The efficacy of ultrasonic irrigation to remove artificially placed dentine debris from human root canals prepared using instruments of varying taper

Effect of Apical Preparation Size and Preparation Taper on Smear Layer Removal Using Two Different Irrigation Needles: A Scanning Electron Microscopy Study

OBJECTIVES

 The aim of this study was to determine the effect of apical preparation size and preparation taper on smear layer removal using a metallic needle and a new polymer needle (IrriFlex, Produits Dentaires SA "PD," Vevey, Switzerland).

MATERIALS AND METHODS

 One hundred and eight single-rooted teeth with one canal were randomly divided into four groups according to the preparation and irrigation needle used: G1-30, 0.04 and IrriFlex (n = 25); G2-25, 0.06 and IrriFlex (n = 25); G3-30, 0.04 and metallic needle (n = 25); and G4-25, 0.06 and metallic needle (n = 25). All groups received the same final irrigation protocol and sonic activation. Each tooth was sectioned and observed under a scanning electron microscope (SEM).

STATISTICAL ANALYSIS

 Data were statistically analyzed by using one-way and two-way analysis of variance on ranks with a significance level at p = 0.05.

RESULTS

 For all groups, there was significantly higher smear layer in the apical third (p < 0.001) compared with the coronal and middle thirds. The 25, 0.06 preparation demonstrated better cleaning efficiency than the 30, 0.04 preparation throughout the canal when irrigated with a metallic needle; however, there were no significant differences in the middle and apical thirds when IrriFlex was used. There were also no differences of smear layer removal between G1 and G3 and G2 and G4 in the coronal part. In the middle and apical parts, G1 showed better elimination of smear layer compared with G3. There were slight differences in the middle third between G2 and G4, while G2 showed less cleaning efficiency compared with G4 in the apical third (p = 0.022).

CONCLUSION

 All groups showed less smear layer in the middle and coronal thirds of the canal compared with the apical third. The 25, 0.06 preparation was more effective in removing smear layer compared with the 30, 0.04 preparation. IrriFlex improved irrigation in the 30, 0.04 preparation, while its efficacy was less evident in the 25, 0.06 preparation.

The Effectiveness of Three Different Irrigant Activation Methods in the Elimination of Enterococcus faecalis from Root Canals

Background and Objective: Eliminating intracanal Enterococcus faecalis (E. faecalis) is challenging because of its ability to penetrate deep dentinal tubules and its high resistance to many chemicals. This study evaluated the effectiveness of conventional needle irrigation and three different irrigant activation methods in reducing E. faecalis. Methods: The root canals of extracted teeth were shaped, contaminated with E. faecalis, and incubated for three weeks. They were randomly allocated to four experimental groups of 15 teeth each according to the final irrigation method: group 1, conventional needle irrigation; group 2, passive ultrasonic (PU) irrigation; group 3, XP-endo Finisher (XPF); and group 4, laser-activated (LA) irrigation. Bacterial samples were taken and cultured before and after these final irrigation procedures. The colony-forming units were counted, and the bacterial reduction percentages of each group were calculated. The Kruskal-Wallis and Dunnet tests were used for statistical analysis. Results: All irrigant activation methods were significantly more effective than conventional needle irrigation. Although the LA group generated more negative samples than PU, there was no statistically significant difference between the LA and PU groups. LA was significantly more effective than the XPF, whereas PU and XPF were statistically similar. Conclusions: Within the limitations of this study, the final irrigation with LA and PU showed the best reductive effect on E. faecalis colonies. Considering that the LA group had more negative samples, it may be chosen as an alternative to enhance root canal disinfection, especially in difficult cases.

Analysis of Cutting Capacity, Surface Finishing, and Mechanical Properties of NiTi Instruments 25/.04: ROTATE and LOGIC 2

INTRODUCTION

In an effort to enhance the quality of mechanized endodontic instruments, various thermal treatment methods, and design modifications have been suggested. However, upon evaluation, these endodontic instruments may exhibit microscopic irregularities. The objective of this in vitro study was to analyze the cutting capacity, surface finish, and mechanical properties of Nickel-Titanium 25/.04 Rotate (VDW GmbH, Munich, Germany) and LOGIC 2 (Easy Equipamentos Odontológicos, Belo Horizonte, MG, Brazil) rotary instruments.

METHODOLOGY

Twenty rotary instruments were divided into 2 groups: GR, the group with ROTATE instruments (n = 10); and GL2, the group with LOGIC 2 instruments (n = 10). They were evaluated for roughness, using a profilometer, for bending resistance, buckling resistance, and cutting capacity using a universal testing machine, as well as for torsional strength (torque and angular deflection) using a torquemeter. The instruments were visualized before and after the mechanical tests through scanning electron microscopy.

RESULTS

GR showed better surface finish in terms of roughness, greater cutting capacity, and greater angular deflection than GL2 (P < .05). However, GL2 showed better flexibility than GR (P < .05). GL2 and GR did not show statistically significant differences in terms of buckling and torque (P > .05).

CONCLUSION

The ROTATE and LOGIC 2 rotary instruments differed in their surface finish, cutting capacity, and mechanical properties, except for their buckling resistance and required fracture torque.

Effect of the progressive taper enlargement of buccal root canals of three-rooted maxillary molars: A stepwise micro-CT study

This study evaluated unprepared canal areas, volume of dentine removal, and dentine thickness after the progressive enlargement of the buccal canals of 22 maxillary molars, with and without the MB2, using instruments with the same tip size (0.25 mm) but 4 different tapers (0.03, 0.05, 0.06 and 0.08 v). Micro-CT scans were performed after each instrument. Data were compared using a general linear mixed model post hoc comparisons with Kenward-Roger for Wald F tests (α = 5%). After each treatment step, it was observed an increase in the percentage volume of removed dentine and a decrease in the unprepared areas and dentine thickness at the pericervical region of all canals (p < 0.05). The percentage reduction of dentine thickness in MB2 canal was higher than in the mesiobuccal and distobuccal canals (p < 0.05). Knowledge of pre-operative dimensions and dentine thickness before enlargement of buccal canals of maxillary molars is an important factor to avoid excessive dentine removal.

Does minimally invasive canal preparation provide higher fracture resistance of endodontically treated teeth? A systematic review of in vitro studies

This systematic review aimed to investigate whether minimally invasive root canal preparation ensures higher fracture resistance compared to conventional root canal preparation in endodontically treated teeth (ETT). A comprehensive search strategy was conducted on the "PubMed, Web of Science, and Scopus" databases, alongside reference and hand searches, with language restrictions applied. Two independent reviews selected pertinent laboratory studies that explored the effect of minimally invasive root canal preparation on fracture resistance, in comparison to larger preparation counterparts. The quality of the studies was assessed, and the risk of bias was categorized as low, moderate, or high. The electronic search yielded a total of 1,767 articles. After applying eligibility criteria, 8 studies were included. Given the low methodological quality of these studies and the large variability of fracture resistance values, the impact of reduced apical size and/or taper on the fracture resistance of the ETT can be considered uncertain. This systematic review could not reveal sufficient evidence regarding the effect of minimally invasive preparation on increasing fracture resistance of ETT, primarily due to the inherent limitations of the studies and the moderate risk of bias.

The Contribution of Various In Vitro Methodologies to Comprehending the Filling Ability of Root Canal Pastes in Primary Teeth

A void-free obturation during root canal treatment on primary teeth is currently very difficult to attain. In this study, the pulpectomy filling abilities of Bio-C Pulpecto (Angelus, Basil, Londrina, Paraná, Brazil) and of zinc oxide eugenol, or "ZOE" (DenPro, Prevest, New York, NY, USA), were compared using several in vitro techniques. Therefore, 30 primary anterior teeth were used in the present in vitro study. Analysis of variance (ANOVA), including a multiple comparison procedure (Holm-Sidak method, Dunn's Method, or Tukey test), was used. On micro-CT, Bio-C Pulpecto exhibited higher void percentages than did ZOE (10.3 ± 3.8%, and 3.5 ± 1.3%), respectively (p < 0.05). With digital microscopy, higher total void percentages were found in the BC (13.2 ± 26.7%) group compared to the ZOE (2.7 ± 2.8%) group (p < 0.05). With the CLSM, mean tubular penetration depths were higher for Bio-C Pulpecto than for ZOE in all canal thirds (p < 0.05). SEM images demonstrated no tags into dentinal tubules in either group throughout the three thirds. Moreover, higher statistically significant flowability was found for Bio-C (2.657 ± 0.06 mm) compared to ZOE (1.8 ± 0.13 mm) (p < 0.05). The findings of this study indicate that neither ZOE nor Bio-C Pulpecto appears to meet the criteria for an ideal root canal filling paste for primary teeth. This study laid the groundwork for future research by determining how micro-CT, digital microscopy, SEM, and CLSM contribute to our understanding of the filling process of primary teeth. More thorough research on the mechanism of root canal obturation on primary teeth is required to achieve a long-term successful root canal therapy in young children.

Taper 0.06 Versus Taper 0.04: The Impact on the Danger Zone

INTRODUCTION

This study aimed to evaluate the effects of root canal enlargement on the danger zone (DZ) of mandibular molars.

METHODS

Thirty mesial roots of mandibular first molars were scanned in micro-computed tomography (S1). Canals were sequentially enlarged with rotary instruments up to sizes 30/0.04 (S2) and 30/0.06 (S3). The dentin thickness was measured at 0.1-mm intervals after each preparation step (n = 2964 slices). Root level and position of the DZ were also recorded. Data were compared using analysis of variance with Bonferroni pairwise comparison, Cochran's Q method, and Pearson's test (α = 5%).

RESULTS

Comparing the specimens before (S1) and after (S2 and S3) preparations showed a significant reduction in the thickness of the DZ (P < .05), as well as between S2 and S3 steps (P < .05). At S1, the DZ was mostly located in the middle third of the root, but after preparation, it shifted toward the coronal direction (P < .05). Both S2 (P = .004, r = 0.508) and S3 (P = .004, r = 0.506) preparation steps showed a positive correlation between canal length and the root level of the DZ. At S1, the DZ was positioned toward the distal and mesial in 73.4% (n = 22) and 26.6% (n = 8) of the specimens, respectively. After S3, the number of specimens with DZ positioned toward the mesial aspect of the root significantly reduced to 3.3% (n = 1), whereas none of the specimens with DZ positioned toward the distal changed its position after root canal enlargements (P > .05).

CONCLUSION

Overall, the enlargement of mesial canals of mandibular first molars with final instruments sizes 30/0.04 and 30/0.06 affected the thickness, root level, and position of the DZ.

Effectiveness of various irrigant activation techniques on the penetration of sodium hypochlorite into lateral canals of mature permanent teeth: A systematic review and meta-analysis

Objective

This review aimed to systematically review the effectiveness of various irrigant activation techniques (IATs) on the penetration of sodium hypochlorite (NaOCl) into the lateral canals of mature permanent teeth.

Methods

Electronic databases including MEDLINE (via PubMed), Scopus, ProQuest, and Cochrane Library were searched to identify laboratory studies evaluating the penetration of NaOCl into lateral canals following the use of apical negative pressure irrigation (ANP), passive ultrasonic irrigation (PUI), sonic irrigation (SI), and/or manual dynamic activation (MDA) techniques. Meta-analysis was performed for individual IATs in comparison with CNI into the lateral canals of both straight and curved root canals. On the basis of the previous literature and parameters, the risk of bias of the selected studies was evaluated with the help of a customized tool.

Results

Of the 983 records screened, 12 studies were selected to include in the systematic review, and 10 studies were selected for the meta-analysis. The total quality assessment across the included studies indicated a high quality (83.3%). Overall, the meta-analysis demonstrated IATs had significant improvement in the penetration of NaOCl into the lateral canals of straight canals (34.3%) over CNI. The subgroup analysis of individual IATs demonstrated PUI (60.9%) to be superior in the penetration into lateral canals of straight canals.

Conclusions

IATs improved the irrigant penetration into lateral canals and therefore their use during routine endodontic practice is recommended. In straight canals, PUI is the most effective IAT followed by ANP, SI, and MDA techniques.

Effect of Dentin Desensitizer Containing Novel Bioactive Glass on the Permeability of Dentin

The objective of this study was to evaluate the effect of novel bioactive glass (BAG)-containing desensitizers on the permeability of dentin. Experimental dentin desensitizers containing 3 wt% BAG with or without acidic functional monomers (10-MDP or 4-META) were prepared. A commercial desensitizer, Seal & Protect (SNP), was used as a control. To evaluate the permeability of dentin, real-time dentinal fluid flow (DFF) rates were measured at four different time points (demineralized, immediately after desensitizer application, after two weeks in simulated body fluid (SBF), and post-ultrasonication). The DFF reduction rate (ΔDFF) was also calculated. The surface changes were analyzed using field emission scanning electron microscopy (FE-SEM). Raman spectroscopy was performed to analyze chemical changes on the dentin surface. The ΔDFF of the desensitizers containing BAG, BAG with 10-MDP, and BAG with 4-META significantly increased after two weeks of SBF storage and post-ultrasonication compared to the SNP at each time point (p < 0.05). Multiple precipitates were observed on the surfaces of the three BAG-containing desensitizers. Raman spectroscopy revealed hydroxyapatite (HAp) peaks on the dentin surfaces treated with the three BAG-containing desensitizers. Novel BAG-containing dentin desensitizers can reduce the DFF rate about 70.84 to 77.09% in the aspect of reduction of DFF through the HAp precipitations after two weeks of SBF storage.

An Umbrella Review of Systematic Reviews and Meta-Analyses Evaluating the Success Rate of Prosthetic Restorations on Endodontically Treated Teeth

Materials and Methods

The electronic search was conducted in the MEDLINE/PubMed, Cochrane, and Google Scholar databases until November 2020, regardless of language limitations. The inclusion criterion was as follows: S/M-R regarding prosthetic restorations in endodontically treated teeth. Three qualified researchers evaluated the inclusion criteria and bias risk. The fourth investigator was referred to when facing any doubtfulness.

Results

From 43 achieved S/M-R, 14 studies were selected for this inquiry. Primary extracted information included success rate, survival rate, and postendodontic failure rate. Five S/M-R had a moderate risk of bias, and nine S/M-R had a low risk of bias and were considered strong clinical evidence in this examination. According to the low-risk reports, the success rate of fiber posts was higher than that of metal posts; the rate of root fracture in metallic and fiber posts was alike; the failure rate for fiber posts was comparable to fixed partial dentures or single crowns; the construction of endocrowns was likely to perform better than intracanal posts, composite resin, or inlay/onlay restorations.

Conclusion

It appears that with practice and experience, deciding which type of restoration to choose changes. In dental restorations associated with root canal therapy, the single crowns are likely to be a proper option. Nevertheless, due to the heterogeneity of the studies, more clinical assessments are required to achieve more specific findings in this field.

Removal of Accumulated Hard Tissue Debris (AHTD) from Root Canals with an Electric Current Device: A MicroCT Preliminary Report

In modern endodontics, removal of accumulated hard tissue debris (AHTD) from root canals is requested. In the last decade, different irrigating solutions and activation methods have been successfully tested. Sonic activation has been shown to be effective in the removal of AHTD. Electric current has been tested before in restorative dentistry, but not in endodontics. An experimental electric current delivering device was compared in the removal of AHTD, using microCT analyses. Fifteen single-rooted teeth were shaped with TruNatomy system endodontic files and divided into three groups: negative control group: specimens underwent no activation; EA group: specimens were activated with EndoActivator (EA); EB group: specimens were activated with ElectroBond (EB). The 2D images, 3D images and morphometric analysis from the microCT showed a statistically significant increased AHTD removal when EB was used. Results of the present preliminary study showed that the irrigant activation with ElectroBond is encouraging when compared to EndoActivator along the entire root canal system. The AHTD was significantly statistically reduced, validating the clinical use of electric fields in endodontics.

Present status and future directions -Management of curved and calcified root canals

Root canal curvature and calcification introduce factors that increase the risk of procedural accidents during root canal treatment. The inability to achieve patency to the apical third, asymmetrical dentine removal leading to transportation, perforation and instrument fracture inside the curved trajectories are some of the procedural problems that might jeopardize the management of intraradicular infection and result in poor treatment outcomes. In fact, curved and constricted canals introduce such complexity that total instrumentation concepts and specially designed instruments have been developed to deal with the challenge. This narrative review seeks to provide and consolidate the principles necessary for understanding the dynamics of curved and constricted canal management and to improve the understanding for future developments in this field.

Comparison of the efficacy of three different supplementary cleaning protocols in root-filled teeth with a bioceramic sealer after retreatment-a micro-computed tomographic study

OBJECTIVE

The present study evaluated the efficacy of three different supplementary cleaning protocols on the removal of bioceramic-based root canal filling materials from oval-shaped canals.

MATERIALS AND METHODS

A total of 36 human mandibular premolars were instrumented and obturated with gutta-percha and iRoot SP using the single-cone technique. Retreatment was performed with ProTaper Universal retreatment files. The samples were randomly divided into the following supplementary cleaning protocols: conventional syringe irrigation (CSI), passive ultrasonic irrigation (PUI), and XP-endo Finisher R (XPR). The samples underwent micro-CT scanning to quantify the amount of residual filling materials after retreatment and after performing the cleaning protocols. The volume of filling material removal was analyzed by one-way analysis of variance and post hoc Bonferroni and Games-Howell tests (P < 0.05).

RESULTS

There were significant differences in the amount of root canal filling material removal in every comparison group (P < 0.05). The XPR removed significantly more residual filling materials (P < 0.01) followed by PUI and CSI (P < 0.05). Similar efficacy was found in the total root canal and all root thirds.

CONCLUSIONS

The additional use of XP-endo Finisher R and passive ultrasonic irrigation effectively removed the bioceramic-obturated root filling materials from the oval-shaped canals. However, none of the techniques completely removed the filling materials.

CLINICAL RELEVANCE

The XP-endo Finisher R and passive ultrasonic irrigation exhibited greater efficacy compared with syringe irrigation in the reduction of residual filling materials after retreatment in root-filled teeth with a bioceramic sealer.

Conservative shaping combined with three-dimensional cleaning can be a powerful tool: Case series

Conservative endodontics has been introduced about a decade ago. Since then, it has been demonstrated that less canal preparations lead to more dentin preservation resulted in decreased stress on tooth structure, mainly in the coronal third of the root, and potentially a higher resistance to fracture. In addition, smaller and larger canal preparations were comparable with regard to the cleanliness of the root canal. The purpose of this case series was to report on the outcome of root canal treatments following a conservative canal preparation, followed by three-dimensional cleaning technique (intracanal heating and ultrasonic activation of NaOCl).

Efficacy of continuous apical negative ultrasonic irrigation (CANUI) in penetration of simulated lateral canals in extracted teeth

The aim of this study was to evaluate the efficacy of continuous apical negative ultrasonic irrigation into simulated lateral canals and the apical third in straight and curved root canals. Two simulated lateral canals were created 2, 4 and 6 mm from the working length in 120 single-rooted teeth (6 canals/tooth, n = 360 straight, n = 360 curved). The teeth were randomly divided into 3 experimental groups: positive pressure irrigation (PPI) (n = 20); passive ultrasonic irrigation (PUI) (n = 20); continuous apical negative ultrasonic irrigation (CANUI) (n = 20). 20% Chinese ink was added to a 5% sodium hypochlorite solution and delivered into the root canals. The results showed a significantly higher (P < 0.05) penetration of irrigant into the lateral canals and up to working length in the CANUI group for straight and curved roots. CANUI improves penetration into the lateral canals and up to the working length of the cleared teeth in straight and curved roots.

On comprehensive analysis of root canal shaping ability of three endodontic files of different kinematics

Infection of the tooth's root canal requires what is called root canal treatment (RTC). The most important part of endodontic treatment is to shape the root canal and remove its infected portion using endodontic files of various protocols, kinematics and designs that suit the particular geometry. Cleaning and Shaping the canal efficiently remove the root canal bacterial biofilms or tissue remnants while keeping its natural geometry. The result is determined by shaping the ability of the relevant endodontic file. In the available literature, no norm has been established for the measurement of various endodontic files' ability to do effective shaping. We present in this study a method to analyse and measure the shaping ability of endodontic files of three different kinematics.

Does the ultrasonic activation of sealer hinder the root canal retreatment?

OBJECTIVES

To evaluate if the ultrasonic activation of sealer hinders the root canal retreatment.

MATERIALS AND METHODS

Thirty mandibular premolars were prepared using the ProTaper Universal system (Dentsply) until the instrument F3 (0.30/0.09). The canals were distributed into 2 groups (n = 15), according to the filling technique: NUact group - sealer without ultrasonic activation + gutta-percha cones and Uact group - sealer with ultrasonic activation + gutta-percha cones. The canals were re-instrumented with Largo burs, followed by the instrument R50 (0.50/0.05) of the Reciproc system. The time required to perform re-instrumentation was recorded (s). The roots were longitudinally cleaved, and the total area of root canal and remaining filling material were quantified (%). The ANOVA test was applied to the data and complemented by Student's t test (P < 0.05).

RESULTS

Uact group had higher percentage of remaining filling material than NUact group (P < 0.05). When the root thirds were considered, there was statistically significant difference only for Uact group at the apical third (P < 0.05). There was no difference between groups regarding the time required to perform re-instrumentation (P > 0.05).

CONCLUSIONS

Ultrasonic activation of sealer leads to a higher percentage of remaining filling material attached to the root canal walls. However, it did not affect the retreatment time.

CLINICAL SIGNIFICANCE

Ultrasonic activation increases sealer penetration into dentinal tubules, improving its resistance to dislodgement. However, there is no scientific evidence to prove if ultrasonic activation of sealer hinders its removal when root canal retreatment is necessary.

Chemical and mechanical influence of root canal irrigation on biofilm removal from lateral morphological features of simulated root canals, dentine discs and dentinal tubules

Aim

To investigate the anti‐biofilm efficacy of irrigation using a simulated root canal model, the chemical effect of irrigants against biofilms grown on dentine discs and their impact on biofilm viscoelasticity, the efficacy of the irrigants in decontaminating infected dentinal tubules and the capacity of bacteria to regrow.

Methodology

Biofilm removal, viscoelastic analysis of remaining biofilms and bacterial viability were evaluated using a simulated root canal model with lateral morphological features, dentine discs and a dentinal tubule model, respectively. Experiments were conducted using a two‐phase irrigation protocol. Phase 1: a modified salt solution (RISA) and sodium hypochlorite (NaOCl) were used at a low flow rate to evaluate the chemical action of the irrigants. Ultrasonic activation (US) of a chemically inert solution (buffer) was used to evaluate the mechanical efficacy of irrigation. Phase 2: a final irrigation with buffer at a high flow rate was performed for all groups. Optical coherence tomography (OCT), low load compression testing (LLCT) and confocal scanning laser microscopy analysis were used in the different models. One‐way analysis of variance (anova) was performed for the OCT and LLCT analysis, whilst Kruskal–Wallis and Wilcoxon ranked tests for the dentinal tubule model.

Results

US and high flow rate removed significantly more biofilm from the artificial lateral canal. For biofilm removal from the artificial isthmus, no significant differences were found between the groups. Within‐group analysis revealed significant differences between the steps of the experiment, with the exception of NaOCl. For the dentine discs, no significant differences regarding biofilm removal and viscoelasticity were detected. In the dentinal tubule model, NaOCl exhibited the greatest anti‐biofilm efficacy.

Conclusions

The mechanical effect of irrigation is important for biofilm removal. An extra high flow irrigation rate resulted in greater biofilm removal than US in the artificial isthmus. The mechanical effect of US seemed to be more effective when the surface contact biofilm–irrigant was small. After the irrigation procedures, the remaining biofilm could survive after a 5‐day period. RISA and NaOCl seemed to alter post‐treatment remaining biofilms.

Comparison of Five Different Irrigation Techniques on Smear Layer Removal in Apical Thirds of Root Canals of Mandibular First Premolar: A Scanning Electron Microscopic Study

Aim:

This study was conducted to compare smear layer removal by five different irrigation techniques—conventional needle irrigation (CI), manual dynamic activation (MDA), passive ultrasonic irrigation (PUI), sonic irrigation (SI), and negative apical pressure (NAP).

Materials and Methods:

Fifty freshly extracted mandibular first premolars were cleaned and shaped by One Curve rotary files and 3% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. The samples were divided into five equal groups (n = 10), according to the final irrigation activation technique: Group I, CI; Group II, MDA; Group III, PUI; Group IV, SI; and Group V, NAP. The samples were prepared and observed under a scanning electron microscope. The photomicrographs were recorded and evaluated with a scoring system.

Results:

Group I and Group II had the highest scores, which showed a statistically significant difference between the other groups (P < 0.05). This was followed by PUI, NAP, and SI.

Conclusion:

Final irrigation activation with SI and NAP resulted in the better removal of smear layer when compared to that with other groups.

Antibiofilm Activity of Three Different Irrigation Techniques: An in Vitro Study

The microbial infection of the endodontic space occurs in a necrotic tooth as a result of dental caries, trauma, periodontal disease, or previous root canal therapy. The disruption of the biofilms and the reduction of the bacterial load inside root canals are crucial for the success of root canal therapy. The aim of this study was to compare, in vitro, the antibiofilm efficacy of a novel passive sonic irrigation (PSI) device with passive ultrasonic irrigation (PUI) and conventional needle irrigation (CNI). Forty-four single-rooted human teeth were inoculated with a culture of E. faecalis for 28 days. The specimens were randomly divided into three groups: PUI, CNI, and PSI (n = 12). The activation protocols were performed using both 17% EDTA and 5.25% NaOCl. Residual bacterial biofilm was taken by means of a canal brush and colony-forming unit (CFU) were counted. The data were analyzed using one-way ANOVA and Games-Howell's post hoc tests. A major reduction in CFU was observed in the PSI and PUI groups, in comparison with the CNI group. No difference was found (p > 0.05) in terms of CFU reduction between PSI and PUI. PSI could be as effective as PUI in the removal of bacterial biofilms from straight root canals.

Efficacy of various solutions in preventing orange-brown precipitate formed during alternate use of sodium hypochlorite and chlorhexidine: An in vitro study

Aim

The study evaluated the effectiveness of three intermediate endodontic irrigating solutions in eliminating the residual sodium hypochlorite (NaOCl), thus preventing the formation of the orange-brown precipitate when 2% chlorhexidine (CHX) is used as the final irrigant.

Materials and Methods

A total of 40 extracted human maxillary anterior teeth were selected, disinfected, and decoronated to obtain a standardized length of 10 mm. The teeth were prepared with Protaper universal rotary files until size F4 using 2.5% NaOCl as an irrigant during instrumentation. The teeth were then randomly divided into four groups of 10 samples each based on the irrigating solutions used during final wash sequence as follows: Group A - (2.5% NaOCl and 2% CHX), Group B - (2.5% NaOCl followed by 70% Isopropyl Alcohol and 2% CHX), Group C - (2.5% NaOCl followed by 6.25% sodium metabisulfite and 2% CHX), and Group D - (2.5% NaOCl followed by 3.86% sodium Thiosulfate and 2% CHX). The roots were sectioned longitudinally and the canal surface was evaluated under dental operating microscope (×16) for the presence of orange-brown precipitate. The results were tabulated as per scoring criteria and statistically analyzed.

Statistical Analysis Used

One-way ANOVA test and post hoc Tukey's test.

Results

The lowest mean score was observed in Group C, followed by Group D and Group B, respectively. In comparison, there was a statistically significant (P < 0.001) difference in results between Group C and the other experimental groups. However, there was no statistically significant difference between Group B and Group D.

Conclusion

Sodium metabisulfite was found to be very effective in preventing the formation of orange-brown precipitate.

Investigations into in situ Enterococcus faecalis biofilm removal by passive and active sodium hypochlorite irrigation delivered into the lateral canal of a simulated root canal model

AIM

To investigate in situ Enterococcus faecalis biofilm removal from the lateral canal of a simulated root canal system using passive or active irrigation protocols.

METHODOLOGY

Root canal models (n = 43) were manufactured from transparent resin materials using 3D printing. Each canal was created with an 18 mm length, apical size 30, a .06 taper and a lateral canal of 3 mm length, with 0.3 mm diameter. Biofilms were grown in the lateral canal and apical 3 mm of the main canal for 10 days. Three models from each group were examined for residual biofilm using SEM. The other forty models were divided into four groups (n = 10). The models were observed under a fluorescence microscope. Following 60 s of 9 mL of 2.5% NaOCl irrigation using syringe and needle, the irrigant was either left stagnant in the canal or activated using gutta-percha, sonic or ultrasonic methods for 30 s. Images were then captured every second using an external camera. The residual biofilm percentages were measured using image analysis software. The data were analysed using generalized linear mixed models. A significance level of 0.05 was used throughout.

RESULTS

The greatest level of biofilm removal was obtained with ultrasonic agitation (66.76%) followed by sonic (45.49%), manual agitation (43.97%) and passive irrigation groups (38.67%), respectively. The differences were significant between the residual biofilm in the passive irrigation and both sonic and ultrasonic groups (P = 0.001).

CONCLUSION

Agitation resulted in better penetration of 2.5% NaOCl into the lateral canal of an artificial root canal model. Ultrasonic agitation of NaOCl improved the removal of biofilm.

In vitro comparison of gutta-percha-filled area percentages in root canals instrumented and obturated with different techniques

Purpose:

To evaluate the efficacy of different obturation techniques in root canals instrumented either by hand or rotary instruments with regard to the percentage of gutta- percha-filled area (PGFA).

Materials and Methods:

One hundred and sixty extracted mandibular premolars with single, straight root canals were studied. Root canals were prepared to an apical size of 30 by hand with a modified crown-down technique or the ProTaper and HEROShaper systems. Teeth were divided into eight groups (n=20) according to the following instrumentation and obturation techniques: G1: Hand files+lateral condensation (LC), G2: Hand files+Thermafil, G3: ProTaper+LC, G4: ProTaper+single-cone, G5: ProTaper+ProTaper-Obturator, G6: HEROShaper+LC, G7: HEROShaper+single-cone, G8: HEROShaper+HEROfill. Horizontal sections were cut at 1, 3, 5, 7, 9, 11 and 13 mm from the apical foramen. A total of 1120 sections obtained were digitally photographed under a stereomicroscope set at 48X magnification. The cross-sectional area of the canal and the gutta-percha was measured by digital image analysis and the PGFA was calculated for each section.

Results:

The mean of the PGFA in Thermafil (G2), ProTaper-Obturator (G5) and HEROfill (G8) groups was significantly higher than the other groups. In G3 and G4, PGFA showed no significant difference in the apical segments whereas PGFA was significantly higher at the middle and coronal segments in G3. In G6 and G7, PGFA showed no significant difference in the apical and middle segments whereas PGFA was significantly higher at the coronal segments in G6.

Conclusion:

The carrier-based gutta-percha obturation systems revealed significantly higher PGFA in comparison to single-cone and lateral condensation techniques.

Canal cleanliness using different irrigation activation systems: a SEM evaluation

OBJECTIVES

The purpose of this study was to assess the efficacy of different final irrigation activation methods in removing debris and smear layer in the apical, middle, and coronal portion of straight root canals.

MATERIAL AND METHODS

Straight root canals of 58 freshly extracted mandibular premolars were used. Root canals were prepared to size 40.06. Irrigation was performed using 3% sodium hypochlorite. Samples were divided into four equal groups (n = 12) according to the irrigation activation techniques: (A) manual irrigation (MI), (B) EndoActivator (EA) (Dentsply Maillefer, Ballaigues, Switzerland), (C) sonic activation EDDY (EDDY; VDW, Munich, Germany), and (D) passive ultrasonic irrigation (PUI). Ten teeth served as negative controls. Roots were split longitudinally, and the canal walls were subjected to scanning electron microscopy. The presence of debris and smear layer at coronal, middle, and apical levels were evaluated using a 5-point scoring system and statistically analyzed using Kruskal-Wallis and chi-square tests.

RESULTS

Canal cleanliness decreased from coronal to apical (P = 0.035). Significantly more debris was removed with EA, EDDY, and PUI compared to MI (P < 0.001; total values), but no differences were observed in the different portions of the root canals (P > 0.05). Smear layer removal with PUI, EA, and EDDY was not significantly different (P > 0.05), but only EDDY and PUI were superior to MI (P < 0.01).

CONCLUSION

All activation methods created nearly debris-free canal walls and were superior compared to manual irrigation (P < 0.001). EDDY and PUI also showed significantly better smear layer scores compared to manual irrigation.

CLINICAL RELEVANCE

The sonic activation system EDDY performed equally as well as PUI, and both methods were significantly superior compared with manual irrigation in straight root canals with regard to debris and smear layer removal.

Apical negative pressure irrigation versus syringe irrigation: a systematic review of cleaning and disinfection of the root canal system

The aim of this study was to systematically review and critically analyse the published data on the treatment outcome (primary outcome) and on the cleaning and disinfection of root canals (secondary outcomes) achieved by negative pressure irrigation as compared to syringe irrigation. An electronic search was conducted in EMBASE, LILACS, PubMed, SciELO, Scopus and Web of Knowledge using both free-text keywords and controlled vocabulary. Additional studies were sought through hand searching of endodontic journals and of the relevant chapters of endodontic textbooks. No language restriction was imposed. The retrieved studies were screened by two reviewers according to predefined criteria. Included studies were critically appraised and the extracted data were arranged in tables. The electronic search and hand search retrieved 489 titles. One clinical study and 14 in vitro studies were finally included in the review; none of these studies assessed treatment outcome, four studies assessed the antimicrobial effect, seven studies evaluated the removal of pulp tissue remnants, and four studies investigated the removal of hard tissue debris or both hard tissue debris and pulp tissue remnants. Poor standardization and description of the protocols was evident. Inconclusive results were reported about the cleaning and disinfection accomplished by the two irrigation methods. Negative pressure irrigation was more effective under certain conditions when compared to suboptimal syringe irrigation; however, the variability of the protocols hindered quantitative synthesis. There is insufficient evidence to claim general superiority of any one of these methods. The level of the available evidence is low, and the conclusions should be interpreted with caution.

Influence of Taper of Root Canal Shape on the Intracanal Bacterial Reduction

Objectives:

Taper is a factor that determines final root canal dimensions and consequently, the space available for the cleaning action of irrigants. Therefore, the aim of this study was to investigate the influence of taper on intracanal bacterial reduction.

Methods:

Sterilized root canals of 25 mandibular incisors were inoculated with E. faecalis and then divided into two experimental groups and one control group (A= saline, B= NaOCl + EDTA and C= control, not prepared). Groups A and B were prepared to an apical size of #30/0.04, a culture was obtained and then prepared to #30/0.08 and cultured again. Final irrigation sequence was 30 ml of saline for group A and 10 ml of 17% EDTA followed by 10 ml of 2.5% NaOCl and 10 ml of saline for group B. The CFU ml^-1 of the pre- and two post-operative samplings were recorded. Values were compared by performing ANOVA and FDR for multiple hypothesis testing.

Results:

No statistically significant difference between initial CFU ml^-1 readings was recorded, whereas significant differences between group A and B at both 4% and 8% tapers were noted. Furthermore, a linear-dependent reduction of CFU ml^-1 was recorded in each group from non-instrumented root canals to #30/0.04 and subsequently to #30/0.08. The positive control group shows the expected reduction of bacterial count.

Conclusion:

Chemomechanical instrumentation was more efficient at reducing E. faecalis when the taper of root canals increased from 4% to 8% and NaOCl plus EDTA led to a greater intracanal bacterial reduction than saline, regardless of the taper achieved.

Efficacy of passive ultrasonic irrigation in removing root filling material during endodontic retreatment

Abstract Introduction The aim of endodontic retreatment is to remove the previous root filling materials completely to allow for the subsequent steps of cleaning, canal shaping and filling replacement. Objective To evaluate the efficacy of passive ultrasonic irrigation (PUI) in the removal of residual root filling material after removing the bulk of the root filling with nickel-titanium rotary instruments. Material and method Eighteen mesial isthmus-containing roots of human mandibular molars were prepared and filled. The root canal filling was removed with the ProTaper Retreatment system and K-files. The specimens were randomized into 2 groups (n = 9), both irrigated with 2.5% NaOCl and 17% EDTA. In the conventional group, an irrigation syringe was used. In the PUI group, the PUI technique was used. The roots were sectioned longitudinally and evaluated under stereomicroscopy. Student’s t test was used to compare groups and the general linear model was used to compare the apical, cervical, and middle root thirds within each group, in regard to the percentages of remaining residual filling material. Result There was no statistically significant intergroup difference, irrespective of which root third was evaluated (P > 0.05). In the PUI group, the apical third showed a significantly higher percentage of residual filling material, in comparison with the cervical (P = 0.038) and middle (P = 0.029) thirds. Conclusion The PUI technique was not more effective than the conventional irrigation technique in removing residual root filling material during endodontic retreatment in root canals with a complex anatomy.

Comparison of Penetration of Irrigant Activated by Traditional Methods with A Novel Technique

INTRODUCTION

The effectiveness of irrigation depends upon various irrigation activation methods & devices used.

AIM

To compare and evaluate the penetration of irrigant upto working length and into simulated lateral canals using four different irrigation activation techniques.

MATERIALS AND METHODS

The root canals of 60 single-rooted teeth were instrumented using the proTaper rotary system. After decalcification of each sample tooth, three simulated lateral canals were created at 2mm, 4mm and 6mm levels from the root apex using a 06-size C+ file. After clearing the samples they were randomly assigned into four experimental groups (n=15) and 1ml of Irrigating Contrast Solution (ICS) was delivered into all samples and then it is activated with 4 different methods Group I-Conventional syringe and needle, Group II - Sonic activation with Endo activator, Group III - Ultrasonic activation with ultrasonic tips and Group IV - Activation using reciprocation movement. All the samples were examined under a stereomicroscope and irrigant penetration was evaluated by means of penetration of ICS.

RESULTS

Group III and Group IV resulted in better penetration of ICS into lateral canals at 2mm and 4mm depth (p<0.001), when compared with Group I and II. At lateral canals 6mm all the groups except Group I, had shown 100 % penetration.

CONCLUSION

The activation of irrigant using reciprocation was able to achieve penetration of irrigating contrast solution both up to the working length and into lateral canals. Hence the clinical significance of this method of irrigant activation is that it can be used for effective penetration of irrigants both upto working length and into lateral canals.

Comparison of efficacy of various root canal irrigation systems in removal of smear layer generated at apical third: An SEM study

Aim:

The aim of the study is to compare the efficacy of different irrigation systems comparing irrigation with syringe and needle (Dispo Van), Max-I-Probe needle (Dentsply Maillefer), EndoActivator (Dentsply Maillefer), and EndoVac (Sybron Endo) in removing the smear layer generated at apical third.

Materials and Methods:

Instrumentation was done in 40 extracted premolars using different irrigation regimes (Group 1, saline and syringe; Group 2, Max-I-Probe needles with NaOCl and ethylenediaminetetraacetic acid (EDTA); Group 3, irrigant activation with EndoActivator using needlesNaOCl and EDTA; and Group 4, irrigation with EndoVac using needles NaOCl and EDTA).

Statistical Analysis Used:

The percentage of debris was seen with scanning electron microscope (SEM) and evaluated using one-way analysis of variance (ANOVA), Kruskal-Wallis test, followed by Mann-Whitney test for significance.

Results:

The mean score ± standard deviation for the conventional group was 2.8 ± 0.42 with median value of 3.00 (2-3). The results for the Max-I-Probe needle group were 2.3 ± 0.48 with median value of 2.00 (2-3) The mean debris score for EndoActivator group were 0.8 ± 0.42 with median value of 1 (0-1). The mean debris score for EndoVac group were 0.4 ± 0.52 with median value of 1 (0-1).

Conclusion:

EndoVac and EndoActivator performed much better than other available systems in removing the smear layer from apical third. So they should be incorporated as a regular part of the irrigation regime.

Effectiveness of different irrigation procedures for removal of dentin debris from a simulated internal resorption cavity

PURPOSE

The aim of this study was to compare the efficiency of different final irrigation techniques to remove artificially placed dentinal debris from a simulated internal root resorption (IRR) cavity.

METHODS

Seventy teeth were prepared using the ProTaper system. The roots were then split longitudinally into two halves, in each of which standardized IRR cavities were prepared. Five teeth were set aside to serve as negative control group. Each cavity of the remaining 65 teeth was filled with dentin debris mixed with 2.5% NaOCl. Another 5 teeth (positive control) were not subjected to the debris removal procedure. Sixty teeth were randomly divided into four experimental groups (n = 15), according to the final irrigation technique used: conventional syringe irrigation (CSI), the Self-Adjusting File (SAF), passive ultrasonic irrigation (PUI), and the EndoActivator (EA). Ten milliliters of 2.5% NaOCl was used during the debris removal procedure. The root halves were disassembled, and the amount of remaining debris was evaluated under a stereomicroscope at 30× magnification.

RESULTS

SAF and PUI removed debris significantly better than CSI and EA (P<.05). CSI was the least effective in debris removal (p<0.05).

CONCLUSIONS

None of the irrigation techniques used was able to completely remove debris from simulated IRR cavities.

Root Canal Penetration of a Sodium Hypochlorite Mixture Using Sonic or Ultrasonic Activation

The purpose of this ex vivo study was to determine, in "open" and "closed" systems, whether the design has an influence on the penetration length of sodium hypochlorite mixed with a radiopaque contrast medium, measured in millimeters, when delivered using positive pressure (PP) and using sonic (SI) or passive ultrasonic (PUI) activation. Sixty single-rooted teeth were divided into two groups: open and closed systems (n=30). Root canal shaping was performed to a working length of 17 mm. The samples were divided into three sub-groups (n=10) according to irrigant delivery and activation: PP, and SI or PUI activation. By using radiographs, penetration length was measured, and vapor lock was assessed. For the closed group, the penetration distance means were: PP 15.715 (±0.898) mm, SI 16.299 (±0.738) mm and PUI 16.813 (±0.465) mm, with vapor lock occurring in 53.3% of the specimens. In the open group, penetration to 17 mm occurred in 97.6% of the samples, and no vapor lock occurred. Irrigant penetration and distribution evaluation using open and closed systems provide significantly different results. For closed systems, PUI is the most effective in delivering the irrigant to working length, followed by SI.

Sonochemical characterisation of ultrasonic dental descalers

An ultrasonic dental descaling instrument has been characterised using sonochemical techniques. Mapping the emission from luminol solution revealed the distribution of cavitation produced in water around the tips. Hydroxyl radical production rates arising from water sonolysis were measured using terephthalate dosimetry and found to be in the range of μmolmin(-1), comparable with those from a sonochemical horn. Removal of an ink coating from a glass slide showed that cleaning occurred primarily where the tip contacted the surface but was also observed in regions where cavitation occurred even when the tip did not contact the surface. Differences in behaviour were noted between different tip designs and computer simulation of the acoustic pressure distributions using COMSOL showed the reasons behind the different behaviour of the tip designs.

Effectiveness of final irrigant protocols for debris removal from simulated canal irregularities

INTRODUCTION

The aim of this in vitro study was to compare the effectiveness of saline, 2.5% sodium hypochlorite, and 2% chlorhexidine, with or without passive ultrasonic irrigation (PUI), in debris removal from simulated canal irregularities within prepared root canals.

METHODS

Ninety bovine lateral incisors were randomly divided into 3 main groups (n = 30) based on the irrigant and prepared with hand files attached to an oscillating handpiece (NSK, Tokyo, Japan) up to a size #80 K-file. Next, the teeth were split longitudinally, and a standardized groove was prepared into the apical third and filled with dentin debris. After the halves were reassembled, they were placed in a muffle. Each main group was randomly subdivided into 2 groups (n = 14) and was treated with different final irrigation protocols. In the sodium hypochlorite/PUI, chlorhexidine/PUI, and saline/PUI groups, the solution was ultrasonically activated 3 times for 20 seconds. In the remaining groups, PUI was not performed. Specimens were scored for debris removal and analyzed under a scanning electron microscope.

RESULTS

An association was observed between the score of debris removal and protocols using PUI (P < .05). No association was observed between the scores of debris removal and the irrigants (P = .87).

CONCLUSIONS

Final irrigation protocols that used PUI were more effective in removing debris from simulated canal irregularities into the apical third than those that did not use it.

Influence of Different Apical Preparations on Root Canal Cleanliness in Human Molars: a SEM Study

OBJECTIVES

To compare the influence of type and dimensions of the apical preparation on the cleanliness of the apical area in molars.

MATERIAL AND METHODS

A total of 120 root canals (MB and DB root canals from 30 maxillary molars and mesial root canals from 30 mandibular molars) were instrumented with Mtwo NiTi rotary instruments to a size 25/0.06 taper and were equally divided into three different experimental groups depending on the subsequently apical root canal preparation: Group 1: no further apical preparation, Group 2: apical preparation with Mtwo files to a size 40/0.04 taper, Group 3: apical preparation with Mtwo Apical Files. All root canals were observed through scanning electron microscopy (SEM). Presence of superficial debris and smear layer was evaluated using a score system. Data were statistically analysed using the Kruskal-Wallis and Bonferroni tests with a level of significance set at P < 0.05.

RESULTS

Kruskal-Wallis test revealed no differences among groups in the middle and coronal third (P > 0.05), while at the apical level, there was a significant difference for both residual debris and presence of smear layer between Group 1 and both Group 2 (P = 0.003 and P = 0.014) and 3 (P = 0.012 and P = 0.021), while no difference was present between Group 2 and Group 3 (P = 0.871 and P = 0.923).

CONCLUSIONS

Cleanliness of the apical third in terms of debris and smear layer was statistically better when an apical preparation was performed to a size 40/0.04 taper or with the use of the Mtwo Apical Files.

Efficacy of needle irrigation, EndoActivator, and photon-initiated photoacoustic streaming technique on removal of double and triple antibiotic pastes

INTRODUCTION

Photon-induced photoacoustic streaming (PIPS) is a novel technique used for the removal of material on root canal walls, such as bacteria and the smear layer. This study evaluated the efficacy of needle irrigation, the EndoActivator System (Dentsply Tulsa Dental Specialties, Tulsa, OK), and PIPS on the removal of antibiotic pastes from an artificial groove created in a root canal.

METHODS

Root canal preparation was performed up to size #40 on 84 extracted single-rooted teeth using ProTaper rotary instruments (Dentsply Maillefer, Ballaigues, Switzerland). The specimens were then split longitudinally, and 2 standardized grooves were prepared in the coronal and apical part of each segment. Double (DAP) and triple antibiotic pastes (TAP) were placed in the grooves for 4 weeks, and the root halves were reassembled. Needle irrigation, the EndoActivator System, and PIPS were used for the removal of DAP and TAP. The root segments were disassembled, and the amount of remaining antibiotic pastes was evaluated under a stereomicroscope at 20× magnification using a 4-grade scoring system. The data were evaluated statistically using Mann-Whitney U tests with a 95% confidence level (P = .05).

RESULTS

PIPS removed significantly more antibiotic pastes than the EndoActivator and needle irrigation (P < .001). The EndoActivator was superior to needle irrigation in removing antibiotic pastes (P < .001). There were no statistically significant differences between DAP and TAP and between coronal and apical thirds in their removing from artificially created grooves (P > .05).

CONCLUSIONS

PIPS was more effective in removing both DAP and TAP from artificial grooves in root canals than the EndoActivator System and needle irrigation. The EndoActivator was also more effective than needle irrigation. It is difficult to completely remove antibiotic pastes from root canals.

Effectiveness of passive ultrasonic irrigation in improving elimination of smear layer and opening dentinal tubules

Objective: To compare the ability to eliminate debris and open dentinal tubules of different ultrasound irrigation procedures. Study Design: Forty extracted single-rooted human teeth were instrumented with mechanical rotatory instrumentation, and divided into four groups: (n=10) according to the final irrigation technique: group A (control), 2.5% NaOCl irrigation with the Miraject needle and no ultrasonic agitation; group B, passive ultrasonic irrigation (PUI) with 2.5% NaOCl and Irrisafe 20 tips; group C, PUI with 2.5% NaOCl and Irrisafe 25 tips; group D, PUI with 2.5% NaOCl and K 25 tips. The amount of debris and the number of opened dentinal tubules was established by scanning electronic microscope. Data were compared using the Kruskal Wallis test. Results: Irrisafe tips (groups B and C) opened up more dentinal tubules and eliminated more debris than conventional irrigation (p<0.05) in the apical third. The middle third shows no significant differences between groups. Irrisafe 25 was more effective than conventional irrigation and K tips (p<0.05) in the coronal third. Conclusions: Ultrasonic activation of the irrigation with Irrisafe tips was the most effective procedure for eliminating the debris and opening up dentinal tubules, especially in the apical third.

Key words:Pasive ultrasonic irrigation, irrigation, sodium hypochlorite.

Irrigation protocol among endodontic faculty and post-graduate students in dental colleges of India: A survey

Background:

Irrigation protocol is the most critical step during the disinfection of an infected root canal system.

Aim:

The purpose of this study was to determine the root canal irrigation trends being practiced among the endodontic teaching faculty and post-graduate students in the dental colleges present in India.

Materials and Methods:

A postal invitation to participate in this national survey was sent to the Department of Conservative Dentistry and Endodontic of 294 Dental Colleges present in India. A total of 2389 forms were successfully delivered out of which 794 duly filled forms were received back. Survey participants were asked about their irrigant selection, irrigant concentration, smear layer removal protocol, and use of adjuncts during irrigation.

Results:

This survey elicited a positive response rate of 33.23%. Our data indicated that 92.8% of respondents use sodium hypochlorite (NaOCl) as the primary endodontic irrigant, with 26 gauge needle being most preferred for syringe irrigation, with 49.3% of them using it at a concentration of 2.6-4.0%. 68% of our respondents aim to remove the smear layer during the endodontic treatment while 47% reported using ultrasonic activation as an adjunct during their irrigation protocol.

Conclusions:

The findings of this survey are that the majority of teaching institutions in India are employing NaOCl (2.6-4.0%) as the primary endodontic irrigant. The concept of smear layer removal is high (68%), and there is a general trend (78%) to modify the irrigation protocol according to the status of the pulp, status of the periapex and in retreatment cases.