ProTaper Universal Retreatment Research Articles

Evaluation of canal patency and cleanliness following retreatment of bioceramic sealer-obturated root canals using three different irrigant activation protocols.

This study evaluated the effectiveness of three different irrigant activation techniques in cleaning and establishing patency during retreatment of root canals obturated with gutta-percha and bioceramic sealer. 60 extracted premolars with oval-shaped canals were instrumented and obturated with gutta-percha and EndosequenceBC sealer using the 'warm hydraulic condensation' technique. The teeth were retreated using Protaper Universal Retreatment and XP-Endo Shaper system and divided into four groups according to the irrigant activation protocol used: control, passive ultrasonic irrigation (PUI), Endovac irrigation (EVI) and XP-Endo Finisher R (XPFR). Apical patency was achieved in all the samples of the XPFR group (100%), which showed a significantly higher success rate compared with the control (73.3%) and EVI groups (73.3%) (p < 0.05). The scanning electron microscopic evaluation revealed significantly cleaner middle and apical third root canals in the PUI and XPFR groups compared with the control group (p < 0.05). These findings suggest that XPFR effectively cleans and establishes patency in root canals filled with bioceramic sealers.

The Effect of XP-endo Finisher R and PIPS Technique Using Er: YAG Laser on Removal of Gutta-percha in Root Canals Obturated with Two Different Obturation Techniques

Background: The aim of this study is to compare the efficacy of XP-endo finisher R file and PIPS technique using Er: YAG laser on removal of gutta-percha in root canals obturated with two different obturation techniques. Methods: The root canals of sixty single-rooted teeth were prepared with ProTaper Next Rotary instruments up to X3 (Dentsply, Ballaigues, Switzerland). Half of the root canals were obturated with cold lateral condensation technique and the other half with System B technique (Kerr Corporation, CA, USA) and BioRoot RCS sealer (Setodent, Louisville, USA) was used in all groups as a root canal sealer. After one week, all root canals were retreated using Protaper Universal retreatment instruments (Dentsply, Ballaigues, Switzerland) and enlarged to ProTaper Next X5 File at the working length. Both groups were divided into 3 subgroups according to the additional cleaning methods: control group without an additional cleaning method, XP-endo Finisher R or PIPS technique using Er: YAG laser. Finally, all teeth were split longitudinally and images were taken using an operation microscope (Carl Zeiss, Heidelberg, Germany). The images were analyzed by Image J program. Two-way ANOVA and Tukey tests were used for statistical analysis. Results: There was a statistically significant difference between the canal filling techniques applied in the evaluation of remnants (p=0.010). There was no significant difference between additional cleaning methods (p=0.196). Conclusion: Within the limitations of this study, cleanliness is more difficult in root canals obturated with System B technique. Use of additional cleaning method was not effective in removal of root canal filling materials.

ProTaper universal retreatment retreatment potential in oval-shaped canals filled with different obturation techniques—A micro-computed tomography study

Abstract Aim: The objective of this in vitro micro-computed tomography investigation is to assess the efficacy of the ProTaper Universal Retreatment System in retreating oval-shaped root canals filled with three obturation procedures. Materials and Methods: Thirty-six lower incisors with a single oval root canal were prepared using XP-Endo Shaper up to size 30/0.04, and allocated into three equal groups based on the filling technique: Group 1: Warm vertical condensation technique; Group 2: GuttaCore obturators; Group 3: Cold lateral condensation technique. All samples were further retreated using the ProTaper Universal Retreatment system. Micro-CT analysis was performed before and after the retreatment procedure. Statistical analysis was performed with a significance level of 0.05. Data analysis was conducted using the Kolmogorov-Smirnov and Kruskal–Wallis H tests. Results: The best performance of the files was achieved when the removal of the filling in the entire canal was considered. However, this outcome was not statistically significant when compared with the other observed root canal levels. The retreatment procedure could not ensure thorough cleanliness of the canal walls from filling remnants, regardless of the obturation technique and observational level. Conclusions: The ProTaper Universal Retreatment system used for the removal of gutta-percha and sealer in oval-shaped root canals demonstrated equal effectiveness, regardless of the obturation technique used.

Comparative evaluation of incidence of dentinal defects after root canal preparation using three different endodontic retreatment systems - An in vitro study.

Safe and efficient removal of all root filling materials from the root canal system without compromising radicular dentin structure is essential for optimal nonsurgical retreatment. The aim of this study was to evaluate and compare the incidence of dentinal defects caused during root canal filling removal using conventional, rotary, and reciprocating retreatment file systems. A detailed protocol explaining purpose and procedures of the study was submitted to the Institutional Ethics Committee and ethical clearance obtained. Sixty human maxillary permanent central incisors were collected and decoronated to 12-mm standardized length. The canals prepared up to a master apical file size F3 with Protaper hand files, obturated using AH plus sealer, examined under the stereomicroscope (×40 magnification): Group I: Control (n = 15), Group II: Conventional (n = 15), Group III: Protaper Universal Retreatment Files (n = 15), and Group IV: Reciproc Blue (n = 15). After instrumentation, teeth were sectioned at 3, 6, and 9 mm from the apex to evaluate the presence of dentinal defects under the stereomicroscope. Statistics were performed using the SPSS, version, 25 (SPSS Inc., Chicago, IL, USA). Initially, normality test was done using the Shapiro-Wilk test and data were not normally distributed followed by Kruskal-Wallis test. P < 0.05 is considered statistically significant. Maximum percentage increase in dentinal defects was observed in Protaper Universal Retreatment Files followed by Conventional method and Reciproc Blue. Significantly Reciproc Blue reduced the incidence of dentinal defects after root canal preparation.

Comparative analysis of novel heat-treated retreatment file system on the removal of obturating material using nano-computed tomography.

The aim of nonsurgical retreatment is to remove the previous filling material followed by chemo-mechanical preparation of the canal to achieve proper disinfection of the root canal system. This is then followed by re-obturation. This study evaluates the time taken to retrieve the gutta-percha and the quantity of remaining filling material after retreatment with two different file systems. The quantity of remaining filling material was assessed using nano-computed tomography (CT) due to its increased accuracy. Forty extracted single-rooted teeth were split into two groups at random and decoronated and obturated at a standard root length of 16 mm. Solite RS3 (SRS-3) Retreatment and ProTaper Universal Retreatment (PTUR) systems were used to retrieve the gutta-percha after a preoperative nano-CT scan. Postoperative nano-CT scan was taken and both the scans were superimposed to quantify the remaining filling material. The time taken to remove gutta-percha was measured using a stopwatch. The statistical analysis comparing the two groups was conducted using the independent t-test. The quantitative analysis of remaining filling material using nano-CT showed no statistical difference between both the file systems used (P > 0.05). However, SRS-3 took significantly less time in the removal of gutta-percha (P < 0.05). Hence, we can conclude that there is no significant difference in the amount of remaining filling material between both the file systems. However, time taken to remove the gutta-percha was lesser in SRS-3 compared to PTUR file system.

In vitro evaluation of filling material removal and apical debris extrusion after retreatment using Reciproc blue, Hyflex EDM and ProTaper retreatment files

ObjectivesTo evaluate the amount of remaining filing material and apical debris extrusion after retreatment using Reciproc Blue, Hyflex EDM and ProTaper Retreatment Files.Materials and methodsThirty-six extracted permanent mandibular first molars with moderately curved mesial roots were selected. Mesiobuccal canals were prepared using the ProTaper Next system up to size X2 and filled using gutta-percha and Adseal sealer via cold lateral compaction. Teeth were randomly divided into three equal groups (n = 12): Group 1: Reciproc Blue (RB)(VDW, Germany), Group 2: Hyflex EDM (HEDM)(Coltene/Whaledent, Switzerland), Group 3: ProTaper Universal Retreatment file system + ProTaper Next file system (PTUR + PTN)( Dentsply Maillefer, Switzerland). Eppendorf tubes were used to collect the apically extruded debris. Cone-beam computed tomographic scans were taken prior to and after retreatment and the volume of remaining filling material was assessed at the coronal, middle and apical levels. Statistical analysis was performed using the Kruskal–Wallis test, Friedman's test and Wilcoxon Sign Rank test. Significance level was set at p value 0.05.ResultsThere were no statistically significant differences among the three groups in the reduction of the volume of the filling material or in the amount of apically extruded debris.ConclusionAll the tested filing systems showed similar efficacy in removing the filling material, however, none of them could achieve its complete removal. Apical extrusion of debris occurred with all the systems used with no significant difference between the three groups.

Comparison of the dentin tubule penetration of AH Plus, WellRoot ST, and MTA BioSeal after obturation, retreatment, and re-shaping of the root canals.

It was aimed to compare the dentine tubule penetration of AH Plus, MTA Bioseal, and WellRoot ST after filling, retreating, and reshaping the root canals by using a novel microscopic method. Seventy-five mandibular incisors with single root canals were shaped with Protaper Next system (PTN; X2-25/0.06) The teeth were obturated with AH Plus labeled with Rhodamin B and MTA Bioseal or WellRoot ST sealer which were labeled with Fluo-3. Then the root canal fillings were removed with Protaper Universal Retreatment files. At the last stage, the teeth were reshaped with PTN (X3-30/0.07). The samples were transversally sectioned and examined using a Cytation 5 reader and Gen5 software regarding the mean and the maximum depth of sealer penetration. No significant difference was observed between the groups, except for the 6 mm level after reshaping the root canals (p < .05). It is not possible to completely remove the sealer remnants from the dentin walls even after reshaping the root canals. RESEARCH HIGHLIGHTS: Even after reshaping the root canals in the retreatment procedure, it is not possible to completely remove the filling residues of the epoxy-resin-based, calcium-silicate-based and MTA-based endodontic pastes from the dentin walls.

Evaluation of Root Dentin Damage during Retreatment Procedure using Various Engine-Driven Retreatment File Systems-A Micro-CT Study.

The aim of this research was to assess the damage to root dentin that arises from retreatment with different engine-driven NiTi retreatment files employing micro-computed tomography. Sixty mandibular premolar teeth having a single root and root canal that were recently extracted were gathered and stored. The specimens were de-coronated at the cementoenamel junction under water irrigation to achieve a homogeneous root length of 16 millimeters. Gutta-percha cones were coated with sealants and placed within the radicular canal till the WL. All sixty premolars were randomly assigned to one of the following three groups, with every group comprising 20 sample teeth each. Group 1: MTwo Retreatment files, Group 2: ProTaper Universal Retreatment files, Group 3: Edge File XR Retreatment rotary files. The quantity of root dentinal injury was estimated by deducting the dentin volume (mm3) in the pre- and post-therapy micro-CT scans at apical, middle, and cervical 3rd points. An intra-group comparative scrutiny showed that lower radicular dentinal injury was noted at apical 3rd (0.31 ± 0.16, 0.62 ± 0.02) in Edge File XR Retreatment file system and MTwo Retreatment file system in that order. The statistically significant disparity was seen amid the MTwo Retreatment file, Edge File XR Retreatment file system and ProTaper Universal Retreatment file, Edge File XR Retreatment file system with P value of 0.001on intergroup assessment. In spite of the limitations that this research had, it was inferred that each assessed file system proficiently eradicated the obturated material through the retreatment procedure performed. In addition, it was seen that the Edge File XR group showed lesser root dentin damage in contrast to MTwo and ProTaper Universal file systems.

Evaluation of Apically Extruded Debris During Retreatment Procedures Using Various File Systems in Teeth With Simulated Apical Root Resorption: An In Vitro Study.

Aim The aim of this study was to compare the amount of debris produced apically during the removal of root canal obturating material by using various files in extracted teeth with simulated apical root resorption. Materials and methods An in vitro study was conducted in the root canals of 90 extracted mandibular premolar teeth that were prepared with a ProTaper Gold rotary file (Dentsply Maillefer, Ballaigues, Switzerland) and filled with gutta-percha and an AH Plus sealer (Dentsply Maillefer, Ballaigues, Switzerland) using a cold lateral compaction technique. A total of 45 mandibular premolar teeth were randomly assigned to three control groups (i.e., the ProTaper Universal retreatment file (Dentsply Maillefer), the Reciproc Blue file (VDW, Munich, Germany), and the HyFlex Remover file(Coltene/Whaledent, Altstatten, Switzerland)for the removal of root canal filling material, whereas the remaining 45 teeth were treated as the experimental group and their apical portion was modified to simulate apical root resorption. The teeth of this experimental group were randomly divided into three subgroups according to the same three techniques used with the control groups for the removal of root canal filling materials. The apically extruded debris was collected into pre-weighed borosilicate glass tubes and then dried. The mean weight of the apically extruded debris was assessed using an analytical balance to an accuracy of 10-4 g. Further, the data were analyzed using the Kruskal-Wallis test and Tukey's post hoc test. Results In the simulated apical root resorption groups, all file systems were associated with significantly more debris extrusion than the groups without simulated root resorption (a< 0.05). In both the control groups and experimental groups, the ProTaper Universal retreatment file was associated with the least weight of the apically extruded debris (a < 0.05), followed by the Reciproc Blue file and the HyFlex Remover file. Conclusion The amount of debris extruded apically was significantly greater in the teeth with simulated apical root resorption than in those without it. Further, during the removal of the root canal filling materials, HyFlex Remover was associated with significantly more apically extruded debris in all groups.

Evaluation of Residual Root Canal Sealer Removal Efficacy of Different Irrigation Activation Techniques by Confocal Laser Microscopy Analysis

Objective: The purpose of this study was to use confocal laser microscopy analysis to evaluate the effectiveness of conventional needle irrigation (CNI), EndoActivator (EA), and EDDY during endodontic retreatment.&#x0D; Methods: This study included 45 maxillary incisor teeth with a single root and canal. Root canals were prepared with ProTaper Universal files (Dentsply Sirona, Ballaigues, Switzerland) and obturated with labeled sealer mixed with 0.1% Rhodamine B and gutta percha according to single cone techniques. Initial root canal filling material was removed using ProTaper Universal Retreatment files and F4 files. Teeth randomly were divided into 3 groups (n = 15) depending on the activation technique: CNI, EA (Dentsply, Tulsa Dental Specialties, Tulsa, OK), and EDDY (VDW, Munich, Germany). Confocal laser microscopy was used to evaluate the penetration area, depth, and percentage of the residual sealer in the apical, middle, and coronal sections after irrigation activation.&#x0D; Results: In all sections, the EDDY group had a lower penetration area of residual sealer than the CNI group (P&lt; .05). In comparison to the coronal section, the penetration percentage of the CNI and EA groups was lower in the apical section (P&lt; .05). In the CNI group, the penetration depth was higher at the coronal section than at the apical and middle sections (P&lt; .05), and it was higher at the coronal section than at the apical section.&#x0D; Conclusion: Within the limitations of this study, none of the activation systems tested could completely remove the residual sealer. However, the lowest residual sealer was seen after using EA and EDDY.

Efficiency of ProTaper Universal Retreatment, Reciproc Blue and XP-endo Shaper in the removal of a bioceramic-based root canal filling.

This in vitro study aimed to assess the performance of ProTaper Universal Retreatment (PTUR), Reciproc Blue (RB), and XP-endo Shaper (XPS) system in the removal of bioceramic root canal filling. Forty-five human single-rooted mandibular premolars were prepared up to 30/.04 and filled with Endosequence BC sealer and BC points before being assigned into three groups (n=15). The root canal fillings were removed until reaching predetermined working length (WL) with PTUR in group 1, RB in group 2, and XPS in group 3. During the removal of the filling material, apically extruded debris was collected in pre-weighed Eppendorf tubes, and operation time was recorded with a digital chronometer. Reaching the WL and maintaining apical patency were evaluated separately. The data were statistically analyzed using Kruskal Wallis and Mann Whitney U tests. The mean amount of extruded debris was highest in the PTUR group, although all instruments caused apical extrusion of debris. The mean time for reaching WL was longest for RB and shortest for XPS, with significant differences among the groups (p<0.05). Although the difference was not significant (p=0.799), in the PTUR group the WL was reached in 93.3% of the samples, which was higher than other groups (86.7%). All tested systems caused a certain amount of debris extrusion. XPS was associated with less extrusion while regaining more rapid access to the periapical area than PTUR and RB.

Effectiveness of Two Endodontic Instruments in Calcium Silicate-Based Sealer Retreatment.

The objective of the present in vitro work was to investigate the effectiveness and time required for the removal of calcium silicate-based sealer using two rotary retreatment systems. Sixty extracted, single-canal, lower premolars were used. After obturation using the single-cone technique with calcium silicate-based sealer, samples were divided into four groups according to the technique of desobturation: Group 1 (G1): D-Race; Group 2 (G2): D-Race followed by the use of XP-Endo Finisher R; Group 3 (G3): Protaper Universal Retreatment; and Group 4 (G4): Protaper Universal Retreatment followed by the use of XP-Endo Finisher R. Cone beam computed tomography (CBCT) images were used to calculate the remaining filling materials at the middle and apical thirds. Times required to perform each method were recorded. Scanning electron microscopy (SEM) and digital microscopy were used to evaluate the remaining filling materials. Data were statistically analyzed using the t-test and one way ANOVA on ranks tests. No statistically significant difference was found between G1 and G3 after CBCT observations (p > 0.05). Xp-Endo Finisher R significantly increased the ability to remove materials regardless of the initially used retreatment system (p < 0.05). Statistically significant longer time was found in G3 and G4 compared to G1 and G2, respectively (p < 0.05), to reach the full working length. No retreatment system was able to totally remove the calcium silicate-based sealer from the root canal at the middle and apical thirds (p > 0.05). Digital microscopy demonstrated that the residual materials were the remaining sealers on the canal walls. SEM showed the mineral depositions of calcium silicate materials onto the canal walls and into the dentinal tubules. However, that calcium silicate materials provide mineral deposition into the dentinal tubules might indicate that the traditional irrigants could not be sufficient to remove calcium silicate-based materials from the root canal, and other agents should be used to make retreatment considerably easier.

Effect of different retreatment files using different kinematics on the release of inflammatory mediators in root canal retreatment of single-rooted teeth: a randomized clinical trial.

This randomized clinical trial aimed to evaluate the effect of two rotaries (ProTaper Universal Retreatment (PTUR)), D-Race (DR) + XP-Endo Finisher R (XPFR) and one reciprocating (Reciproc Blue (RB) retreatment techniques on the release of neuropeptides (Substance P, calcitonin gene-related peptide (CGRP)), and cytokines (IL-6 and IL-10) in periapical fluid in root canal retreatment of single-rooted teeth. In this randomized clinical trial (ClinicalTrials.gov ID: NCT05039502), seventy-five patients scheduled for retreatment were randomly divided into 3 groups according to the file system used to remove root canal filling materials (n = 25): PTUR, RB, and DR + XPFR. After reshaping and disinfection of the root canals, periapical fluid samples were taken, and the levels of Substance P, CGRP, IL-6, and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA) test. Data were analyzed using the Kruskal-Wallis and chi-square tests. The level of significance was set as p = 0. 05. All the allocated participants received the intervention and were analyzed. There was no statistically significant difference among groups in terms of gender, age, tooth localization, and the distribution of analgesic use after treatment (p values 0.799, 0.095, 0.637, 1.000, respectively). No statistically significant difference was found in terms of the levels of Substance P, CGRP, and IL-10 among groups (p > .05), except IL-6. PTUR, RB, and DR + XPFR files have comparable results in the expression of inflammatory mediators. Retreatment files powered with rotary or reciprocating motion produced similar neuropeptide and cytokine levels in patients.

Comparative Evaluation Of Amount Of Apically Extruded Debris In Endodontic Retreatment Procedures Using Four Different File Systems- An Invitro Study

Objective(s): To compare the amount of apical debris extruded during endodontic retreatment procedures performed using H files, R-Endo Retreatment files, GPR files and ProTaper Universal Retreatment files.&#x0D; Materials and Methods: The conventional coronal access cavity was prepared for 40 extracted Mandibular Premolars. The root canals were prepared with ProTaper Next Rotary files till X1. Obturation was done by combination of Lateral and Vertical Compaction technique. All the samples were later attached to Eppendorf tubes. The samples were then divided into four groups each containing 10 samples on the basis of different retreatment files to be used. After complete removal of root canal filling material, the debris and the root filling material remnants adhered was collected in preattached Eppendorf tubes. For final weight computation and comparison, the weight of empty tube was deducted from the weight of tube accommodating the debris. ANOVA and Tukey test were applied for statistical analysis.&#x0D; Results: The R-Endo retreatment files showed minimum apical extrusion of debris than all the other examined files in the study. The apical extrusion of debris for R Endo min to max was -0.045 to 0.009. However, there was no statistically significant difference in amount of apical extrusion of debris by different files system (p&gt;0.005).&#x0D; Conclusion(s): There was no significant difference between the groups in apical extrusion of debris. Also rotary retreatment files showed lesser apical of debris than Hedstrom hand files. R Endo extruded less debris apically in this study.&#x0D; Keywords: Apical extrusion of debris; Gutta-percha; Retreatment files.

Comparative Evaluation of Different Retreatment Files for Gutta-percha Removal from Curved Root Canals Accessed with Novel Ultra-conservative Opening: An In-vitro Study

Introduction: In endodontic retreatment, gutta-percha removal must be done correctly in order to assure a successful outcome following failed procedures. The goal of this study was to compare the effectiveness of stainless-steel hand files with three different nickel-titanium rotary instrument systems for removing guttapercha using ultra-conservative access opening in curved canals. Aim: To compare the efficacy of different rotary instruments for removing obturating material from root canals with Ninja access in mandibular mesiobuccal moderately curved canals measured radiographically using Cone-beam Computed Tomography (CBCT). Materials and Methods: An in-vitro study was conducted in the Conservative and Endodontics department, Karnavati School of Dentistry, Karnavati University, Gandhinagar, Gujarat, India in the time period of June 2022 to July 2022. Forty extracted human mandibular molar teeth were accessed through Ultraconservative opening (Ninja Access). After preparing the root canals, they were sealed using gutta-percha and AH Plus sealer through lateral compaction. The teeth were then stored for one week. The samples were divided into four groups according to the rotary file used: Group I- Hedstrom Files; Group II- Pro taper Universal Retreatment (PTUR) Files; Group III- Neoendo Retreatment Files; Group IV- R-Endo Retreatment. The amount of remaining filling material after the retreatment procedure was checked with CBCT. The statistical analysis was performed using R statistical analysis software version 4.1.0 for windows. Results: In sagittal section, there was significant difference of residual filling material between the four file systems in middle third only (p=0.048) while significant difference was seen only in apical third in the coronal section (p=0.011). However, the three rotary retreatment files left significantly less remnants than Hedström files during removal of the gutta-percha. The time taken for retreatment was significantly higher for Hedström files (398.90±20.717) sec followed by R-endo retreatment files (274.30±14.407). Conclusion: H file was the least effective in removing guttapercha from the canals when compared to the other three file systems. The Neo-Endo rotary retreatment system was faster.

Micro-CT evaluation of the removal of root fillings using rotary and reciprocating systems supplemented by XP-Endo Finisher, the Self-Adjusting File, or Er,Cr:YSGG laser.

This study aimed to compare the effectiveness of a single-file reciprocating system (WaveOne Gold, WOG) and a multi-file rotary system (ProTaper Universal Retreatment, PTUR) in removing canal filling from severely curved canals and to evaluate the possible adjunctive effects of XP-Endo Finisher (XPF), the Self-Adjusting File (SAF), and an erbium, chromium: yttrium, scandium, gallium garnet (Er,Cr:YSGG) laser using micro-computed tomography (μCT). Sixty-six curved mandibular molars were divided into 2 groups based on the retreatment technique and then into 3 based on the supplementary method. The residual filling volumes and root canals were evaluated with μCT before and after retreatment, and after the supplementary steps. The data were statistically analyzed with the t-test, Mann-Whitney U test, analysis of covariance, and factorial analysis of variance (p < 0.05). PTUR and WOG showed no significant difference in removing filling materials (p > 0.05). The supplementary techniques were significantly more effective than reciprocating or rotary systems only (p < 0.01). The supplementary steps showed no significant differences in canal filling removal effectiveness (p > 0.05), but XPF showed less dentin reduction than the SAF and Er,Cr:YSGG laser (p < 0.01). The supplementary methods significantly decreased the volume of residual filling materials. XPF caused minimal changes in root canal volume and might be preferred for retreatment in curved root canals. Supplementary approaches after retreatment procedures may improve root canal cleanliness.

A study on three rotary retreatment systems in removing Gutta-percha and sealer

Background: To study rotary retreatment systems in removal of gutta-percha and sealer.Materials and methods: A total of 15 subjects were enrolled. The samples were randomly divided into three groups according to the file system used to remove gutta-percha was performed (n=5): ProTaper Universal Retreatment, ProTaper NEXT and Edge File XR NiTi system. The p- value less than 0.05 was considered statistically significant. Results: The percentage of removal of root canal filling has been recorded. The Protaper Universal R shows median 95.12, minimum 92.03 and maximum 99.12. The Edge file XR shows median value 98.16 and maximum value of 99.80. Conclusion: Edge File XR can be used as an alternative to ProTaper Universal Retreatment files.

Quantitative Assessment of Apically Extruded Debris after Single-Files Supplemental Retreatment considering Apical Patency Influence: In Vitro Study.

This study aims to assess the impact of re-establishing apical patency on the quantity of debris extruded through the apex after three supplementary retreatment files (TruNatomy (TRN), WaveOne Gold (WOG), and XP endo Finisher R (XPFR)). Eighty single-rooted mandibular premolars were prepared with ProTaper Universal rotary systems (PTU) up to F3 and obturated. The samples were divided into two main groups according to the presence or absence of the apical patency (n = 40), GI with apical patency and GII without apical patency. Based on the file system, which was adopted to eliminate the previous filling, each group had four subgroups (n = 10). In GI PTUR and GII PTUR, ProTaper Universal retreatment files (PTUR) were utilized only to remove the most primary filling material (control groups). In the other groups (PTUR) used, it was first followed by supplementary files. The quantity of debris extruded by different retreatment file systems was determined and compared to the corresponding control group with or without apical patency. Data were analyzed using a two-way ANOVA with a post hoc Tukey's multiple comparison test at a 5% significance level. There was a statistically significant difference among the control and experimental groups. XPFR had the least quantity of extruded debris. Apical patency did not affect the debris extrusion. All tested files led to a significant apical debris extrusion regardless of apical patency.

Efficacy of different Er:YAG laser-activated photoacoustic streaming modes compared to passive ultrasonic irrigation in the retreatment of curved root canals.

To evaluate the efficacy of passive ultrasonic irrigation (PUI) and super short pulse (SSP) and shock wave-enhanced emission photoacoustic streaming (SWEEPS) modes of Er:YAG laser-activated irrigation (LAI) with two different laser tips, in removing filling remnants after conventional retreatment in severely curved root canals. The study sample consisted of 40 extracted molars with curved mesiobuccal root canals. The canals were instrumented with ProTaper Next and filled with an epoxy resin-based sealer and gutta-percha using continuous wave vertical compaction and warm injection back-filling. After retreatment with ProTaper Universal Retreatment system and sodium hypochlorite (NaOCl), all samples were randomly divided into four groups (n = 10) according to the final irrigation technique: PUI, LAI/SSP, SWEEPS/flat-tip, and SWEEPS/radial-tip, using 6mL of 3% NaOCl for an activation time of 3 × 30s. The samples were subjected to micro-CT scans after root canal filling, retreatment, and final irrigation. The filling material volume and percentage reduction were calculated. All tested irrigation techniques were successful in the elimination of the filling remnants after the retreatment (p < 0.001). The LAI/SSP group showed a higher reduction rate than the SWEEPS/flat-tip group (p = 0.032). No significant differences were found between the other groups (p > 0.05). All tested techniques improved the removal of filling material during retreatment in curved canals. LAI/SSP showed slightly better results than other techniques. The study highlights the need for additional activated irrigation after the retreatment of curved root canals. The choice between PUI and LAI is not decisive for success.

Effectiveness of three different rotary systems in removing gutta percha from root canals

Background: The present study was conducted for comparing the effectiveness of three different Rotary systems in removing gutta percha from root canals. Materials &amp; methods: 30 single rooted freshly extracted, mandibular premolars were collected and stored in 10% formalin until further use. Crowns of selected teeth were decoronated using diamond disc to standardize the working length to 16 mm for each specimen. Access preparation was done on each tooth and a size 10 K-type file was inserted into the canal until it was visible at the apical foramen to ensure that the canal was patent. Afterwards, all the specimens were randomly divided into three study groups according to type of retreatment system. Group A: ProTaper Universal retreatment Ni–Ti rotary instrumentation system, Group B: Mtwo retreatment Ni–Ti rotary instrumentation system, and Group C: R-Endo Ni–Ti rotary instrumentation system. After tooth splitting, each half of every specimen was separately imaged. Digitized images of each third of the root canal of each half of every specimen were obtained and evaluated.