Final Irrigation Protocol Research Articles

Influence of final irrigation protocols and type of resin cement on bond strength of glass fiber posts in root dentin previously treated with photodynamic therapy.

This study aimed to evaluate the influence of final irrigation protocols and type of resin cement on the bond strength of glass fiber posts (GFPs) in root dentin previously treated with photodynamic therapy (PDT). One hundred root canals were prepared up to #4 Gates Glidden drill to receive the GFPs. All samples were subjected to PDT, and randomly divided into five groups (n = 20) according to final irrigation protocol: distilled water + ultrasonic activation [US]; 17% EDTA; QMix; 17% EDTA + US; and QMix + US. Each group was randomly divided into 2 subgroups (n = 10) according to the type of resin cement used for cementation of GFPs: Rely-X ARC dual-resin; or Rely-X U200 (#M, St Paul, MN, USA) self-adhesive resin cement. Bond strength was evaluated using the push-out test. Failure patterns were observed under an optical microscope. Bond strengths were compared using two-way ANOVA, followed by the Tukey post-hoc test; failure modes were compared using the chi-squared test (α = 5%). The use of US over final irrigants improved the bond strength of GFPs, regardless of resin cement used (p < 0.05). The type of resin cement did not influence the bond strength of GFPs (p < 0.05). There was a higher predominance of cohesive failure in all groups, regardless of resin cement tested (p < 0.05). The use of US on final irrigation improved the bond strength of GFPs, while the type of resin cement (dual or self-adhesive) did not influence the bond strength of GFPs in root dentin previously treated with PDT.

Influence of final irrigation protocols and endodontic sealer on bond strength of root filling material with root dentin previously treated with photodynamic therapy.

The aim of this study was to evaluate the influence of final irrigation protocols and endodontic sealer on bond strength of root filling material on root dentin previously treated with photodynamic therapy (PDT). One hundred root canals were prepared up to #F3 file of Pro-Taper system to receive the root filling material. All samples were submitted to PDT and randomly divided into five groups (n = 20) according to final irrigation protocols: Group 1-distilled water + ultrasonic activation (US); Group 2-17% EDTA; Group 3-QMix; Group 4-17% EDTA + US; Group 5-QMix + US. Each group was randomly divided into two subgroups (n = 10), according to the endodontic sealer used for cementation of gutta-percha points: AH Plus or MTA Fillapex. The bond strength was evaluated by a push-out test. The patterns of failure were observed under optical microscopy. The bond strength was evaluated using a two-way Anova followed by the Tukey post-hoc test, and the failure mode was evaluated using the chi-square test (α = 5%). The use of 17% EDTA and QMix associated or not to US improved the bond strength of root filling material with either endodontic sealer (p < 0.05). AH Plus showed higher bond strength than MTA Fillapex (p < 0.05). There was a higher predominance of cohesive failure in all groups, regardless of the tested final irrigation protocols and endodontic sealer (p < 0.05). The use of 17% EDTA and QMix, regardless of association with US, and the use of AH Plus improve the bond strength of the root filling material on root dentin previously treated with PDT.

Micro-CT evaluation of sonically and ultrasonically activated irrigation on the removal of hard-tissue debris from isthmus-containing mesial root canal systems of mandibular molars.

To evaluate the efficacy of sonically and ultrasonically activated irrigation on removal of accumulated hard-tissue debris (AHTD) in mesial root canal systems of mandibular molars using micro-computed tomographic (micro-CT) analysis. Forty mesial roots of mandibular molars with two independent canals joined apically by an isthmus (Vertucci type II) were selected. The root canals were instrumented using Reciproc R25 instruments, and specimens were scanned at a resolution of 10.5μm. Subsequently, n=10 roots were assigned to each of the four final irrigation groups such that the group means and variances were almost identical: sonically activated irrigation with EndoActivator (EA) or EDDY (ED), ultrasonically activated irrigation (UAI) and manual irrigation without activation (MI). The final irrigation procedures were performed using a total of 5mL 1% NaOCl and 5mL 15% EDTA per canal over 5 min with activation time of 4×20 s. Reconstructed data sets were coregistered, and the mean percentage reduction of AHTD after final irrigation was compared statistically between groups using analysis of variance at a significance level set at 5%. A significant reduction of AHTD was achieved after final irrigation in all groups (P<0.05), ranging from 44.1% to 66.8%. The vol% of debris after irrigation was 3.7±1.9% for EA, 3.3±2.3% for ED, 2.1±1.6% for UAI and 4.4±2.3% for MI, with no significant difference between groups (P>0.05). None of the final irrigation protocols completely removed AHTD from mesial root canal systems in extracted human mandibular molars. Sonically and ultrasonically activated irrigation performed no better compared to manual irrigation.

Formation of Precipitates on the Surface of Root Dentin After Various Final Irrigation Protocols

Canal irrigation represents one of the most important procedures in the debridement of the canal space along with the mechanical instrumentation.

Efficiency of XP endo Shaper (XPS) and irrigation protocol on the quality of cleaning the apical third of root canal: SEM study

Background/Aim: The aim of this study was to evaluate the efficacy of new rotary NiTi instrument XP-endo SHAPER (XPS) used with two irrigation protocols on the root canal cleaning in the apical area. Material and Methods: The research was conducted on 30 single-rooted teeth extracted for orthodontic reasons which were divided into the two groups. Instrumentation of the canals was conducted with XPS instrument and 2% solution of NaOCl was used as irrigant. Instrumentation in the first group was performed using a conventional continuous irrigation, in the second group, protocol of final irrigation was performed intermittently in 3 cycles. The SEM analysis of the apical third of the canal was performed on longitudinal root cross-section standardized photomicrography with a magnification of 2000X. Results: Results showed that a thicker smear layer was observed in the first group and with continuous irrigation protocol (2,10) in relation to the intermittent irrigation protocol in 3 cycles (1,96), but without significant differences. The walls of the root canal in the apical third of the samples of the second group were slightly cleaner (73.3%) in comparison with the teeth of the first group (64, 7%), but also without significant differences. Conclusions: The use of XPS and 2% solution of NaOCl in the root canal enables efficient cleaning of the apical third of tooth. The final irrigation protocol in three cycles improves the efficiency of the smear layer removal in the apical segment of the canal.

Scanning electron microscopic observation of primary tooth dentin following final irrigation with 95% ethanol: An in vitro study.

The beneficial effects of irrigants during endodontic treatment are well known; however, it may have some deleterious effects on the internal root canal wall, thereby altering its physical properties. The purpose of the study was to assess the effect of 95% ethanol on morphological characteristics of primary root dentin. Biomechanical preparation was done in twenty extracted single-rooted primary anterior teeth using Rotary ProTaper Universal System. Samples were divided into two groups based on the final irrigation protocol: nonalcohol group (NAG) and alcohol group (AG). 3% sodium hypochlorite and 17% ethylenediaminetetraacetic acid were used for irrigation in both the groups, whereas 95% ethanol was used as a final irrigant in AG. After the treatment, these teeth were longitudinally sectioned and studied under the scanning electron microscope (SEM). SEM observation of NAG showed scattered debris with unaffected morphology of dentinal tubules (DT). In AG, DT showed severe erosion with the loss of peritubular and intertubular dentin. A final rinse with 95% ethanol can change the morphology of the internal root surface and aid in smear layer removal in primary teeth.

Effect of proanthocyanidin and bamboo salt on the push-out bond strength of an epoxy resin sealer to sodium hypochlorite-treated root dentin: An in vitro study

Background:In endodontic therapy, final irrigation is often done with sodium hypochlorite (NaOCl). This jeopardizes the bond strength between the epoxy resin sealer, used subsequently in obturation and radicular dentin. This study aimed to analyze the effect of natural antioxidants, 6.5% proanthocyanidin (PA) and 25% bamboo salt (BS) on the reversal of NaOCl-induced reduced bond strength of an epoxy resin sealer to dentin.Materials and Methods:Thirty-three single-rooted extracted human teeth were randomly divided into three groups based on the final irrigation protocol: group 1 (saline), Group 2 (6.5% PA), and Group 3 (25% BS). The canals were cleaned, shaped, and obturated with gutta-percha and AH Plus sealer. 1.5 mm-thick root slices made from coronal, middle, and apical thirds of the canal were subjected to push-out bond strength (PBS) testing. The data were statistically analyzed using Kruskal–Wallis and Dunn's post hoc test (P < 0.05).Results:5.25% NaOCl significantly decreased the bond strength of AH Plus to dentin (P < 0.05). Both 6.5% PA and 25% BS were capable of reversing the compromised PBS of AH Plus to NaOCl-treated dentin.Conclusion:Final irrigation with antioxidants such as PA and BS eliminates the risk of reduced bond strength of AH Plus to root canal walls, which ensues following the use of NaOCl as an irrigant.

Erosive Potential of 1% Phytic Acid on Radicular Dentine at Different Time Intervals.

Objective:The objective of this in-vitro study was to compare the erosive potential and smear layer removal ability of 1% Phytic acid (IP6) and 17% Ethylenediaminetetaacetic acid (EDTA).Methods:Canal preparation of 225 single rooted extracted human teeth was performed with Protaper NiTi rotary instruments. Teeth were divided into three groups according to the final irrigation protocol. Group 1: Saline irrigation (n=75), Group 2: 17% EDTA (n=75), Group 3: 1% Phytic Acid (n=75). Roots were splitted and observed under Scanning Electron Microscope (SEM) for erosion and smear layer removal. Mean differences between the groups for smear layer removal and erosion were assessed using the Kruskal Wallis and Mann Whitney U test. (P≤0.05) Friedman and Willcoxon Signed Rank tests were used to make comparisons within the groups.Results:Group 3 was significantly less erosive than Group 2 at all root portions (P<0.001). With regards to smear layer removal, group 2 (EDTA) removed more smear layer compared to group 3 (Phytic acid) at all root portions (P<0.001). Both 17% EDTA and 1% IP6 removed significantly less smear layer in the apical root portion. Intra group comparisons revealed no significant differences at any root level. There was a time dependent increase in erosion and smear layer removal in Group 2, with severe erosion at 5 minutes time interval. In Group 3, however, there was moderate erosion and smear removal at 3 and 5 minutes interval.Conclusion:IP6 at the concentration of 1% and pH 3 was less erosive than 17% EDTA. It exhibited moderate smear layer removal ability.

Effect of Final Irrigation Protocol on Dentin Microhardness

Endodontic therapy is essentially a debridement procedure that requires the removal of the irritants of the canal and periapical tissue if success is to be gained. The debridement may include instrumentation of the canal, placement of medicament and irrigants. Complete cleaning of the root-canal system requires the use of irrigants that dissolve organic and inorganic material. The study aimed to evaluate changes in dentin microhardness after canal irrigation with different solutions. Twenty four freshly extracted human mandibular molars (distal roots with single canals) were used. 10mm root length was taken as standard length. The roots were embedded into auto polymerizing acrylic resin using plastic molds before the canals preparation and micro hardness test. The distal roots were prepared with one shape rotary file. Before the preparation each root was irrigated with 1ml distilled water. Then the roots were divided into four groups according to the final irrigation protocol: Group A: NaOCl 2.5%, Group B: EDTA 17%, Group C: Citric Acid 40%, Group D: Distilled Water. For (Vicker microhardness test) the same load and time 500 g test load for 20 seconds, will be conducted three times at distance 0.5mm from canal lumen ; thus there will be 9 indentations on each specimen surface. An average of the three readings for each test condition will be recorded as the VHN value of a specimen. Comparing all four groups statistically there was no significant difference among them. The mean values were found more reduced in EDTA group followed by NaOCL group, and then Control and Citric Acid groups. All the groups showed reduction in dentin microhardness. EDTA group showed the maximum reduction followed by NaOCL group, and least with Citric Acid group.

Micro-CT comparison of XP-endo Finisher and passive ultrasonic irrigation as final irrigation protocols on the removal of accumulated hard-tissue debris from oval shaped-canals.

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. 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%. The final irrigation protocols were highly similar in terms of volumetric percentage reduction of AHTD (P = 1.000). 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. 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.

Irrigation trends among members of the Chilean Endodontic Society

Introduction: The aim of this study is to determine the current trends of irrigation during root canal therapy by specialists who are members of the Chilean Endodontic Society. Materials and Method: A survey (Survey Monkey®-SurveyMonkey.com) was e-mailed to the 485 members of the Chilean Endodontic Society. The instrument was translated and adapted from the survey "Irrigation trends among American Association of Endodontists members: A web-based survey" applied in the USA in 2012. Participants answered a set of 16 questions that included irrigant selection, irrigant concentration, the adopted protocol, techniques or devices for irrigant activation. Results: 99% of respondents use sodium hypochlorite as the main irrigant. Data indicate that 74% of respondents use hypochlorite at a concentration of 5%. Most respondents (94%) also include EDTA in their usual practice. In addition, 90% of respondents reported that they activate the irrigating agent, and 94% confirmed that they perform a final irrigation protocol. Conclusion: The majority of respondents use sodium hypochlorite as the main irrigant at a concentration of 5%, use ethylenediaminetetraacetic acid (EDTA) as a smear removal agent, activate the irrigant, and perform a final irrigation protocol.

Influence of ultrasonic activation using different final irrigants on antimicrobial activity, smear layer removal and bond strength of filling material.

The aim of this study was to evaluate the influence of ultrasonic activation (US) over final irrigants on antimicrobial activity, smear layer removal and bond strength. The root canals of 180 extracted human teeth were distributed into three experimental tests (n = 60). In each test, the samples were subdivided into six groups (n = 10) according to final irrigation protocols: G1:distilled water (DW); G2:DW + US; G3:17% EDTA; G4:QMix; G5:17% EDTA + US; and G6:QMix + US. The antimicrobial activity was evaluated by counting of colony-forming units (CFUs), the smear layer removal by scanning electron microscopy and the bond strength by push-out test. Statistical analysis was performed for each evaluation (α = 5%). Groups 4 and 6 provided higher bacterial reduction, groups 5 and 6 provided higher smear layer removal, groups 3, 4, 5 and 6 provided the higher bond strength (P < 0.05). US activation did not improve the antimicrobial activity and the bond strength, whereas it improved the smear layer removal.

Micro-CT evaluation of different final irrigation protocols on the removal of hard-tissue debris from isthmus-containing mesial root of mandibular molars

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. 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 20mL of solution (16mL of 5.25% NaOCl and 4mL of 17% EDTA) in a total time of 5min 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%. 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). 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. 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.

Evaluation of 17% EDTA and 10% citric acid in smear layer removal and tubular dentin sealer penetration.

The purpose of this study was to compare the efficacy of different chelating solutions (17% EDTA and 10% citric acid) on the smear layer removal, and their effect on tubular dentin sealer penetration. Sixty root canals were prepared and distributed into four groups (n = 15) according to the final irrigation protocol: G1, final irrigation with 2.5 mL of distilled water; G2, final irrigation with 2.5 mL of 2.5% sodium hypochlorite solution; G3, final irrigation with 2.5 mL of 17% EDTA; and G4, final irrigation with 2.5 mL of 10% citric acid. Five specimens from each group were not filled to assess smear layer removal by scanning electron microscopy. Ten specimens from each group were filled for analysis of sealer penetration into dentinal tubules by confocal laser scanning microscopy. Smear layer removal (Kruskal-Wallis and Dunn's tests) and sealer penetration (F and Tukey's tests) were statistically analyzed with 95% of significance level. G3 and G4 had greater smear layer removal rates in the cervical and middle thirds, in comparison with G1 and G2 (p < .05). G3 and G4 had the highest percentages of sealer penetration in all thirds, in comparison with G1 and G2 (p < .05). Smear layer removal was effective only at the cervical and middle thirds when the chelating solutions were used. Sealer penetration into the dentinal tubules significantly increased in all root thirds when the specimens were treated with both chelating solutions.

Cytotoxicity, genotoxicity and antibacterial activity of poly(vinyl alcohol)-coated silver nanoparticles and farnesol as irrigating solutions

ObjectiveTo evaluate the cytotoxicity, genotoxicity and antibacterial activity of poly(vinyl alcohol)-coated silver nanoparticles (AgNPs-PVA) and farnesol (FAR). DesignThe cytotoxicity (% of cell viability) was evaluated by MTT assay and the genotoxicity (% of DNA in the tail) was evaluated by Comet assay. Root canal disinfection with different irrigating protocols was evaluated ex vivo in human teeth contaminated with Enterococcus faecalis for 21days. Three microbiological samples were collected: initial (after contamination); post-irrigation (after irrigation); and final (after 7days). After each sample, the number of log 10 CFU mL−1 was determined. Statistical analyses was performed using two-way ANOVA and Bonferroni post-hoc tests for MTT assay, Kruskal-Wallis and Dunn post-hoc tests for Cometa and antibacterial assays (α=0.05). ResultsThe MTT assay showed that AgNPs and FAR were less cytotoxic that sodium hypochlorite (NaOCl) and showed a lower% of DNA in the tail, in comparison with H2O2 (positive control − C+). In the post-irrigation microbiological sample, all the irrigating protocols were more effective than C+ (without irrigation). NaOCl/saline, NaOCl/saline/AgNPs-PVA and NaOCl/saline/FAR led to complete bacterial elimination (p >0.05). In comparison with the initial sample, both the post-irrigation and the final samples showed microbial reduction (p < 0.05). ConclusionsAgNPs-PVA and FAR showed low cytotoxicity and genotoxicity, and exhibit potential for use as a final endodontic irrigation protocols.

Efficacy of different irrigant protocols and application systems on sealer penetration using a stepwise CLSM analysis.

This study compared several irrigation protocols and application systems for sealer penetration into dentinal tubules. Single-rooted-human teeth were divided into 5 experimental groups (n = 15) and a control group (n = 5), according to final irrigation protocols: standard needle irrigation (SNI); Vibringe; Vibringe + NaviTip FX (Vibringe NFX); Endo Spray (ES); and passive-ultrasonic-irrigation (PUI). Following obturation of the root canals, the percentage of the sealer penetration was measured at different depths using stepwise CLSM analysis. The sealer penetration in the experimental groups was significantly higher than the control group at all levels (p < .05). No significant differences were observed between Vibringe and SNI or Vibringe NFX, ES, and PUI at all depths (p > .05). The Vibringe NFX, ES, and PUI groups allowed deeper sealer penetration than SNI at 100, 250, and 500 μm levels (p < .05). The irrigant activation, the needle design, and the application form (syringe or spray) may impact the quality of the seal that is achieved with root canal filling.

Effect of Final Irrigation Protocol and Etching Mode on Bond Strength of a Multimode Adhesive in the Root Canal.

To analyze the effects of ethanol for final post space irrigation and etching mode on the bond strength of fiber posts luted with a mild multimode adhesive (pH 2.3) as compared with a reference group using a self-adhesive resin cement (SAR). Human anterior teeth were endodontically treated. After post space preparation, the root canals were irrigated using 1% sodium hypochlorite (NaOCl) applied with passive ultrasonic irrigation, followed by either distilled water (control) or distilled water and ethanol 99% as final post space irrigation. Fiber posts were luted using Futurabond U in self-etch mode (FU-SE), Futurabond U in etch-and-rinse mode (FU-ER), or Futurabond DC (SE) in combination with a dual-curing core buildup material (Grandio Core, all VOCO); alternatively, posts were inserted using a self-adhesive composite cement (RelyX Unicem 2, 3M ESPE). Bond strengths were evaluated using push-out tests following thermocycling (TC) and storage in 0.9% NaCl for 3 months. Mean push-out bond strengths (MPa) were significantly affected by the luting system (p < 0.0005) but not by the irrigation protocol (p = 0.068; ANOVA), although a significant interaction between the factors "luting agent" and "pre-treatment" was observed. FU E&R (21.28 [4.34]) and RX (20.12 [7.32]) revealed significantly higher bond strengths compared to FU SE (15.9 [6.02]), whereas F DC (18.8 [6.9]) did not differ significantly from all other groups. Ethanol pre-treatment increased bond strength in the apical part of the root canal for all materials, with the exception of FU E&R. Mild multimode adhesives exhibit comparable mean bond strengths to a SAR cement within the root canal for luting fiber posts if applied in an etch-and-rinse mode. Using this approach, ethanol application has no positive effects on bond strength.

Effect of ultrasonic activation on the reduction of bacteria and endotoxins in root canals: a randomized clinical trial.

This randomized clinical trial aimed to compare the effectiveness of ultrasonic activation with that of nonactivated irrigation on the removal of bacteria and endotoxin from root canals. Fifty patients with necrotic pulps and asymptomatic apical periodontitis were randomly allocated into two groups according to the final irrigation protocol after root canal preparation: Group UI - ultrasonic irrigation (n=25) and Group NI - needle irrigation (n=25). The root canals were medicated with calcium hydroxide for 14days. Microbiological sampling was performed before (S1) and after the root canal preparation (S2), after the irrigation protocols (S3) and after the removal of the intracanal medication (S4). Total bacteria counts were determined by qPCR and the endotoxin levels by the limulus amebocyte lysate assay. Intragroup analyses were performed using the Wilcoxon test for related samples, whereas intergroup analyses were performed using the Mann-Whitney U-test (P<0.05). All S1 samples were positive for bacteria, with median numbers of 1.49×106 and 8.55×105 bacterial cells for the UI and NI groups, respectively. This number significantly decreased in S2 samples (UI: 1.41×104 ; NI: 3.53×104 ; both with P<0.001). After final irrigation protocols, there was a significant decrease in bacterial load from S2 to S3 samples in both groups (UI: 4.29×103 ; NI: 1.08×104 ; P<0.01). Intergroup analysis revealed a significant difference between irrigation methods regarding bacterial counts in S3 samples (P<0.05). In contrast, no significant differences were observed between groups for endotoxin levels (P>0.05). Ultrasonic activation was more effective than nonactivated irrigation for reducing the number of bacteria but not the endotoxin levels in root canals of teeth with apical periodontitis.

Influence of ultrasonic activation over final irrigants in the removal of photosensitizer from root canal walls after photodynamic therapy

IntroductionThe aim of the present study was to evaluate the influence of ultrasonic activation (US) of the final irrigant in the removal of the photosensitizer from root canal walls after photodynamic therapy. MethodsThe root canals of 60 single-rooted bovine extracted teeth were filled with 0.01% methylene blue and submitted to photodynamic therapy for 90s. After that, the roots were divided into six groups (n=10) according to the final irrigation protocol: distilled water (DW), DW+US, 17% EDTA, QMix, EDTA+US, and QMix+US. Then, the samples were submitted to scanning electron microscopy where a scoring system was used to evaluate the images and effectiveness of proposed treatments in the cervical, middle and apical regions of the root canals. The data were statistically analyzed by the Kruskal-Wallis and Mann-Whitney U tests for intergroup comparisons as well as the Wilcoxon and Friedman tests for intragroup comparisons at 5% of significance. ResultsThe 17% EDTA+US and QMix+US treatments were most effective in the removal of the photosensitizer in all regions of the root canal; the difference was statistically significant when compared to all other groups (p<0.05). There were no significant differences in the intragroup analysis comparing the effectiveness in the different regions of the same group (p<0.05). ConclusionsUS can aid 17% EDTA and QMix in removing the photosensitizer after photodynamic therapy and contributes to cleaning root canal walls.

The use of auxiliary devices during irrigation to increase the cleaning ability of a chelating agent.

ObjectivesThis study investigated the cleaning ability of ultrasonically activated irrigation (UAI) and a novel activation system with reciprocating motion (EC, EasyClean, Easy Equipamentos Odontológicos) when used with a relatively new chelating agent (QMix, Dentsply). In addition, the effect of QMix solution when used for a shorter (1 minute) and a longer application time (3 minutes) was investigated.Materials and MethodsFifty permanent human teeth were prepared with K3 rotary system and 6% sodium hypochlorite. Samples were randomly assigned to five groups (n = 10) according to the final irrigation protocol: G1, negative control (distilled water); G2, positive control (QMix 1 minute); G3, QMix 1 minute/UAI; G4, QMix 1 minute/EC; G5, QMix 3 minutes. Subsequently the teeth were prepared and three photomicrographs were obtained in each root third of root walls, by scanning electron microscopy. Two blinded and pre-calibrated examiners evaluated the images using a four-category scoring system. Data were statistically analyzed using Kruskal-Wallis and Dunn tests (p < 0.05).ResultsThere were differences among groups (p < 0.05). UAI showed better cleaning ability than EC (p < 0.05). There were improvements when QMix was used with auxiliary devices in comparison with conventional irrigation (p < 0.05). Conventional irrigation for 3 minutes presented significantly better results than its use for 1 minute (p < 0.05).ConclusionsQMix should be used for 1 minute when it is used with UAI, since this final irrigation protocol showed the best performance and also allowed clinical optimization of this procedure.