HyFlex EDM Research Articles

Accuracy of electronic apex locators using heat-treated Ni-Ti file.

This study investigated the accuracy of two electronic apex locators (DentaPort and Bingo) using heat-treated nickel-titanium files. The true root canal length of 30 single-rooted teeth was determined using K files. Next, the electronically measured length was determined using two nickel-titanium files (ProGlider and HyFlex EDM Glide Path File) with two electronic apex locators at the 'APEX' marks. The accuracy of the electronic apex locator was evaluated by comparing the true root canal length and electronically measured length for each measurement. There was no significant difference between the measurements with two nickel-titanium files, and all differences between true root canal length and electronically measured length were within ±0.5 mm regardless of the type of nickel-titanium files or electronic apex locators. Based on the results, the heat treatment of the nickel-titanium files showed no adverse effects on the working length determination using electronic apex locators.

Fatigue strength of Bassi LogicTM and Hyflex EDM endodontic instruments in an artificial canal with an extreme curvature

The objective of this study was to perform a comparative analysis of the fatigue strength of NiTi instruments in an in vitro model (artificial canal). Ten Hyflex EDM instruments (tip: 10; taper: .05) (Coltene/Whaledent, Altstätten, Switzerland) and ten Bassi LogicTM instruments (tip: 15; taper: .05) (Bassi Endo, Belo Horizonte, Brazil) were used. For the static bending fatigue strength test, we used a stainless-steel artificial canal with a 5-mm curvature radius, 90º curvature, and inner diameter of 1.5 mm. The instruments were run in the artificial canal until the occurrence of fracture. The time was recorded and the number of cycles was calculated. The length of the fragments was measured and three samples from each group were analyzed using scanning electron micrscopy for the characterization of metal fatigue. The data were compared using the nonparametric Man-Whitney test (samples with non-normal distribution), with the significance level set at 5% (p<0.05). Bassi LogicTM instruments tolerated a greater number of cycles compared to the Hyflex EDM (p < 0.05). Significant differences in fragment size were also found between groups (p < 0.05). Mean fragment size was larger among the Hyflex EDM instruments compared to the Bassi LogicTM instruments.The Bassi LogicTM 15.05 exhibited greater fatigue strength in artificial canals with an accentuated curvature compared to Hyflex EDM 10.05.

Comparison of Cyclic Fatigue Resistance of Novel TruNatomy Files with Conventional Endodontic Files: An In Vitro SEM Study

To compare and analyze the cyclic fatigue resistance of novel TruNatomy files against the conventionally used rotary files and reciprocating files in a simulated canal system with curvatures in the middle, apical portions root, and S-shaped canal employing scanning electron microscopy. Endodontic files tested in the study include ProTaper, HyFlex EDM, Reciproc blue, and TruNatomy files operated in a simulated root canal system. A total of 96 files were employed in this study. They were categorized into four groups. Group 1 employed 24 TruNatomy files, group 2 employed 24 ProTaper gold files, group 3 employed 24 HyFlex EDM files, and group 4 employed 24 Reciproc blue files. All the groups employed eight files each under three subgroups namely A, B, and C representing middle, apical, and double curvatures, respectively. Artificial grooves were incorporated in the stainless steel blocks having three different curvatures. All the file systems were operated with a torque-controlled electric motor. The files were engaged in the artificial canal until the occurrence of fracture. The time required for the fracture was noted. Length of fractured tip was measured using the digital Vernier caliper. The number of cycles of failure (NCF) was calculated. The fractured parts were subjected to scanning electron microscope to analyze the mode of fracture. TruNatomy files had the highest mean NCF values of 588.01 in middle curvature, 1,321 in apical curvature, and 642.5 in S-shaped curvature HyFlex EDM and Reciproc blue file system exhibited comparable cyclic fatigue resistance among them. ProTaper gold file system exhibited least mean NCF values of 158.13 in the middle, 196.5 in the apical curvature, and 116.88 in the S-shaped canal system. Middle portion fractured first than the apical curvature. The mean length of fractured segments was found to be insignificant among the experimental study groups tested. All the file systems employed in the study had good cyclic fatigue resistance while TruNatomy files had the highest cyclic fatigue resistance while HyFlex EDM and Reciproc blue had comparable fatigue resistance. ProTaper gold file system had the least fatigue resistance at different radius of curvature in the simulated canal system in the apical and middle portions and S-shaped root canal. The selection of file systems in cleaning and shaping protocols is an enigma to the endodontics. This in vitro study explored the selection protocols for the execution of root canal preparation. Heat treatment of nickel-titanium (NiTi) endodontic files had improved the cyclic fatigue résistance significantly enhancing the clinical life of file systems.

Comparison of surface defects in Protaper Next and Hyflex EDM files after single clinical use: A stereoscopic evaluation.

To compare the surface defects created on the ProTaper Next files versus HyFlex Electrical Discharge Machining files after single clinical use in molars. The cross-sectional study was conducted in the dental department of the Aga Khan University Hospital, Karachi, from December 2018 to June 2019, and comprised Nickel-Titanium files belonging to HyFlex Electrical Discharge Machining and ProTaper Next to perform complete root canal treatment of molar teeth. The files were first visually examined and then analysed under 25.6x magnification using a stereomicroscope for the evaluation of surface defects. A photographic record was maintained and studied. Data was analysed using SPSS 23.0. Of the 114 files, 38(33.3%) each were ProTaper Next X1, ProTaper Next X2 and HyFlex Electrical Discharge Machining. The number of files showing defects under microscopic evaluation were 17(14.9%). Deformation of the cutting edge was the most frequently seen defect type, found in 9(7.9%) files. The frequency of fractured files was 4(3.5%). The odds of microscopic defects in HyFlex Electrical Discharge Machining files was 2.64 times that of ProTaper Next files. Even after single clinical use, HyFlex Electrical Discharge Machining files were more likely to get microscopic defects on their surface compared to ProTaper files.

Scanning electron microscopy evaluation of smear layer generated by rotary instrumentation techniques: An in-vitro study

To evaluate the Smear layer generated by three rotary instrumentation techniques Thirty single-rooted freshly extracted teeth were selected for this study, teeth were decoronated at the level of CEJ (Cemento enamel junction) and were divided into three groups for cleaning and shaping of root canals, group I (protaper gold) group II (M two) group III (Hyflex EDM) After splitting the roots longitudinally, the Smear layer generated by each instrument for each root canal was evaluated using a scanning electron microscope and the data obtained was statistically analyzed using Kruskal Wallis and Mann-Whitney U test. Instrumentation with Protaper gold (Group 1) showed the maximum amount of Smear layer generation followed by Hyflex EDM (Group 3) files and VDW Mtwo (Group 2) showed the least values of Smear layer generation. Within the limitations of the study, it can be concluded that Mtwo (group 2) showed better results in removing the Smear layer than Protaper gold and Hyflex EDM file systems.

Microtomographic Evaluation of Canal Centralization and Dentine Removal after Canal Preparation with Two Rotary Systems: HyFlex EDM and ProTaper Next.

Objective This study compared the ProTaper Next (PTN; Dentsply Sirona, Tulsa, Oklahoma, United States) and HyFlex EDM (HEDM; Coltene/Whaledent AG, Alstätten, Switzerland) systems using micro–computed tomography (CT). Materials and Methods Twenty-one mesial roots classified as Vertucci's type IV from extracted mandibular first molars with curvatures between 20 and 40 degrees were selected. The teeth were scanned using a micro-CT before and after root canal preparation by both systems, applied to the same root, in alternating canals. The following parameters were analyzed: canal centering, apical transportation, root canal diameter/root diameter. Results No statistically significant differences between both systems were observed for any of the assessed morphological parameters ( p > 0.05). All canals presented diameter enlargement of more than 40% in relation to root diameter in the cervical and middle segments. No statistically significant difference was noted between the HEDM and PTN groups. The wear percentage for the HEDM group in the cervical and middle thirds were 49.66 ± 8.65 and 46.48 ± 14.29, respectively, and 51.02 ± 11.81 and 45.48 ± 10.79 for the PTN group, respectively. Conclusion Both systems displayed similar mandibular molar mesial canals preparation, with no differences noted for any of the assessed parameters. Both groups showed increased canal diameter in the cervical and middle thirds by more than 40%.

Comparison of root canal shaping ability of different heat-treated NiTi single files: a micro-CT study.

The purpose of this study was to evaluate the root canal shaping abilities of different heat-treated NiTi engine--driven single files. A total of 45 mandibular first molar teeth with a root canal curvature of between 25 and 35 degrees were selected for this in vitro study. The mesial roots were separated and scanned with micro-CT. The specimens were randomly divided into three groups. Root canal preparations were performed using HyFlex EDM OneFile in Group 1; OneCurve (25/06) in Group 2, and WaveOne Gold Primary in Group 3. Root canals were scanned again with micro-- CT after root canal preparation. Apical transportation value and centering ability ratio of files were evaluated using the preinstrumentation and postinstrumentation micro-CT images at 1, 2, 3, 4, and 7 mm. The data were statistically analyzed using the Kruskal-Wallis test. The Bonferroni-Dunn test was used for multiple comparisons. The level of statistical significance was set at P < .05. There was no significant difference between the apical transportation values of experimental groups in mesiodistal direction (P > .05) and buccolingual direction (P > .05). The OneCurve file group showed better centering ability in the buccolingual direction than the WaveOne Gold file group at 4 mm (P = .048). The difference between the centering ability values of experimental groups was not significant at other levels (P > .05). According to the results of this study, all tested single files caused apical transportation and showed similar centering ratio at most of the root sections.

Comparison between the rotary (Hyflex EDM®) and manual (k-file) technique for instrumentation of primary molars: a 12-month randomized clinical follow-up study.

Rotational instrumentation is an alternative for the clinical practice of pediatric dentists. However, there are few records in the literature on the clinical and radiographic aspects of treated teeth over time.Objectives:Compare instrumentation time and filling quality between manual (k-file) and rotary (Hyflex EDM®) files, and clinically and radiographically follow-up the treated teeth for 12 months. Moreover, the characteristics of glass ionomer restorations and their interference in the treatment prognosis over time were evaluated.Methodology:In total, 40 children with pulp involvement in primary molars received treatment with Hyflex EDM® or manual rotary files, performed by an operator. Clinical and radiographic aspects were observed at different times to determine the effectiveness of each technique.Results:The rotary system reduced instrumentation time when compared to the use of manual files (p≤0.05), but there was no difference in filling quality between the groups (p≥0.05). Moreover, both types of instrumentation were effective for 12 months (p≥0.05), and restoration retention influenced the emergence of periapical lesions (p≤0.05).Conclusion:Although rotary files reduce clinical time, the clinical and radiographic aspects of both techniques were similar over 12 months. Moreover, restoration retention has been shown to be related to treatment prognosis.

Assessment of postoperative pain after single-visit root canal treatment using rotary and reciprocating file systems: an in vivo study.

BackgroundVarious instrument kinematics used in single-visit endodontics influence the occurrence of pain after endodontic therapy. This study aimed to evaluate the occurrence of pain after mechanical instrumentation with Hyflex EDM (HEDM) and WaveOne Gold (WOG) during single-visit endodontic therapy.MethodsSixty patients diagnosed with asymptomatic irreversible pulpitis and normal apical tissues in mandibular premolar teeth were included in the study for single-visit root canal therapy. The patients were divided into two groups (n = 30) according to the rotary instrument used during root canal preparation (group A [HEDM] and group B [WOG]). Pain was evaluated after endodontic therapy at 8, 24, and 48 h intervals using the visual analog scale (VAS). Data obtained were analyzed using the chi-square test, independent t-test, MannWhitney U test, and Wilcoxon matched-pairs test.ResultsStatistically significant differences were observed between the two groups (P < 0.001) at 8, 24, and 48 h, with WOG exhibiting less pain than HEDM files.ConclusionPostoperative pain was lower in the WOG file system than in the HEDM file system after single-visit root canal therapy at 8, 24, and 48 h.

Evaluation of temperature effect on cyclic fatigue resistance of nickeltitanium instruments in a double-curved canal: a comparative study

Objective: To investigate the effect of room and body temperatures on cyclic fatigue resistance of three endodonticnickel-titanium rotary files: Hyflex EDM (HEDM) (Coltene/Whaledent, Switzerland), WaveOne Gold (WOG)(Dentsply Maillefer, Switzer), and EdgeOne Fire (EOF) (EdgeEndo, Albuquerque, New Mexico, USA) in a doublecurvedcanal. Material and Methods: In this study, Sixty NiTi rotary files were used. These files were dividedinto three groups (n = 20 for each group). Group A: HEDM (size 25, taper 0.08), group B: WOG (size 25, taper0.07), and group C: EOF (size 25, taper 0.07). Each group was subdivided into two subgroups (n=10 for eachsubgroup). One of the subgroup was subjected to cyclic fatigue test at room temperature (20±1°C), while theother subgroup was subjected to cyclic fatigue test at body temperature (37±1°C). These files were tested by usinga custom-made artificial canal with a double curvature (coronal curve: 60° curvature with 5 mm radius; apicalcurve: 70° curvature with 2 mm radius). All instruments were rotated according to the manufacturer instructionsuntil the fracture occurred by using electric endodontic motor (Wave One, Dentsply Maillefer, Ballaigues,Switzerland). The number of cycles to fracture (NCF) and the fractured fragment length (FL) were recordedfor each endodontic file. The data were gathered and statistically analyzed using shapiro-wilk test and two-wayANOVA test. The statistical significance was set at 0.05. Results: The NCF of WOG and EOF were significantlylower at body temperature as compared to room temperature (p&lt;-0.05), whereas no difference was observedin NCF of HEDM at body and room temperatures (p&gt;0.05). At 20±1°C, the results showed a non-significantdifference between NCF of WOG and EOF (p&gt;0.05), while the NCF of HEDM was significantly lower than theother groups (p&lt;-0.05). At 37±1°C, the results showed a non-significant difference in NCF among the testedendodontic files (p&lt;-0.05). There is non-significant difference in FL of each group at (20±1°C) and (37±1°C)(p&gt;0.05). No statistical difference in FL among the tested files at room and body temperatures (p&gt;0.05).Conclusion: The temperature has a significant effect on cyclic fatigue resistance of EOF and WOG, whereas noeffect was observed on cyclic fatigue resistance of HEDM. WOG and EOF had a comparable NCF, while HEDMhad a lower NCF than other groups at room temperature. At body temperature, all tested files have a comparableNCF. These results were attributed to the type of the alloy and heat treated that was used to manufacture theseendodontic files. The cyclic fatigue test should be done at body temperature. KEYWORDSBody temperature; Cyclic fatigue; EdgeOne fire; Hyflex EDM; WaveOne Gold.

Effects of Chitosan, NaOCl, and EDTA Irrigation Solutions on the Cyclic Fatigue Resistance of Three Nickel–Titanium Endodontic Rotary Files: An In Vitro Study

Introduction The goal of this study was to compare the impact of NaOCl, EDTA, and chitosan on the cyclic fatigue of 2Shape, HyFlex EDM, and RACE EVO. Methods A total of 120 new 2Shape (n = 40), HyFlex EDM (n = 40), and RACE EVO (n = 40) files were subdivided randomly into four groups (n = 10): Group (A) with no immersion, Group (B) with immersion in 5.25% NaOCl for 5 min, Group (C) with immersion in 17% EDTA for 5 min, and Group (D) with immersion in 0.2% chitosan for 5 min. The files were rotated in an artificial canal with a 5 mm radius and a 60° curvature at body temperature until they fractured, and the number of cycles to fracture was measured. ANOVA test and Tukey post-hoc test were used to analyze the data. Results Immersion of the files in NaOCl, EDTA, or chitosan solutions had no significant effect on the number of cycles to fracture (P > 0.05). Conclusion The irrigation solutions did not have any influence on the cyclic fatigue of the tested files.

An in vitro evaluation of canal transportation and centering ability of ProTaper Universal, Hyflex EDM, and WaveOne gold using microcomputed tomography

An in vitro evaluation of canal transportation and centering ability of ProTaper Universal, Hyflex EDM, and WaveOne gold using microcomputed tomography

Comparative evaluation of apically extruded debris using three different thermomechanically heat treated file systems with two different motions: An in vitro study.

Introduction and Aim:Postoperative inflammation and endodontic failure occur due to apical extrusion of debris. The purpose of this in vitro study was to assess the amount of apically extruded debris during the root canal preparation using rotary and reciprocating nickel-titanium instrumentation systems.Materials and Methods:The mesiobuccal canals of seventy five mature, human mandibular molars were randomly divided into three groups (n = 25 teeth/group). Each group was instrumented using one of the three different instrumentation systems: Hyflex EDM (HEDM) rotary file, Flexicon X7 rotary, and Flexicon X1 reciprocating files. The canals were irrigated using distilled water. The debris extruded apically was collected in preweighed Eppendorf tubes and assessed with an electronic balance and compared.Statistical Analysis:Data were statistically analyzed by one-way analysis of variance and the intergroup comparison with single factor ANOVA.Results:The Flexicon X1 reciprocating system showed the maximum amount of apical extrusion of debris among all the groups. The least amount of debris was observed in Flexicon X7 rotary instrument (P > 0.05).Conclusion:Flexicon X7 rotary extruded significantly lesser amount of debris than Flexicon X1 reciprocating and HEDM rotary file systems.

Farklı Taperlı Koronal Genişletme Enstrümanlarının Rotasyonel ve Resiprokal Tek Eğe Sistemlerindeki Dentin Çatlağı Oluşumuna Etkisinin İncelenmesi: İn Vitro Çalışma

Objective: The purpose of this study was to evaluate the effect of using single-file with different tapered coronal flaring files on dentinal crack. Material and Methods: Human extracted mandibular premolars (n=128) were selected and divided into four groups (n=32) based on the coronal flaring instruments; Group 1, One Flare; Group 2, Endoflare; Group 3, Gates Glidden Drills; Group 4, Control Group. Specimens divided into four subgroups based on the single file system (n=8): Subgroup A, HyFlex EDM: Subgroup B, Reciproc Blue: Subgroup C, One Shape: Subgroup D, WaveOne Gold. All roots were then sectioned at 3, 6, and 9 mm from the apex. The sections were inspected under a stereo-microscope at 2.5X and 5X to determine the presence of microcracks. The data were analyzed using the chi-square test (p=0.05). Results: There was no statistically significant difference between the distributions of dentinal cracks caused by the use of single-file systems with different coronal flaring files (p>0.05). There was no statistically significant difference between the distributions of dentinal cracks according to single file systems (p>0.05). There was also no statistically significant difference between the distributions of dentinal cracks according to coronal flaring files (p>0.05). Conclusion: The use of coronal flaring instruments combinations with single file systems reduced the observation of dentin cracks. One Flare files caused less dentinal cracks than the other instruments test.

Root canal length changes during mechanical preparation due to different cervical enlargement patterns.

This study aimed to evaluate the root canal real length (RL) changes due to the mechanical instrumentation use with different flaring magnitudes. After access cavity, 60 mesial root canals of mandibular molars were randomly separated in three groups: Hyflex EDM (HF; #25/.12, #10/.05 e #25/~), Reciproc Blue (RB; R25), and MTwo (M2; #10/.04, #15/.05, #20/.06 e #25/.06). The RL was defined as the apical limit, and 2.5% sodium hypochlorite irrigating solution was chosen. After the access cavity (RL 1), cervical flaring (RL 2), and complete chemical-mechanical preparation (RL 3), the RL was evaluated. The RL was evaluated by a blind examiner with the aid of a microscope (16x) placing the endodontic file stop at the coronary reference. When comparing length measurements, the RL was shorter before instrumentation than that after instrumentation. A reduction of 0.65 mm (HF), 0.61 mm (RB), and 0.48 mm (M2) was observed. However, among groups, no statistical differences were found (p > 0.05). Under the conditions tested, it can be inferred that all mechanical systems provoked RL variations, which emphasizes the need for constant verification of the odontometry, mainly before root canal obturation.

Cleaning Efficiency of XP Finisher, XP Finisher R and Passive Ultrasonic Irrigation Following Retreatment of Teeth Obturated with TotalFill HiFlow Bioceramic Sealer.

ObjectiveThe aim of the study was to compare the cleaning efficiency of XP Finisher (FKG Dentaire, La Chaux-de-Fonds, Switzerland), XP Finisher R (FKG Dentaire), and passive ultrasonic irrigation after root canal retreatment.MethodsA total of 75 single-rooted human teeth were decoronated, instrumented using HyFlex EDM rotary files (Coltène/Whaledent Inc., Altstätten, Switzerland), and filled with gutta-percha and the TotalFill HiFlow bioceramic sealer (FKG Dentaire) using the warm vertical compaction technique. Retreatment was performed with D-Race rotary files (FKG Dentaire). Samples were randomly divided into five groups according to the activation protocol used. Samples were sectioned longitudinally and prepared for the scanning electron microscope. The percentages of cleaned canal walls in each third of the canal were determined using the ImageJ software. The one-way ANOVA test was used to make comparisons among all of the tested groups, with a pairwise comparison made with the Bonferroni correction. The significance level was set at P≤0.05.ResultsResults showed that none of the activation techniques used resulted in complete canal cleanliness. However, XP Finisher R and XP Finisher had better cleaning ability compared with passive ultrasonic irrigation in all thirds of each root canal (P<0.001).ConclusionThe cleaning efficiency of XP Finisher R and XP Finisher was superior to that of passive ultrasonic irrigation after the retreatment of the hydraulic calcium silicate sealer.

Comparison of cyclic fatigue resistance of different and novel heat-treated nickel-titanium rotary file systems at the intracanal temperature

Aim: The aim of this study was to compare the cyclic fatigue resistance of different heat-treated nickel-titanium rotary systems at intracanal temperature. &#x0D; Methodology: A total of 90 OneCurve (Micro-Mega, Besançon, France), VDW.ROTATE (VDW Dental, Munich, Germany), Typhoon (Clinician’s Choice, New Milford, CT, USA), HyFlex EDM (Coltene/Whaledent AG, Altstatten, Switzerland), and EndoArt Gold and Blue (Inci Dental, Istanbul, Turkey) (n = 15) rotary files (#25/0.06) were tested at intracanal temperature (35.5 ℃) using a dynamic model in a stainless-steel artificial canal with an inner diameter of 1.5 mm, 60° angle of curvature, and 2 mm radius of curvature. Testing was conducted until fracturing, at which time the device stopped automatically, and the number of rotations was calculated as seconds. Lengths of fractured parts were measured using a digital caliper. One-way ANOVA test followed by Tukey’s test was used to compare the groups. Scanning electron microscopic evaluation was performed to confirm the types of fracture.&#x0D; Results: EndoArt Blue group had a significantly higher mean time to fracture in all groups, followed by the HyFlex EDM, VDW.ROTATE, OneCurve, EndoArt Gold, and Typhoon. In addition, the HyFlex EDM and VDW.ROTATE groups had no significant differences between each other and were significantly better than the others. No significant differences were found between the OneCurve, EndoArt Gold, and Typhoon groups (p&gt;0.05).&#x0D; Conclusion: This is the first study in the literature for EndoArt NiTi files and the second study for VDW.ROTATE that evaluated cyclic fatigue resistance. Novel EndoArt Blue files exhibited significantly greater cyclic fatigue resistance than the other NiTi files.&#x0D; &#x0D; How to cite this article: Güneç HG, Keskin NB, Haznedaroğlu F. Comparison of cyclic fatigue resistance of different and novel heat-treated nickel-titanium rotary file systems at intracanal temperature. Int Dent Res 2021;11(3):158-64. https://doi.org/10.5577/intdentres.2021.vol11.no3.4&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Comparison of Canal Transportation in TruNatomy, ProTaper Gold, and Hyflex Electric Discharge Machining File Using Cone-beam Computed Tomography

This study was carried out to compare canal transportation in three new rotary file systems, namely TruNatomy, ProTaper Gold, and Hyflex Electric Discharge Machining file system, using cone-beam computed tomography. The study was conducted on 105 extracted teeth consisting of 60 extracted mandibular first molars and 45 mandibular second premolars involving the mesiolingual canal of mandibular first molar and the root canal of second premolar. The teeth were randomly divided into three groups of 35 out of which each group consisted of 20 mandibular first molars and 15 mandibular second premolars. The TruNatomy rotary file was used in group I, ProTaper Gold was used in group II, and Hyflex Electric Discharge Machining was used in group III. Cone-beam computed tomography scan images were obtained both before and after instrumentation. Changes caused by preparation in the coronal, middle, and apical thirds were determined on cone-beam computed tomography scans and analyzed using the Kruskal-Wallis test at p ≤ 0.05 level of significance. TruNatomy showed least amount of canal transportation as compared with other two file systems at all the three levels of canals. ProTaper Gold showed maximum amount of canal transportation as compared with other two file systems at all the three levels of canals. The Hyflex EDM rotary file system showed transportation, which was more than the TruNatomy file system while it was less than that of ProTaper Gold. The difference was statically significant at the middle one-third level (p = 0.03) and at the coronal level (p = 0.02). The TruNatomy system has least amount of canal transportation as compared with ProTaper Gold and Hyflex EDM system. With potential to preserve tooth structure, this file has an added advantage over other rotary file systems. The TruNatomy file system has been recently introduced with good cyclic fatigue resistance. It is necessary to evaluate the root canal transportation caused by the TruNatomy file.

Evaluation of the Apically Extruded Debris During Canal Preparation by WaveOne Gold, Hyflex EDM and XP-endo Shaper, Anin Vitro Study

Objective: The main cause of this in vitro study was to measure and compare the amount of debris extruded apically using three NiTi single rotary files (primary WaveOne Gold file, Hyflex EDM file, and the XP-endo Shaper). &#x0D; Methods: Palatal root of sixty freshly extracted human maxillary molar teeth were sectioned at 12 mm, and inserted through the center of a rubber stopper of a pre-weighed collecting vial except for the coronal quarter of the root. Then separated three groups in accordance with their (n =20) system. G I: primary WaveOne Gold single file system (Dentsply-Maillefer, Ballaigues, Switzerland)., G II: Hyflex EDM single file system (Colten/Whaledent, Germany). and G III: Xp-endo Shaper single file system (FKG, Switzerland) used, the 1mm irrigation with distilled water applied for washing the instruments, apical debris was collected and dried at 100° C. Sequential weights were obtained for each vial, and the distinction between the weights of the vial (pre- instrumentation and post- instrumentation), considered debris weight. Data were analyzed statistically using the One-way ANOVA test and LSD test, p≤ 0.05 was considered for data analysis value. &#x0D; Results: All rotary systems applied in this study showed apical extrusion of debris. GIII showed the significantly highest amount of debris (p&lt; 0.001) compared to GI and GII, whereas, mean value differences of Hyflex and WaveOne Gold were statistically non- significant (p&gt;0.05). &#x0D; Conclusions: The Hyflex EDM showed the lowest mean value of debris extruded apically compared to WaveOne Gold and Xp-endo Shaper. XP-endo Shaper had the highest mean value of debris extruded apically.

Retreatment of Experimental Carrier-Based Obturators with the Remover NiTi Instrument: Evaluation of Apical Extrusion and Effects of New Kinematics.

The objective of this study is to evaluate the retreatment time and weight of apically extruded debris yielded by two different kinematics during the removal of different root canal filling materials. Forty straight single-rooted extracted teeth were instrumented with HyFlex CM files and obturated with two different techniques: 25.04 HyFlex experimental carrier-based obturators (Coltène/Whaledent, Altstätten, Switzerland) (group 1) or 25.04 single gutta-percha cones (Roeko Coltène/Whaledent, Altstätten, Switzerland) (group 2) and Guttaflow Bioseal as the sealer. Samples were divided into four subgroups (n = 10) according to the used kinematics for the removal of root canal filling materials: continuous rotation (A) or retreatment motion (B) with a Remover and HyFlex EDM Nickel-Titanium instruments activated with a CanalPro Jeni micromotor (Coltène/Whaledent, Altstätten, Switzerland). Time for retreatment was digitally recorded, and debris extruded from the apex was collected in Eppendorf tubes and weighted with an analytical balance. Data on retreatment time and apical extrusion were statistically analyzed with the Kruskal–Wallis test (p < 0.05). Working length was achieved in all the retreated samples. The removal of root filling material resulted significantly faster with the Jeni mode (p < 0.001), and the difference was significant for the removal of both filling materials (p < 0.05). No significant differences on debris extrusion between single cone and experimental obturators groups were noted (p > 0.05), and no significant differences between kinematics (continuous rotation vs. Jeni motion) were observed (p > 0.05). All the tested retreatment strategies lead to an extrusion of material from the apex, and the weight of apically extruded debris was similar. The use of the innovative CanalPro Jeni kinematics accelerates the time for the removal of root filling materials.