Effectiveness of different irrigation techniques on smear layer removal in apical thirds of mesial root canals of permanent mandibular first molar: A scanning electron microscopic study

A Comparative Evaluation of the Cleaning Efficacy of Five Different Root Canal Irrigation Devices: A Histological Study

OBJECTIVES

 This study is aimed to evaluate the cleaning efficacy of five different irrigation systems as SonicMax, RinsEndo, EndoVac, passive ultrasonic irrigation (PUI), and manual needle irrigation (MNI) to histologically evaluate the presence of organic structures and the penetration of irrigation solution.

MATERIALS AND METHODS

 Forty-two single-rooted, extracted human mandibular premolars were used in the study. Each tooth was decoronated at the cementoenamel junction and the root canals were instrumented using ProTaper rotary instruments in a crown-down manner. The specimens were randomly divided into five experimental groups (n = 7) Group (1) SonicMax, group (2) RinsEndo,group (3) EndoVac, group (4) PUI, group (5) MNI, and the control groups (n = 7). Each system used 2.5% sodium hypochlorite (NaOCl), 17% ethylenediamine tetraacetic acid (EDTA), and 2.5% NaOCl, respectively, in the experimental groups. The control group did not receive any final irrigation.The measurements were analyzed by employing two-way analysis of variance multivariate results to show significant differences between the length of the dentin tubules in the apical, middle, and coronal of the six groups. The post-hoc test was used when groups were compared by pairs.

RESULTS

 The results of this study indicate that among the five groups, the RinsEndo and EndoVac were found to be most effective in the cleaning of root canals. The RinsEndo shows highly significant results in the cleaning efficiency of the coronal and middle parts compared with the other groups. The cleaning efficiency in the apical area was the same for RinsEndo and EndoVac.

CONCLUSION

 The result of our study indicates that RinsEndo and EndoVac may be more effective in clinical practice.

Calcium Silicate-Based Sealer Dentinal Tubule Penetration-A Systematic Review of In Vitro Studies

The aim of this systematic review was to perform a qualitative synthesis of in vitro studies which evaluate and compare the penetration of calcium silicate-based sealers into dentinal tubules. A systematic advanced search was performed in Scopus, Embase, Medline (via PubMed), Web of Science, and Cochrane databases on the 1 December 2022. In vitro studies that compared the tubular penetration of at least two calcium silicate-based sealers in extracted human teeth were eligible. PRILE 2021 guidelines were used for the assessment of the risk of bias included studies. The search identified a total of 680 preliminary records, among which 12 studies were eligible for review. The most used methodology to evaluate sealer penetration was the use of a fluorochrome together with the tested sealers and the analysis of their penetration under confocal laser microscopy. Regarding the results of the included studies, calcium silicate-based sealers exhibit a favorable dentinal tubule penetration. Tubular penetration, however, can be affected by factors such as the irrigation protocol, sealer activation, the filling method used, and root canal morphology. EndoSequence BC Sealer showed the highest sealer penetration among the tested sealers. The influence of different fluorochromes on the results of dentinal tubule penetration studies should also be further explored. The in vitro nature of the included studies limits the applicability of the results into the clinical setting. Prospero registration: CRD42022383896.

Cleaning efficacy of EDDY versus ultrasonically-activated irrigation in root canals: a systematic review and meta-analysis

BACKGROUND

Ultrasonically-activated irrigation (UAI) is effective in root canal irrigation but may damage canal walls. EDDY is a sonic activation system with flexible working tips that cause no harm to dentinal walls. This review explores the intracanal cleaning efficacy of EDDY compared with UAI in vitro.

METHODS

The systematic review was registered in the PROSPERO database (CRD42021235826). A literature search was conducted in six electronic databases. In vitro studies that compared the removal of smear layer, debris, soft tissue or microbes in root canals between EDDY and UAI were included. Data extraction and quality assessment were performed. Meta-analyses were conducted on smear layer removal and debris elimination with the standardized mean difference (SMD). Heterogeneity was measured using the I² test and the Chi² test. The random-effect model was used when I² > 50%, or p < 0.1, otherwise the fixed-effect model was applied. The level of significance was set at p < 0.05.

RESULTS

19 articles were included in this systematic review and 7 articles were included in meta-analyses. Meta-analyses on smear layer removal showed unimportant differences between EDDY and UAI at any canal third (coronal [SMD = 0.08, 95% confidence interval (95%CI): -0.29 to 0.45; p = 0.44, I² = 0%]; middle [SMD = 0.02, 95% CI: -0.44 to 0.47; p = 0.94, I² = 0%]; apical [SMD = 0.01, 95%CI: -0.35 to 0.38; p = 0.70, I² = 0%]). Meta-analyses on debris removal evaluated by scanning electron microscope (coronal [SMD = 0.03, 95% CI: -0.41 to 0.46; p = 0.27, I² = 23%]; middle [SMD = -0.24, 95% CI: -0.83 to 0.35; p = 0.80, I² = 0%]; apical [SMD = 0.24, 95%CI: -0.20 to 0.67; p = 0.36, I² = 2%]) and micro-CT (SMD = 0.36, 95% CI: -0.67 to 1.40; p = 0.03, I² = 70%) both found insignificant differences. No meta-analysis was undertaken on soft-tissue removal and disinfection due to the various study designs, but the qualitative analyses implied that EDDY achieved similar performance to UAI in both aspects.

CONCLUSIONS

Limited evidence indicated that EDDY was comparable to UAI in removing smear layer, debris, soft tissue and microbes ex vivo. Considering UAI may damage canal walls, EDDY might be a substitute for UAI in irrigation activation. But more randomized clinical trials are required to explore the clinical extrapolation of the results in this review.

Histological Investigation of the Cleaning Effectiveness of Different Biomechanic Processes of Isthmus in Lower Molars

Objectives This study aimed to evaluate the efficacy of different instruments (Hyflex, ROTATE, and hand files) and irrigation methods (EndoUltra, EndoActivator, and side-perforated syringe) in the mesial root canal of a mandibular first molar with isthmuses.

Materials and Methods Sixty-three mandibular molar teeth with isthmus were selected using cone beam computed tomography (CBCT) images. The root canals were instrumented with Hyflex, ROTATE, or hand files (21 of each) and three of each as control group and the specimens were embedded in silicone blocks. Final irrigation was performed with the perforated syringe or ultrasonic (EndoUltra) or sonic irrigation (EndoActivator). All canals were irrigated using 5.25% NaOCl solution (15 mL). Then, the roots were stained with hematoxylin–eosin, and specimens were sliced for histologic evaluation. The isthmus regions (2.7, 3, 4.7, and 5 mm from the apex) were analyzed, and the percentage of debris was calculated.

Statistical Analysis All data were statistically analyzed using one-way analysis of variance and Tukey's tests.

Results Both Hyflex and ROTATE groups showed less debris compared with the hand instrument group (P < 0.05). When irrigation methods were compared, EndoUltra showed the least, followed by EndoActivator and perforated needle irrigation having the maximum debris (p < 0.05). When sections were compared, the maximum debris was found in the apical section and the least in the coronal section (p < 0.05).

Conclusion Although none of the methods cleaned the isthmus completely, nickel–titanium (NiTi) systems and ultrasonic and sonic systems removed more debris than the side-perforated needle syringe irrigation.

The Effect of Passive Ultrasonic Irrigation and XP-Endo Finisher on Post-operative Pain after Endodontic Retreatment on Patients (Randomized Controlled Clinical Trial)

AIM: To evaluate the effect of passive ultrasonic irrigation or XP-Endo Finisher on postoperative pain in patients with underextended filling in previously endodontically treated mandibular first molar teeth requiring endodontic retreatment using visual analog scale (VAS) scale at 6, 12, 24, 48, 72 h, and 7 daytime intervals. METHODS: Seventy-eight patients with mandibular first molars which need endodontic retreatment were randomly allocated into one of three separate groups (n = 26); NaviTip group (control), XP-Endo Finisher group, or Ultra X group. Data were statistically analyzed with a significance level of p ≤ 0.05. RESULTS: XP-Endo Finisher agitation and ultrasonic agitation as a final irrigation protocol showed significantly lower pain values than the control group, but there was no significant difference in pain values between the experimental groups. CONCLUSION: Within the limitation of this study, it can be concluded that agitation techniques used during endodontic retreatment decreased the incidence and intensity of post-operative pain.

Intratubular penetration capacity of HiFlow bioceramic sealer used with warm obturation techniques and single cone: A confocal laser scanning microscopic study

Objective

The aim of this paper was to evaluate the intratubular penetration area of a bioceramic sealer, using continuous wave (CW), vertical condensation (VC) with two different types of gutta-percha (conventional (NG) and bioceramic-coated (BG)) and single cone (SC) technique with BG gutta-percha, in different root thirds.

Methods

A total of 150 mature single-root human teeth (including incisors, canines and premolars) were prepared and randomly divided into five groups (n = 30). Teeth were filled using a bioceramic sealer (TotalFill BC Sealer HiFlow ®) and two different types of gutta-percha, with CW and VC techniques, the teeth in the control group were filled with SC technique and BG gutta-percha. The teeth were sectioned and evaluated as one-third portions in each case under a confocal laser microscope. The penetration area measurements were carried out with the Autocad ® programme. Data was analyzed using the one-factor ANOVA test (p < 0.05) and Post Hoc Test (p < 0.05).

Results

The ANOVA Test showed significant differences in the penetration areas of the five obturation techniques (P < 0.05). The Post Hoc Test exhibited significant differences in multiple comparisons (P < 0.05). There was more dentinal tubule penetration in the coronal third than in the apical third in all techniques.

Conclusions

The intratubular penetration of the bioceramic sealer was influenced by the obturation techniques tested, but not by the different gutta-percha tested. There was more penetration of sealer in the warm obturation techniques than the SC, regardless of the type of gutta-percha used.

Post-operative Pain after Different Root Canal Irrigant Activation Methods in Patients with Acute Apical Periodontitis (Randomized Clinical Trial)

Objective To evaluate the degree of postoperative pain in patients with necrotic teeth with symptomatic apical periodontitis after applying ultrasonic irrigation or manual dynamic agitation. Methods Seventy-eight patients diagnosed with necrotic mandibular first molar with symptomatic apical periodontitis were randomly allocated into 1 of 3 separate groups (n=26); Manual Dynamic Agitation group, Ultra X group, or NaviTip group (control). After a single-visit root canal treatment and a specific method of agitation, depending on each group, the patients were given a questionnaire on which they would mark the degree of pain in a scale from 0 to 10 at 6, 12, 24, 48, 72 hours and 7 days post-operative. Data were statistically analyzed with a significance level of P ≤ 0.05. Results Final irrigation protocol including Ultrasonic agitation and NaviTip (control) groups showed significantly lower values of pain than the MDA group. There was a reduction in pain values by time in all groups. Conclusion There was significantly less pain associated with passive ultrasonic agitation and side vented needle (NaviTip) irrigation compared to Manual Dynamic Agitation.

Efficacy of sonic and ultrasonic activation during endodontic treatment: a Meta-analysis of in vitro studies

OBJECTIVE

To ensure a successful endodontic treatment, it is important to have a proper disinfection of the root canal. The current study compares the root canal cleanliness and smear layer score between sonic and ultrasonic activation.

METHOD

Systematic literature review was implemented, using 12 databases. All in vitro studies comparing the efficacy of sonic and ultrasonic activation and reporting at least one outcome of interest were included.

RESULTS

At the apical level, pooling the data in the random-effects model (I²=64%, p = .1) revealed a statistically significant lower smear layer score within the sonic activation group (MD-0.48; 95% CI-0.92, -0.04; p = .03). Furthermore, there was a statistically significant lower push-out bond strength value among the sonic group, in contrast to the ultrasonic group at the middle (MD-0.69; 95% CI-1.13, -0.25; p = .002) and at the apical levels (MD-0.78; 95% CI-1.09, -0.46; p < .0001) of the root canal.

CONCLUSIONS

Sonic activation accomplished advancement relative to ultrasonic agitation in removing the smear layer, while ultrasonic activation resulted in significant cohesion between the sealers and the dentine tubules, decreasing the vulnerability of apical leakage and tooth fracture.

An in vitro radiological evaluation of irrigant penetration in the root canals using three different irrigation systems: Waterpik WP-100 device, passive irrigation, and manual dynamic irrigation systems

Background:

Instrumentation and irrigation of the root canal facilitating effective debridement is considered the most important single factor in the prevention and treatment of endodontic diseases.

Aim:

The aim of the study was to evaluate the depth of penetration of the irrigant depending on the final activation using Waterpik device modified with NaviTip needle, passive irrigation, and manual dynamic activation using the radiopaque solution in conjunction with digital dental radiography.

Materials and Methods:

Ninety freshly extracted single-rooted mandibular premolars based on the inclusion and exclusion criteria were used for this study. Access cavity preparation was done for all the samples, and the working length of each sample was determined using a size 10-k file. The radiopaque solution (Urografin) was delivered into (Groups A, B, and C) prepared canal of samples at the rate of 1 ml in 30 s with up-and-down motion.

Results:

The test results showed that Waterpik WP-100 group showed significantly high infiltration index values as compared to passive irrigation and manual irrigation group at P < 0.002 and P = 0.007, respectively.

Conclusion:

Sonic irrigation using a Waterpik device modified with a NaviTip needle permits better infiltration of the irrigant.

Impact of Warm Vertical Compaction on the Sealing Ability of Calcium Silicate-Based Sealers: A Confocal Microscopic Evaluation

The aim of this in vitro study was to evaluate the dentinal tubule penetration of two calcium silicate-based sealers used in warm vertical compaction (WVC) obturation technique in comparison with the single cone (SC) technique by confocal laser scanning microscopy (CLSM). The null hypothesis was that both obturation techniques produced similar sealer penetration depths at 1 and 5 mm from the apex. Forty-four mandibular single-rooted premolars were randomly divided into four equally experimental groups (n = 10) and two control groups (n = 2) according to the type of sealer (Bio-C Angelus, Londrína, PR, Brazil or HiFlow Brasseler, Savannah, GA, USA) with either SC or WVC. The sealers were mixed with a fluorescent dye Rhodamine B (0.1%) to enable the assessment under the CLSM. All the specimens were sectioned horizontally at 1 and 5 mm from the apex. The maximum penetration depth was calculated using the ImageJ Software (ImageJ, NIH). Data were analyzed by Mann-Whitney U and Kruskal-Wallis tests (p < 0.05). A significant difference was shown between the four groups at 1 mm (p = 0.0116), whereas similar results were observed at 5 mm (p = 0.20). WVC allowed better diffusion for both sealers at 1 mm (p = 0.01) and 5 mm (p = 0.034). The maximum penetration of the Bio-C and HiFlow sealers was more important at 5 mm with the two obturation techniques. Within the limitations of this study, WVC enhanced the penetration of calcium silicate-based sealers into the dentinal tubules in comparison with the SC technique at both levels.

Analysis of the smear layer generated by different activation systems: an in vitro study

OBJECTIVES

To evaluate via scanning electron microscopy the amount of smear layer generated during the use of sonic and ultrasonic activation systems with standardized short-term intentional contacts with the canal walls.

METHODOLOGY

Seventy single-root human teeth were randomly assigned to 2 control (n = 5 each): NC (negative control), PC (positive control) and four experimental groups (n = 15 each): NC (negative control), PC (positive control), G1 (passive ultrasonic irrigation with Irrisafe), G2 (ultrasonic irrigation with EndoUltra), G3 (sonic irrigation with Endoactivator), G4 (sonic irrigation with Eddy). Samples were instrumented with ProTaper Next®. An irrigation protocol with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) was followed for both PC and the experimental groups. Standardized intentional contacts were made in the mesial walls during 5 s at WL - 2 mm in all experimental groups. Two calibrated evaluators scored the smear layer generated with an ordinal scale by scanning electron microscopy. The weighted kappa coefficient (K_w) was calculated to determine the inter-observer agreement. Post-consensus ordinal data were analyzed using the ordinal (linear) chi-square test.

RESULTS

When the agitation file is in contact with dentine walls, Irrisafe® significantly generated the least amount of smear layer in the coronal third (p < 0.05). Both in the middle and apical third, activation with Irrisafe® also showed statistically significant better results than Eddy™ and EndoUltra®. Endoactivator® showed significant better results than EndoUltra® and Eddy™ in the apical third (p < 0.05).

CONCLUSIONS

Irrisafe generated the least amount of smear layer in the entire canal and similar to Endoactivator in the apical third when the agitation file is in contact with dentine walls.

CLINICAL RELEVANCE

The smear layer is generated during activation. It is common to apply irrigation protocols where after the removal of the smear layer using chelants, a final rinse and activation is carried out but there are no previous studies analyzing the possible creation of a new smear layer with this final activation.

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.

Effect of ultrasonic activation on calcium ion quantification, smear layer removal, and canal cleaning efficacy of demineralizing irrigants

Background

Effective removal of smear layer ensures better penetration of irrigants ensuring root canal disinfection and has the potential of sealing dentinal tubules during obturation.

Aim

The aim of this study is to evaluate the canal cleaning efficacy and calcium ion liberation with the use of demineralizing irrigants, namely, 17% ethylenediaminetetraacetic acid (EDTA), 7% maleic acid, and 10% citric acid with or without ultrasonic (US) activation.

Materials and Methods

Crowns of 62 extracted maxillary central incisors were decoronated and root canals prepared. Based on the final irrigant teeth were divided into following groups (n = 10), namely, 10% citric acid, 7% maleic acid, 17% EDTA, and 10% citric acid with US activation, 7% maleic acid with US activation, and 17% EDTA with US activation. Irrigants were subjected to inductively coupled plasma-atomic emission spectroscopy followed by debris scoring and scanning electron microscope analysis.

Statistical Analysis

One-way analysis of variance with the Bonferroni's correction for multiple testing was employed.

Results

About 10% citric acid with US activation liberated the highest calcium ions and removed the maximum smear layer.

Conclusions

Citric acid with US activation is a potentially effective irrigation regimen with sodium hypochlorite.

A Scanning Electron Microscope Evaluation of Smear Layer Removal and Antimicrobial Action of Mixture of Tetracycline, Acid and Detergent, Sodium Hypochlorite, Ethylenediaminetetraacetic Acid, and Chlorhexidine Gluconate: An In vitro Study

Objectives:

The main objective is to evaluate the efficiency in removal of smear layer of mixture of tetracycline, acid and detergent (MTAD), sodium hypochlorite (NaOCl), ethylenediaminetetraacetic acid (EDTA) and chlorhexidine gluconate by scanning electron microscope (SEM) evaluation and also to evaluate the antimicrobial action of the same irrigants against standard culture strains of Enterococcus faecalis.

Materials and Methods:

This study included 60 extracted permanent teeth with single root canal. The sample was categorized into five groups with 12 teeth in each group. Root canals were enlarged till size 40 with K-files. One group was kept as control and irrigated only with saline. Other four groups used 5% NaOCl as irrigant during instrumentation and MTAD, 5% NaOCl, 17% EDTA, and 2% chlorhexidine gluconate as final rinse. Teeth were split and examined under SEM. To test the antibacterial action, the zone of inhibition method using agar plates was used. Obtained data were statistically analyzed by SPSS version 17 (SPSS Inc., Chicago, IL, USA).

Results:

MTAD and 17% EDTA removed smear layer from all regions of the root canals. About 5% NaOCl and 2% chlorhexidine gluconate were ineffective in removing the smear layer. The mean zone of inhibition formed by the irrigants was in the following order; MTAD (40.5 mm), 2% chlorhexidine gluconate (29.375 mm), 17% EDTA (24.125 mm), 5% NaOCl (22.125 mm), and saline (zero).

Conclusion:

MTAD showed high smear layer removal efficacy, but no significant difference was found to that of 17% EDTA. As the dimensions of the zones of inhibition showed, MTAD has got highest antibacterial action against E. faecalis, followed by 2% chlorhexidine gluconate, 17% EDTA, and 5% NaOCl. However, the exact correlation of in vitro study results to clinical conditions is impossible due to the variables involved.

Efficacy of irrigant activation techniques in removing intracanal smear layer and debris from mature permanent teeth: a systematic review and meta-analysis

AIMS

To establish whether irrigant activation techniques (IATs) result in greater intracanal smear layer and debris removal than conventional needle irrigation (CNI).

METHODOLOGY

Six electronic databases were searched to identify scanning electron microscopy studies evaluating smear layer and/or debris removal following the use of manual dynamic activation (MDA), passive ultrasonic irrigation (PUI), sonic irrigation (SI) or apical negative pressure (ANP) IATs in mature permanent teeth. Meta-analyses were performed for each canal segment (coronal, middle, apical and apical 1 mm) in addition to subgroup analyses for individual IATs with respect to CNI. Outcomes were presented as standardized mean differences (SMD) alongside 95% confidence intervals (95% CI) and chi-squared analysis.

RESULTS

From 252 citations, 16 studies were identified. The meta-analyses demonstrated significant improvements in coronal (SMD: 1.15, 95% CI: 0.72-1.57 / SMD: 0.54, 95% CI: 0.29-0.80), middle (SMD: 1.30, 95% CI: 0.59-2.53 / SMD: 0.8, 95% CI: 0.58-1.13) and apical thirds (SMD: 1.22, 95% CI: 0.83-1.62 / SMD: 1.86, 95% CI: 0.76-2.96) for smear layer and debris removal, respectively. In the apical 1 mm IATs improved cleanliness; however, differences were insignificant (SMD: 1.15, 95% CI: -0.47-2.77). Chi-squared analysis revealed heterogeneity scores of 79.3-92.8% and 0.0-93.5% for smear layer and debris removal, respectively.

CONCLUSIONS

IATs improve intracanal cleanliness across a substantial portion of the canal, and therefore, their use is recommended throughout root canal preparation. However, current data is too heterogeneous to compare and identify superiority of an individual technique highlighting the need to standardize experimental protocols and develop a more representative research model to investigate the in vivo impact of IATs on clinical outcomes and periapical healing following root canal treatment.

Comparative Evaluation of Cleaning Efficacy using Four Novel Nickel-titanium Rotary Instruments: An in vitro Scanning Electron Microscope Study

AIM

The aim of the study was to compare the cleaning efficacy (debris and smear layer removal) of two multifile rotary systems (MTwo and Silk) and two single-file rotary systems (F6 Skytaper and NeoNiTi).

MATERIALS AND METHODS

Eighty mesial canals of mandibular first molars were cleaned and shaped using four nickel-titanium (NiTi) rotary instruments to size # 25 and 3% NaOCl and 17% ethylenediaminetetraacetic acid (EDTA). Samples were randomly divided into four equal groups (n = 20) according to instrumentation: Group I, Mtwo; group II, Silk; group III, F6 Skytaper; group IV, NeoNiTi. Samples were split longitudinally and examined under scanning electron microscope (SEM) for debris and smear layer removal in coronal, middle, and apical thirds of each root canal.

RESULTS

F6 skytaper and Mtwo groups showed significantly higher debris removal than Silk and NeoNiTi groups in apical third of root canal as well as when compared with NeoNiTi group in middle third. F6 Skytaper group showed significantly higher debris and smear layer removal than Silk group in coronal third. There was statistically significant difference among all thirds of root canal in terms of debris removal in Silk and NeoNiTi groups. There was statistically significant difference among all thirds of root canal in F6 Skytaper and NeoNiTi groups in terms of smear layer removal.

CONCLUSION

F6 Skytaper single-file rotary instrumentation showed the maximum cleaning efficacy followed by Mtwo multifile rotary instrumentation in all thirds of root canal.

CLINICAL SIGNIFICANCE

F6 Skytaper rotary instrument is most efficient followed by Mtwo rotary instrument among all rotary instruments.

Ultrasonic versus sonic activation of the final irrigant in root canals instrumented with rotary/reciprocating files: An in-vitro scanning electron microscopy analysis

Aim:

To compare the smear layer and debris removal in root canals instrumented with two different kinematic motions after ultrasonic and sonic irrigation activation.

Materials and Methods:

Eighty freshly extracted teeth were selected for the study and randomly divided the samples into two groups (n = 40) for instrumentation with either rotary ProTaper NEXT (PTN) or reciprocating WaveOne (WO) file systems. These (n = 40) were further divided into two groups (n = 20) where the final irrigant was activated using either Ultrasonics (Passive Ultrasonic Irrigation; PUI) or Sonics (EndoActivator; EA). Group 1: PTN + EA; Group 2: PTN + PUI; Group 3: WO + EA; and Group 4: WO + PUI. During instrumentation, a total of 4 ml of 5.25% NaOCl was used for irrigation. The final irrigation protocol included NaOCl and Smear Clear Solution. The samples were processed by scanning electron microscopic examination for debris and smear layer scoring, and statistical analysis was done.

Results:

The mean debris and smear layer score was less in the group instrumented by PTN with sonic activation of the irrigant.

Conclusion:

A combination of PTN instrumentation with sonic irrigation activation by EA is more effective in debris and smear layer removal in the groups tested.