Nickel-titanium Rotary Systems Research Articles

Cryotherapy Treatment Effect on Heat-Treated Nickel-Titanium (NiTi) Rotary Single-File System: An In Vitro Comparative Study by Finite Element Analysis

Cryotherapy Treatment Effect on Heat-Treated Nickel-Titanium (NiTi) Rotary Single-File System: An In Vitro Comparative Study by Finite Element Analysis

Deviation of Root Canal Curvature Using Three Types of Rotary Instruments: An In Vitro Study

One of the essential requirements for a successful endodontic treatment is efficient cleaning and shaping. Since its introduction, the nickel-titanium rotary system has gained popularity due to its elasticity and suppleness in the creation of curved root canals. To assess the deviation in root canal curvature in severely curved root canals following three different rotary file system preparations. Thirty-six human permanent mandibular first molars were chosen and stored in regular saline after being newly extracted with the curve mesial root. To standardize length at 13 mm, the mesial roots were separated from the tooth and the crown was removed. The three groups of teeth were A, B, and C. Groups A, B, and C were equipped with rotary variable taper instruments, reciprocating variable taper instruments, and rotary constant taper control memory instruments, respectively, in their mesio buccal canals. The instruments were never pressed apically; instead, they were employed in the canal with a constant, gentle passive movement. With frequent and copious irrigation using 5.25% sodium hypochlorite solution and 17% ethylene diamine tetra acetic acid, all canals were shaped and cleansed. To assess the curvature deviation, periapical radiographs were taken both before and after preparation. By using the Schneider method to measure the pre- and post-instrument canal curvatures, the deviation was found. The Wilcoxon test was employed for numerous pairwise comparisons across distinct groups, and the Kruskal-Wallis test was used to conduct statistical analysis among three groups. The p-value of less than 0.05 was deemed statistically significant. Compared to groups A and B, group C had the least variation of canal curvature. The current study concludes that a 4% rotating constant taper control memory instrument works better than a rotary variable taper instrument or a reciprocating variable taper instrument for shaping a curved canal.

Comparative evaluation of cyclic fatigue resistance of thermomechanically treated NiTi rotary instruments in simulated curved canals with two different radii of curvature: An in vitro Study.

This study aimed to compare the effect of heat treatment on the cyclic fatigue resistance of three different nickel-titanium rotary file systems: TruNatomy, HyFlex CM, and NeoEndo flex in simulated curved canals at two different radii of curvatures. A total of 60 NiTi rotary files of three types were used, and the samples were divided into three groups TruNatomy, HyFlex CM, and NeoEndo flex. All the instruments were subjected to cyclic fatigue testing using a stainless steel custom-made canal model with a 60° angle of curvature and two radii of curvature 5 mm and 3 mm; the number of cycles to fracture and length of the fractured segment was measured. The separated instruments were subjected to fractographic analysis under scanning electron microscope. The number of cycles to failure to fracture a file at a 3 mm radius of curvature is significantly less as compared to a 5 mm radius of curvature (HCM > TRN > NE). Within the limitation of the present study, there was a positive correlation between the radius of curvature and fatigue life of NiTi files.

Micro-computed tomographic evaluation of the shaping ability of three nickel-titanium rotary systems in the middle mesial canal of mandibular first molars: an ex vivo study based on 3D printed tooth replicas

BackgroundThe preparation of the middle mesial (MM) canal of mandibular molars represents a challenge because it is often curved, narrow, and close to the root concave. The purpose of this study was to evaluate the ex vivo shaping ability of 3 nickel-titanium (NiTi) rotary systems in the MM canal using 3D printed resin tooth replicas.MethodsA permanent mandibular first molar with a MM canal was acquired from a pool of extracted teeth and reproduced by a 3D printer. The resin tooth replicas (n = 18) were equally assigned to 3 groups for the evaluation of the shaping abilities of 3 NiTi rotary systems (OneShape [OS], Twisted Files [TF], and ProTaper Gold [PTG]) according to the manufacturer’s recommendations. The tooth replicas were scanned by micro-computed tomography (micro-CT) twice before and after instrumentation of the mesiobuccal (MB), mesiolingual (ML), and MM root canals. After 3D reconstruction, the canal straightening, change of root canal volume and surface area, the mesial and distal canal wall thickness and canal transportation at the levels of 1, 2, and 3 mm below furcation were assessed. One-way variance analysis and Turkey’s post hoc test were used for comparisons of the means among different groups, and paired-t test was used to compare the mesial and distal sides of the mesial roots.ResultsAs compared with OS and TF, the use of PTG in preparation of MM canals resulted in significantly more straightening of canal curvature (p < 0.05), greater post-instrumentation canal volume and surface area, and thinner mesial and distal remaining canal wall thickness at 1, 2 and 3 mm below furcation (all p < 0.05). Regarding the root canal transportation in the mesiodistal direction, there was no significant difference among the 3 instruments (all p > 0.05) after the preparation of the MB and ML canals. However, in the MM canal, more pronounced transportation was detected in the PTG group at 2 mm below furcation, and in the TF group at 3 mm below furcation as compared with the other 2 systems (both p < 0.05).Conclusions3D printed tooth replicas have the advantages of consistency and can be an ideal model to evaluate the shaping ability of different instruments in the MM canal. OS and TF files performed similarly and both are appropriate for shaping the MM canal, while PTG may cause excessive and uneven resin removal, especially near the furcation, and may lead to root fragility and procedural errors.

Shaping Ability of Three Different Rotary Nickel Titanium Systems An In Vitro Study

Shaping Ability of Three Different Rotary Nickel Titanium Systems An In Vitro Study

The Influence of Nickel-Titanium (Ni-Ti) Rotary Instrument Systems on Debris and Smear Layer Formation in Endodontic Procedures: An In Vitro Scanning Electron Microscopy Study.

Background Successful endodontic treatment relies on the effective removal of debris and the prevention of smear layer formation within the root canals. The choice of nickel-titanium (Ni-Ti) rotary instrument systems can significantly impact these outcomes. Aim This study aims to evaluate and compare the debris and smear layer formation in root canals of extracted mandibular second premolar teeth following instrumentation with the ProTaper Universal (Dentsply Sirona,Charlotte, NC) (Group II), Twisted File (Kerr Endodontics, Gilbert, AZ) (Group III), and XP Endo (FKG Dentaire,La Chaux-de-Fonds, Switzerland) (Group IV) Ni-Ti rotary instrument systems. Methods In this in vitro study, 60 extracted mandibular second premolar teeth were randomly divided into four groups, each containing 15 teeth. Group I served as the control with no instrumentation. Groups II, III, and IV were instrumented with the ProTaper Universal rotary file, the Twisted File, and the XP Endo file systems, respectively. Debris and smear layer formation were evaluated through scanning electron microscopy (SEM), and photomicrographs were scored using a standardized index. Results Group II (ProTaper) exhibited the highest mean debris and smear layer scores, with values of 3.50 and 2.70, respectively. Group IV (XP Endo) demonstrated the least debris and smear layer formation, with mean scores of 2.65 and 2.08, respectively. Statistical analysis confirmed significant differences among the groups for both debris and smear layer formation. Conclusion The results highlight the practical importance of selecting appropriate Ni-Ti rotary instrument systems to minimize debris and smear layer formation during endodontic procedures. The XP Endo file system showed promise as a favorable choice in this regard, but further clinical research is needed to validate these findings.

Comparative Evaluation of the Incidence of Dentin Microcracks Following Biomechanical Preparation Using Four Different Nickel-Titanium Rotary File Systems: An In Vitro Study.

Biomechanical preparation has gotten easier over time with the development of nickel-titanium (NiTi) rotary instruments. Despite their benefits, research has shown that these files frequently result in microcracks in the root canal dentin, which can fracture the roots. Such mishaps should be prevented, as they compromise the integrity of the root and reduce the long-term survival of endodontically treated teeth. This study was conducted at Government Dental College and Hospital, Patiala, Punjab, India. Eighty permanent mandibular premolar teeth were included. All the roots were inspected for any pre-existing cracks or craze lines under a stereomicroscope. The teeth were decoronated and then divided into four groups (n = 20): Group I: TruNatomy, Group II: Neoendo Flex, Group III: ProTaper Gold, and Group IV: 2Shape. The samples were instrumented according to the group to which they belonged. The roots were then sectioned horizontally at 3 mm and 6 mm from the apex and examined under a stereomicroscope at 40xfor the presence of microcracks. The data were analyzed using the IBM SPSS Statistics for Windows, version 26 (released 2019; IBM Corp., Armonk, New York, United States). A chi-square test was applied, and the level of significance was set at p < 0.05. The highest incidence of microcracks was associated with ProTaper Gold (65%), followed by Neoendo Flex (45%), TruNatomy (20%), and 2Shape (20%). All rotary instruments resulted in dentinal damage. ProTaper Gold exhibited the highest frequency of dentin cracks. TruNatomy and 2Shape exhibited satisfactory results with minimal crack formation.

Effect of Sterilization and Irrigating Solutions on Nanostructure Alteration of Ni-Ti Rotary Instruments in Endodontics: An Atomic Force Microscopic Study.

This study aimed to evaluate the effect of 5.25% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA) and sterilization on the nanostructural alteration of nickel titanium (Ni-Ti) rotary file systems in endodontics using the atomic force microscopy (AFM). The study was performed on four commercially available rotary Ni-Ti files: group I-Vortex Blue (Dentsply), group II-ProTaper Next (Dentsply), group III-Mtwo (VDW), and group IV-iRaCe (FKG). Each group was divided into four subgroups (n = 4), that is, subgroup A-control (new rotary file), subgroup B-subjected for five cycles of autoclave, subgroup C-immersed in 5.25% NaOCl for 5 minutes, and subgroup D-immersed in 17% EDTA solutions for 5 minutes. All the specimens were evaluated with AFM using roughness average (RA) and root-mean-square (RMS) values for surface roughness. Among control groups, Vortex Blue showed the least RA and RMS values; the highest surface roughness was seen with Mtwo files. All the Ni-Ti rotary files showed a statistically significant (P <0.05) increase in surface hardness when subjected to autoclave and treatment with different irrigating solutions. In particular, 17% EDTA caused the highest surface deterioration in all the groups. AFM analysis revealed increased surface roughness values recorded for all the rotary files when treated with irrigating solutions and autoclave cycles.

Modern nickel-titanium rotary systems in endodontic treatment

Background: One of the most important steps in endodontic treatment is the preparation of a uniform space, the use of endodontic irrigant and creating space for the endodontic filling. Therefore, improving endodontic treatment techniques is one of the most important tasks of modern dentistry. The success and effectiveness of endodontic treatment is largely determined by the quality of chemo-mechanical root canal treatment. In recent years there has been a major emphasis on the use of rotary mechanical instrumentation systems, namely the use of nickel-titanium (NiTi) alloys, which due to their properties represent a favorable flexibility in the instrumentation of difficult anatomies. Material and methods: 20 patients were examined and treated. They were divided into 2 groups: for the treatment of 6 patients was applied the Protaper Universal rotary system. In the second group of 14 patients to whom mechanical instrumentation was applied, were 7 patients following the Protaper Next and the other 7 Dc Taper with different pulpal and periodontal diseases. Results: Mechanical instrumentation was performed on different nosological entities, the prevalence being acute pulpitis. Among instrumented teeth, the prevalence was on the side of pluriradicular teeth. Conclusions: The practical application of different NiTi rotary systems has to be determined individually, as each clinical case has its own practical properties. But the success of an endodontic treatment depends not only on the rotary instruments used and, on the method, chosen, but also on the practitioner’s experience, detailed knowledge of the properties and step-by-step instrumentation protocols.

The Incidence Of Dentinal Micro-Cracks Associated With Root Canal Preparation With Different Nickel Titanium Rotary Systems: An In-Vitro Study

The Incidence Of Dentinal Micro-Cracks Associated With Root Canal Preparation With Different Nickel Titanium Rotary Systems: An In-Vitro Study

Efficacy of three Nickel Titanium rotary file systems in removal of intracanal filling material (In vitro study)

Efficacy of three Nickel Titanium rotary file systems in removal of intracanal filling material (In vitro study)

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

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

Comparative evaluation of canal transportation and canal centering ability in oval canals with newer nickel-titanium rotary single file systems - A cone-beam computed tomography study.

The purpose of this study was to evaluate and compare the centering ability and canal transportation of TruNatomy, OneCurve, and Jizai file systems to assess their performance in oval-shaped canals using cone-beam computed tomography imaging. Forty-two fully formed single-rooted mandibular premolars were selected with a buccolingual canal size 2-2.5 times the mesiodistal size at 5 mm from the apex, with 0°-10° canal curvature with a 5-6 mm radius, at 5 mm from the apex. The teeth were divided into three groups (n = 14) and prepared with TruNatomy, OneCurve, and Jizai files based on the manufacturer's instructions. Cone-beam computed tomographic images were taken before and after instrumentation. The canal transportation and centering ability was calculated at 3, 6, and 9 mm from the apex in both mesiodistal and buccolingual directions. Intergroup comparison was done using Kolmogorov-Smirnov test. Intragroup comparison was done using Freidman test. A comparison of categorical variables was done using the Chi-square test. The results obtained did not present any statistically significant difference between the three groups, with TruNatomy and OneCurve showing relatively lesser canal transportation and better centering ratio when compared to the Jizai file system. It can, therefore, be concluded that all three systems used in the study are capable of safely preparing root canals with minimal errors.

Comparison of Different Rotary Nickel–titanium Systems to Evaluate Coronal Leakage of Root Canals: An in Vitro Study

Comparison of Different Rotary Nickel–titanium Systems to Evaluate Coronal Leakage of Root Canals: An in Vitro Study

Mechanical Properties and Root Canal Shaping Ability of a Nickel-Titanium Rotary System for Minimally Invasive Endodontic Treatment: A Comparative In Vitro Study.

Selection of an appropriate nickel-titanium (NiTi) rotary system is important for minimally invasive endodontic treatment, which aims to preserve as much root canal dentin as possible. This study aimed to evaluate selected mechanical properties and the root canal shaping ability of TruNatomy (TRN), a NiTi rotary system designed for minimally invasive endodontic shaping, in comparison with existing instruments: HyFlex EDM (HEDM), ProTaper Next (PTN), and WaveOne Gold (WOG). Load values measured with a cantilever bending test were ranked as TRN &lt; HEDM &lt; WOG &lt; PTN (p &lt; 0.05). A dynamic cyclic fatigue test revealed that the number of cycles to fracture was ranked as HEDM &gt; WOG &gt; TRN &gt; PTN (p &lt; 0.05). Torque and vertical force generated during instrumentation of J-shaped artificial resin canals were measured using an automated instrumentation device connected to a torque and vertical force measuring system; TRN exhibited smaller torque and vertical force values in most comparisons with the other instruments. The canal centering ratio for TRN was smaller than or comparable to that for the other instruments except for WOG at the apex level. Under the present experimental conditions, TRN showed higher flexibility and lower torque and vertical force values than the other instruments.

Comparative Assessment of The Fracture Resistance of Teeth Instrumented by Two Different Nickel Titanium Rotary Systems

Aim: This study aimed to compare the fracture resistance exhibited by roots on instrumentation using two endodontic rotary systems: SANI S3 and EdgeEndo X7 rotary file systems. Materials and Methods: Sixty recently extracted human mandibular premolars comprising single root canals were selected in this study. All specimens were decoronated and mounted perpendicularly in self-cure acrylic resin blocks exposing 6 mm of the roots out of the acrylic resin blocks. The specimens were divided into two experimental groups, according to NiTi rotary systems used and one control group (n = 20). After instrumentation, the specimens of both experimental groups were then filled using master Gutta-percha cones size 35 (0.04 taper) and obturation was done using continuous wave compaction technique. The specimens were kept at 37 °C and 100% humidity for 2 weeks to allow complete setting of the sealer. Root fracture resistance was assessed using a universal testing machine (Instron) and the amount of load necessary for root fracture was recorded in Newtons (N). Statistics: Data were collected, tabulated and statistically analyzed using one-way ANOVA test and Tukey’s posthoc test. Results: Group C (control) exhibited the highest mean fracture force (357.13 ± 20.61) while group A (SANI S3) showed the lowest mean fracture force (192.60 ± 22.73). One-way ANOVA test showed statistically significant differences between tested groups. Regarding inter-group comparisons using Tukey’s test, there was a significant statistical difference between groups (A and B) and between groups (A and C). Furthermore, there was a statistically significant difference between groups (B and C). (P?0.05) Conclusion: 1-Root canal instrumentation with NiTi rotary files possessed a negative impact on roots and higher risks of root fractures compared to intact unprepared roots. 2-Design of NiTi files with improved cutting efficiency could diminish the risk of crack formation in root canal dentinal walls.

Comparative Evaluation of Shaping Ability and Cleaning Efficiency of Three Different Nickel-Titanium Rotary Systems

Comparative Evaluation of Shaping Ability and Cleaning Efficiency of Three Different Nickel-Titanium Rotary Systems

Optimization of endodontic root canal treatment in pediatric dentistry (a systematic literature review)

Early loss of primary teeth is an important problem in pediatric dentistry. One of the most difficult aspects during treatment of the complications of caries in primary teeth is the duration of treatment. The introduction of rotary nickel-titanium systems made endodontic treatment in primary teeth easier and faster. Thereby, the aim of the present work was to conduct a systematic review with elements of the network meta-analysis and an indirect comparison of different rotary endodontic systems in terms of the time spent for endodontic treatment in primary tooth canals using the common comparator «manual treatment with K-files». Seven articles were included in the final analysis, which revealed statistically significant heterogeneity of the included data from laboratory randomized controlled trials (ProTaper/K-file: I2 = 85; p = 0.00001 and Mtwo/K-file: I2 = 95; p = 0.00001). A systematic review of the articles revealed a trend toward designating the Mtwo (VDW) system as the least time-consuming mechanical root canal preparation in primary teeth.

Effect of Different Nickel–Titanium Rotary Systems on Dentinal Crack Formation During Root Canal Preparation in Primary Molars: An in Vitro Study

Effect of Different Nickel–Titanium Rotary Systems on Dentinal Crack Formation During Root Canal Preparation in Primary Molars: An in Vitro Study

Comparative assessment of canal transportation and centering ratio of three heat treated rotary systems in severely curved simulated resin block

Objectives: The purpose of this study was to measure and compare the canal transportation and centering ratio at different levels of simulated curved canals of the endodontic resin blocks, which were prepared by using of three diverse thermally treated Nickel Titanium rotary systems: Edge File X7, One Curve and 2Shape. Forty five simulated curved canals of 40° degree curvature were randomly distributed into three groups of fifteen canals; each canal was prepared to an apical size of 25. Transportation measurements were taken at three different levels, correspondingly (Pre and post)operative images of the simulated canals were taken in a standardized technique using USB stereomicroscope to gain the images, under magnification of 30X. Image arrangement was done using Photoshop CS 2019. Moreover, an evaluation of canal shape was determined using Digimizer Image Analysis Software under magnification of 300X e. After earning the data of canal transportation centering ratio, then statistical analyses by means of Shapiro-Wilk, ANOVA with post hoc Tukey’s test were performed. Results showed that One Curve group revealed significantly lower amount of canal transportation and better centering ability, followed by Edge File X7 and finally 2Shape.