Analysis of the penetration of NaOCl 5.25% into dentinal tubules using different irrigation protocols: An ex vivo study

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.

Assessment of different irrigation techniques on the penetration depth of different sealers into dentinal tubules by confocal laser scanning microscope: An in vitro comparative study

Background

The effective disinfection of the entire root canal system aids in the penetration of irrigants into the dentinal tubules further improving sealer penetration and achieving a three-dimensional seal in endodontically treated teeth. Various final irrigation techniques can be employed to achieve this goal. Therefore, this study intended to assess and compare the efficacy of three final irrigation techniques on the depth of penetration of two root canal sealers into dentinal tubules using confocal laser scanning microscope (CLSM).

Methods

Forty-eight single-rooted mandibular premolars were selected and decoronated to a length of 12 mm. All the samples were prepared using ProTaper Gold rotary files and divided into three groups: Group 1 - Conventional syringe irrigation (CSI), Group 2 - passive ultrasonic irrigation (PUI), and Group 3 - Pro-agitator tip system (PATS). Each group was divided into two subgroups: Subgroup A - AH Plus and Subgroup B - GuttaFlow Bioseal (GFB). Then, sealers were mixed with 0.1% rhodamine B dye and the samples were obturated. All the samples were sectioned at 2 mm and 5 mm from the apex and visualized under confocal laser scanning microscope (CLSM) (10×) for maximum mean penetration depth and percentage of sealer penetration. Statistical analysis was done using the independent t-test and one-way analysis of variance test, followed by Tukey's Post hoc analysis.

Results

PUI performed better in the apical third, whereas PUI and PATS showed comparable results in the middle third for both depth and percentage of sealer penetration. Among the two sealers, GFB performed better than AH Plus in both the apical and middle third. These values were statistically significant. (P < 0.05).

Conclusion

Final irrigation activation with PUI or PATS can significantly improve sealer penetration. The average depth of penetration of GFB both at the middle and apical third of the root was significantly superior to AH Plus.

Antimicrobial efficacy of two commercially available herbal products with and without ultrasonic activation in primary endodontic infections: A randomized clinical trial

Background

Effective irrigation is crucial for successful endodontic treatment. Traditional irrigants like sodium hypochlorite (NaOCl) have been widely used, but there is a growing interest in exploring natural alternatives for their potential antimicrobial properties.

Objective

The study aims to compare the antimicrobial efficacy of Neem, Bitter Gourd, and NaOCl, with and without ultrasonic activation in managing primary endodontic infections.

Materials and Methods

Ninety patients were randomly assigned six groups (n = 15) Group 1: NaOCl, Group 2: NaOCl with passive ultrasonic irrigation (PUI), Group 3: Neem juice, Group 4: Neem juice with PUI, Group 5: Bitter gourd juice, and Group 6: Bitter gourd juice with PUI. Bacteriological samples were collected before (S1) and after (S2) shaping, plated on brain heart infusion agar, and colony counting was done after 24 h.

Statistical Analysis Used

Shapiro-Wilk test, one-way ANOVA, post hoc Tukey analysis, and paired t-test.

Results

All the groups demonstrated a significant reduction in bacterial count. Groups with PUI (2, 4, 6) demonstrated higher mean bacterial reduction than their counterparts without PUI (1, 3, 5).

Conclusion

Neem and Bitter gourd juices, particularly when used with PUI, demonstrated antimicrobial efficacy comparable to NaOCl with PUI.

Comparative evaluation of antifungal activity of Sodium Hypochlorite, Calcium Hypochlorite and modified Salt Solution associated with passive ultrasonic irrigation against Candida albicans - An In-Vitro study

Aim

The study evaluated the antifungal activity of sodium hypochlorite (NaOCl), calcium hypochlorite (Ca(OCl)2), and modified salt solution (MSS) assisted with passive ultrasonic irrigation against Candida albicans.

Materials and Methods

One hundred and thirty-six single-rooted premolars were decoronated and enlarged up to a file #45, autoclaved, inoculated with C. albicans, and incubated for 72 h. The samples were randomly distributed into eight groups (n = 17) according to the protocol for decontamination G1: No treatment, G2: Distilled water (DW), G3: 2.5% NaOCl, G4: 2.5% NaOCl + ultrasonic activation (US), G5: 2.5% Ca(OCl)2, G6: 2.5% Ca(OCl)2 + US, G7: MSS, G8: MSS + US. Microbiological testing (Colony forming Unit [CFU] counting) was performed before and after the treatment.

Statistical Analysis

Data were subjected to the one-way analysis of variance followed by the Tukey's post hoc test (P < 0.05).

Results and Conclusion

Groups 1 and 2 showed the highest mean contamination (5.41 and 4.31 log10 CFU/mL, respectively), which was statistically different from all the other groups (P < 0.001). G4 showed the lowest mean contamination (0.24 log10 CFU/mL) with statistically significant value (P < 0.001). 2.5% NaOCl with ultrasonic activation can aid in significant fungal reduction. Ultrasonic activation of 2.5% NaOCl, 2.5% Ca(OCl)2, and MSS was also found to have improved antifungal activity against C. albicans.

The efficiency of different irrigation activation techniques in the removal of calcium silicate-based endodontic sealer from artificially created groove

This study evaluated the removal of a calcium silicate-based sealer (EndoSeal MTA) with needle irrigation (NI), passive ultrasonic irrigation (PUI), XP-endo Finisher (XPF) and EDDY. A total of 56 human mandibular premolars were instrumented up to size 40.04 taper. The roots were separated longitudinally, and grooves were prepared with an ultrasonic tip at one-half of each root canal. The grooves were covered with EndoSeal MTA and re-attached roots were investigated based on the activation techniques applied. The results showed that significantly more material (p < 0.05) was removed in the EDDY group compared to the NI, PUI and XPF groups in the apical region. In the coronal region, no significant difference was observed between EDDY, XPF and PUI (p > 0.05), whereas all the latter were significantly more effective than NI (p < 0.05). These findings show that the removal of EndoSeal MTA can be more effective with EDDY compared to XPF, PUI and NI in the apical region.

Comparative evaluation of four different root canal irrigation techniques for apical extrusion of sodium hypochlorite - An in vitro study

Objective

This study compared the potential for apical extrusion of sodium hypochlorite (NaOCl) when using needle irrigation (NI), passive ultrasonic irrigation (PUI), passive subsonic irrigation (PSI), and negative pressure system (NP).

Materials and Methods

One hundred freshly extracted human permanent anterior teeth with complete root formation were embedded rigidly in agarose gel-containing cresol purple. Teeth were randomly allocated to six groups: G1-NI; G2-PUI; G3-PSI; G4-NP; G5-positive control; and G6-negative control. The chemomechanical preparation was completed and 12 ml of 3% NaOCl was delivered for 180 s in all groups. Dye diffusion was standardized by doing gel photography after the NaOCl final irrigation the Chi-square test and Kruskal-Wallis one-way analysis of variance test were used for the data analysis.

Results

G1 had statistically significant apical extrusion compared to G2 (P = 0.001), G3 (P = 0.001), and G4 (P = 0.001) groups. G4 showed the least amount of apical extrusion.

Conclusions

pH-sensitive gel model is useful in evaluating NaOCl extrusion. NP produced least NaOCl extrusion as compared to the other three systems. Due consideration should be given to the potential for apical extrusion of the irrigant before the selection of an irrigation system.

Comparable Effectiveness of Photon-Induced Photoacoustic Streaming with XP-Endo Finisher and Passive Ultrasonic Irrigation on Removing Residual Root Canal Filling Materials from Oval Canals

Objective: This study aimed to evaluate the effectiveness of photon-induced photoacoustic streaming (PIPS), XP-endo Finisher (XPF), and passive ultrasonic irrigation (PUI) for the removal of root canal filling materials from oval root canals. Background: Various adjunctive irrigation techniques following mechanical preparation have been applied to enhance removal of fillings during root canal retreatment. However, whether there is superiority of one approach over others remains controversial. Methods: Thirty extracted single-rooted teeth with oval-shaped canals were instrumented with the ProTaper Next (PTN) system and obturated with the warm vertical compaction technique. After storage at 37°C for 1 month, retreatment was performed with the PTN system up to size X4. The teeth were then randomly assigned into three groups (n = 10) that were, respectively, subjected to supplementary irrigation with different protocols: PIPS, PUI, and XPF, followed by measurement of filling material volumes using high-resolution micro-computed tomography. Results: The PTN preparation resulted in significant reductions in residual filling materials (p < 0.05), whereas PIPS, PUI, and XPF moderately improved the removal of the remnants (p > 0.05). The residual filling materials after supplementary irrigation ranged from 0.384 ± 0.181 to 0.421 ± 0.143 mm³ in oval canals. There was no significant difference in the effectiveness among the PIPS, PUI, and XPF approaches (p > 0.05). Conclusions: Mechanical preparations are useful for removing most root fillings during retreatment in oval-shaped canals. PIPS can reduce residual root-filling materials to the similar extent as PUI and XPF.

Cleaning and Disinfecting Oval-Shaped Root Canals: Ex Vivo Evaluation of Three Rotary Instrumentation Systems with Passive Ultrasonic Irrigation

Background and Objectives: Successful root canal treatment depends on the thorough removal of biofilms through chemomechanical preparation. This study aimed to investigate and compare the cleaning and disinfecting efficiency of oval-shaped root canals using XP-endo Shaper (XPS), ProTaper Next (PTN), and HyFlex CM (HCM) in combination with passive ultrasonic irrigation (PUI). Materials and Methods: Ninety extracted teeth were contaminated and randomly divided into three groups: XPS, PTN, and HCM. Each group was assigned to three subgroups: subgroup A (sterile saline), subgroup B (3% sodium hypochlorite and 17% ethylenediaminetetraacetic acid), and subgroup C (3% sodium hypochlorite, 17% ethylenediaminetetraacetic acid, and PUI). Bacterial sampling was conducted both from baseline samples and samples after chemomechanical preparation. Scanning electron microscopy (SEM) was used to evaluate the residue bacterial biofilms, hard tissue debris, and smear layers on the buccolingual walls of oval-shaped root canals. Results: When combined with sterile saline, XPS demonstrated a higher reduction of bacterial counts and was more effective in eradicating Enterococcus faecalis in the middle third of the canals compared to the other instruments (p < 0.05). Additionally, when used with antimicrobial irrigants, XPS was more effective in disinfecting the coronal third of the canals than the other instruments (p < 0.05). Furthermore, XPS reduced hard tissue debris more effectively in the middle third of canals than in the apical third (p < 0.05). Conclusions: XPS outperforms PTN and HCM in disinfecting oval-shaped root canals. Despite the fact that combining XPS and PUI improves cleaning and disinfecting, removing hard tissue debris from the critical apical area remains challenging.

Evolution of the combined effect of different irrigation solutions and activation techniques on the removal of smear layer and dentin microhardness in oval-shaped root canal: An in-vitro study

The aim of this in vitro study was to evaluate the effect of three final irrigants, namely QMix, MTAD and EDTA, combined with three irrigation techniques, namely conventional needle irrigation (CNI), passive ultrasonic irrigation (PUI) and photon-induced photoacoustic streaming (PIPS), on smear layer removal, dentin mineral content and microhardness in oval-shaped canals.    130 decoronated premolars with single, oval root canals were equally divided into1 blank control group and 12 treatment groups (n=10) according to the final irrigation protocols. Roots in treatment groups were instrumented with ProTaper Gold to size F4 and subjected to final irrigation. Smear layer removal was assessed by using a four-level scoring system under an environmental scanning electron microscope. Energy dispersive X-ray spectroscopy was performed to measure the dentin mineral content. Dentin microhardness was measured by Knoop microhardness testing. Statistical analysis of the data was performed by using Kruskal-Wallis test, followed by Dunn's post hoc test with Bonferroni correction. PUI- and PIPS-activated QMix and EDTA removed smear layer more effectively than MTAD groups (p<0.05). Regarding the dentin mineral content and microhardness, QMix groups yielded the least calcium (Ca), phosphorus (P)  and Ca/P ratio, followed by EDTA groups and MTAD groups (p<0.05). QMix groups produced significantly lower dentin microhardness values and higher hardness reduction percentages than MTAD groups (p<0.05).  Within the limitations of the present study, it was concluded that QMix and EDTA were superior to MTAD in smear layer removal, especially when activated by PUI and PIPS, but these agents produced more pronounced effect on dentin mineral content and microhardness than MTAD.

Influence of different irrigant activation methods on apical debris extrusion and bacterial elimination from infected root canals

Introduction

The study aimed to determine the apical debris extrusion and microbial elimination from infected root canals after using different irrigant activation methods.

Materials and Methods

Forty freshly extracted human mandibular premolars were selected and randomly assigned to four groups (n = 10). The teeth were mechanically prepared, sterilized, and inoculated with Enterococcus faecalis for 1 week. Irrigation was done with 3% sodium hypochlorite following conventional syringe irrigation-Group 1, manual dynamic agitation (MDA)-Group 2, passive ultrasonic irrigation (PUI)-UltraX -Group 3, and sonic irrigation (SI)-EndoActivator -Group 4, and the extruded debris were collected using Myers and Montgomery model. The microbial samples were taken from the canals using sterile paper points, cultured and recorded as colonies. The amount of extruded debris was measured by subtracting the final weight of the Eppendorf tube with debris from the initial weight of the tube.

Results

I. Group 3 showed the least apical debris extrusion (P < 0.05), followed by Groups 2 and 1 and the highest with Group 4. II. Group 3 showed the least colony-forming units (CFUs)/ml, followed by Group 4, and finally, Group 2 showed lesser mean CFUs/ml compared to Group 1 (P < 0.05).

Conclusion

All the irrigation activation methods were associated with apical debris extrusion, with the PUI system extruding the least amount of debris compared to the other groups. Irrigation activation techniques were beneficial in reducing the microbial load from the infected canals with the PUI system showing a complete elimination of the microbes, followed by SI and MDA.

Retreatability of calcium silicate-based root canal sealer using reciprocating instrumentation with different irrigation activation techniques in single-rooted canals

This study analysed the bioceramic sealer cleaning ability of two chemo-mechanical systems in intact and restored teeth. Thirty-two single-rooted teeth were used, and half of them restored with a pre-endodontic composite restoration (PCR). All samples were instrumented with a size 40 Reciproc Blue file and filled with BioRoot RCS. Canals were retreated using the R40 and then R50 Reciproc Blue. The samples were divided into four experimental groups (n = 8): intact teeth/passive ultrasonic irrigation (PUI) (G1), intact teeth/shock wave-enhanced emission photoacoustic streaming (SWEEPS) (G2), PCR/PUI (G3) and PCR/SWEEPS (G4). The samples were scanned by micro-CT before and after retreatment, and the volume of remaining filling material was evaluated. The minor percentage of residues were observed in G2, with a volume of 0.447 ± 0.356% of the endodontic space (P < 0.001). The Reciproc/SWEEPS technique showed the better performance in intact teeth compared with PUI technique. Pre-endodontic restoration did not significantly affect the effectiveness of sealer removal.

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.

Influence of volume of endodontic irrigants used in different irrigation techniques on root canal dentin microhardness

Introduction

Overzealous application of endodontic irrigants affects the root canal dentin mechanical properties. The effect of volume of endodontic irrigants on the microhardness of root canal dentin has not been studied.

Aim

This study assessed the effect of volume of endodontic irrigants used in different final irrigation activation techniques on root canal dentin microhardness (RCDM).

Methodology

Sixty human maxillary central incisors were embedded in acrylic resin in Kuttler's endodontic cube to the level of cementoenamel junction. The root samples were randomly divided into 4 experimental groups (n = 15): Group-NI-needle irrigation, Group-PUI-continuous passive ultrasonic irrigation, Group-EndoVac-apical negative pressure system, Group combination- EndoVac + PUI irrigation. Root canals were instrumented up to size 40 (F4). The resin mounted specimens were sectioned longitudinally into two halves and were reassembled in Kuttler's kube to carry out final irrigation activation. A predetermined standardized volume of irrigants was used in each group. The RCDM was measured after root canal instrumentation and after final irrigation using Vicker microhardness tester (coronal, middle, and apical third). The reduction in RCDM values (p < 0.0086) were analyzed using Kruskal Wallis and Mann Whitney-U tests.

Results

Reduction in RCDM was observed with all the endodontic irrigating techniques tested. EndoVac and combination irrigation techniques showed maximum reduction in RCDM in all thirds of root canal.

Conclusion

It is concluded that the volume of irrigants and agitation plays a role in reducing RCDM. The overall volume of irrigants to cause maximum reduction was 25 ml, beyond which neither volume nor agitation affects RCDM.

The effectiveness of ethylenediaminetetraacetic, etidronic, and peracetic acids activated with ultrasonics or diode laser on calcium hydroxide removal from root canal walls

Background

To assess the efficiency of ethylenediaminetetraacetic acid (EDTA), etidronic (HEBP), and peracetic (PAA) acids agitated with ultrasonic energy or diode laser on removing calcium hydroxide (CH) dressings from root canal walls.

Material and Methods

Single root canals of eighty extracted human teeth were chemomechanically instrumented and filled with CH. Sixty teeth were divided into six experimental groups (n = 10) according to the applied irrigation regimens for the removal of CH: Group 1: 5.25% NaOCl-17% EDTA, Passive ultrasonic irrigation (PUI); Group 2: 5.25% NaOCl + 9% HEBP, PUI; Group 3: 5.25% NaOCl-2% PAA, PUI; Group 4: 5.25% NaOCl-17% EDTA, Diode laser-activated irrigation (LAI); Group 5: 5.25% NaOCl + 9% HEBP, LAI; Group 6: 5.25% NaOCl-2% PAA, LAI. The other 20 teeth were served as negative (n = 10) and positive controls (n = 10). The residuary amount of CH was scored in coronal, middle, and apical thirds of the root canals by using scanning electron microscope. The data were statistically analyzed using Kruskal-Wallis H with Bonferroni adjusted Mann-Whitney U test with a significance level of 0.05.

Results

Etidronic acid activated with ultrasonics or diode laser removed the highest amount of CH from the middle third of root canals, compared to the other irrigation regimens (P < 0.001). Although the residual CH scores of PAA-PUI, PAA-LAI, and EDTA-PUI, EDTA-LAI groups were not statistically different from each other (P > 0.05), lower amount of CH was observed in the PAA-PUI and PAA-LAI groups.

Conclusions

Use of etidronic acid activated with ultrasonics or diode laser can be an appropriate irrigation regimen for CH removal from root canal system.

Comparative Evaluation of the Effectiveness of Rotary Instrumentation over Manual Instrumentation with Ultrasonic Irrigation on Incidence, Duration, and Intensity of Postendodontic Pain: An In vivo Study

AIM

The aim of this study was to compare the effectiveness of rotary instrumentation over manual instrumentation with ultrasonic irrigation on incidence, duration, and intensity of postendodontic pain (PEP).

SUBJECTS AND METHODS

Eighty patients, with asymptomatic irreversible pulpitis in maxillary anterior teeth, were selected and treated with single-visit endodontic treatment. Patients were randomly divided into 2 groups (40 each), Group A (K files using step-back technique) and Group B (ProTaper Next using crown-down technique) along with passive ultrasonic irrigation. Patients were recalled, examined, and asked to fill up questionnaire after 24 h, 48 h, and 7 days. On the basis of response given in the feedback forms, incidence, duration, and intensity of PEP were evaluated.

RESULTS

Statistical analysis of the data was carried out using Chi-square test, and level of significance (P < 0.05) was evaluated. More incidence of pain was noticed in Group A when compared with Group B. Significant difference found between two groups (χ ² = 22.759; P = 0.001). There was also statistically significant difference between two groups at different time intervals.

CONCLUSION

Both instrumentation techniques under investigation cause PEP. The incidence of pain was more in manual technique than rotary technique. The duration of pain was higher in manual group than rotary group at different time intervals.

To compare the continuous and intermittent irrigation method on the removal of dentin debris from root canals and to evaluate the dynamics of irrigant flow using computational fluid dynamics

Aim:

This study aimed to compare the efficiency of continuous and intermittent irrigating methods on the removal of dentin debris from the simulated grooves and to evaluate the dynamics of irrigant using computational fluid dynamics (CFD).

Methodology:

Seventy-five extracted human permanent maxillary canines were selected. Access cavities were made, working length was determined, and canals were prepared by crown down technique. The teeth were split longitudinally and standard groove 2.0 mm in length was made in split halves and each groove was filled with dentin debris and the images were taken under a microscope (E200). The halves were re-assembled and divided into five groups based on different irrigation methods. Group 1: ultrasonic Irrigation with continuous flow for 3.0 min; Group 2: ultrasonic irrigation with continuous flow for 1.5 min; Group 3: ultrasonic irrigation with intermittent flow for 3.0 min; Group 4: ultrasonic irrigation with the intermittent flow for 1.5 min; and Group 5: syringe irrigation for 1 min. The root halves were again separated and re-evaluated for debris elimination after the irrigation protocol for all the groups separately. The effect of time and method of passive ultrasonic irrigation were compared. For the computational fluid analysis, a GAMBIT 2.2 (Ansys) software was used for mesh construction. FLUENT 6.2 (Ansys) software was used to set the boundary conditions and reconstruction of the canal; flow patterns and turbulence were graphically constructed.

Results:

The continuous irrigation methods were better at debris removal than intermittent irrigation flow methods. The CFD showed that the turbulence of flow of irrigant was dependent on the inlet velocity and pressure of the irrigant.

Conclusion:

Debris removal from the simulated grooves was better with continuous irrigation compared with intermittent irrigation. CFD study revealed that the turbulence that was affected by the velocity and pressure of the irrigant introduced and is a variable entity.

The effectiveness of passive ultrasonic irrigation and the easy-clean instrument for removing remnants of filling material

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.

Efficiency of Different Endodontic Irrigation and Activation Systems, Self-Adjusting File Instrumentation/Irrigation System, and XP-Endo Finisher in Removal of the Intracanal Smear Layer: An Ex vivo Scanning Electron Microscope Study

Aim:

This ex vivo study was designed to evaluate and compare different endodontic irrigation and activation systems, the self-adjusting file (SAF) instrumentation/irrigation system, and XP-endo finisher for removal of intracanal smear layer.

Materials and Methods:

Fifty recently extracted, noncarious human intact single-rooted premolars were selected and divided into five groups (n = 10) according to the root canal irrigation systems; syringe and needle irrigation, passive ultrasonic irrigation (PUI), EndoVac irrigation system, SAF system, and XP-endo finisher. All groups were prepared to apical size F4 file except for the SAF group which was prepared to apical size 20 K-file and then instrumented with the SAF file. Each sample was subjected to final irrigation using different irrigation/activation systems. After splitting the samples, one half of each root was selected for examination under scanning electron microscope. The irrigation systems were compared using the Fisher's exact test with significance set at P < 0.05.

Results:

In the coronal part, there was no difference among the groups. In the mid-root section, the results of the PUI, EndoVac, SAF, and XP-endo finisher groups tended to be better than syringe and needle irrigation, but the difference was not significant. The apical part of the canal, the SAF system, and XP-endo finisher group seemed to be cleaner than those of the EndoVac group, but this difference was not significant.

Conclusions:

Within the limitations of the present study, SAF system and XP-endo finisher group cleaned the apical part of the canal more efficiently than EndoVac, PUI, and syringe and needle irrigation.

Debris Removal Using a Hydroxyapatite Nanoparticle-Containing Solution (Vector Polish) with Sonic or Ultrasonic Agitation

Chemomechanical preparation of the root canal system is considered to be the most important part of root canal treatment, including both mechanical removal of tissue remnants and dentine chips, and chemical elimination of biofilm and microorganisms. A number of different solutions and agitation techniques have been proposed for that purpose. It was the aim of the present study to investigate whether root canal cleanliness can be improved by using a hydroxyapatite nanoparticle-containing solution with and without sonic or ultrasonic agitation. Seventy-four single-rooted teeth were divided into four experimental groups (n = 15) and two control groups (n = 7). All teeth were split longitudinally and a groove and three holes were cut into the root canal wall and filled with dentinal debris. Final irrigation was performed using sodium hypochlorite or a hydroxyapatite nanoparticle-containing solution (Vector polish) activated with a sonically or an ultrasonically driven endodontic file. Two calibrated investigators rated the remaining debris using a four-score scale. The results were analyzed using a non-parametric test with α < 0.05. Sonic and ultrasonic irrigation with sodium hypochlorite cleaned the grooves and holes well from debris. The hydroxyapatite nanoparticles activated by a sonic file cleaned grooves and holes equally well. Ultrasonically activated nanoparticles performance was clearly inferior. The syringe control-group left large amounts of debris in grooves and holes. The use of the hydroxyapatite nanoparticles used in this study did not improve removal of debris.

Multispecies biofilm removal by XP-endo Finisher and passive ultrasonic irrigation: A scanning electron microscopy study

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.

Effect of Different Irrigation Activation Techniques on Sealer Penetration: A Confocal Laser Microscopy Study

OBJECTIVE

To compare the efficiency of a new sonic powered irrigation system named EDDY (VDW, Munich, Germany), passive ultrasonic irrigation (PUI) and conventional needle irrigation (CNI) in root canal sealer penetration.

METHODS

A total of 45 mandibular premolars were instrumented up to size 30, 0.9 taper and randomly divided into three groups (n = 15) depending on the final irrigation activation technique: EDDY, PUI or CNI. After the final irrigation procedures, the root canals were obturated with labelled sealer mixed with 0.1% rhodamine B. Transverse sections at 3, 5 and 7 mm from the root apex were examined using confocal laser scanning microscopy. The maximum depth and total area and percentage of sealer penetration were measured using ImageJ analysis software (National Institutes of Health, Bethesda, MD, USA).

RESULTS

In the EDDY group, the penetration depth was higher compared to the CNI group in the apical and middle sections and compared to the PUI group in the apical section (P ˂ 0.05). The penetration area in the EDDY group was higher compared to the CNI group in all sections and compared to the PUI group in the coronal section (P ˂ 0.05). The percentage of penetration was higher in the EDDY group compared to the CNI group in all sections and compared to the PUI group in the coronal section (P ˂ 0.05).

CONCLUSION

In the present study, sealer penetration was superior in the EDDY group than the CNI group in the apical section. In the middle and coronal sections, sealer penetration was similar for the EDDY and PUI groups.

Efficacy of passive ultrasonic irrigation in the removal of three different intracanal medicaments - An in-vitro study

Background

A successful root canal treatment involves the elimination of microorganisms, and prevents them from reinfecting the root and/or peri-radicular tissues. This can be mainly achieved by efficient cleaning and shaping of the root canal system. Due to the complexity of the root canal morphology, hand and rotary files cannot clean areas such as the isthmuses and lateral canals. In such cases, effective irrigation and the use of intracanal medicaments are essential. Medicaments that are applied should be removed before obturation.

Aim

To evaluate the efficacy of passive ultrasonic irrigation in the removal of three different intracanal medicaments - Triple antibiotic paste (TAP), Odontopaste, and Metapex using a stereomicroscope.

Methodology

A total of 45 single-rooted human teeth were selected and decoronated. The root canals were shaped with ProTaper rotary files. The specimens were fixed in modified Eppendorf vials with silicone material. The roots were split longitudinally, and a standardized groove was prepared in the apical part. The teeth were randomly divided into three groups each containing 15 samples based on the intracanal medicament used: TAP, Odontopaste, and Metapex.

.

The root halves were reassembled with sticky wax and remounted in the Eppendorf vial. Each specimen was irrigated with 3% NaOCl and agitated using a passive ultrasonic device. The root segments were disassembled. Digital images were obtained using a stereomicroscope.

Results

The data were evaluated statistically using Kruskal-Wallis and Mann-Whitney U tests. There was a statistically significant difference in the remaining intracanal medicament score (P < 0.05).

Conclusion

Odontopaste showed the least remaining amount score, whereas TAP and Metapex showed greater retention within the dentin.

Efficacy of EDDY, ultrasonic activation, XP-endo Finisher and needle irrigation on the removal of mTAP from artificially created grooves in root canals

This study analysed the effect of needle irrigation (NI), passive ultrasonic irrigation (PUI), EDDY and the use of the XP-endo Finisher (XPF) on the removal of modified triple antibiotic paste (mTAP) from artificially created grooves in root canals. Forty-eight maxillary incisors were prepared up to size 50, with a standard groove on one surface of the root canal wall and filled with mTAP. Re-attached roots were analysed based on the activation techniques applied for 180 s with 5 ml 3% sodium hypochlorite. The results showed that EDDY was more effective at removing mTAP than PUI, XPF and needle irrigation (P < 0.05), whereas XPF and PUI were significantly more effective than needle irrigation. (P < 0.05). No significant difference in mTAP removal was observed between XPF and PUI (P > 0.05). These findings suggest that the removal of mTAP can be more efficiently achieved with EDDY than with XPF, PUI or NI.

Comparison of Anti-Bacterial Efficacy between Passive Ultrasonic Irrigation and 980 nm-GaAlAs Laser Application in Two Root Types

Background and Objectives: The purpose of the present study was to investigate the anti-bacterial efficacy of passive ultrasonic irrigation (PUI) and a 980-nm-gallium-aluminum-arsenide (GaAlAs) laser using a real-time DNA-based quantitative polymerase chain reaction (qPCR) assay and scanning electron microscopy (SEM). Materials and Methods: Eighty-six extracted single- and double-rooted human teeth were used in the experiment. The following four experimental groups were evaluated, as well as a control group: group 1: single root + PUI (n = 20); group 2: single root + laser application (n = 20); group 3: double roots + PUI (n = 20); group 4: double roots + laser application (n =20); control group (n = 6): 3 single roots, 3 double roots. The qPCR assay was performed in three stages to evaluate the efficacy of the adjunctive method against Enterococcus faecalis. SEM analysis was also used to examine the microstructure of root canal surfaces. The data were statistically analyzed using the Friedman test and the Kruskal–Wallis test with Bonferroni adjustment. Results: The decrease in the DNA levels from S1 (before preparation) to S2 (just after preparation) was highly significant in all groups, and decreases in DNA levels from S2 to S3 (after incubation for 1 week) were found in all experimental groups except group 1. An inter-group analysis showed that PUI was significantly more effective in terms of antibacterial efficacy than GaAlAs laser irradiation in single root (p < 0.05). However, in double roots, experimental groups did not show significantly lower DNA levels than the control group (p > 0.05). SEM images showed that cleaning of the root canal surface and reduction of dentin debris were achieved only in single-rooted teeth when using PUI application. Conclusions: Two adjunctive methods were effective in reducing E. faecalis in single rooted tooth.

Evaluation of smear layer removal of radicular Dentin in comparison with different irrigation devices: An in vitro study

Aim:

The aim of this study was to evaluate the efficacy of smear layer removal from the root canals using 2 ml of 5.25% sodium hypochlorite passive ultrasonic irrigation, EndoVac, and diode laser during endodontic therapy.

Materials and Methods:

Forty single-rooted human teeth were selected. Access cavity preparation was done. Working length was determined. Instrumentation was initiated with ISO hand files number 15 k file, followed by ProTaper rotary files size F3. Two milliliters of 5.25% NaOCl was used as an irrigant after every instrumentation, with a final flush of 17% EDTA, followed by a rinse with 3 ml of distilled water. Teeth samples were divided into four groups – Group I (n = 10) conventional irrigation with 5.25% NaOCl, 17% EDTA for 1 min, Group II (n = 10) instrumented and irrigated with ultrasonic activation for 1 min, Group III (n = 10) instrumented and irrigated with EndoVac for 1 min, Group IV (n = 10) (analyzed with irradiation of 2 W continuous wave of 910 nm diode laser). Teeth samples were then sectioned longitudinally. Scanning electron microscope examination of canals was done for evaluating smear layer at different levels. Statistical data analysis was done by one-way ANOVA test to evaluate the smear layer score at a significance level of P ≤ 0.05.

Results:

Group III and Group IV have a minimal amount of smear layer at the apical third when compared to Group I and Group II which was statistically significant with a P < 0.05.

Conclusion:

Diode laser and EndoVac performed better in removing the smear layer when compared with 2 ml of 5.25% sodium hypochlorite and ultrasonic irrigation.

Effect of final irrigation protocols on the fracture resistance of roots with varying dentine thickness

This study evaluated the effects of 9% etidronic acid (HEBP) and 17% ethylenediaminetetraacetic acid (EDTA) used either with conventional syringe irrigation (CSI) or passive ultrasonic irrigation (PUI) on the fracture resistance of roots with different dentine thickness. The root canals of 120 extracted teeth were widened, leaving dentinal walls with different thicknesses of either 0.75 mm, 1.50 mm, or 2.25 mm with 40 teeth in each group. Within each of these groups, four subgroups (n = 10) were formed according to the final irrigation regimens applied: 2.5% NaOCl-17% EDTA with CSI; 2.5% NaOCl-17% EDTA with PUI; 2.5% NaOCl + 9% HEBP with CSI; 2.5% NaOCl + 9% HEBP with PUI. The irrigated root canals were obturated with AH Plus sealer and gutta-percha cones. A compressive vertical loading was applied to the samples and the force at fracture was recorded. Data were statistically analysed using a multiple linear regression analysis. The most influencing factor for the fracture strength of roots was the remaining dentine thickness, followed by the irrigation method, and then the irrigation solution. The samples irrigated using PUI were statistically significantly more resistant to fracture than those using CSI (mean difference = 116.3 N; 95% CI = [53.9, 178.6] N). The application of HEBP was associated with higher resistance to fracture than the application of EDTA (mean difference = 71.0 N; 95% CI = [8.6, 133.3] N).

Evaluation and comparison on the wettability of three root canal sealers after three different irrigant activation techniques: An in vitro study

Background

Wettability of root canal sealers to the root canal wall plays a significant role in the attainment of a fluid-tight seal.

Aims

This study aimed to evaluate and compare the wettability of three different root canal sealers on the root canal walls after three different irrigant activation techniques using the contact angle meter.

Subjects and Methods

Thirty-six single-rooted mandibular premolars after decoronation and cleaning and shaping up to size #35 were randomly divided into three groups with 12 samples in each group (n = 12) based on the different activation techniques: Group I (passive irrigation with side-vented needle), Group II (manual dynamic agitation), and Group III (passive ultrasonic irrigation). Root segments were split longitudinally and were subdivided into three subgroups based on the root canal sealers tested with four samples in each subgroup (n = 4): Subgroup A (Tubliseal EWT), Subgroup B (AH Plus), and Subgroup C (Endosequence BC sealer). A controlled volume droplet of sealer was placed on each specimen and was subjected to the contact angle meter.

Statistical Analysis

Data were statistically analyzed using the one-way ANOVA and Tukey's post hoc test at a significance level of 0.05 (P < 0.05).

Results

A statistically significant difference was seen among all the groups and subgroups with the highest contact angle value for Group III and Subgroup C and the least value for Group I and Subgroup A.

Conclusions

Passive irrigation with side-vented needle and Tubli-Seal EWT showed better wettability on dentin.

Real-time intracanal temperature measurement comparing mechanically and laser-activated irrigation to syringe irrigation

Antibacterial activity and tissue dilution of sodium hypochlorite (NaOCl) are improved by moderately heating the irrigant. Temperature can be risen by preheating or intracanal activation. To assess intracanal temperature development of NaOCl during irrigation activation and syringe activation (SI) in a closed system at 37°C, Type-K thermocouples were inserted close to the root canal of one human single-rooted maxillary canine at the apex and 5 and 10 mm from the apical foramen via drilled holes. The root was positioned in a plastic vial filled with alginate simulating surrounding biological structures. Experiments were performed in a closed environment at 37°C (n = 14): EA: EndoActivator (Dentsply Sirona), EDDY: EDDY (VDW), PUI: passive ultrasonic irrigation, PIPS: Photon-induced photoacoustic streaming (Fotona), S60: SI of 60°C-NaOCl, S45: SI of 45°C-NaOCl, and S20: SI of 20°C-NaOCl. S45, PUI and EDDY lead to minor intracanal temperature increases. EA and PIPS did not influence the intracanal temperature. SI with 60°C-NaOCl resulted in higher intracanal temperatures than activation systems. Temperature dissipation into simulated tissues buffered intracanal temperature changes.

Evaluation of in vitro biofilm elimination of Enterococcus faecalis 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 the Rotary Instrument XP-Endo Finisher in the Removal of Calcium Hydroxide Intracanal Medicament in Combination with Different Irrigation Techniques: A Microtomographic Study

OBJECTIVES

This study aims to evaluate the efficacy of the rotary instrument XP-endo Finisher for the removal of Ca(OH)₂ aided by different irrigation regimens.

METHODS

Sixteen double-rooted upper premolar human teeth were selected for the study. Thirty-two canals were prepared using a ProTaper Next rotary system up to X3. Then, the canals were filled with Ca(OH)₂. The volume of Ca(OH)₂ inside the canals was measured by microcomputed tomography (micro-CT). After that, the teeth were randomly allocated into two experimental groups, i.e., A and B (n = 16 canals). In group A, Ca(OH)₂ was removed using the master apical file (X3). In group B, Ca(OH)₂ was removed using a XP-endo finisher. In half of both groups (n = 8), syringe irrigation (SI) was used, while passive ultrasonic irrigation (PUI) was used for the other half. After removal, the remaining volume of Ca(OH)₂ was measured. All data were statistically analyzed using two-way ANOVA with Tukey's post hoc test.

RESULTS

The percentages of remaining Ca(OH)₂ in the apical thirds of all canals were significantly higher as compared with the middle and coronal thirds in all groups (p < 0.05). There was no significant difference between different files and techniques (p > 0.05).

CLINICAL SIGNIFICANCE

This study presents a new method for the removal of Ca(OH)₂ from root canals.

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.

Apical extrusion of debris following the use of single-file rotary/reciprocating systems, combined with syringe or ultrasonically-facilitated canal irrigation

Aim:

The aim of the study is to quantify the amount of debris extrusion after instrumentation with single-file rotary and reciprocating systems used either with conventional irrigation (CI) or passive ultrasonic irrigation (PUI) systems.

Methodology:

Sixty extracted human mandibular incisors were randomly assigned to two groups (n = 30); rotary single-file system, One Shape (OS-Group 1) and reciprocating single-file system, WaveOne (WO-Group 2) instruments. The two groups were further subdivided into two subgroups (n = 15); (A) PUI and (B) CI. The apically extruded debris was collected in preweighed glass vials as per the Myers and Montgomery method. After drying, the mean weight of debris was assessed with a microbalance and statistically analyzed using analysis of variance and Student's t-test.

Results:

The reciprocating file system produced significantly more debris compared to the rotary file system using either of the irrigation systems (P = 0.04). CI produced significantly more (P = 0.02) debris extrusion compared to PUI irrespective of the file system used.

Conclusion:

Under the conditions of this study, both systems caused apical debris extrusion. Rotary single-file system produced less debris extrusion compared to reciprocating single-file system. Use of PUI may be advocated as an alternative to CI, as it causes lesser apical debris extrusion.

Er,Cr:YSGG Laser-Activated Irrigation and Passive Ultrasonic Irrigation: Comparison of Two Strategies for Root Canal Disinfection

Objective: To compare the antibacterial effectiveness of 0.5% sodium hypochlorite (NaOCl) activated by the Er,Cr:YSGG laser-activated irrigation (LAI) and passive ultrasonic irrigation (PUI) against a 10-day-old intracanal Enterococcus faecalis biofilm. Background: LAI and PUI are regarded as alternative methods to release the irrigant in the inner regions of the root canal system achieving enhanced cleaning ability. Nevertheless, little evidence regarding the activation of low concentrations of NaOCl has been reported. Materials and methods: Seventy-two single-rooted teeth were instrumented, inoculated (E. faecalis ATCC 29212), and incubated for 10 days to allow biofilm formation. Specimens were randomly divided into six groups (n = 12 each): (1) 0.5% NaOCl+Er,Cr:YSGG LAI, (2) saline+Er,Cr:YSGG LAI, (3) 0.5% NaOCl+PUI, (4) saline+PUI, (5) positive control (no treatment), and (6) negative control (no bacteria). The activation time was distributed as follows: 30 sec of activation, followed by a rest phase of 30 sec, and ending with 30 sec of activation. The number of bacterial survivors was determined by plate counting. Results: Both irrigation regimens LAI and PUI reduced the number of colony-forming unit. Moreover, LAI +0.5% NaOCl and the rest of groups significantly differ (p < 0.001 for all comparisons). Conclusions: Er,Cr:YSGG LAI proved to be more effective than PUI in enhancing the antimicrobial activity of 0.5% NaOCl against 10-day-old intracanal E. faecalis biofilms.

Comparison of the Efficacy of Different Techniques for the Removal of Root Canal Filling Material in Artificial Teeth: A Micro-Computed Tomography Study

This study aimed to assess the efficacy of canal filling material removal using three different techniques after filling with a Gutta-Percha (GP) cone and calcium silicate-based sealer, by measuring the percentage of volume debris of GP and sealer remaining intracanal with micro computed tomography (micro-CT). The filling material was removed from 30 plastic teeth by a nickel-titanium (Ni-Ti) rotary retreatment system. Final irrigation was performed with 2 mL of saline and 10 specimens were randomly allocated to a conventional group. In the passive ultrasonic irrigation (PUI) group, ultrasonic irrigation was added to the conventional group (n = 10). In the Gentlefile Brush (GF Brush) group, irrigation with GF Brush was added to the conventional group (n = 10). Remaining filling material was measured using micro-CT imaging analysis. The total mean volume of residual filling material after retreatment in the conventional group, PUI group and GF Brush group were 4.84896 mm³, 0.80702 mm³, and 0.05248 mm³, respectively. The percentage of filling material remaining intracanal was 6.76% in the conventional group, 1.12% in the PUI group and 0.07% in the GF Brush group. This study shows that the cleaning effect of the GF Brush system is superior to those of Ni-Ti retreatment files and the PUI system in the apical area.

[In vitro evaluation of the effectiveness of XP-endo Finisher file on smear layer removal after root canal instrumentation]

OBJECTIVE

This study aimed to evaluate the effectiveness of XP-endo Finisher (XPF) file and passive ultrasonic irrigation (PUI) in the smear layer removal of the root canal.

METHODS

A total of 60 human single-rooted premolars were selected and decoronated to standardize their canal length to 16 mm. Tooth samples were prepared using a S3 rotary system to prepare root canal with the file size of 3S and then randomly divided into 6 groups according to the final irrigation protocol, as follows: XPF 3 mL of 3% NaOCl for 1 min (group A); XPF 3 mL of 3% NaOCl for 1 min, followed by 4 mL of 17% ethylene diamine tetraacetic acid (EDTA) for 1 min (group B); PUI of 3 mL of 3% NaOCl for 1 min (group C); PUI of 3 mL of 3% NaOCl for 1 min, followed by 4 mL of 17% EDTA for 1 min (group D); 3 mL of 3% NaOCl for 1 min by using a syringe and a 30 G side-vented needle (group E); and 3 mL of 3% NaOCl for 1 min by using a syringe and a 30 G side-vented needle, followed by 4 mL of 17% EDTA for 1 min (group F). After the completion of the root canal preparation, the teeth were split into two longitudinally. The mean numbers of the visible open dentinal tubules in the apical and middle thirds of the root canals were evaluated via scanning electron microscope.

RESULTS

The whole surfaces of the root canals in groups A, C, and E were covered by a smear layer. Groups A and C possessed significantly higher number of visible open dentinal tubules than in group E (P<0.05), with statistically insignificant difference between groups A and C (P>0.05). The apical third of the samples in groups B and D and in the middle thirds of canals in group F exhibited a small amount of smear layer, and the dentinal tubules were open or semi-open. The root canal surfaces in the apical third of the samples in group F were covered by a smear layer, and the dentinal tubules were sealed or semisealed. The smear layers in the middle third of the samples in groups B and D were removed, and the dentinal tubules were more visibly open than those of the four other groups (P<0.05). The difference between groups B and D were statistically insignificant (P>0.05).

CONCLUSIONS

The difference between XPF and PUI in terms of the smear layer removal of the root canals was insignificant. Hence, XPF, as a new irrigation agitation technique, can aid in improving smear layer removal.

Scanning electron microscopic evaluation of smear layer removal at the apical third of root canals using diode laser, endoActivator, and ultrasonics with chitosan: An in vitro study

Aim

The aim of this study was to compare the effect of diode laser, endoActivator, and passive ultrasonics for smear layer removal at the apical third from root canals with 0.2% chitosan.

Materials and Methods

A total of 40 mandibular premolars were decoronated to establish a working length of 12 mm and shaped with ProTaper rotary files up to size F3. In Group A, canals were irrigated with 1 ml of 0.2% chitosan. In Group B, canals were initially irrigated with 0.8 ml of 0.2% chitosan and the remaining 0.2 ml was activated with diode laser. In Group C, canals were irrigated with 1 ml of 0.2% chitosan which was activated with endoActivator. In Group D, canals were irrigated with 0.2% chitosan and activated with passive ultrasonics. All samples were finally flushed with 3 ml of distilled water. The percentage of smear layer removal was analyzed with a scanning electron microscope examination at ×1000 and ×3000. Data were analyzed using Statistical Package for the Social Sciences version 16.0 (SPSS Inc., Chicago, IL, USA) at a significance level of P < 0.05.

Results

The mean value for Group B when compared to Group C for the removal of smear layer was higher, but there was no statistically significant difference between the two groups (P < 0.068 and P < 0.295). Both Group B and Group C showed a statistically significant difference (P < 0.001) when compared to Group A and Group D for the removal of smear layer.

Conclusion

Diode laser and endoActivator with 0.2% chitosan proved better in the removal of the smear layer when compared to passive ultrasonic irrigation.

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).

Evaluation of Two Shaping Systems and Two Ultrasonic Irrigation Devices in Removing Root Canal Filling Material from Mesial Roots of Mandibular Molars: A Micro CT Study

We assessed the efficiency of two shaping file systems and two passive ultrasonic irrigation (PUI) devices for removing filling material during retreatment. The mesial canals from 44 extracted mandibular molars were prepared and obturated. The teeth were randomly divided into two groups, and then one group was retreated with Reciproc R25 (VDW, Munich, Germany) (n = 44) and the other group was retreated with 2Shape (TS, Micro Mega, Besançon, France) (n = 44). A micro-computed tomography (CT) scan was taken before and after the retreatment to assess the volume of the filling material remnants. The teeth were then randomly divided into four groups to test two different PUI devices: Irrisafe (Satelec Acteon Group, Merignac, France) and Endo Ultra (Vista Dental Products, Racine, WI, USA). The teeth in Group A were retreated with 2Shape to test the Endo Ultra (n = 22) device, the teeth in Group B were retreated with 2Shape in order to test the Irrisafe (n = 22) device, the teeth in Group C were retreated with Reciproc to test the Endo Ultra (n = 22) device, and Group D was retreated with Reciproc to test the Irrisafe (n = 22) device. A third micro-CT scan was taken after the retreatment to test the PUIs. The percentage of Gutta-Percha (GP) and sealer removed was 94.75% for TS2 (p < 0.001) and 89.3% for R25 (p < 0.001). The PUI significantly enhanced the removal of the filling material by 0.76% for Group A (p < 0.001), 1.47% for Group B (p < 0.001), 2.61% for Group C (p < 0.001), and by 1.66% for Group D (p < 0.001). 2Shape was more effective at removing the GP and sealer during retreatment (p = 0.018). The supplementary approach with PUI significantly improved filling material removal, with no statistical difference between the four groups (p = 0.106).

Comparative Evaluation of Depth of Penetration of Root Canal Irrigant After Using Manual, Passive Ultrasonic, and Diode Laser-Assisted Irrigant Activation Technique

AIM:

The aim of this study was to compare and evaluate the penetration depth of irrigant after using manual, passive ultrasonic, and diode laser–assisted irrigant activation technique.

Materials and Methods:

Ninety extracted single-rooted human mandibular premolars were selected (N = 90). Teeth were decoronated and working length was standardized for 12 mm. Root canals were shaped using ProTaper Universal F3. Saline was used as an irrigant in between every successful instrumentation. After completion of chemomechanical preparation, root canals were filled with Rhodamine-B-labeled sodium hypochlorite (3%). Teeth samples were divided into three experimental groups. In Group 1 (n = 30), manual irrigant activation was performed for 30 seconds with master cone gutta-percha (F3) in gentle up and down motion. In Group 2 (n = 30), ultrasonic irrigant activation was performed using passive ultrasonic endo tips for 30 seconds. In Group 3 (n = 30), laser activation was performed using diode laser for 30 seconds with 200-µm tips. Transverse sections were made at 2, 5, and 8 mm from the root apex and were observed under confocal laser scanning microscopy. Maximum penetration depth of irrigant was recorded and statistically analyzed.

Result:

In the all three groups, coronal third (sections at 8 mm from root apex) showed the highest penetration depth of irrigant. Laser activation (Group 3) showed the highest penetration depth in all the three sections when compared with manual and passive ultrasonic irrigant activation. One-way analysis of variance and post hoc test showed there were significantly high differences among all the three groups and also at all three levels (P < 0.05).

Conclusion:

Diode laser–assisted irrigant activation technique had better penetration depth in all the three aspects of root dentin.

Passive ultrasonic irrigation in root canal: systematic review and meta-analysis

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.

Effect of intracanal time of triple antibiotic paste on its removal from simulated immature roots using passive ultrasonic irrigation and XP-endo Finisher

Background. The aim of this study was to evaluate the effectiveness of different irrigation techniques in the removal of triple antibiotic paste (TAP), which was applied for 7, 21 or 90 days, from simulated root canals of immature teeth.

Methods. The root canal spaces of 190 maxillary canine teeth were filled with TAP and randomly divided into a control and 3 experimental groups according to the intracanal medicament period (7, 21 or 90 days). Syringe irrigation (SI), passive ultrasonic irrigation (PUI) and XP-endo Finisher (XP) were used for the removal of TAP (n=20). The amount of remaining medicament was calculated under a stereomicroscope using a 4-grade scoring system. Kruskal-Wallis H and Wilcoxon signedrank tests were used for statistical analyses (P<0.05).

Results. The mean percentage of residual TAP was significantly greater in the SI group compared to PUI and XP at all the time intervals (P<0.05). Paste removal efficacy of PUI was not affected by the intracanal time of TAP (P>0.05), whereas the efficacy of SI and XP was significantly affected (P<0.05). No significant differences were detected between PUI and XP at 7- and 21-day intervals (P>0.05); however, at 90-day interval, PUI removed significantly greater amount of TAP than XP did (P<0.05).

Conclusion. The time of the TAP in the root canal negatively affected the removal efficacy of the SI and XP-Endo Finisher; however, it did not affect the efficacy of the PUI.

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

AIM

To assess the penetration of sodium hypochlorite (NaOCl) gel or NaOCl solutions with surfactants, and the effect of passive ultrasonic irrigation (PUI) on penetration into dentinal tubules.

METHODOLOGY

Bovine incisor root canals were instrumented, the roots sectioned and the dentine blocks obtained were stained with crystal violet. Dentine blocks (n = 10 per group) were exposed to 3% NaOCl gel or 3% NaOCl solution for 10 and 20 min. Other dentine blocks (n = 10 per group) were exposed to Chlor-Extra (6% NaOCl + surfactant), 6% NaOCl, 2.5% NaOCl with 0.2% cetrimide and 2.5% NaOCl for 10 and 20 min. The penetration depth of irrigants into dentinal tubules was measured in micrometres by viewing the bleached crystal violet under a stereomicroscope. Additionally, bovine incisor root canals, instrumented and stained with crystal violet, were distributed into two groups (n = 10) and irrigated with 2.5% NaOCl with PUI or conventional syringe irrigation (CSI). The penetration depth of irrigants into dentinal tubules was assessed 3 and 7 mm from the apex. Statistical analysis was performed by ANOVA and Tukey tests (α = 0.05).

RESULTS

There was significantly greater penetration of 3% NaOCl solution into dentinal tubules compared with the gel form (P < 0.05). There was no difference (P > 0.05) between 6% NaOCl and Chlor-Extra, and between 2.5% NaOCl and 2.5% NaOCl + cetrimide. PUI significantly increased the penetration depth of NaOCl into dentinal tubules when compared with CSI (P < 0.05).

CONCLUSIONS

In extracted bovine incisors, NaOCl gel penetrated less into dentinal tubules than NaOCl solution. The addition of surfactants did not increase the penetration depth. The use of PUI significantly increased NaOCl penetration into dentinal tubules.

Computed microtomography study of untreated, shaped and filled mesiobuccal canals of maxillary first molars

This study assessed the effectiveness of modern endodontic shaping and filling procedures on mesiobuccal roots of maxillary molars with two canals. The canals of 20 mesiobuccal roots were treated with Mtwo rotary files, passive ultrasonic irrigation and Guttafusion obturators. X-ray computed microtomography analysis was carried out prior to treatment, after canal shaping and after canal filling to determine the alterations of the canal volume before and after the instrumentation, the volume of the hard tissue debris, and percentage of the volume occupied by filling materials. The shaping instruments and filling materials reached only partially the endodontic space of the second mesiobuccal canal and the accessory endodontic structures. Canal irregularities, ramifications, and interconnections were accumulation sites of hard tissue debris. This study demonstrated that rotary files, passive ultrasonic irrigation and carrier-based filling systems could be partially effective for the treatment of the mesiobuccal canals and their accessory endodontic structures.

Effects of plasma jet, dielectric barrier discharge, photodynamic therapy and sodium hypochlorite on infected curved root canals

The aim of this investigation was to evaluate the effects of 2 different cold atmospheric plasma (CAP) sources, photodynamic therapy and sodium hypochlorite (NaOCl), on infected root canals. Therefore, 50 standardized curved human root canals were infected with Enterococcus faecalis and assigned to 5 groups-negative control (NC), plasma jet (CAP I), dielectric barrier discharge (CAP II), photodynamic therapy (PDT) and NaOCl + passive ultrasonic irrigation-for 30 s. Colony forming units (CFUs) were determined. NaOCl was significantly more effective at reducing CFUs than all test groups (P < .0001 [Mann-Whitney U test]) in both parts of the root canal. CFUs in PDT were significantly lower than those in CAP II (P = .015), and those in CAP I were lower than those in CAP II (P = .05). Among all other groups and in the apical parts, no significant differences were found (P > .05).

Comparative evaluation of the amount of debris extruded apically using conventional syringe, passive ultrasonic irrigation and EndoIrrigator Plus system: An in vitro study

Aim:

The aim of this study is to compare the effects of conventional syringe, passive ultrasonic irrigation (PUI), and EndoIrrigator Plus on the amount of apically extruded debris.

Materials and Methods:

Thirty extracted human mandibular premolars were selected and randomly assigned to three groups (n = 10). The root canals were irrigated with conventional syringe, PUI, and EndoIrrigator Plus. Sodium hypochlorite was used as an irrigant, and debris was collected in a previously described experimental model (Myers and Montgomery 1991). It was then stored in an incubator at 37°C for 10 days to evaporate the irrigant before weighing the dry debris. The mean weight of debris was assessed, one-way analysis of variance was used for comparison of values, and post hoc Tukey's test was used between groups (P = 0.05).

Results:

The EndoIrrigator Plus group extruded significantly less debris than PUI and conventional syringe groups (P < 0.05). Furthermore, PUI group extruded significantly less debris than conventional syringe irrigation group (P < 0.05).

Conclusions:

1. All the three irrigation systems were associated with apical extrusion of debris, 2. EndoIrrigator Plus system extruded significantly less debris than the PUI system and the conventional syringe irrigation system, 3. PUI system extruded significantly less debris than the conventional syringe irrigation system.

Effect of ultrasonic activation of photosensitizer dye temoporfin (Foscan) on antimicrobial photodynamic therapy: An ex vivo study

Aim:

The aim of this study is to evaluate the effectiveness of ultrasonic activation of photosensitizer (PS) drug Foscan in the elimination of endodontic pathogen from root canal system.

Materials and Methods:

The minimal bactericidal concentration of “Foscan” was determined using disc diffusion and broth dilution method. Forty-eight extracted single-rooted premolars with periapical pathology were used for the study. After access opening, the first microbial sample was taken. The teeth were then randomly divided into four groups: Group 1: Chemomechanical debridement (CMD), Group 2: CMD and passive ultrasonic irrigation (CMD + PUI), Group 3: CMD and antimicrobial photodynamic therapy (aPDT), and Group 4: CMD and aPDT with activation by ultrasonics. After antimicrobial protocols, the second microbiological sample was collected. The samples were analyzed by multiplex polymerase chain reaction for the effectiveness of four antimicrobial protocols on Fusobacterium nucleatum, Prevotella intermedia, Porphyromonas gingivalis, and Treponema denticola.

Statistical Analysis Used:

Wilcoxon signed-rank test and Mann–Whitney U-test with the significant level P < 0.05, using IBM SPSS statistics 20 version software.

Results:

Foscan at concentration of 3.125 μg/ml was chosen for antimicrobial analysis. The prevalence of T. denticola, F. nucleatum, P. gingivalis, and P. intermedia was 79.17%, 70.84%, 70.83%, and 58.33%, respectively. Group 4 showed highest bacterial reduction of 99.51%, followed by Group 1 which showed bacterial reduction of 97.35%.

Conclusions:

Foscan can be used as an effective PS dye at low concentration with minimal tendency for tooth discoloration. Ultrasonic activation of PS dye facilitated better diffusion into dentinal tubules and biofilm obtaining greater bacterial reduction.

Removal of calcium hydroxide intracanal medicament by different irrigants and irrigating techniques: a cone beam computed tomography analysis

The aim of this study was to use cone beam computed tomography (CBCT) to evaluate the removal of calcium hydroxide (Ca[OH]2) from root canals after using different irrigation and activation protocols. Root canals (n = 128) were filled with Ca(OH)2 and scanned using CBCT. The Ca(OH)2 was removed after 1 week using 1 of 12 groups (G1-G12) according to the final irrigating solution: G1, 6% sodium hypochlorite (NaOCl) + 18% etidronic acid (EA) with no activation; G2, NaOCL + EA + passive ultrasonic irrigation (PUI); G3, NaOCl + EA + Finishing File (FF); G4, NaOCl + EA + NaviTip FX irrigation needle (NTFX); G5, 3% NaOCl + 17% ethylenediaminetetraacetic acid (EDTA) with no activation; G6, NaOCl + EDTA + PUI; G7, NaOCl + EDTA + FF; G8, NaOCl + EDTA + NTFX; G9, 3% NaOCl with no activation; G10, NaOCl + PUI; G11, NaOCl + FF; G12, NaOCL + NTFX. The amount of residual Ca(OH)2 was assessed by CBCT. Group comparisons were performed using 1-way analysis of variance and Student-Newman-Keuls post hoc test (P = 0.05). Group 7 showed the least residual Ca(OH)2 (10.83%), which was not significantly different from G6 (13.79%) (P > 0.05). The percentage of residual Ca(OH)2 found in these 2 groups was significantly less than that found in the other groups (P < 0.05). None of the protocols could completely remove Ca(OH)2 from the root canal system, but the plastic rotary FF and PUI, in conjunction with NaOCl and EDTA, removed significantly more Ca(OH)2 than the other irrigation activation protocols tested.

Efficacy of self-adjusting file, XP-endo finisher and passive ultrasonic irrigation on the removal of calcium hydroxide paste from an artificial standardized groove

The purpose of this study was to compare the effectiveness of self-adjusting file (SAF), XP-endo finisher (XP), passive ultrasonic irrigation (PUI) and conventional syringe and needle irrigation (SNI) in the removal of Ca(OH)₂ from an artificial groove. Eighty mandibular incisors with single oval canals were prepared to size 40/0.04 and split longitudinally. A standardised groove was prepared in the apical third and filled with Ca(OH)₂ . The root halves were reassembled and divided into two control groups (n = 4) and four experimental groups (n = 18) according to the removal methods used. The amount of residual Ca(OH)₂ was evaluated using a four-grade scoring system. The differences among the groups were analysed using the Kruskal-Wallis test (P < 0.05). SAF, XP and PUI removed significantly more Ca(OH)₂ than SNI (P < 0.001), although there were no significant differences among them (P = 0.209). None of the tested methods could completely clean Ca(OH)₂ from the groove.

Influence of Passive Ultrasonic Irrigation on the Removal of Root Canal Filling Material in Straight Root Canals

Objective

This study evaluates the efficacy of passive ultrasonic irrigation (PUI) in removing root canal filling material from endodontically treated teeth after using one of two reciprocating systems, Reciproc (VDW, Munich, Germany) or WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), or one nickel-titanium (NiTi) rotary system, ProTaper Universal Retreatment (Dentsply Maillefer).

Methods

One hundred and twenty straight root canals of extracted human maxillary incisors were instrumented and then obturated. The specimens were divided into six groups (n=20) as follows: Group R, Reciproc R25 instrument without PUI; Group W, WaveOne Primary instrument without PUI; Group PT, ProTaper Universal Retreatment system without PUI; Group R-PUI, Reciproc R25 with PUI; Group W-PUI, WaveOne Primary with PUI and Group PT-PUI, ProTaper Universal Retreatment system with PUI. After removing the filling material, the teeth were cleaved longitudinally and photographed. The total canal space and remaining material were quantified with the aid of an imaging software tool. The Kruskal-Wallis test was used to identify significant differences between the groups.

Results

No statistically significant differences (P>0.05) in residual filling material were observed between the groups.

Conclusion

The use of PUI did not improve the removal of filling material from the root canals, regardless of the previously used instrumentation system.

A cone-beam computed tomography assessment of the efficacy of different irrigation devices for removal of silicone oil-based calcium hydroxide from root canal system

BACKGROUND

Most often used intracanal medicament is calcium hydroxide (Ca(OH)₂). Removal of Ca(OH)₂ before obturation is mandatory. Different irrigation solutions and devices were tested in the previous study for this purpose.

AIM

The aim of this study was to evaluate the comparative efficacy of different irrigation techniques in removing intracanal medicament using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

Cleaning and shaping was carried out in 42 freshly extracted single-rooted mandibular first premolars using Protaper Rotary Files. Intracanal medicament (silicone oil-based Ca(OH)₂ paste) was placed and left for 2 weeks in the root canal. Medicament was then removed by five different irrigation techniques: EndoActivator, EndoVac, ultrasonic irrigation with Endo-U-File, F-file, and Max-i-Probe needle. Changes in volume percentage were measured using CBCT and results were statistically analyzed using Levene's statistics and ANOVA.

RESULTS

Remnants of Ca(OH)₂ were found in all experimental groups. No significant difference was detected among the groups. F-file showed maximum removal efficacy of approximately 48%.

CONCLUSION

(1) There is no statistically significant difference between any irrigation technique for removal of oil-based Ca(OH)₂. (2) F-file demonstrated better results among all the other systems.