ProTaper Universal Retreatment Files Research Articles

Evaluation of apically extruded debris during root canal filling material removal in teeth with external apical root resorption: a comparison of different obturation techniques

BackgroundRoot canal retreatment is necessary when initial treatment fails. Nickel-titanium systems help remove filling materials; however, some methods can cause canal content extrusion, resulting in inflammation and delayed healing. This study aimed to examine the impact of different preparation techniques and endodontic file systems on apical debris volume to limit material dispersion to periradicular tissues.MethodsNinety extracted maxillary incisors were evaluated. Simulated apical root resorption was created by removing the apical 2 mm of the root. The teeth were divided into two groups: one filled with a single cone and the other with cold lateral compaction (CLC). Each group was further divided into three subgroups (n = 15 each): Subgroup 1 used Reciproc R25 for removal and R50 for final preparation; Subgroup 2 used ProTaper Universal Retreatment (PTUR) files D1, D2, and D3 for removal and ProTaper Next X5 for finalization; and Subgroup 3 used VDW.Rotate Retreatment (VDW.RotateR) for removal and VDW.Rotate 50.04 for completion. Debris from retreatment was collected in pre-weighed tubes to determine the amount. The apical extrusion data underwent a two-way analysis of variance.ResultsThe Reciproc group had a mean extruded debris weight of 0.54 ± 0.24 mg, higher than the PTUR (0.28 ± 0.15 mg) and VDW.RotateR (0.39 ± 0.29 mg) groups (p < 0.05). The single-cone technique (SCT) resulted in a mean debris weight of 0.34 ± 0.23 mg, lower than the CLC technique, which had a mean of 0.46 ± 0.27 mg (p < 0.05). SCT had a shorter retreatment duration (111.12 ± 33.46 s) compared to CLC (176.26 ± 52.26 s) (p < 0.05).ConclusionThe Reciproc file system and the CLC obturation technique resulted in greater apical debris extrusion than the other methods. SCT was quicker than CLC. The Reciproc groups are more susceptible to apex extrusion during retreatment.

Time Required for Root Canal Retreatment Using Continuous Rotation, Reciprocation, and Optimum Torque Reverse Motions: An In-Vitro Study.

Objective This study aims to evaluate the time required for canal preparation using three different movement kinematics during retreatment: continuous rotational motion, reciprocating motion, and optimum torque reverse (OTR) motion. Materials and methods The sample comprised 45 single-canal mandibular first premolars. The crowns were sectioned to standardize the root length to 16 mm. The root canals were prepared using the AF Gold mechanical preparation system (25/06). The roots were obturated using the lateral condensation technique and kept at 100% humidity at 37°C for seven days. The sample was randomly divided based on the movement pattern used during retreatment into three groups (N = 15): group 1 is continuous rotational motion using the ProTaper Universal Retreatment system; group 2 is reciprocating motion using the WaveOne Gold system; and group 3 is OTR motion using the ProTaper Universal Retreatment system. The retreatment time was measured in seconds by summing two times: T1 (time to reach the apex) and T2 (time to achieve adequate cleaning). The data were statistically analyzed using a one-way ANOVA with a significance level of α = 0.05. Results The results showed that the time required for canal preparation during retreatment with WaveOne Gold files using reciprocating motion was significantly longer than the time needed with ProTaper Universal Retreatment files using continuous rotary motion or OTR motion (P < 0.05). Conclusions The use of OTR motion did not affect the canal preparation time when used with files designed for continuous rotary motion retreatment. The use of WaveOne Gold files for canal preparation during retreatment was associated with a longer working time than ProTaper Universal Retreatment files.

Comparative Evaluation of the Removal of Gutta Percha From the Root Canal Using Various Retreatment File Systems With and Without Magnification: An In Vitro Study.

The main goal was to compare the efficacy of gutta percha (GP)removal from the root canal using the Neo Endo Retreatment file system, Solite RS3, and ProTaper Universal Retreatment (PTUR) files with and without magnification under a direct operative microscope using stereomicroscopic evaluation. Sixty single-rooted teeth were randomly assigned to one of three groups after obturation till F2 mastercone with resin sealer: Group 1 (n=20): Neo Endo Retreatment Files, Group 2 (n=20): Solite RS3, Group 3 (n=20): PTUR files. Each group was further separated into two subgroups: Subgroup 1: without magnification (no direct operative microscope) and Subgroup 2: with magnification under a direct operative microscope at 12× magnification. After retreatment, the roots were grooved buccolingually and split into two halves using a diamond disc with the help of a chisel. The samples were examined under a stereomicroscope. Images were captured in a digital camera and analyzed using image analyzing software Image Pro v10 (Media Cybernetics). The Neo Endo retreatment file system had a significantly greater percentage of remaining obturating material than the Solite RS3 Retreatment and PTUR file systems (p<0.05) in both groups with and without magnification. In the group without magnification, Solite RS3 showed a significant difference compared to ProTaper (p<0.05). In the group with magnification, there was no significant difference between the ProTaper Universal retreatment file system and Solite RS3 (p=0.589). Retreatment performed without magnification had more remnant GP when compared to the retreatment procedure performed under magnification of the direct operative microscope. Under stereomicroscopic evaluation, the remnant GP was higher in the Neo Endo File System both with and without magnification than in the Solite Retreatment and PTUR file systems. ProTaper showed moderate significance in removing the obturation than Solite RS3 in the magnification group. The Solite RS3 file system performed as efficiently as the PTUR file system.

Micro-Computed Tomography Analysis of Resin and Calcium Silicate Based Sealers Removal in Mandibular Molars Curved Canals.

The removal of the root canal sealer is an important factor in nonsurgical retreatment. The aim of this study was to compare the removal of AH Plus, Well Root ST, and AH Plus Bioceramic Sealer using Protaper Universal retreatment files. The curved mesio-buccal canals of extracted mandibular molars were prepared with the Protaper Gold file system (up to F2). Specimens were randomly divided into 3 groups and filled with the single cone technique using AH Plus, Well-Root ST, and AH Plus Bioceramic Sealer, respectively. After two weeks, the root canal filling of all specimens was removed using Protaper Universal retreatment files. All specimens were scanned using micro-CT. The remaining volume of the root canal filling was recorded in total and the coronal, middle, and apical third of each specimen. Well-Root ST and AH Plus Bioceramic Sealer groups had a higher percentage of total remaining filling material than the AH Plus group (P<0.05). This study has shown that the volume of remaining root canal filling was significantly higher in the samples filled with calcium silicate-based sealers.

Comparative evaluation of the remaining dentin thickness using Solite RS3 and ProTaper Universal retreatment files: A nanocomputed tomography study

Comparative evaluation of the remaining dentin thickness using Solite RS3 and ProTaper Universal retreatment files: A nanocomputed tomography study

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.

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 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.

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.

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.

Assessment of Root Dentin Defect during Retreatment Procedure using Various NiTi Hand and Rotary Retreatment Files

Aim:The aim of the current study was to evaluate the radicular dentin defect during retreatment employed diverse NiTi hand and rotary retreatment file systems.Materials and Methods:Eighty mandibular premolars with a single root and root canal that were recently extracted were gathered and stored. The premolars were subject to decoronation at cementoenamel junction (CEJ) beneath irrigation with water to attain a uniform radicular length of 16 mm. Gutta-percha cones were covered with sealer and introduced into the root canal up to the working length. Eighty teeth were allocated at random into four groups with each group consisting of 20 samples. Group I: Control, Group II: EdgeFile XR retreatment rotary files, Group III: ProTaper Universal retreatment files, and Group IV: MTwo retreatment files. Under constant water cooling, the roots were cut flat with a diamond disc at apical third (3 mm), middle third (6 mm), and cervical third (9 mm) points. Stereomicroscope was employed to visualize the sections below × 20 magnification.Results:A statistically significant difference was noted among the groups with respect to the formation of radicular dentinal defects at 3 mm (P < 0.01) and 6 mm (P < 0.001), while the sections at 9 mm did not exhibit any statistically significant difference (P > 0.598).Conclusion:Despite the limitations in this study, it was concluded that all the evaluated file systems efficiently eliminated root canal filling during the retreatment. In addition, it was noted that the EdgeFile XR group exhibited fewer root dentin defects in comparison with the MTwo and ProTaper Universal group of files.

An in vitro study to compare the efficacy of 2 different rotary instruments for GP removal using 2 different sealers

Background: Failure of endodontic treatment may necessitate retreatment by removing gutta percha from root canals. The present study evaluated the efficiency of retreating gutta-percha obturated root canalas with protaper universal retreatment files, NRT GPR retreatment files while using the sealers, AH plus and Endofill for obturation. Materials and Methods: 80 maxillary premolars were decoronated to obtain a standardized root length of 15 mm. Canals were obturated using thermoplasticized gutta percha (GP) with either AH Plus or Endofill as sealer. Teeth were divided into 4 groups, with 20 teeth in each group, and gutta percha removal was done using (PTUR Protaper universal retreatment), NRT GPR (Nickel titanium gutta percha remover), for studying their efficiency in terms of total operating time and GP remnants left in the canal. Results: The order of efficiency in terms of time and gutta percha (GP) removal was PTUR &gt; NRT GPR. The difference in GP removal was not statistically significant but the time taken for removal was statistically significant. The use of AH Plus sealer showed more remnants than Endofill sealer and the file system followed the same order of efficiency, but the difference was not statistically significant.

Comparative evaluation of different irrigating and irrigant activation system in removal of gutta-percha/sealer during retreatment: An in vitro Micro-CT study

BackgroundThe aim of the study was to compare the efficacy of different irrigation and irrigant activation system used as an adjuvant to retreatment rotary files in removal of gutta-percha and sealer from endodontic retreatment using Micro-CT. Method64 extracted permanent maxillary central incisor teeth with single canal, were collected and decoronated to standard length of 16 mm. Instrumentation was done using rotary files and obturation was performed using GuttaCore and AH plus sealer. After setting of sealer, initial removal of filling material was performed using ProTaper universal retreatment files (D1, D2, D3). All 64 sample were randomised into four groups (n = 16) Group1: Endodontic syringe irrigation, Group 2: Passive Ultasonic Irrigation (PUI), Group 3: EndoActivator, and Group 4: EndoVac. Micro-CT scanning was performed after obturation, initial removal of filling material by retreatment file and after using experimental protocols of each group, and volume of remaining filling material was calculated using Dolphin software. Statistical analysis performed with one-way ANOVA followed by Tukey's post hoc. ResultsA significant reduction in the volume of residual obturation material were found between each group. PUI was superior to the sonic (EndoActivator), negative pressure irrigation technique (EndoVac) and positive pressure irrigation at the coronal, middle third and apical third of the root canal. However, none of the supplementary techniques were able to completely remove the residual obturation material. ConclusionPUI and EndoActivator were found better in remaining filling material removal, demonstrating clinically useful as supplementary technique in removing remaining obturation material during endodontic retreatment.

A comparative evaluation of retrievability of three different obturating systems using protaper universal rotary retreatment files: An in vitro cone-beam computed tomography analysis

Aim: The aim of this in-vitro study was to comparatively evaluate the ease of retreatment in canals, obturated through GuttaFlow 2, GuttaCore, and conventional Lateral compaction technique using ProTaper Universal Retreatment (PTUR) Files.Materials and Methods: Sixty single-rooted mandibular premolars were selected and the canals were instrumented with ProTaper Universal rotary files up to size #F3. Samples were randomly divided into three experimental groups of 20 teeth each and obturated using three different obturating systems (GROUP I-Lateral compaction technique, GROUP II-GuttaFlow 2, GROUP III-GuttaCore). All the groups underwent cone-beam computed tomography (CBCT) analysis following which retrieval of the previous root canal filling was done using the PTUR files. Post retreatment CBCT images were used to assess the amount of remaining obturating material at varying depths (3 mm, 6 mm, and 12 mm) for all three groups. Statistical analysis was performed using repeated measures analysis of variance and ANOVA.Results: Irrespective of the obturating system used, filling material could not be removed completely from the root canal walls. Significantly more amount of obturating material was observed in the apical third than the middle third and coronal third of the root canal space (P < 0.05). When comparing the groups, the maximum percentage of remaining obturating material was seen in Group III (GuttaCore) followed by Group I (lateral compaction), with the least being observed in Group II (GuttaFlow2).Conclusion: The GuttaCore technique utilizing carrier-based gutta-percha had the maximum amount of remaining obturating material after retreatment when compared to the GuttaFlow2 and Lateral Compaction techniques.

Comparative evaluation of effectiveness of manual and various rotary retreatment techniques for removal of root canal filling material: An in-vitro study

Aim: This study intended to compare the effectiveness of manual files H-files and ProTaper universal retreatment (PTUR), R-Endo retreatment, and gutta-percha removal (GPR) Mani retreatment rotary files for removing root canal filling material.Materials and Methods: Eighty mandibular premolars with single canal were selected. The canals were enlarged with ProTaper rotary files up to F2 and obturated using the lateral condensation technique. Then, the samples were randomly divided into four groups and retreated using hand files and rotary retreatment files. The area of remaining root canal filling material was evaluated by splitting the tooth using a stereomicroscope with ×10 and auto computer-aided design software and the percentage of remaining filling material on canal walls was calculated with equation: area % of remaining filling material = area of remaining material ×100/area of canal. One-way ANOVA was carried out to compare the groups and post hoc Tukey's test for pairwise association with each of four groups.Results: Group A (H-files) showed 61.87% of remaining filling material, Group B (PTUR) showed 24.94%, Group C (R-Endo) showed 37.12%, and Group D (GPR Mani) showed 45.95% of remaining root canal filling material.Conclusions: All the groups showed residual root canal filling material. Least was seen in group retreated using PTUR files and maximum was seen in group retreated with H-files.

THREE DIFFERENT RETREATMENT ROTARY SYSTEMS IN REMOVAL OF GUTTA PERCHA AND SEALER FROM ROOT CANAL SYSTEM

Studies on removability and these three methods' efficacy in retreatment are few. In order to examine the effectiveness, cleansing capacity, and safety of various systems in root canal retreatment, the current research was undertaken. The results of this in-vitro comparison study on root canal retreatment utilising Hedström files, ProTaper universal retreatment files, R-Endo, and MTwo R rotary instruments with regard to effectiveness, cleaning ability for the complete removal of Gutta-percha (GP), sealer, as well as instrument deformation have resulted in the following outcome. Under experimental circumstances, neither hand nor rotary files were able to entirely remove all of the evaluated filler materials during retreatment. The statistical analysis made use of one-way ANOVA and Tukey's post hoc analysis. Rotary retreatment systems eliminated GP with AH-plus sealers more successfully. In comparison to the Hedström files, there was a significant statistical difference in favor of the NiTi system.

Effectiveness of different rotary file systems in removing the root canal filling material: A micro-computed tomography study.

Background. This study aimed to examine the retreatment efficiency of four NiTi rotary file systems with micro-computed tomography (micro-CT). Methods. Forty premolar teeth were shaped up to F2 using the ProTaper Universal rotary file system and obturated with MTA Fillapex. The root canals were scanned with micro-CT to evaluate the volume of root canal filling before retreatment. The samples were randomly divided into four groups according to the file system used to remove root canal filling material (n=10): ProTaper Universal Retreatment, ProTaper NEXT, EdgeFile XR, and EdgeFile® X3 NiTi system. All the samples were scanned with a micro-CT device for the second time to evaluate the amount of residual filling material in the root canals. The percentages of filling material removed from root canals were calculated. Additionally, the time spent on the removal of the root canal filling material was recorded. The data were analyzed using the Shapiro-Wilk and Kruskal-Wallis tests. Results. There were no significant differences between the groups in the percentage of root canal filling material removal. However, a statistically significant difference was found between the groups in the time required to reach the apex and remove the entire filling material. The time required to remove the root canal filling material was higher in the EdgeFile® X3 group. Conclusion. NiTi files manufactured for root canal preparation can be used effectively and safely to remove root canal filling materials. EdgeFile XR produced for retreatment can be used as an alternative to ProTaper Universal Retreatment files.

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.

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. 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). 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. 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. 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.