI (Passive Ultrasonic Irrigation)) and 6 variables of interest (Post-operative pain, periapical healing, antibacterial efficacy, canal and/or isthmus cleanliness, debridement efficacy and delivery up to working length) were evaluated in the 17 included articles. The risk of bias and quality of the selected articles were moderate. Results showed that mechanical active irrigation reduces post-operative pain. It improved debridement, canal/isthmus cleanliness. It also improved delivery of irrigant up to working length. Bacterial count was more with active irrigation, though not significant. There is no effect on long-term periapical healing.Conclusion:It may be concluded that mechanical active irrigation devices are beneficial in reducing post-operative pain and improving canal and isthmus cleanliness during Endodontics.

Irrigation effectiveness of continuous ultrasonic irrigation system: An ex vivo study.

This study evaluated the irrigation extrusion and smear layer (SL) removal of continuous ultrasonic irrigation (CUI). Forty root canals were shaped, embedded in warm sterile saline agar colored with 1% acid red, and distributed into four groups; three groups had the final irrigation sequence of sodium hypochlorite and EDTA solutions performed by using syringe irrigation (SI), EndoVac (EV), and CUI, respectively. Group 4 had the canals ultrasonically irrigated with saline (CUIS). Irrigant extrusion was verified by a color change of the agar. The SL was evaluated under scanning electron microscope. Irrigant extrusion was observed in two and four teeth in the CUI and SI, respectively, whilst none had irrigant extruded in the EV. In term of SL, the CUI was comparable to EV at 1 and 3 mm but different to SI at 1 mm. Although CUI might clean the root canal system effectively, it was unable to avoid irrigant extrusion.