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The aim of this study was to compare of four different nickel‐titanium (Ni‐Ti) endodontic files and evaluate in terms of cyclic fatigue resistance and metallurgical properties. Four different type Ni‐Ti root canal files Protaper Next X2 (PTN) (Dentsply Maillefer, Ballaigues, Switzerland), One Curve (OC) #25.06 (Micro Mega, Besancon, France), EndoPlus Flex Plus Gold X2 (EPG) (Turkuaz Dental, Denizli, Turkey), and EndoPlus Flex Plus Blue #25.06 (EPB) (Turkuaz Dental, Denizli, Turkey) files were tested for cyclic fatigue resistance (n = 20). During experiments artificial zirconia block canal was used. The artificial canal designed with curvature 60° and 5‐mm radius. The number of cyclic to fracture (NCF) was noted. Fractured length (FL) parts of Ni‐Ti files were recorded to assessment of fracture volumetric point. All fractured surfaces of Ni‐Ti files were assessed by scanning electron microscope (SEM) to confirm the type of fractures. Descriptive evaluation become accomplished for the fundamental composition of units with the aid of using energy‐dispersive x‐ray spectroscopy (EDX). NCF data were evaluated via Bonferroni test with post hoc multiple comparison method. OC showed the highest NCF values (p <.05). The standardization of the study was confirmed as the FL of files was statistically similar in length (p >.05). SEM analysis confirmed that all scanned samples were fractured due to cyclic fatigue. EDX analysis confirmed that EPB established the poorest Ni content file. Research Highlights: The cyclic fatigue‐related failure of One Curve was significantly more resistant than Protaper Next and EndoPlus files.Scanning electron microscopy images showed that One Curve and Protaper Next have round tipsEnergy dispersive x‐ray spectroscopy showed that all four endodontic instruments mainly have Nickel and Titanium elements [ABSTRACT FROM AUTHOR]

This study aims to compare the shaping ability of three systems using micro‐computed tomography (micro‐CT). Moderately‐curved mesial canals of 36 mandibular molars were assigned to three groups (n = 24); Protaper Next (PTN, 0.25, 0.06), WaveOne Gold (WOG, 0.25, 0.07), TruNatomy (TRN, 0.25, 0.04), and instrumentation was performed. Pre‐ and post‐micro‐CT scans were obtained. Canal volume and surface, structure model index (SMI), centroid shift, canal transportation, and untouched canal were analyzed. One‐way ANOVA and Student's t‐test were used for statistics. There was no difference in SMI, centroid shift, and centering ability between the study groups (p >.05). Removed dentin and canal surface changes were lower in TRN, while untouched dentin walls were higher (p <.05). Cross‐sections became more rounded (p <.05), but not significant between groups (p >.05). Considering the removed dentin by TRN, it can be used in critical dentin thickness, such as the danger zone (DZ). PTN, WOG, and WOG kept the original canal course similarly. Untouched dentin by TRN (41%) was wider than PTN and WOG, consequently, meticulous irrigation is recommended. TRN, which provides a controlled increase in canal volume, can be used in thin dentin such as the DZ, however, its use should be supported by copious irrigation and brushing considering the rate of untouched dentin walls. Research Highlights: TRN presented a higher untouched dentin wall compared to PTN and WOG.Canal volume and surface changes were the lowest in the TRN group.The centering abilities were similar in PTN, WOG, and TRN. [ABSTRACT FROM AUTHOR]

Context: To improve efficiency, biomechanical preparation in root canal treatment is shifting from manual SS to nickel-titanium (NiTi) rotary devices. While multi-file NiTi systems entail crack and fracture issues, modern single-file systems address these concerns. Aims: The aim of this study was to evaluate and compare the effects of different torque settings on dentinal crack formation using single-file systems (SFS) (One Curve [OC]) and multi-file systems (ProTaper Next [PTN]) at different levels of the tooth. Subjects and Methods: The study was conducted on 45 freshly extracted human mandibular premolars divided into groups: OC at minimal and maximal torque, PTN at minimal and maximal torque, and a control group. After canal preparation, teeth were horizontally sectioned at 3, 6, and 9 mm from the apex, and then examined for cracks using a stereomicroscope. Statistical Analysis Used: This was analyzed using Chi-square test. Results: PTN group: Highest crack rates at the middle (55.6%) and apical (77.8%) thirds with maximum torque; OC group: Highest rates at the middle (22.2%) with minimal torque and apical (11.1%) with maximum torque. Conclusions: Maximal torque settings had more incidence of cracks compared to minimal torque settings. It can be stated that SFS (OC) produced less cracks compared to multi-file system (PTN) at both minimal and maximal torque settings. [ABSTRACT FROM AUTHOR]

Shaping Ability of Three Different Rotary Nickel Titanium Systems An In Vitro StudyAim: The aim of the study was to compare the changes in transportation and changes in curvature after instrumentation in WaveOne Gold (WOG) system and One Curve (OC) system. Protaper Next (PTN) system was used as reference for comparison.Material and Methods: A Sixty-five human mandibular first molars were selected. Teeth were randomly allocated into three groups (n=15): Group 1: PTN; Group 2: WOG; Group 3: OC. Cone beam computed tomography (CBCT) were taken for all specimens before instrumentation. Pre instrumentation evaluation for angle of curvature was done using Schneider method. Also, transportation was evaluated using Gambill’s method. After instrumentation, radiographs (CBCT) were taken and changes in transportation and curvature were measured using Planmecca Romexis software. One-way ANOVA was used to compare between different groups, followed by Tukey’s Post Hoc test for multiple comparisons.Results: After root canal instrumentation, regarding transportation, Results showed significant difference between all groups at 6mm level as PTN group showed highest transportation (P=0.09). While there’s insignificance between 3mm and 9 mm level. As for changes in curvature, there was insignificant difference between groups (P=0.46).Conclusion: Single file system respected the original canal anatomy compared with multi-sequence file system.

Purpose: Pulpectomy can be used for the management of deep dentinal carious lesions in primary teeth which can be restored. Mechanical preparation of root canals can be performed using hand or NiTi rotary files. However, this may cause dentinal stress and consequently dentinal microcracks. Hence, the aim was comparative evaluation of hand and rotary file systems on dentinal microcrack formation during pulpectomy procedure in primary teeth. Methods: 60 extracted primary molar teeth were selected comprising of 80 root canals. Simple random sampling was used to divide root canals into four groups (n = 20): Group A—Hedstrom file, Group B—Pro AF Baby Gold rotary, Group C—ProTaper Next rotary, and Group D—unprepared group. Assessment was conducted on presence or absence of microcracks using Chi square test (p < 0.05). Results: The total number of microcracks in Group A: one (5%), Group B: four (20%), Group C: nine (45%) and Group D: zero (0%) which was statistically significant (p = 0.002). At cervical third, the number of microcracks seen with Group A: one (5%), Group B: zero (0%), Group C: five (25%) and Group D: zero (0%) (p = 0.005). At the middle third, the number of microcracks seen in Group A: zero (0%), Group B: four (20%), Group C: four (20%) and Group D: zero (0%) (p = 0.029). Conclusion: The study concluded that dentinal microcracks are formed with both hand and rotary file systems in primary teeth. ProTaper Next showed significantly higher number of microcracks, followed by ProAF Baby Gold and H files. [ABSTRACT FROM AUTHOR]

Background: To determine the amount of apical extrusion between various file systems during the retreatment procedure and to determine the effect of taper on the same. Materials and Method: Seventy mandibular extracted premolars were taken, and preparation was performed using a Woodpecker file (Woodpecker Medical Instrument Co., Ltd., Guilin, China) (25/0.06). The gutta-percha (GP) was removed from each specimen with H file (#40/0.02) to simulate retreatment in seven groups (n = 10) using ProTaper Next (PTN;Dentsply, Maillefer, Ballaigues, Switzerland) (PTN) (30/0.07), Reciproc (25/0.08), Hyflex CM (30/0.06), Mtwo (30/0.05), Neoendo flex (30/0.04), Neoendo hybrid (30/0.04), and Flexicon file (30/0.06). The specimens were held with the help of a rubber stopper and put in the Eppendorf tube of volume 4 mL (pre-weighed before retreatment). The debris that was on the root surface of the specimen was washed with distilled water with 1 mL volume, kept in the oven, and then again weighed after 7 days. Results: Apical extrusion was found in the following order: HYFLEX CM (LEAST) < FLEXICON < PROTAPER NEXT < RECIPROC < NEOENDO FLEX < NEOENDO HYBRID < MTWO (HIGHEST). Conclusion: W Hyflex CM and Flexicon files showed lesser extrusion of debris than others.

Aim: The purpose of this comparative in vitro study was to investigate the cyclic fatigue resistance (CFR) of two different rotary endodontic file systems, namely, TruNatomy and ProTaper Next filing systems. Material and Methods: A stainless steel artificial canal with a 60° curvature angle and a 5 mm radius of curvature was used to simulate clinical settings to carry out the test. Twenty ProTaper Next X2 files and 20 TruNatomy Prime files were used to run a total of forty instruments until a fracture occurred, and the amount of time it took for the fracture to occur was taken into account. The files were driven by an endodontic motor set when the settings were adjusted according to the manufacturer’s recommendations. A digital meter was employed to record the duration until fracture occurrence, thus ensuring precision. Results: The TruNatomy files had a larger mean cycle fatigue life, which indicates that they have a higher resistance. Conclusions: Given the constraints of this in vitro testing, the CFR of TruNatomy files was found to be significantly higher than that of ProTaper Next files.

Introduction: Obturation of the canal space, efficient disinfection, and thorough canal debridement are essential components of endodontic therapy success. A crucial first step is biomechanical preparation. Objectives: This study set out to assess various file systems’ cleaning efficacy in terms of the thickness of dentin that remained after cleaning. Materials and Method: Twenty permanently removed anterior teeth were used in the investigation, and they were split into two groups: Group B used reciprocating WaveOne file systems, and Group A used ProTaper Next (PTN). After obtaining a pre-CBCT scan, the corresponding file groups proceeded with biomechanical preparation. A post-CBCT scan was obtained, and the dentin thickness remaining was compared between the pre- and post-CBCT scans. Statistics were used to analyze the data. Result: Dentin thickness decrease was shown to be minimal for ProTaper Next (PTN) and maximal for WaveOne; nonetheless, the intergroup comparison was deemed to be highly inconsequential. Conclusion: After biomechanical preparation, WaveOne is a highly recommended rotary endodontic device that does not significantly reduce the residual dentin thickness.

Aim: The purpose of this comparative in vitro study was to investigate the cyclic fatigue resistance (CFR) of two different rotary endodontic file systems, namely, TruNatomy and ProTaper Next filing systems. Material and Methods: A stainless steel artificial canal with a 60° curvature angle and a 5 mm radius of curvature was used to simulate clinical settings to carry out the test. Twenty ProTaper Next X2 files and 20 TruNatomy Prime files were used to run a total of forty instruments until a fracture occurred, and the amount of time it took for the fracture to occur was taken into account. The files were driven by an endodontic motor set when the settings were adjusted according to the manufacturer’s recommendations. A digital meter was employed to record the duration until fracture occurrence, thus ensuring precision. Results: The TruNatomy files had a larger mean cycle fatigue life, which indicates that they have a higher resistance. Conclusions: Given the constraints of this in vitro testing, the CFR of TruNatomy files was found to be significantly higher than that of ProTaper Next files. [ABSTRACT FROM AUTHOR]

Background: To determine the amount of apical extrusion between various file systems during the retreatment procedure and to determine the effect of taper on the same. Materials and Method: Seventy mandibular extracted premolars were taken, and preparation was performed using a Woodpecker file (Woodpecker Medical Instrument Co., Ltd., Guilin, China) (25/0.06). The gutta‑percha (GP) was removed from each specimen with H file (#40/0.02) to simulate retreatment in seven groups (n = 10) using ProTaper Next (PTN;Dentsply, Maillefer, Ballaigues, Switzerland) (PTN) (30/0.07), Reciproc (25/0.08), Hyflex CM (30/0.06), Mtwo (30/0.05), Neoendo flex (30/0.04), Neoendo hybrid (30/0.04), and Flexicon file (30/0.06). The specimens were held with the help of a rubber stopper and put in the Eppendorf tube of volume 4 mL (pre‑weighed before retreatment). The debris that was on the root surface of the specimen was washed with distilled water with 1 mL volume, kept in the oven, and then again weighed after 7 days. Results: Apical extrusion was found in the following order: HYFLEX CM (LEAST) < FLEXICON < PROTAPER NEXT < RECIPROC < NEOENDO FLEX < NEOENDO HYBRID < MTWO (HIGHEST). Conclusion: W Hyflex CM and Flexicon files showed lesser extrusion of debris than others. [ABSTRACT FROM AUTHOR]

Introduction: Obturation of the canal space, efficient disinfection, and thorough canal debridement are essential components of endodontic therapy success. A crucial first step is biomechanical preparation. Objectives: This study set out to assess various file systems’ cleaning efficacy in terms of the thickness of dentin that remained after cleaning. Materials and Method: Twenty permanently removed anterior teeth were used in the investigation, and they were split into two groups: Group B used reciprocating WaveOne file systems, and Group A used ProTaper Next (PTN). After obtaining a pre‑CBCT scan, the corresponding file groups proceeded with biomechanical preparation. A post‑CBCT scan was obtained, and the dentin thickness remaining was compared between the pre‑ and post‑CBCT scans. Statistics were used to analyze the data. Result: Dentin thickness decrease was shown to be minimal for ProTaper Next (PTN) and maximal for WaveOne; nonetheless, the intergroup comparison was deemed to be highly inconsequential. Conclusion: After biomechanical preparation, WaveOne is a highly recommended rotary endodontic device that does not significantly reduce the residual dentin thickness. [ABSTRACT FROM AUTHOR]

Introduction: Numerous nickel–titanium (NiTi) rotary systems have been released on the market with noncutting tips, various cross sections, and production techniques. This research was carried out to assess the quantity of remaining dentin thickness of mandibular first molar root canal at 3, 6, and 9 mm far from the anatomic peak that prepared through contemporary rotating systems with different metallurgical properties with a cone-beam computed tomography (CBCT). Materials and Methods: In this investigation, 45 human mandibular first molars that had been extracted were employed. Teeth were accordingly divided into three main groups through the NiTi rotary system that was utilized in canal instrumentation (15 teeth each), such that all ranges of curvatures were equally represented in each group – Group A: EdgeFile X3 rotating system, Group B: ProTaper Next (PTN) rotating system, and Group C: ProTaper (PT) rotating system. The samples were scanned before and after instrumentation using CBCT, and by deducing the instrumented canals from the uninstrumented counterpart, the remaining dentin thickness for each root canal is calculated at three levels of each root (3, 6, and 9 mm away from the root end). Data were statistically analyzed. Results: A significantly higher mean value was scored in PT, followed by PTN, and the lowest value was found in X3 of canal transportation at the level of 3 mm (P < 0.001), whereas at the 6- and 9-mm levels, there was no substantial difference statistically through the levels. Conclusion: The EdgeFile X3 showed the lowest canal transportation at a 3-mm level from the apex in comparison to the other tested files. [ABSTRACT FROM AUTHOR]

Introduction: Rotary nickel–titanium files are subjected to shear and flexural stresses during instrumentation. Increasing the rotational speed may reduce the shear stresses but can deteriorate the fatigue life of the file. This in vitro study aimed to address the influence of three rotational speeds 300, 500, and 700 RPM on the apical force and torque generated during instrumentation as well as on file fracture. Materials and Methods: A total of 48 simulated canals were divided into three groups: 300, 500, and 700 RPM (n = 16). Each canal was instrumented using a ProTaper Next XA orifice opener to prepare the coronal third and an X2 shaper to prepare the middle and apical thirds. A new set of files (XA and X2) was used to prepare four canals. A customized setup was used to evaluate the maximum apical force and torque corresponding to each third of the canal. The files were inspected for deformation or fracture using a stereomicroscope. Force and torque data were analyzed using analysis of variance and Post hoc Tukey test at 5% significance. Results: Five hundred and 700 RPM generated a significantly lower apical force and torque than 300 RPM at all canal thirds (P < 0.001). However, 700 RPM was superior to 500 RPM at the coronal third only (P < 0.001). No incidence of deformation or fracture was reported in any group. Conclusions: In resin artificial canals, increasing the rotational speed of the tested ProTaper Next files resulted in significantly less apical force and torque without increasing the incidence of fracture. Further studies involving natural teeth are required to validate these results using natural teeth. [ABSTRACT FROM AUTHOR]

Introduction: The restricted access cavity and the remaining roof of the pulp chamber may change the angle at which the instrument enters the root canal, which could have an impact on the effectiveness of chemo-mechanical canal preparation, potentially leading to endodontic mishaps. Aim: To evaluate the effect of the Traditional Endodontic Cavity (TEC) and Conservative Endodontic Cavity (CEC) on the amount of Root Dentin Removal (RDR) and the related Apical Debris Extrusion (ADE) in the curved root canals prepared with ProTaper Next (PTN) and TruNatomy (TN). Materials and Methods: The in-vitro study included a total of 120 extracted human mandibular molars, separated into four groups (n=30) based on the type of endodontic cavity and file used: TEC-TN, CEC-TN, TEC-PTN, and CEC-PTN. Before biomechanical preparation, Cone Beam Computed Tomography (CBCT) scans were taken. During the preparation, apically extruded debris was collected in Eppendorf tubes. After canal preparation, a post-CBCT scan was performed, and the RDR was evaluated by comparing the pre- and post-CBCT scans. To determine the amount of ADE, the weight of the clear tubes was subtracted from the weight of the tubes containing the debris. The data were analysed using one-way analysis of variance and post-hoc Tukey test. The significance level was set at p

Background: During mechanical preparation of the primary root canal, the original anatomy of the tooth should be preserved and the instrument should be perfectly balanced centrally into the canal space for reducing the probability of canal transportation. The aim of this research was to compare canal transportation and canal centring ability in primary root canals using ProTaper Next (Dentsply Mailfair,), AF baby (Fanta), and Kidzo Elephant (Endostar, Poldent Sp.) files. Materials and methods: Eighteen root canals were randomly divided into 3 experimental groups (n = 6 in each group). Instrumentation was performed using ProTaper Next, Fanta AF baby, and Kidzo Elephant files in groups 1, 2, and 3, respectively. During the instrumentation procedure, the irrigation of 2 mL of 1.5% sodium hypochlorite between each file was done, followed by 5 mL of 17% ethylenediaminetetraacetic acid as a final irrigating solution. Cone-beam computed tomography images were obtained before and after instrumentation. Each group was evaluated for transportation and centring ratios. Results: On comparing all the tested groups within each root canal level canal transportation, the results revealed a statistically nonsignificant difference in the buccolingual direction (P > 0.05). Meanwhile, in the mesiodistal direction, group 1 showed a statistically highly significant difference compared to groups 2 and 3 at the cervical level (P < .01). However, in both middle and apical root canal levels, there was a statistically nonsignificant difference amongst all groups (P > 0.05). Regarding the centring ability comparison of the 3 groups within each root canal level, there was a statistically nonsignificant difference amongst all groups (P > 0.05) in both buccolingual and mesiodistal directions. Conclusions: The ProTaper Next regular rotary file and the paediatric rotary files showed no difference in canal transportation and centring ability in the buccolingual direction, while in the mesiodistal direction at the cervical root canal level, the ProTaper Next showed high transportation liability.

Introduction: The restricted access cavity and the remaining roof of the pulp chamber may change the angle at which the instrument enters the root canal, which could have an impact on the effectiveness of chemo-mechanical canal preparation, potentially leading to endodontic mishaps. Aim: To evaluate the effect of the Traditional Endodontic Cavity (TEC) and Conservative Endodontic Cavity (CEC) on the amount of Root Dentin Removal (RDR) and the related Apical Debris Extrusion (ADE) in the curved root canals prepared with ProTaper Next (PTN) and TruNatomy (TN). Materials and Methods: The in-vitro study included a total of 120 extracted human mandibular molars, separated into four groups (n=30) based on the type of endodontic cavity and file used: TEC-TN, CEC-TN, TEC-PTN, and CEC-PTN. Before biomechanical preparation, Cone Beam Computed Tomography (CBCT) scans were taken. During the preparation, apically extruded debris was collected in Eppendorf tubes. After canal preparation, a post-CBCT scan was performed, and the RDR was evaluated by comparing the pre- and post-CBCT scans. To determine the amount of ADE, the weight of the clear tubes was subtracted from the weight of the tubes containing the debris. The data were analysed using one-way analysis of variance and post-hoc Tukey test. The significance level was set at p<0.05. Results: Analysis and comparison of four groups each with n=-30 extracted mandibular molars was done in the present study. The CEC-PTN group showed the highest total RDR of 0.32. Additionally, the CEC-PTN group produced the highest ADE with statistically significant differences between the TECTN, CEC-TN, and TEC-PTN groups (p<0.05). Conclusion: The CEC causes engagement of the rotary instrument with the dentinal wall, leading to RDR, debris production, and ultimately more ADE compared to TEC. The TN file caused less RDR and ADE in both endodontic access cavities compared to the PTN file. [ABSTRACT FROM AUTHOR]

Anuj Bhardwaj,1,2 Rudra Kumar Gupta,1 Ayfer Atav Ates,3 Dian Agustin Wahjuningrum,2 Burçin Ar&inodot;can,4 Taher AlOmari,5 Alexander Maniangat Luke,6,7 Ajinkya M Pawar2,8 1Department of Conservative Dentistry and Endodontics, College of Dental Science and Hospital, Indore, India; 2Department of Conservative Dentistry, Universitas Airlangga, Surabaya, Indonesia; 3Department of Endodontics, Istinye University, Faculty of Dentistry, Istanbul, Turkey; 4Department of Endodontics, Bahçe&scedil;ehir University, School of Dental Medicine, Istanbul, Turkey; 5Department of Conservative Dentistry, Jordan University of Science and Technology, Al-Ramtha, Jordan; 6Department of Clinical Science, College of Dentistry, Ajman University, Ajman, United Arab Emirates; 7Center of Medical and Bio-allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates; 8Department of Conservative Dentistry and Endodontics, Nair Hospital Dental College, Mumbai, 400008, IndiaCorrespondence: Dian Agustin Wahjuningrum, Department of Conservative Dentistry, Faculty of Dental Medicine, Universitas Airlangga, Surabaya, 60132, Indonesia, Email dian-agustin-w@fkg.unair.ac.id Alexander Maniangat Luke, Department of Clinical Science, College of Dentistry, Ajman University, J1 Building C Block, Al-Jurf 346, Ajman, United Arab Emirates, Email a.luke@ajman.ac.aePurpose: This prospective single-blind, parallel-group, randomized clinical trial was aimed to compare the effect of three different rotary instrumentation systems ProTaper Next (PTN), Self-Adjusting File (SAF) and XP-endo Shaper (XPS) on postoperative pain and analgesic intakes.Patients and Methods: A total of 159 molars diagnosed with symptomatic irreversible pulpitis were randomly divided into three study groups according to the instrumentation techniques: PTN (n = 54), SAF (n = 52), and XPS (n = 53). The preoperative pain scores were taken before the onset of treatment in the groups. After a single appointment for root canal treatment, the patients were asked to rate the level of their pain according to the Visual Analog Scale (VAS) of 100 mm at 6, 24, 48, and 72-hour post-treatment intervals. Ibuprofen was prescribed to be taken while experiencing pain; patients were requested to note the number of pills consumed at intervals after treatment.Results: The patients in SAF and XPS groups had lower mean VAS scores than the PTN group at 24-, 48-, and 72-hour intervals (p < 0.05). The most common analgesic intake was optimally seen in the PTN group at a 6-hour interval. All shaping procedures caused postoperative pain, whose intensity decreased with time.Conclusion: The SAF and XPS groups had a lesser intensity of pain as well as minimum analgesic intakes as compared to the PTN group. All instrumentation systems moderately caused pain, and the PTN group experienced the highest pain among others.Keywords: postoperative pain, ProTaper next, randomized clinical trial, root canal treatment, XP-endo shaper, patient satisfaction

Background: Endodontic success depends on the complete cleaning and shaping of the root canal. In order to achieve this goal, debris removal is essential. Even with improvements in instrument design, apical debris extrusion continues to be a cause of periradicular inflammation. The current study aimed to compare the amount of apically extruded debris throughout the canal instrumentation with TruNatomy, ProTaper Next, 2Shape rotary systems. Methods: A total of 60 freshly extracted single‑rooted mandibular premolars were used. An access opening was made, and a working length was estimated. The samples were arbitrarily allocated into three groups i.e. Group I: TruNatomy (n = 20), Group II: ProTaper Next (n = 20), Group III: 2Shape (n = 20). During the canal instrumentation, the extruded debris were collected in preweighed Eppendorf tubes. Post-instrumentation, the tubes were placed in a hot air oven at 140°C for five hours. For calculating the dry debris weight, the tube’s pre-instrumentation weight was deducted from the post-instrumentation weight. The data was analysed using one‑way analysis of variance and post hoc Tukey’s test. Results: Extrusion of debris was noted in all the specimens. TruNatomy rotary system showed least debris extrusion in comparison to ProTaper Next and 2Shape (P < 0.05). However, the results were statistically non-significant between ProTaper Next and 2Shape (P > 0.05). Conclusions: It was noted that all instruments apically extruded debris, with TruNatomy system being related to minimum extrusion.

Aim: The aim of this study was to evaluate the number of bacteria extruded from the tooth apex after root canal instrumentation using three nickel-titanium rotary systems. Materials and methods: A total of 55 mandibular premolars were extirpated and inserted into glass bottles. The root canals were contaminated with Enterococcus faecalis. The teeth were divided into four groups: ProTaper Universal, ProTaper Next, ProTaper Gold (all Dentsply Sirona, Charlotte, NC, USA) and the control group. For the first three groups, comprised of 15 teeth each, preparation was implemented with ProTaper Universal, ProTaper Next and ProTaper Gold files, respectively. No instrumentation was performed in the control group, comprised of 10 teeth. The solution in the bottles was investigated using the classical bacteria-counting technique. Data were analysed using a Kruskal-Wallis one-way analysis of variance and Mann-Whitney U tests. Results: The mean number of colony-forming units in the ProTaper Universal and ProTaper Gold groups was significantly higher than in the ProTaper Next group (P < 0.05). The difference between the ProTaper Universal and ProTaper Gold groups was not statistically significant (P > 0.05). Conclusions: All instrumentation techniques caused extrusion of intracanal bacteria. The ProTaper Universal and ProTaper Gold groups produced significantly more bacterial extrusion than the ProTaper Next group. [ABSTRACT FROM AUTHOR]

Objectives: The present randomised clinical study aimed to evaluate the effect of OneShape and ProTaper Next rotary systems on the removal of endotoxins from root canals of teeth with asymptomatic necrotic pulp. Materials and methods: 30 patients were randomly allocated into two groups (n = 15) according to the type of rotary system used in the mechanical preparation: group OneShape (OS) or group ProTaper Next (PN). Samples were collected before and after mechanical preparation and the quantification of endotoxins was conducted using the human enzyme-linked immunosorbent assay (ELISA) kit. Statistical analyses were performed using the Mann-Whitney U test to compare the two groups, and the Wilcoxon signed rank test to study the changes after treatment within each group. The significance level was set at P ≤ 0.05. Results: The group OS showed a statistically significant reduction in the endotoxin levels after treatment (P < 0.001, effect size = 0.880). In the PN group there was a statistically significant reduction in endotoxin levels after treatment (P < 0.001, effect size = 0.931). In the OS group a statistically significant median percentage reduction in endotoxin levels was observed compared with the group PN (P < 0.05). Conclusions: ProTaper Next was more effective than OneShape in reducing endotoxins from root canals of teeth with asymptomatic necrotic pulp. [ABSTRACT FROM AUTHOR]

Background: Endodontic success depends on the complete cleaning and shaping of the root canal. In order to achieve this goal, debris removal is essential. Even with improvements in instrument design, apical debris extrusion continues to be a cause of periradicular inflammation. The current study aimed to compare the amount of apically extruded debris throughout the canal instrumentation with TruNatomy, ProTaper Next, 2Shape rotary systems. Methods: A total of 60 freshly extracted single‑rooted mandibular premolars were used. An access opening was made, and a working length was estimated. The samples were arbitrarily allocated into three groups i.e. Group I: TruNatomy (n = 20), Group II: ProTaper Next (n = 20), Group III: 2Shape (n = 20). During the canal instrumentation, the extruded debris were collected in preweighed Eppendorf tubes. Post-instrumentation, the tubes were placed in a hot air oven at 140°C for five hours. For calculating the dry debris weight, the tube’s pre-instrumentation weight was deducted from the post-instrumentation weight. The data was analysed using one‑way analysis of variance and post hoc Tukey’s test. Results: Extrusion of debris was noted in all the specimens. TruNatomy rotary system showed least debris extrusion in comparison to ProTaper Next and 2Shape (P < 0.05). However, the results were statistically non-significant between ProTaper Next and 2Shape (P > 0.05). Conclusions: It was noted that all instruments apically extruded debris, with TruNatomy system being related to minimum extrusion.

Background. This study compared the ability of thermally treated files in shaping simulated canals with double curvature. Fifty-six canals were enlarged to a final size of 25 with ProTaper Next (PTN) or ZenFlex (ZF). Materials. Half of the samples were shaped with cooled files (nD14 each). The amount of removed resin was measured and canal deviation was determined at eight levels. Shaping time and maximum shaping torque values were also recorded. Data were statistically analyzed using analysis of variance and LSD, Kruskal-Wallis, and chi-square tests at a 0.05 significance level. Results. Compared to PTN and cooled PTN, ZF and cooled ZF required lesser time to shape the canals. The maximum torques were found comparable between the groups. All the groups generated negligible deviations at every canal level evaluated and maintained the canal geometry. Although not significant, the cooled PTN and ZF files exhibited lesser canal deviations than their counterparts. Conclusion. All groups demonstrated similar shaping ability whilst maintaining the original curvature of the canal in simulated canals with double curvature. However, ZF groups were able to shape the canals faster than PTN groups. There was a trend that cooled files made lesser canal deviations compared to their counterparts. [ABSTRACT FROM AUTHOR]

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Aim: The aim of this study was to compare and evaluate the severity of PEP using ProTaper Gold (PTG), ProTaper Next (PTN), and F-One rotary files in single-visit endodontic (SVE) treatment. Materials and Methods: In a randomized factorial clinical trial, 150 patients indicated for endodontic treatment in maxillary molars and mandibular molars were selected. They were separated into three groups: Group 1 (PTG), Group 2 (PTN), and Group 3 (F-One). SVE treatment was done under local anesthesia. The intensity of PEP was assessed using the Visual Analog Scale (VAS) after 24, 48, 72 h, and 1 week. Finally, the data were tabulated and statistically analyzed using SPSS software. VAS was analyzed using analysis of variance test with Scheffe's post hoc test. Results: PEP was less in Group 3 (F-One) and Group 2 (PTN) as compared to Group 1 (PTG) at 24.48 h which is statistically significant (P < 0.05), whereas the difference between PTN and F-One was statistically insignificant. Conclusion: All file systems showed PEP, but the intensity of pain was minimum in F-One single rotary file system followed by PTN and PTG Multi-file systems. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to compare and evaluate the severity of PEP using ProTaper Gold (PTG), ProTaper Next (PTN), and F-One rotary files in single-visit endodontic (SVE) treatment. Materials and Methods: In a randomized factorial clinical trial, 150 patients indicated for endodontic treatment in maxillary molars and mandibular molars were selected. They were separated into three groups: Group 1 (PTG), Group 2 (PTN), and Group 3 (F-One). SVE treatment was done under local anesthesia. The intensity of PEP was assessed using the Visual Analog Scale (VAS) after 24, 48, 72 h, and 1 week. Finally, the data were tabulated and statistically analyzed using SPSS software. VAS was analyzed using analysis of variance test with Scheffe's post hoc test. Results: PEP was less in Group 3 (F-One) and Group 2 (PTN) as compared to Group 1 (PTG) at 24.48 h which is statistically significant (P < 0.05), whereas the difference between PTN and F-One was statistically insignificant. Conclusion: All file systems showed PEP, but the intensity of pain was minimum in F-One single rotary file system followed by PTN and PTG Multi-file systems.

Background: Endodontic success depends on the complete cleaning and shaping of the root canal. In order to achieve this goal, debris removal is essential. Even with improvements in instrument design, apical debris extrusion continues to be a cause of periradicular inflammation. The current study aimed to compare the amount of apically extruded debris throughout the canal instrumentation with TruNatomy, ProTaper Next, 2Shape rotary systems. Methods: A total of 60 freshly extracted single‑rooted mandibular premolars were use. An access opening was made, and a working length was estimated. The samples were arbitrarily allocated into three groups i.e. Group I: TruNatomy (n = 20), Group II: ProTaper Next (n = 20), Group III: 2Shape (n = 20). During the canal instrumentation, the extruded debris were collected in preweighed Eppendorf tubes. Post-instrumentation, the tubes were placed in a hot air oven at 140°C for five hours. For calculating the dry debris weight, the tube’s pre-instrumentation weight was deducted from the post-instrumentation weight. The data was analysed using one‑way analysis of variance and post hoc Tukey’s test. Results: Extrusion of debris was noted in all the specimens. TruNatomy rotary system showed least debris extrusion in comparison to ProTaper Next and 2Shape (P < 0.05). However, the results were statistically non-significant between ProTaper Next and 2Shape (P > 0.05). Conclusions: It was noted that all instruments apically extruded debris, with TruNatomy system being related to minimum extrusion.

TruNatomy (TN), ProTaper Next (PTN), HyFlex electric discharge machining (EDM), and HyFlex controlled memory (CM), following root canal preparation. Materials and Methods: Sixty extracted single-canal mandibular premolars were used. The root canal preparation was done with TN, HyFlex EDM, PTN, or HyFlex CM files. The preweight debris, which was extruded apically, was collected in the Eppendorf tube and later on incubated at 670°C for 3 days and weighed again to record the extruded debris. Results: The result showed that there was a significant reduction in debris extrusion by TN system, followed by PTN system, HyFlex EDM, and maximum extrusion in HyFlex CM ( P < 0.05). Between the PTN and TN groups as well as between the HyFlex EDM and HyFlex CM groups, statistically significant difference was not observed ( P > 0.05). Conclusion: Apical debris extrusion is the inherent nature of the all file systems. Nevertheless, the TN file system produced substantially minimum debris extrusion among other systems compared in the study. [ABSTRACT FROM AUTHOR]

Background This study compared the ability of thermally treated files in shaping simulated canals with double curvature. Fifty-six canals were enlarged to a final size of 25 with ProTaper Next (PTN) or ZenFlex (ZF). Materials Half of the samples were shaped with cooled files (n = 14 each). The amount of removed resin was measured and canal deviation was determined at eight levels. Shaping time and maximum shaping torque values were also recorded. Data were statistically analyzed using analysis of variance and LSD, Kruskal–Wallis, and chi-square tests at a 0.05 significance level. Results Compared to PTN and cooled PTN, ZF and cooled ZF required lesser time to shape the canals. The maximum torques were found comparable between the groups. All the groups generated negligible deviations at every canal level evaluated and maintained the canal geometry. Although not significant, the cooled PTN and ZF files exhibited lesser canal deviations than their counterparts. Conclusion All groups demonstrated similar shaping ability whilst maintaining the original curvature of the canal in simulated canals with double curvature. However, ZF groups were able to shape the canals faster than PTN groups. There was a trend that cooled files made lesser canal deviations compared to their counterparts.

Purpose: Gentlefile (GF) is a newly developed stainless steel rotary system claimed to have superior shaping ability compared to nickel-titanium (NiTi) rotary systems. The purpose of this study was to compare the incidence of the canal transportation and centring ability of ProTaper Next (PTN) and GF rotary systems. Methods and materials: Thirty-two mesiobuccal root canals of mandibular molars with an angle of curvature ranging from 25 to 40 degrees were randomly divided into two groups of 16 canals each according to the instrument used for preparation: PTN or GF files. Cone beam computed tomography (CBCT) was used before and after preparation of the samples to assess the amount of canal transportation and centring ability at 3, 6 and 9 mm from the apex. Data were scored and statistically analysed using independent t test. The significance level was set at P ≤ 0.05. Results: The GF system produced more canal transportation than the PTN system at 3 and 6 mm with a statistically significant difference (P ≤ 0.05), whereas at 9 mm there was no statistically significant difference between the two systems (P > 0.05). PTN showed better centring ability than the GF at 6 mm and this difference was statistically significant (P ≤ 0.05) However, at 3 and 9 mm there was no significant difference between the two systems (P > 0.05). Conclusions: Under the limitations of this study both systems produced canal transportation but the PTN system resulted in better root canal preparation with a lesser degree of canal transportation and better centring ability than the GF system. [ABSTRACT FROM AUTHOR]

Introduction Root canal preparation is one of the most important active phases in the treatment of infected and noninfected teeth. Nickel-titanium (NiTi) instruments are increasingly used in endodontic therapy due to their superior properties compared to those made of stainless steel. The aim of this research was to perform an analysis and comparison of cyclic fatigue in ProTaper Universal and ProTaper Next rotary NiTi instruments in full rotation in simulated canals. Material and methods Twelve ProTaper Next and twelve ProTaper Universal instruments were analyzed in the study. The instruments were tested in an artificial canal stuffed in a metal block at an angle of 45° and a corner radius of 5 mm. The operating time of each instrument until fracture was measured and the number of cycles to fracture (NCF) calculated. Results ProTaper Next instruments showed greater resistance to cyclic fatigue compared to ProTaper Universal. The NCF value was significantly higher in ProTaper Next (1,296.83±20.2) instruments (p

Objectives: This study was aimed to evaluate the cause-effect relationship between canal preparation with ProTaper Next (PTN) and ProTaper Gold (PTG) using optimum torque reverse (OTR) motion or continuous rotation and dentinal crack formation. Materials and Methods: Fifty distobuccal roots of human maxillary first molars were divided into five groups; Group I: PTG Full rotation, Group II: PTG in OTR, Group III: PTN Full rotation, Group IV: PTN in OTR, Group V: unprepared (control group). After mechanical preparation, the distobuccal roots were sectioned horizontally at 3, 6, and 9 mm from the apex. Images were captured using a stereomicroscope at 25X to determine the presence or absence of dentinal cracks. Friedman test was used to compare between root sections followed by Wilcoxon signed-rank test for pairwise comparison. Kruskal–Wallis test was used to compare between tested rotary systems followed by pairwise comparison with Dunn Bonferroni correction (α = 0.05). Results: Crack development was significantly higher in PTG using OTR motion 36.7% followed by PTN using OTR 33.3%, while the control group showed no cracks. PTG and PTN with full rotation showed crack development with 23.3% and 13.3%, respectively. Conclusions: The type of motion kinematics used during mechanical preparation have an impact on dentinal crack formation. Nickel-titanium instruments with larger taper tend to induce more cracks.

Aim: The aim of the study is to evaluate and compare the quantity of apical debris extrusion from the root canals during biomechanical preparation by various rotary (reciprocating, Protaper Next [PTN] continuous) and manual hand filing system and by means of Crown-Down and Step Back techniques. Materials and Methods: Eighty mature, human mandibular premolars with single canals were randomly divided into four groups of twenty teeth each. Each group was instrumented using one of the four instrumentation systems: Group A: WaveOne, Group B: PTN, Group C: Hand file with Crown Down, Group D: Hand file with Step Back. Extruded debris was collected in preweighed Eppendorf tubes and the extruded irrigant was evaporated. The weight of the dry extruded debris was established by comparing the pre and post-instrumentation weight of Eppendorf tubes for each group. Results: Mean comparison of groups in different instrumentation by ANOVA presented that hand file with Step-Back technique is showed maximum amount of apical extrusion debris and continuous rotary file system showed the minimum amount of extrusion debris (P < 0.001). Conclusions: The current ex vivo study demonstrated reciprocating single file WaveOne and continuous rotary multiple file system lead to significantly less debris extrusion than manual hand file techniques. Reciprocating single file WaveOne extruded more debris than continuous rotary PTN multiple file system. More amount of debris was extruded in the group with Step-Back hand filing than Crown-Down technique.

Objective: The purpose of this study was to evaluate the impact of glide path preparation on the incidence of dentinal defects after preparation of severely curved canals using ProTaper Next, F6 SkyTaper, and One Shape instruments. Method and Materials: One hundred and forty human mandibular molars with mesiobuccal canals with angles of curvatures ranging between 25 and 35 degrees and radii ranging between 4 and 9 mm were assigned to seven homogenous groups (n = 20 teeth per group). In half of the teeth of each of the seven groups a manual glide path (size 15) was created prior to instrumentation. The root canals were instrumented using the three different types of instruments to an apical size 25. One group served as control as no canal preparation was performed. Roots were sectioned horizontally at 3, 6, and 9 mm from the apex and evaluated under a microscope using 25-fold magnification. The presence of dentinal defects (complete/ incomplete cracks) was noted and analyzed using Fisher's exact test. Results: No defects were observed in the controls. All canal preparations created dentinal defects. More incomplete and complete cracks were found in the apical (n = 4) and the middle (n = 3) canal third than in the coronal (n = 1), without any significant differences between the three instruments (P > .05). Prior glide path preparation had no significant impact on the incidence of dentinal defects (P > .05). Conclusion: A glide path preparation seems not to be mandatory to reduce the risk of dentinal defects formation when using the tested instruments in severely curved canals. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the cyclic fatigue resistance of Pro Taper NEXT & Reciproc R rotary files in simulated canals with angle of curvatures at 45o and 60 o. Materials and Methods; This study was conducted at HKE' s S.Nijalingappa institute of dental sciences and reasearch institute, Kalaburagi. After considering the inclusion and exclusion criteria the selected samples were divided into two groups, as G1(ProTaper NEXT) and G2(RECIPROC R), further these two groups are divide into 2 subgroups. Results: The mean cyclic fatigue was significantly high in Reciproc R procedure as compared to ProTaper NEXT. Therefore Reciproc R procedure was better as compared to ProTaper NEXT. Conclusion: Cyclic fatigue resistance of Reciproc R was higher than the ProTaper NEXT. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this in vitro study was to investigate the torsional fatigue resistance of different rotary files in straight and curved positions at a simulated intracanal temperature. Methods: Forty-eight size #25 files from ProTaper Universal (PTU), ProTaper Next (PTN) and ProTaper Gold (PTG) were tested for torsional resistance in both straight and curved (90 degrees) positions (n = 8 each). The experiment was conducted at a simulated intracanal temperature of 35 ± 1 °C. The torque gauge was reset before every use, and uniform torsional stress was applied by rotating the file clockwise at a speed of 40 rpm until fracture. Torque failure values were recorded, and fractured surfaces were tested using a scanning electron microscopy (SEM). Statistical analysis of the data was completed using one-way ANOVA and post-hoc test (LSD) in order to compare between the tested systems in each file position. Student’s t-test was also performed to compare between the two positions in each rotary system, and significance level was set at 5%. Results: In the straight position, torsional resistance of PTN was significantly lower than that of PTU and PTG (p 0.05). In the curved position, torsional resistance was found to be comparable among all systems (p > 0.05). Within each system, the curved position resulted in a significantly lower torsional resistance when compared to the straight position (p

Background: The instrumentation technique which produces least amount of apically extruded debris is desirable to use in biomechanical preparation of root canal. Aim: To quantitatively evaluate apically extruded debris during instrumentation with hand K-file, ProTaper Next, and WaveOne. Materials and Methods: Forty-five extracted human single-rooted mandibular premolars with straight, single canal and single apical foramen were selected after radiographic evaluation and divided equally into three groups. Cleaning and shaping was done using hand K-files in step-back technique, ProTaper Next, and WaveOne single-file system. Debris extruded apically was collected into Eppendorf tubes and stored in an incubator at 37°C temperature for 5 days for drying. Weight of dry debris was measured using electronic microbalance with an accuracy of 10-5 g. Statistical Analysis: Student's t-test, with P value < 0.05 is statistically significant. Results: Statistically significant (P < 0.05) amount of debris was extruded by all three instrumentation systems: hand K-file-1.9220 mg, ProTaper Next-1.4940 mg, and WaveOne-0.9940 mg. Least amount of debris produced by WaveOne was statistically significant (P < 0.05) when compared with the other two systems. Conclusion: The WaveOne reciprocating system extruded least amount of debris in comparison to hand K-file and ProTaper Next. [ABSTRACT FROM AUTHOR]

Background. This study aimed to compare the cyclic fatigue resistance of ProTaper Next, Hyflex CM, 2Shape, and TF-Adaptive nickel-titanium endodontic file systems with various alloy properties and production methods and investigate the fractured cross-sectional surface of files due to cyclic fatigue by scanning electron microscopy (SEM). Methods. A total of 120 instruments were used (n=30). For standardization, #25/.06 apical diameter and taper angle were selected for each file system. The experiment of files was subjected to a static cyclic fatigue model. The time for files’ failure was recorded with a digital chronometer and multiplied by the rotation speed to calculate the number of cycles. Kolmogorov-Smirnov, one-way ANOVA, and post hoc Bonferroni analysis were used for statistical analysis. Statistical significance was set at P

Objective: To investigate technical outcome and time efficiency, using ProTaper Universal (PTU) or ProTaper Next (PTN) rotary nickel titanium (NiTi) files, to prepare simulated canals, by undergraduate dental students. Methods: Sixty-six students were randomly assigned to two groups. Both groups prepared two endodontic blocks (n = 66) using PTU and PTN in crossover design. Preparation time was also recorded. The blocks were photographed under magnification and were assessed for procedural errors by two different observers. Data were recorded and analysed by descriptive statistics, generalised mixed model and analysis of variance (ANOVA) using SPSS. Results: The different file systems had a significant effect on the presence or absence of procedural errors, with a significance value of P < 0.001. More successful preparation was achieved with PTN (89%) than PTU (37.5%). There were a total number of procedural errors of n = 58.The highest incidence of procedural errors by different file systems was transportation. The PTU showed 24 transportation errors out of a total of 51 errors and the PTN showed five transportation errors out of a total of seven. PTN demonstrated the quickest mean time of preparation with a P value of P < 0.001. Conclusion: In the hands of novice operators, PTN showed a lower incidence of procedural errors and better time efficacy during instrumentation of simulated canals, compared with PTU. [ABSTRACT FROM AUTHOR]

Objective: To evaluate and compare the volume of removed dentin, transportation, and centering ability of TRUShape (TRS; Dentsply Tulsa Dental Specialties) system with ProTaper Next (PTN; Dentsply Maillefer) by using micro-computed tomography (μCT). Method and Materials: Twenty extracted human mandibular first molars with two separate mesial canals with curvatures of 25 to 35 degrees were divided into two experimental groups (n = 20) according to the rotary nickel-titanium file system used in canal instrumentation as follows: group TRS and group PTN. Canals were scanned before and after instrumentation using μCT to evaluate root canal transportation, centering ratio, and volumetric changes. Data of canal transportation and centering ratio values were analyzed using independent t test. Volume changes data were statistically analyzed using Mann-Whitney test. Statistical significance level was set at P < .05. Results: The PTN group had a significantly lower mean volume of removed dentin (2.09 ± 0.41 mm3) than the TRS group (2.77 ± 0.72 mm3) (P < .05). At the coronal level, there was no significant difference in canal transportation (P = .170) and centering ratio (P = .111) between TRS and PTN groups. However, at the apical and middle levels, the PTN group had a significantly lower mean transportation value and higher centering ratio than the TRS group (P < .05). Conclusion: Root canal preparation with the PTN system revealed better performance with fewer canal aberrations than the TRS system in curved root canals. [ABSTRACT FROM AUTHOR]

Background. This study aimed to evaluate the effects of repeated sterilization cycles on the surface alterations of various nickel-titanium instruments, including ProTaper Next (PTN), TF Adaptive (TFA), HyFlex CM (HCM), and 2Shape (2S). Methods. Twenty-four new NiTi files of four different alloys were selected. The instruments in each group were divided into two equal groups, as follows: control and sterilization. The first group was chosen as the control without applying any sterilization procedure, while in group 2, five cycles of sterilization procedures were applied. The surface topographies were evaluated using scanning electron microscope (SEM) and atomic force microscope (AFM). The root mean square (RMS) and maximum height (MH) values and three-dimensional images were recorded. The data were analyzed with the Shapiro-Wilk test, one-way ANOVA, and post hoc Tukey tests. The statistical significance level was set at P≤0.05. Results. Before the experiment, HCM demonstrated the highest RMS value, and 2S showed the lowest. After the procedures, the RMS and MH values deteriorated on the surface of PTX, TFA, and 2S (P0.05). Conclusion. The initial irregularity on the surface did not affect the rate of alteration. The HCM files demonstrated superior surface properties after several cycles of sterilization. The PTN, TFA, and 2S presented similar surface responses after five cycles of autoclave sterilization.

Purpose Postoperative pain is a common complication in endodontics contributed by multiple etiological factors, which consist canal preparation instruments and kinematics. The aim of this randomized clinical trial compare the postoperative pain in terms of intensity and incidence after the use of different nickel titanium (NiTi) file systems. Patients and Methods In this randomized clinical trial (NCT03791762), a total of 150 patients were root canal treated by 2 experienced endodontists according to a standardised protocol. The subjects were randomly assigned to 1 of the 3 groups according to preparation instrument used: ProTaper Next (Dentsply Sirona, Ballaigues, Switzerland), Reciproc Blue (VDW, Munich, Germany) and WaveOne Gold (Dentsply Sirona). Following preparation the teeth underwent standardized root canal treatment procedures in a single visit. The patients were contacted to gather information about the incidence of pain and intensity at 6th, 12th, 18th, 24th, 48th, and 72nd hours postoperatively. The data were analysed using chi-square, one-way analysis of variance and post hoc Tukey tests and logistic regression analysis with 5% significance threshold. Results No significant difference was found among preparation groups in relation to the intensity of postoperative pain. The incidence of postoperative pain was significantly linked with the preoperative pain presence with odds ratio values ranging between 2.06 and 4.08 irrespective of the preparation technique (P<0.05). Conclusion The effects of reciprocating and the continuous rotary systems on the intensity and incidence of postoperative pain were found to be similar. [ABSTRACT FROM AUTHOR]

This study aimed to examine how downward loads influence the torque/force and shaping outcome of ProTaper NEXT (PTN) rotary instrumentation. PTN X1, X2, and X3 were used to prepare J-shaped resin canals employing a load-controlled automated instrumentation and torque/force measuring device. Depending on the torque values, the handpiece was programmed to move as follows: up and down; downward at a preset downward load of 1 N, 2 N or 3 N (Group 1N, 2N, and 3N, respectively; each n = 10); or upward. The torque/force values and instrumentation time were recorded, and the canal centering ratio was calculated. The results were analyzed using a two-way or one-way analysis of variance and the Tukey test (α = 0.05). At the apex level, Group 3N exhibited the least canal deviation among the three groups (p < 0.05). The downward force was Group 3N > Group 2N > Group 1N (p < 0.05). The upward force, representing the screw-in force, was Group 3N > Group 1N (p < 0.05). The total instrumentation time was Group 1N > Group 3N (p < 0.05). In conclusion, increasing the downward load during PTN rotary instrumentation improved the canal centering ability, reduced the instrumentation time, and increased the upward force. [ABSTRACT FROM AUTHOR]

Objectives: This study was aimed to evaluate the cause-effect relationship between canal preparation with ProTaper Next (PTN) and ProTaper Gold (PTG) using optimum torque reverse (OTR) motion or continuous rotation and dentinal crack formation. Materials and Methods: Fifty distobuccal roots of human maxillary first molars were divided into five groups; Group I: PTG Full rotation, Group II: PTG in OTR, Group III: PTN Full rotation, Group IV: PTN in OTR, Group V: unprepared (control group). After mechanical preparation, the distobuccal roots were sectioned horizontally at 3, 6, and 9 mm from the apex. Images were captured using a stereomicroscope at 25X to determine the presence or absence of dentinal cracks. Friedman test was used to compare between root sections followed by Wilcoxon signed-rank test for pairwise comparison. Kruskal–Wallis test was used to compare between tested rotary systems followed by pairwise comparison with Dunn Bonferroni correction (α = 0.05). Results: Crack development was significantly higher in PTG using OTR motion 36.7% followed by PTN using OTR 33.3%, while the control group showed no cracks. PTG and PTN with full rotation showed crack development with 23.3% and 13.3%, respectively. Conclusions: The type of motion kinematics used during mechanical preparation have an impact on dentinal crack formation. Nickel-titanium instruments with larger taper tend to induce more cracks. [ABSTRACT FROM AUTHOR]

Aim: The aim of the study is to evaluate and compare the quantity of apical debris extrusion from the root canals during biomechanical preparation by various rotary (reciprocating, Protaper Next [PTN] continuous) and manual hand filing system and by means of Crown-Down and Step Back techniques. Materials and Methods: Eighty mature, human mandibular premolars with single canals were randomly divided into four groups of twenty teeth each. Each group was instrumented using one of the four instrumentation systems: Group A: WaveOne, Group B: PTN, Group C: Hand file with Crown Down, Group D: Hand file with Step Back. Extruded debris was collected in preweighed Eppendorf tubes and the extruded irrigant was evaporated. The weight of the dry extruded debris was established by comparing the pre and post-instrumentation weight of Eppendorf tubes for each group. Results: Mean comparison of groups in different instrumentation by ANOVA presented that hand file with Step-Back technique is showed maximum amount of apical extrusion debris and continuous rotary file system showed the minimum amount of extrusion debris (P < 0.001). Conclusions: The current ex vivo study demonstrated reciprocating single file WaveOne and continuous rotary multiple file system lead to significantly less debris extrusion than manual hand file techniques. Reciprocating single file WaveOne extruded more debris than continuous rotary PTN multiple file system. More amount of debris was extruded in the group with Step-Back hand filing than Crown-Down technique. [ABSTRACT FROM AUTHOR]

Background. This research aimed to investigate and compare the amount of apically extruded debris after root canal preparation using ProTaper Next, ProTaper Gold, and TruNatomy systems. Methods. Forty-five extracted mandibular premolar teeth with single canals with similar lengths were used. The root canals were prepared using ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Gold (Dentsply Maillefer, Ballaigues, Switzerland), or TruNatomy (Dentsply Maillefer, Ballaigues, Switzerland) files. Apically extruded debris during preparation was gathered into preweighed Eppendorf tubes. Then the Eppendorf tubes were incubated at 70°C for five days. The Eppendorf tubes were weighed again to determine their final weight plus the extruded debris. Results. The TRN system resulted in significantly less debris extrusion than the PTN system (P0.05). Conclusion. All the instrumentation systems caused apical extrusion of debris. However, the TRN system resulted in significantly less debris extrusion than the other systems.

Background: During the biomechanical preparation of the root canal by rotary file systems, stress is generated within the canal, which leads to dentinal microcrack formation. Such defects are evaluated only under the microscope. Aim: The present study aimed to evaluate dentinal microcrack formation after instrumentation with ProTaper Next (M-wire), Revo S (conventional NiTi), and WaveOne Gold (Gold-wire) file systems under the stereomicroscope. Materials and Methods: Forty single-rooted teeth free from any defect were selected and divided into four groups (Control, PTN, RS, and WOG). Experimental groups were instrumented with file system used in the study, and the control group were left unprepared. Samples were further decoronated and sectioned at 3 mm, 6 mm, and 9 mm from the apex perpendicular to the long axis and examined under a stereomicroscope at ×25 for different types of microcracks (no fracture, complete fracture, partial fracture, and other fracture). Statistical Analysis Used: Data analysis was done by the Chi-square test using the SPSS version 17.0 software. A two-sided (α = 2) P < 0.05 (P < 0.05) was considered statistically significant. Results: The null hypothesis was rejected. There was a statistically significant difference between the groups. All file systems created microcracks in the root dentin. WOG group showed an incidence of 66.7% for no fracture, PTN group had 40% for other fracture, and RS group had 60% for complete fracture. Conclusion: Single file system WOG with gold wire technology proves to be the best choice for canal preparation among the tested groups in terms of least dentinal crack formation.

Aim: The present study aimed to evaluate and compare the microcrack formation in apical root dentin as a result of root canal preparation with different nickel–titanium (NiTi) rotary systems. Materials and Methods: Sixty extracted mandibular premolar teeth with single canals were used. Apical 1 mm of roots was flattened perpendicular to the tooth axis. Forty-five teeth were prepared using ProTaper Next (PTN), ProTaper Gold (PTG), or TruNatomy files. Fifteen teeth were left unprepared as the negative control group. Images of apical surfaces of roots were obtained using a stereomicroscope at × 20 magnification. The presence of microcracks was noted with the help of the images. The data were analyzed with a Chi-square test using MiniTab 17 Statistical Software. Results: There was a statistically significant difference between the PTN and TruNatomy groups (P < 0.05). There was no statistically significant difference between the PTG group and other groups (P > 0.05). Conclusion: Whereas all rotary files created microcracks in the apical root dentin, TRN caused fewer microcracks than other NiTi rotary systems.

Aim: The aim of the study is to compare and evaluate the remaining dentin thickness following biomechanical preparation of teeth using different rotary file systems. Materials and Methodology: Sixty noncarious mandibular premolar teeth were collected and decoronated at the level of cementoenamel junction with a diamond disc. All specimens were randomly divided into 5 experimental groups - ProTaper Next (Dentsply Mallifer), Mtwo (VDW, Antaeus, Munich, Germany), RaCe (FKG, La Chaux-de-Fonds, Switzerland), Hyflex electro-discharge machining (EDM) (Coltene-Whaledent, Allstetten, Switzerland), NeoNiTi (Neolix, France) and 1 control group of 10 teeth each. After mounting the samples on a modeling wax sheet, preoperative cone-beam computed tomography (CBCT) scans were taken. Biomechanical preparation of canals was done following the assigned protocol of manufacturers. Postoperative CBCT scans were taken and comparison was carried out with preoperative scans. Statistical Analysis Used: Difference among the groups was analyzed by post hoc Turkey and analysis of variance tests. A P < 0.05 was considered statistically significant for all tests. Results: A comparison of preinstrumentation and postinstrumentation CBCT images revealed ProTaper Next group to remove more dentin at 7 mm as opposed to other groups in mesiodistal direction. However, no statistical difference was evident between ProTaper Next, MTwo, Race, Hyflex EDM, NeoNiTi file systems at 3 mm, 5 mm, and 7 mm in buccolingual direction. A statistically nonsignificant difference was evident between MTwo, Race, Hyflex EDM, NeoNiTi file systems at 3 mm, 5 mm, and 7 mm in both mesiodistal and buccolingual direction. Conclusion: Race file system performed better and removed lesser dentin in both buccolingual and mesiodistal directions. More dentin was removed at the coronal in mesiodistal direction with the use of ProTaper Next, and significant difference was seen between Protaper Next group and other groups in the study. [ABSTRACT FROM AUTHOR]

Aim: To compare dentinal cracks incidences after root canal preparation using Hand K-files; Rotary files: Protaper NEXT (PTN), Hyflex Controlled Memory (CM); and Reciprocating files: Wave One and Wave One Gold files. Materials and Methods: Hundred extracted human mandibular first premolars with straight root canals were taken postextraction and were allocated randomly into five groups (n = 20 teeth per group). The canals were instrumented using Hand K-files, Protaper Next (PTN), Hyflex CM, Wave One, and Wave One Gold systems. Group 1-Control group comprised of canals prepared by Hand files. Further, the roots were sectioned at three levels: 3, 6, and 9 mm horizontally from the apex using a saw at a low-speed saw and under water cooling. These slices were examined under a stereomicroscope at 25x magnification and the presence of any dentinal cracks was noted. The frequency of cracks was presented in number and percentage. Intergroup comparison of crack frequency was performed using analysis of variance. Results: No cracks were observed in the control group. In all the other groups, dentinal cracks were observed. The rotary files PTN and Hyflex CM files produced significantly fewer dentinal cracks than the reciprocating Wave One and Wave One Gold files (P < 0.05). The reciprocating files significantly produced more cracks apically than the rotary files (P < 0.05). Analyses were performed on SPSS software (windows version 22.0). Conclusion: Instrumentation with file systems can cause crack formation in the dentinal wall of the root canal. Determination of which files to choose for root canal preparation is technique sensitive and each instrument type has own benefits. However, care should be taken while biomechanical preparation to avoid dentinal cracks formation. [ABSTRACT FROM AUTHOR]

Aim: The aim is to compare the apical extrusion of debris during endodontic instrumentation with continuous rotation and reciprocating motion. Materials and Methods: Sixty extracted single-rooted mandibular premolar human teeth were randomly assigned to four groups of 15 teeth each. The canals were then instrumented with the following instrument systems: ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), 2Shape (TS; MicroMega, Besancon, France), Reciproc Blue (RB; VDW, Munich, Germany) and WaveOne Gold (WOG; Dentsply Sirona, Ballaigues, Switzerland). Apically extruded debris during instrumentation was collected into pre-weighed Eppendorf tubes. The Eppendorf tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation weight from postinstrumentation weight of the Eppendorf tubes. The data were analyzed using one-way analysis of variance and Tukey's Post hoc tests. Results: Among the instruments tested in the present study, the least amount of extrusion of debris was seen with TS rotary file system (Group IA) followed by RB (Group IIA) and WOG (Group IIB) (P < 0.05), the results, however, were not found to be statistically significant between them. The maximum amount of debris extrusion was observed with PTN (Group IB) with a statistically significant difference when compared to TS, RB, and WOG file system (P > 0.05). Conclusion: All instruments were associated with apical extrusion of debris with TS rotary file system associated minimum extrusion and PTN, resulting in maximum extrusion of debris.