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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]

Objectives: The study's objective was to contrast the two distinct rotary file techniques used to shape mandibular first molars. Materials and Methods: The investigation involved twenty recently removed mandibular molars. A digital single-lens reflex (DSLR) camera was placed in a fixed position, a muffle block was built, and images of each tooth's three cross sections were obtained. The specimens were split into the following two groups at random: Rotary files from WaveOne were used to prepare group A and Mtwo rotary files were used to prepare group B. Results: At the coronal, middle, and apical thirds of the root canals, WaveOne file system demonstrated improved centering ability compared with the Mtwo file system (P 0.05). Conclusion: When compared to the Mtwo file system, WaveOne file system demonstrated improved centering capabilities and needed significantly less time to build the curved canals.

Objective This study aimed to evaluate the efficacy of three methods in root canal retreatment to remove the filling material in the root canals. Methods Ninety tooth roots filled by gutta percha or plasticized material (n=45, each) were randomly divided into three groups (n=15). WaveOne (WaveOne group), 1#P drill+WaveOne (1#P+WaveOne group), and ultrasound P5 working end ET25+ProTaper Universal (P5+ProTaper Universal group) were used to remove the root canal filling material and prepare for root canal. The operating time of each canal was recorded and the percentage of residual filling material area was measured on the root canal wall of the mesial and distal dissected root section. The degree of deviation of the root canal after operation was measured for the root samples filled by gutta percha. Results The type of root filling material and the method of root canal retreatment had no significant effect on the percentage of residual area of the filling material (P>0.05). However, the remaining filling material area of apical 1/3 of the root canal was significantly higher than that of cervical 1/3 of the root canal (P<0.05). The average operating times for removing gutta-percha or plasticized material in the W and 1#P+WaveOne groups were significantly less than that in the P5+ ProTaper Universal group (P=0.000). The root canal retreatment methods had no significant effect on the curvature of the root canal (P=0.650). Conclusion WaveOne single file's cleaning ability and center positioning ability were similar to those of ProTaper Universal. Moreover, WaveOne can be independently used for most root canals without a pathway when removing the root canal fillings, thereby simplifying the process of root canal retreatment. [ABSTRACT FROM AUTHOR]

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]

Aim: The study aims to compare and evaluate the fracture resistance of endodontically treated bicuspids instrumented with Hand Files, TruNatomy (TRN), ProTaper Next (PTN), ProTaper Gold (PTG), and WaveOne (WO). Materials and Methods: In total, 45 extracted single-rooted human premolar teeth were selected and sectioned at or below the cementoenamel junction to obtain roots 15 mm long. The samples were divided into four experimental groups and one control group (n = 9): instrumentation with nickel-titanium (NiTi) Hand Files (control group), instrumentation with TRN files, instrumentation with PTN files, instrumentation with PTG files, and instrumentation with WO files. The samples were obturated by lateral compaction technique using gutta-percha points and AH Plus sealer. A vertical load was applied to the tooth using the universal testing machine (Tecsol-TSI-BDS-2Kn-Sr No. 170710) for the fracture resistance test. Statistical analysis was performed. Results: The study reported that teeth instrumented with NiTi hand files exhibited the highest fracture resistance when compared to all the rotary and reciprocating file systems. Among rotary and reciprocating instruments, root prepared with TRN files showed the most significant resistance to fracture compared with PTN, PTG, and WO files. Conclusion: Within the limitations of this study, it can be concluded that minimally invasive instrumentation of the system preserves more pericervical dentin, which may increase the resistance to fracture. Results of this study and other studies support the use of minimally tapered instruments to improve the fracture resistance of endodontically treated teeth. [ABSTRACT FROM AUTHOR]

Objective: To compare the effect of glide path established by size 20/0.02 taper hand K-file and size 20/0.04 taper rotary file, on the amount of debris extruded apically during root canal instrumentation by rotary ProTaper Universal (S1-F2) and reciprocating WaveOne (Primary) file systems. Materials and methods: Eighty mandibular molars with curved mesial roots and two separate canals were selected and randomly divided into two groups (n = 40) for glide path preparation using either size 20/0.02 taper hand K-files and size 20/0.04 taper rotary files. These groups were further divided into two (n = 20) for root canal instrumentation by ProTaper Universal and WaveOne files; Group 1: 20/0.02 + ProTaper, Group 2: 20/0.02 + WaveOne, Group 3: 20/0.04 + ProTaper, and Group 4: 20/0.04 + WaveOne. The debris extruded during instrumentation was collected in pre-weighed Eppendorf tubes and stored in an incubator at 70°C for 5 days. Tubes containing the dry, extruded debris were then weighed. One-way analysis of variance was applied to the weights obtained followed by Tukey's post hoc test for multiple comparison. Results: All the groups resulted in debris extrusion. Establishing a glide path with size 20/0.04 taper rotary files, resulted in less debris extrusion, compared to a glide path prepared by size 20/0.02 taper hand K-files (P < 0.001). Conclusion: Creating a glide path with size 20/0.04 rotary file, reduced the debris extrusion in curved root canals during instrumentation by ProTaper Universal and WaveOne. [ABSTRACT FROM AUTHOR]

Objectives: The study's objective was to contrast the two distinct rotary file techniques used to shape mandibular first molars. Materials and Methods: The investigation involved twenty recently removed mandibular molars. A digital single-lens reflex (DSLR) camera was placed in a fixed position, a muffle block was built, and images of each tooth's three cross sections were obtained. The specimens were split into the following two groups at random: Rotary files from WaveOne were used to prepare group A and Mtwo rotary files were used to prepare group B. Results: At the coronal, middle, and apical thirds of the root canals, WaveOne file system demonstrated improved centering ability compared with the Mtwo file system (P 0.05). Conclusion: When compared to the Mtwo file system, WaveOne file system demonstrated improved centering capabilities and needed significantly less time to build the curved canals. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to compare the ability of two reciprocation motion file systems with a continuous rotary system for preparing simulated canals by undergraduate dental students. Methods: Following clinical demonstration and instructions, 84 undergraduate dental students prepared three endodontic training blocks; first using the continuous rotary motion file system (ProTaper Universal) then two reciprocation motion file systems (WaveOne and Reciproc), following manufacturers' instructions, in a crossover study design. Data on preparation time, user preference and procedural errors including ledges, apical zips, file separation, canal transportation and overpreparation were collected. All preparations were assessed using high magnification digital images by three observers. Data analysis was performed using logistic mixed modelling and odds ratios were calculated comparing the methods. Results: Both reciprocation systems exhibited fewer procedural errors than ProTaper Universal. The odds of an error occurring were significantly higher when using Reciproc compared with WaveOne. The odds ratio was 2.8, with a 95% confidence interval of 1.2 - 6.7 (P = 0.020). ProTaper Universal resulted in the highest incidence of ledges (22.6%), separations (10.7%) and transportations (14.3%). The Reciproc system resulted in the highest incidence of both apical zips (6.0%) and over-preparation (8.3%). No file separation occurred while using both reciprocating systems. Conclusions: Both reciprocation systems produced fewer procedural errors than the continuous rotary system. The results with WaveOne were favourable, with a low incidence of procedural errors, a higher student preference and the shortest preparation time. [ABSTRACT FROM AUTHOR]

Aim: To compare the adaptation of thermo-plasticised root canal fillings performed in oval canals instrumented with three file systems, and its potential association with debris remaining in recesses. Material and Methods: Thirty-nine mandibular incisors with oval canals were instrumented with WaveOne, ProTaper Universal files or with the self-adjusting file (SAF) system (n = 13). Root canal fillings were performed with Thermafil, with no sealer. The roots were then cut at 2.0, 3.5, 5.0, 6.5 and 8.0 mm from the apex. Morphometric measurements established the percentage of canal area containing no root canal filling material (ANFM). The presence of debris, as a potential cause for defective adaptation, was evaluated microscopically. ANOVA with repeated measures and the Chisquare test were used; significance was set at P < 0.05. Results: The apical, round part of the canal showed effective filling with no difference between the file systems. In the oval part of the canal, ≥ 3.5 mm from the apex, the WaveOne and ProTaper Universal groups presented means of 15.2 (± 12.4)% and 12.1 (± 7.5)% of ANFM, respectively, and did not differ from each other. The SAF group had a mean of 6.4 (± 7.9)% of ANFM, which differed significantly from the other two groups (P = 0.001). Deficiencies in filling were associated with the presence of debris in un-instrumented recesses. Conclusions: The adaptation of thermo-plasticised gutta-percha in oval canals was affected by debris remaining or packed into un-instrumented canal recesses. Using the SAF system was associated with less debris and with better adaptation, as compared with the rotary or reciprocating files. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to compare the shaping ability of four different single-file systems in severely curved mesiobuccal root canals in extracted human mandibular first molars. Materials and Methods: Sixty extracted intact human mandibular first molars with at least one curved mesial root were collected and used for the study. The study samples (n = 60) were divided into four experimental groups (n = 15 each): WaveOne (WO) (Group I), WaveOne Gold (WOG) (Group II), OneShape (Group III), and F360 (Group IV). The working length was established. All the study samples were prepared with respective file systems according to manufacturer's instructions. Pre- and postinstrumentation radiographs were taken and images were transferred to AutoCAD 2016 to determine the radius of curvature of each root canal. The canal curvature was assessed as a difference between before and after instrumentation to determine canal straightening. The data obtained were subjected to statistical analysis using SPSS version 20.0. Results: The pre- and postinstrumentation readings were compared using one-sample t-test, and difference was found to be statistically significant (P < 0.05). The mean difference in root curvature was estimated by pre- and postinstrumentation readings. According to mean change in the root curvature, the order determined was Group IV < III < II < I. Intergroup comparison was conducted using ANOVA statistical analysis, and it was found to be statistically significant. Conclusion: WOG and WO reciprocating files showed a marked tendency to straighten the severely curved canals, whereas F360 and OneShape continuous files maintained the original canal curvatures well.

Aim: The aim of this study was to compare the NeoEndo and WaveOne retreatment systems concerning the effective removal of epoxy resin-based sealer and gutta-percha during the retreatment of straight root canals. Materials and Method: Sixty extracted, human mandibular first premolars with single straight roots were selected based on cone-beam computed tomography (CBCT) evaluations. The root canals were instrumented with the ProTaper system up to the F3 file and filled with gutta-percha and epoxy resin-based sealer using the cold lateral condensation technique. After 1 month, the samples were randomly divided into two groups (n = 30) according to the retreatment system used: NeoEndo and WaveOne. A CBCT device scanned specimen after the root filling and retreatment procedures, and the decrease in the volume of filling material after each retreatment protocol was measured. The results were analyzed using the paired t-test and additional box-and-whisker plots. Results: The WaveOne removed significantly more material than the NeoEndo (P = 0.005) system. Conclusion: The WaveOne system was more effective than the NeoEndo retreatment system during the removal of filling material.

Background: Teeth with apical periodontitis that either persisted or developed after initial root canal treatment is most often indicated for retreatment procedure. The present study was conducted to compare the WaveOne and NeoEndo retreatment file system for the removal of gutta-percha from the root canal. Materials and Methods: Fifty extracted mandibular first premolars with single straight roots were divided into two groups, Group I-WaveOne and Group II-NeoEndo. All samples were scanned with cone-beam computed tomography after the root filling and retreatment procedures. The decrease in the volume of filling material after each retreatment protocol was measured. Results: The mean volume of gutta-percha in Group I before retreatment was 5.6 and in Group II was 5.3, after retreatment in Group I was 2.7, and in Group II was 4.2. The mean percentage reduction in Group I was 45.2% and in Group II was 23.8%. The difference was significant (P < 0.05). Conclusion: Both systems failed to completely remove gutta-percha. WaveOne was significantly more effective than the NeoEndo retreatment system.

Background: Teeth with apical periodontitis that either persisted or developed after initial root canal treatment is most often indicated for retreatment procedure. The present study was conducted to compare the WaveOne and NeoEndo retreatment file system for the removal of gutta-percha from the root canal. Materials and Methods: Fifty extracted mandibular first premolars with single straight roots were divided into two groups, Group I-WaveOne and Group II-NeoEndo. All samples were scanned with cone-beam computed tomography after the root filling and retreatment procedures. The decrease in the volume of filling material after each retreatment protocol was measured. Results: The mean volume of gutta-percha in Group I before retreatment was 5.6 and in Group II was 5.3, after retreatment in Group I was 2.7, and in Group II was 4.2. The mean percentage reduction in Group I was 45.2% and in Group II was 23.8%. The difference was significant (P < 0.05). Conclusion: Both systems failed to completely remove gutta-percha. WaveOne was significantly more effective than the NeoEndo retreatment system. [ABSTRACT FROM AUTHOR]

Background: Under axial loading, there is stress concentration around the cervical areas especially in the premolars because of their location in the arch. Aim: To evaluate and compare flexural fracture resistance of mandibular premolars after instrumentation with ProTaper®Universal, ProTaper Next®, OneShape®, and WaveOne® endodontic file systems. Methods: Seventy-five mandibular premolar teeth with single straight canals were divided into five different groups (n = 15): Group A: Control, Group B: ProTaper Universal (PTU), Group C: ProTaper Next (PTN), Group D: OneShape, Group E: WaveOne. The teeth were instrumented as per the manufacturer's instructions. After obturation and core placement, the teeth were placed in a customized jig mounted on a universal testing machine where force was applied at 45° on the buccal cusp and the force required to fracture the teeth was noted. Results: Amongst all the instrumented groups, WaveOne showed the highest resistance to fracture (1065.56 ± 175.05) and the control group was 1104.13 ± 188.42. All groups showed a significant difference in the fracture load values with the control group. However, there was a statistically significant (P < 0.05) difference seen with WaveOne vs PTU and WaveOne vs OneShape. Conclusions: Root canals instrumented with reciprocating motion have better flexural fracture resistance than continuous rotary motion. Mandibular premolars when instrumented with ProTaper Universal and OneShape endodontic files showed similar fracture resistance, proving that dentin removal does not depend on the number of files used.

Abstract Finite element analysis was used to evaluate the stress distribution, estimate the residual stresses, bending, and amount of displacement of two nickel-titanium instruments manufactured by the same M-wire technology but with different cross-section. Materials and methods Two brands of Ni-Ti instruments ProTaper NEXT (Dentsply Maillefer), and WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) were scanned with stereomicroscope to produce a two-dimensional model for each file using computer-aided design programs (CAD) (SolidWorks software package), which then was converted into stereolithographic extension to be readable by programming software (MATLAB software) to produce three-dimensional models. The mathematical analysis of files was performed on SolidWorks software package. The mechanical behavior of the two files was analyzed numerically in a SolidWorks package to simulate and measure torsion, bending, and file displacement. Application of a shear moment (torsion) 2.5 N/mm moment of force was applied to the shaft in a clockwise direction, while the last 4 mm of the tip was rigidly constrained to evaluate the stress distribution on each file. As for Cantilever bending, a concentrated load of 1 N at the tip of the file with its shaft rigidly held in place was applied for the finite element models. The vertical displacement was measured and the von Mises stress distribution was evaluated. Results The WaveOne file showed higher torsional stresses accumulation than those accumulated in the ProTaper NEXT. While the ProTaper NEXT showed more bending and file displacement than those showed by WaveOne file. Conclusions The two files rotary models highlighted the different mechanical properties of the files although they share the same manufactured technology M-wire. The ProTaper NEXT showed less torsional stress accumulation and more bending properties.

Objective: To evaluate the incidence and severity of postoperative pain and analgesics intake after root canal treatment of molars using single file systems: WaveOne (WO; Dentsply Maillefer, Ballaigues, Switzerland) and One Shape (OS; Micro Méga, Besançon, France) versus the Self Adjusting File (SAF; ReDentNova, Ra‘anana, Israel). Methods: One hundred and forty-one patients with vital molars indicating for conventional singlevisit root canal treatment were randomly assigned to one of three groups (n = 47) according to the instrumentation system used: WaveOne, One Shape and SAF. Participants were asked to rate the intensity of postoperative pain on a Functional Pain Scale and to record the quantity of prescribed analgesic medication taken after 24 h, 48 h, 72 h and 7 days. Data were statistically analysed using SPSS software (version 20; Chicago, Illinois, USA). Intergroup analysis was performed using the Kruskal-Wallis, followed by Mann-Whitney U tests for intragroup comparison. The Friedman test was applied for comparison between different time intervals. The level of significance was set at P < 0.05. Results: Patients treated with the SAF system were associated with significantly less postoperative pain and lower analgesic intake compared to the other two groups at the four timepoints assessed. Conclusion: The SAF system caused less postoperative pain and lower intake of analgesic medication at the timepoints assessed. [ABSTRACT FROM AUTHOR]

Introduction: Effective cleaning of the root canal system is the primary objective of rotary instrumentation. For three-dimensional obturation of the root canal system, ideal preparation should have a continuously tapering funnel shape from the orifice to the apex. The study aimed to evaluate the shaping ability of two rotary and two reciprocating nickel-titanium (NiTi) single-file instruments on simulated root canals using image analysis software. Materials and Methods: Forty resin blocks with simulated canals of 30° curvature were divided into four experimental groups containing ten samples in each group. The canals were prepared using Reciproc (VDW, Munich, Germany), WaveOne (Dentsply, Maillefer, Ballaigues, Switzerland), OneShape (Micro-Mega, Besancon, France), and F360 (Komet, Brasseler, Lemgo, Germany) size 25 NiTi systems using X Smart Plus (Dentsply). Pre- and post-preparation canals were photographed in a standardized manner and were superimposed. The inner and outer walls of canal curvature were evaluated to determine the most significant change using the image analysis software. Results: The amount of resin removed from the inner walls was less with rotary single-file NiTi systems when compared with reciprocating. Preparation time was less with rotary instruments. No instrument separation was noted. All instrument systems maintained the original canal curvature. Conclusion: Rotary single-file systems maintained the canal curvature better than reciprocating single-file systems.

Introduction: A major objective in root canal treatment is to clean the root canal system. During the process, dentine chips, pulp tissue fragments, necrotic tissue, microorganisms, and intracanal irrigants may be extruded through the apical foramen. This in vitro study was conducted to evaluate the apical extrusion of Enterococcus faecalis with One Shape, F360, WaveOne, and Reciproc endodontic single-file systems. Materials and Methods: Seventy-five human single-rooted mandibular premolar teeth were selected. Endodontic access cavities were prepared. Pulp chamber was accessed, and a pure culture of E. faecalis was used to infect the root canals. Vials with rubber stoppers were selected as the test apparatus. Then, the samples were broadly divided into four main groups with a sample size of 15 teeth. Fifteen previously infected teeth were used as controls. All the root canals were instrumented with the size 25 instruments. A total volume of 2 ml of saline was used for each root canal as irrigant. After 24 h, colonies of bacteria were counted using classical bacterial counting technique as colony-forming units. Statistical Analysis: Data were analyzed statistically using Statistical Package for the Social Sciences, version – 21 (IBM Corp., NY) Software for Windows. Data were expressed in its mean and standard deviation. Results: The results indicated that all the four single-file systems tested caused a measurable apical extrusion of debris. Statistically, significant difference was observed between One Shape, F360, WaveOne, and Reciproc in terms of E. faecalis extrusion, P < 0.05. The highest mean value was with One Shape rotary single-file system and the lowest mean value was with WaveOne reciprocating single-file systems. Conclusion: Within the limitations of the present study, it can be concluded that the reciprocating single-file systems extruded less amount of E. faecalis than compared to rotary single-file systems.

Objectives: To determine the effect of the location of the canal curvature on the fatigue resistance of WaveOne (WO), WaveOne Gold (WOG), Reciproc (Rec), and Reciproc Blue (RecB) files, and to examine the phase transformation behaviors of the reciprocating file systems. Material and methods: The instruments were subjected to fatigue testing in five artificial canals with a curvature of 60° angle and a 3-mm radius. The location of the curvature was unique for each canal. Each file was inserted 16 mm into the canal and operated until fracture occurred. The time to fracture was recorded and the length of the fragment was measured. Differential scanning calorimetry was used to characterize the thermal behavior of the files. The number of cycles to failure was analyzed using two-way analysis of variance and the post hoc Tukey test. The Kruskal-Wallis test was used to compare the mean fragment lengths between groups. Results: The instruments had significantly lower fatigue resistance in canals with curvatures in the middle and coronal canals compared with those with apical curvatures (p < 0.05). At all tested curvature locations, RecB had superior fatigue resistance compared with WO and Rec (p < 0.05). There were no significant differences between WOG and Rec in canals with curvatures in the middle and coronal canals. The DSC thermograms for RecB exhibit a single exothermic peak during cooling but double endothermic peaks during heating indicating that a two-step phase transformation from martensite to R-phase to austenite takes place. Conclusions: The reciprocating instruments experience decreased cyclic fatigue resistance when operated in canals with coronal- and middle-third curvatures when compared with curvatures in the apical-third. Instrumenting coronally positioned curvatures with reciprocating files needs to be performed with caution. Clinical relevance: The location of the root canal's curvature influences the fracture resistance of rotary files that are used with reciprocating movements. Therefore, caution needs to be exercised when using reciprocating instruments in canals with coronal or middle curvatures. [ABSTRACT FROM AUTHOR]

Objective: Since the development of nickel titanium (NiTi) rotary files a number of file systems have been developed, including ProTaper continuous rotary files and the recently developed WaveOne reciprocating files. Previous studies have demonstrated better fatigue resistance of the WaveOne file compared to the ProTaper file. However, no study has compared the effects of reciprocation and continuous rotary motion on transportation and centering ability. Hence, the aim of this study was to compare the two file systems in their transportation and centering ability in mesial roots of mandibular molars using microCT imaging. Method and Materials: Twenty seven extracted mandibular molars with mesiobuccal and mesiolingual canals with separate foramina were used. Pre-instrumentation scans of all teeth were taken, canal curvatures were calculated, and the teeth were randomly divided into two groups. In group 1, the mesiobuccal canals were instrumented with ProTaper files and the mesiolingual canals with WaveOne files. In group 2, the mesiobuccal canals were instrumented with WaveOne files and the mesiolingual canals with ProTaper files. Post-instrumentation scans were performed and the two scans were compared to determine centering ability and transportation at 1, 3, 5, and 7 mm from the apical foramen. Results: Although the WaveOne appeared to stay slightly more centered at the 1, 3, and 5 mm levels and ProTaper showed less transportation at the 1 and 3 mm levels, these differences were not statistically significant. Conclusion: Overall, this study does not support the use of one file system over the other (ProTaper or WaveOne) when comparing transportation and centering ability. Both file systems proved safe for endodontic instrumentation. [ABSTRACT FROM AUTHOR]

Root canal preparation with only one nickel-titanium instrument used in reciprocation has been recently introduced. New endodontic systems using this concept, such as Reciproc and WaveOne, have also been developed. The purpose of this review was to identify publications regarding the evaluation, to present comprehensive and critical summaries of current knowledge, and to provide an update of the single file reciprocating concept. [ABSTRACT FROM AUTHOR]

Abstract Background Comparison of the shaping ability of advanced nickel-titanium (Ni-Ti) instruments is of great interest to the field of endodontics. However, the models used to study canal preparation still lack uniformity, relevance to reality and complexity. The aim of this study was thus to compare the shaping abilities of the ProTaper Next (PN) and WaveOne (WO) Ni-Ti instruments in three-dimensional (3D)-printed teeth, which may overcome the present defects of most real teeth and model teeth including 3D S-shaped canals. Methods Six teeth and their corresponding 3D-printed replicas were prepared using the same kind of Ni-Ti instrument. The pre- and post-preparation volumes, surface areas and transportation of the canals were measured to compare the teeth with their replicas. Twenty 3D-printed teeth with S-shaped canals were used to support the preparation study. The S-shaped canals were then scanned to measure their volumes and surface areas. Next, the two kinds of instruments were used to prepare the 3D-printed canals (n = 10 per group). The volume and surface area of the canals, the transportation along the two curvatures and the percentage of unprepared surface area were measured. Micro-CT and VGstudio2.2 (VG2.2) software were used to perform scans and collect data throughout the research. The paired-samples T test and Kruskal-Wallis H test were used for statistical analysis. Results There was no significant difference between the real canals and the printed ones post-preparation (P > .05). The printed S-shaped root canals had a unified shape, with a small standard deviation and range. The WO group had higher mean values for the volume and superficial area measurements compared with the PN group (P .05). PN caused less transportation at the apical curve than WO did (P

Introduction: The purpose of this study was to evaluate surface topography of WaveOne Gold (WOG) and WaveOne (WO) files using SEM before and after use. Methods: Twelve primary files from each system were scanned for surface defects before instrumentation at 100x and 750x. Each file was planned ti be used to instrument six root canals and then examined under SEM after preparing one, three and six canals at same magnifications. Data were scored and statistically analyzed using Mann Whitney and Friedman tests (p≤ 0.05). Results: Surface defects were detected in both study groups with higher values in WOG group before use. Surface defects significantly increased in both WO and WOG groups after use. WOG group showed significantly greater defects including metal strips, pitting, craters, micro-cracks and blunt edges (p≤ 0.05). Conclusion: WaveOne Gold file has a different metallurgy due to it’s gold finish that does not enhance it’s resistance to surface defects during clinical use.

Background: Endodontic therapy treats inside of the tooth and its success is based upon the triad of thorough canal debridement, effective disinfection, and obturation of the canal space. Thus, one of the most important steps is biomechanical preparation, which is the key stage of endodontic treatment with a predictive success factor if performed properly. Aim: The aim of the study is to evaluate and compare the cleaning efficiency of different file systems in terms of remaining dentin thickness. Materials and Methods: A total of thirty permanent extracted anterior teeth were taken for the study and was divided into three groups – Group I – Manual Protapers, Group II – Rotary Mtwo, and Group III – Reciprocating WaveOne file systems. Pre-cone-beam computed tomography (CBCT) scan was taken followed by biomechanical preparation by the respective file groups. Post-CBCT scan was taken and the pre- and post-CBCT scans were compared for remaining dentin thickness. Data were analyzed with ANOVA (P = 0.001). Statistical Analysis Used: ANOVA test was used in this study. Results: Protaper showed minimum reduction in dentin thickness followed by Mtwo and WaveOne showed maximum reduction in dentin thickness, but the intergroup comparison was found to be highly insignificant. Conclusion: WaveOne is a highly recommended rotary endodontic instrument which does not cause significant lowering in remaining dentin thickness after biomechanical preparation.

Background: Under axial loading, there is stress concentration around the cervical areas especially in the premolars because of their location in the arch.Aim: To evaluate and compare flexural fracture resistance of mandibular premolars after instrumentation with ProTaper®Universal, ProTaper Next®, OneShape®, and WaveOne® endodontic file systems.Methods: Seventy-five mandibular premolar teeth with single straight canals were divided into five different groups (n = 15): Group A: Control, Group B: ProTaper Universal (PTU), Group C: ProTaper Next (PTN), Group D: OneShape, Group E: WaveOne. The teeth were instrumented as per the manufacturer's instructions. After obturation and core placement, the teeth were placed in a customized jig mounted on a universal testing machine where force was applied at 45° on the buccal cusp and the force required to fracture the teeth was noted.Results: Amongst all the instrumented groups, WaveOne showed the highest resistance to fracture (1065.56 ± 175.05) and the control group was 1104.13 ± 188.42. All groups showed a significant difference in the fracture load values with the control group. However, there was a statistically significant (P < 0.05) difference seen with WaveOne vs PTU and WaveOne vs OneShape.Conclusions: Root canals instrumented with reciprocating motion have better flexural fracture resistance than continuous rotary motion. Mandibular premolars when instrumented with ProTaper Universal and OneShape endodontic files showed similar fracture resistance, proving that dentin removal does not depend on the number of files used. [ABSTRACT FROM AUTHOR]

The present paper evaluated the accuracy of two different methods for transferring working length (WL) between manual endodontic instruments and nickel–titanium (NiTi) shaping files. Thirty root canals of extracted permanent teeth were used. Root canals were divided according to canal length (CL) and canal curvature (CC). The reference cusp and the root end were flattened to provide reproducible and accurate measurements. During shaping, the WL measurements were obtained with manual k-files (KF) and transferred to WaveOne (W1) NiTi reciprocating files using the traditional method with the endodontic ruler (method I) and an alternative clinical procedure based on the comparison of the instruments side by side from tip to shank (method II). For each file and each tested method, two measures were taken by two examiners using Rhino (ver. 4.0, McNeel, Seattle, WA, USA) software for a total of 360 (30 × 3 × 2 × 2) measures. Analysis of variance was performed by taking the difference in length (Delta WL, DWL) between files used for the same canal. The difference between methods I and II for WL transfer was found to be statistically significant (df = 1; F = 71.52; p < 0.001). The DWL absolute values obtained with method II were found to be closer to 0 mm (i.e., same length as corresponding KF) than those obtained with method I. Both CL (df = 2; F = 1.27; p = 0.300) and CC (df = 1; F = 2.22; p = 0.149) did not significantly influence WL measurements. With respect to WL transfer, method II seemed to better preserve the correct WL transfer between instruments during the clinical endodontic procedures. [ABSTRACT FROM AUTHOR]

Copyright of Turkiye Klinikleri Journal of Dental Sciences is the property of Turkiye Klinikleri and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The goal of this study was to compare the cyclic fatigue resistance of 5 heat-treated nickel-titanium files in reciprocating movement with the same tip size and different cross sections. Five groups (WaveOne [Dentsply, Ballaigues, Switzerland], WaveOne GOLD [Dentsply], RECIPROC [VDW, Munich, Germany], RECIPROC BLUE [VDW GmbH, Munich, Germany], and TF [Sybron Endo, Glendora, CA] Adaptive) of 24 files each of the rotary files were examined. Cyclic fatigue resistance was compared between groups by determining the time needed to fracture and the number of cycles to failure in a cyclic fatigue testing device with 2 different curvatures, the first with a 5-mm radius of curvature and a 60° angle and the second with a double curvature, coronal curvature of 60° angle and a radius of 5 mm, and an apical curvature of 70° angle and a 2-mm radius. Scanning electron microscopic evaluation was performed at the fracture sites to investigate the types of fracture. RECIPROC BLUE group had a higher mean time to fracture followed by RECIPROC and WaveOne GOLD for both single and double curvature. WaveOne had a higher mean time to fracture in a single curvature canal than TF Adaptive, whereas the opposite was true for a double curvature canal. Both RECIPROC groups were significantly greater in cyclic fatigue resistance in comparison with all other groups (P <.05). WaveOne GOLD was significantly greater than the WaveOne and TF Adaptive groups (P <.05). RECIPROC BLUE files exhibited significantly greater cyclic fatigue resistance compared with other files tested in an S-shaped artificial canal. [ABSTRACT FROM AUTHOR]

This study aimed to compare the surface topographies and nanoscale profiles of intact and used WaveOne, WaveOne Gold, Reciproc, and Reciproc blue nickel–titanium (NiTi) instruments. Sixteen NiTi instruments were evaluated; four from each one of WaveOne (25/0.08), WaveOne Gold (25/0.07), Reciproc (25/0.08), and Reciproc blue (25/0.08) files. Each instrument was used to prepare four curved canals. A three-dimensional nanoscale surface profiler was used to assess instrument surfaces before and after root canal instrumentation. The data were analyzed with one-way analysis of variance using SPSS 21.0 software and set significance at P < 0.05. There were significant differences in surface topography between NiTi instruments. Intact WaveOne and WaveOne Gold instruments had the highest values, followed by the Reciproc and Reciproc blue instruments (P < 0.05). Used WaveOne and WaveOne Gold instruments had the highest values, followed by Reciproc and Reciproc blue instruments (P < 0.05). Some indications of microcracks in qualitatively intact Reciproc blue files were observed, and minor surface cracks in used WaveOne Gold instruments were also observed. Used WaveOne, Reciproc, and Reciproc blue instruments exhibited cracks and microcavities. WaveOne Gold and Reciproc blue instruments had significantly higher levels of surface distortion after root canal instrumentation, and WaveOne exhibited the lowest level of surface deformation. Each of the Reciprocating instruments was safely used to prepare four canals without incident. The three-dimensional stylus profiler provided valuable assessments of the surface topographies of NiTi instruments. [ABSTRACT FROM AUTHOR]

Objective This study aims to evaluate the shaping capability of Pathfile and WaveOne in simulated root canals. Methods A total of 20 simulated resin blocks were divided randomly into two groups, group W prepared with WaveOne alone. Group PW prepared with WaveOne and Pathfile. Preparation time and number of separated instru⁃ ments were measured respectively. Pre ⁃ and post ⁃ operative images were obtained with a scanner and superimposed through Photoshop and ImageJ2X. The changes in canal bending curvature and material removal from the inner and out⁃ er canal walls at 10 points beginning at 1mm from the end point of the canal were measured with ImageJ2X. Centering capability was determined accordingly by comparing and analyzing the material removal from the inner and outer canal walls. Results Two groups have no occurrence of instrument separation, no statics significance in root canal prepara⁃ tion and the changes of root canal working length differences (P > 0.05). But at position of root canal point 4 to 5 mm, the misalignment of group W were 0.085 ± 0.05 mm and -0.312 ± 0.068 mm, the misalignment of group PW were -0.071 ± 0.042 mm, -0.26 ± 0.103 mm (P < 0.05). Conclusion Both two groups instruments showed good performance in preparation but both created some apical transportation. However, group PW exhibited more superior centering capabili⁃ ty than group W in the middle part of the canal.

Aim: The aim of the current study was to compare the effect of WaveOne and Reciproc files in reciprocation versus reverse full rotation movements on cervical dentin thickness by virtue of cone beam computed tomography (CBCT) analysis in curved mesial canals of mandibular first molars. Methods: Mesiobuccal canals of 60 mandibular molars were randomly divided into 4 groups (n = 15): Group 1; WaveOne/Reciprocation, Group 2; WaveOne/Full-Rotation, Group 3; Reciproc/Reciprocation, and Group 4; Reciproc/Full-Rotation. Pre- and post-instrumented CBCT scans were prepared for assessment of cervical dentin thickness changes (2 mm, 4 mm below the highest point of the root furcation) in both groups. Data statistically analyzed using two-way ANOVA test. Results: There was no statistically significant difference between four experimental groups in terms of remaining dentin thickness at 2 and 4 mm levels below the highest point of the furcation (P > 0.05). No separation of instruments occurred in any group. Conclusion: WaveOne and Reciproc files with two different motions have similar effects on cervical of root canals in terms of dentin thickness changes.

Aim: To assess the fracture incidence of instruments from single‐file reciprocating systems when used by students in an endodontic graduate programme. Methodology: Dental records and periapical radiographs of patients treated by students on an endodontic graduate programme using reciprocating systems were assessed. Data on tooth type, number of treated root canals, number of fractured instruments, fragment size, angle, radius, arc length and position of root canal curvature where fractures occurred were tabulated for analysis. The risk of fracture was calculated for each group of teeth, root canal and root thirds, whilst the incidence of fractures reported for the reciprocating systems was compared using the chi‐squared test at 5% significance level. Results: Overall, 2056 root canals (826 teeth) from 810 patients were included. The incidence of fractured files from single‐file reciprocating systems in relation to a number of instrumented canals was 0.92%. Fracture rates of 0.84% and 0.93% were found in 830 and 1226 root canals instrumented with WaveOne and Reciproc systems, respectively. No significant differences were observed between the systems. The highest fracture rate was 52.6% in the mesiobuccal root of mandibular molars. The central angle, radius and arc length of the curvature of root canals where the instruments fractured ranged from 58° to 84°, from 1.7 to 7.2 mm and from 2.4 to 7.6 mm, respectively. Conclusion: The use of WaveOne and Reciproc single‐file reciprocating systems in an endodontic graduate programme was associated with a low incidence of instrument fractures. [ABSTRACT FROM AUTHOR]

Abstract Introduction The purpose of this study was to compare canal transportation and the centering ability of Reciproc (VDW, Munich, Germany), WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), and EdgeFile (EdgeEndo, Albuquerque, NM) rotary systems using cone-beam computed tomographic imaging. Methods Ninety mesiobuccal mandibular first molar uncalcified canals with at least a 19-mm length, a canal curvature of 15°–30° (the Schneider method), and a mature apex were selected. Canals were randomly divided into 3 groups of 30 teeth, and canal preparation with the Reciproc, WaveOne, and EdgeFile systems was performed according to the manufacturers' instructions. Cone-beam computed tomographic images were taken before and after instrumentation in the same position. Apical transportation was calculated in the distances of 2, 3, and 4 mm from the apex. Kruskal-Wallis and Mann-Whitney U tests were used to statistically analyze the data. Results The mean canal transportation was significantly lower with EdgeFile (P <.001) followed by the WaveOne rotary system. Moreover, the centering ability of the EdgeFile system was higher than that of the WaveOne and Reciproc systems. Conclusions The EdgeFile rotary system showed the lowest transportation in both the mesiodistal and buccolingual directions and the highest centering ability. The Reciproc system showed the highest transportation and the lowest centering ability. [ABSTRACT FROM AUTHOR]

A comparison of the abilities of rotary versus reciprocating files to eliminate viable Enterococcus faecalis populations from the long oval root canals of extracted human teeth. Fifty teeth were contaminated and randomly distributed into two groups (n = 25 each): BT‐RaCe group and WaveOne group. Two microbial samples were obtained from each tooth before (S1) and after (S2) instrumentation. The CFUs from the S1 and S2 measurements were calculated and compared between the groups. Both groups showed significantly fewer CFUs in the S2 samples (P < 0.001). In the S2 intragroup comparison, BT‐RaCe resulted in significantly fewer CFUs than WaveOne (P = 0.010). In the direct comparison between the rotary multiple file shaping system and the reciprocating single‐file system, the multiple file system was more efficient at reducing the microbiological load of viable E. faecalis from long oval root canals. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Taibah University Medical Sciences is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Amaç: Tek köklü dişlerden farklı eğe sistemlerini kullanarak kanal içi ilaç olan kalsiyum hidroksit’in (KH) uzaklaştırılmasının değerlendirilmesidir. Gereç ve Yöntemler: Bu çalışmada 30 adet tek köklü çekilmiş insan dişi kullanıldı. Kök kanalları ProTaper F4 eğesine kadar genişletildi. KH patı kök kanallarına çalışma uzunluklarında yerleştirildi. Köklerin koronal kısımlarına pamuk pelet ve geçici bir dolgu maddesi konularak kapatıldı. Daha sonra dişler distile su içinde 37oC’de 7 gün boyunca bekletildi. Sonrasında geçici dolgular kaldırıldı. Kök kanallarındaki KH’ın uzaklaştırılmasında kullanılan yönteme göre örnekler rastgele dört deney grubu (ProTaper Universal F4, ProTaper Next X4, Reciproc 40, WaveOne Large) ve kontrol grubu olmak üzere toplam 5 gruba (n=12) ayrıldı. Kökler bukko-lingual olarak ikiye ayrıldı ve kanal içerisinde kalan artık KH miktarı x 15 büyütmede stereomikroskop altında değerlendirildi. Veriler SPSS programında Cronbach alpha yöntemi ile istatistiksel olarak değerlendirildi. Bulgular: KH’in kök kanallarından tamamen uzaklaştırılamadığı görüldü. Reciproc eğe sistemi ile istatistiksel olarak diğer gruplardan daha fazla KH’i uzaklaştırıldığı belirlendi (P < 0.05). Kontrol grubunda diğer gruplardan daha az KH uzaklaştırılmasına rağmen ProTaper Universal, ProTaper Next ve WaveOne eğe sistemleriyle aralarında istatistiksel olarak anlamlı bir fark görülmedi (P > 0.05). Sonuç: Reciproc eğe sisteminin NaOCl ile birlikte kullanımı kök kanallarından KH’i uzaklaştırmada yalnızca NaOCl kullanımından veya ProTaper Universal, ProTaper Next ve WaveOne eğe sistemlerinden daha etkili olduğu görülmüştür. Ancak, kullanılan tekniklerin hiçbiri kök kanallarından KH’i tamamen uzaklaştıramamaktadır.

The present paper evaluated the accuracy of two different methods for transferring working length (WL) between manual endodontic instruments and nickel–titanium (NiTi) shaping files. Thirty root canals of extracted permanent teeth were used. Root canals were divided according to canal length (CL) and canal curvature (CC). The reference cusp and the root end were flattened to provide reproducible and accurate measurements. During shaping, the WL measurements were obtained with manual k-files (KF) and transferred to WaveOne (W1) NiTi reciprocating files using the traditional method with the endodontic ruler (method I) and an alternative clinical procedure based on the comparison of the instruments side by side from tip to shank (method II). For each file and each tested method, two measures were taken by two examiners using Rhino (ver. 4.0, McNeel, Seattle, WA, USA) software for a total of 360 (30 × 3 × 2 × 2) measures. Analysis of variance was performed by taking the difference in length (Delta WL, DWL) between files used for the same canal. The difference between methods I and II for WL transfer was found to be statistically significant (df = 1; F = 71.52; p < 0.001). The DWL absolute values obtained with method II were found to be closer to 0 mm (i.e., same length as corresponding KF) than those obtained with method I. Both CL (df = 2; F = 1.27; p = 0.300) and CC (df = 1; F = 2.22; p = 0.149) did not significantly influence WL measurements. With respect to WL transfer, method II seemed to better preserve the correct WL transfer between instruments during the clinical endodontic procedures.

Objective To assess the effect of glide path on the amount of apically extruded debris after instrumentation with WaveOne and OneShape.Methods. Forty-eight extracted human mandibular incisorswere assigned to 4 groups. In groups 1 and 2, preparation was completed with WaveOne In groups 3 and 4, canals were prepared with OneShape. Before instrumentation, in groups 1 and 3, glide path was created with PathFile 1, 2, and 3 at working length, whereas in groups 2 and 4, glide path was not performed. The weight of the extruded debris for each group was calculated by comparing the pre- and post-instrumentation weights of the eppendorf tubes. The time required for reaching full WL was also recorded. Data were analyzed by Kruskal–Wallis and Mann–Whitney U tests. Results. There was no difference in the amount of debris extruded between the single file systems (P=0.234). Time required to reach full WL was significantly decreased by creating a glide path (P< 0.05).Conclusion. Creation of a glide path does not significantly affect the apically extruded debris.

Introduction The aim of this study was to evaluate the amount of vertical force induced with WaveOne (WO; Dentsply Sirona, York, PA) and WaveOne Gold (WOG, Dentsply Sirona) systems during the canal shaping of extracted teeth. Methods Thirty canals in 15 maxillary premolars were divided into 2 groups: WO and WOG. The canals were gently shaped with WO/WOG Primary instruments according to the manufacturer's instructions. The vertical forces induced during canal shaping in the apical and coronal directions were recorded. The apically and coronally directed peak forces were used for analysis using the Mann-Whitney U test. The instrumentation time was analyzed using the Student t test. All statistical analyses were performed using SPSS software (Version 22.0; IBM, Armonk, NY) at a 5% significance level. Results The force increased with the successive instrument insertions within each group. The apically and coronally directed peak forces of the WO and WOG groups ranged from 2.89–11.58 N and from 1.53–2.92 N, respectively. In the 3 insertions, WO showed higher peak forces in both directions. For apically directed peak forces, WO had significantly higher peak forces in the first and third insertions than WOG ( P < .01). For coronally directed peak forces, WO had significantly higher values in the first and second insertions ( P < .05). Conclusions The WOG system had significantly lower apically and coronally directed peak force values compared with the WO system. [ABSTRACT FROM AUTHOR]

Background: Apically extruded debris produced during root canal preparation can induce postoperative inflammation and subsequent failure of root canal treatment. Therefore, debris production must be reduced to improve the outcome of root canal treatment. Aim: This study aimed to provide a theoretical basis for the improvement of root canal treatment by comparing the difference in the amount of apically extruded debris produced during the root canal preparation of extracted human teeth with ProTaper Universal (PTU), ProTaper Next (PTN), and WaveOne (WO). Materials and Methods: On March 30, 2017, three researchers searched five electronic databases (PubMed/Medline, Cochrane, Science Direct Online, Embase, and Web of Science) with no time limitations. Only articles written in English were retrieved, and 150 articles were obtained. Then, the three researchers independently selected articles in accordance with previously established inclusion and exclusion criteria, and inconsistent results were discussed. Data were analyzed through meta-analysis for standardized mean difference (SMD). Results: Eight studies met the inclusion criteria and were subjected to qualitative analysis. Four articles showed that PTU produced higher amounts of apical debris than WO; two articles showed that PTU produced lower amounts of apical debris than WO; and three articles showed that PTN produced lower amounts of apical debris than WO. Moreover, one article demonstrated that PTU produced higher amounts of apical debris than PTN. A meta-analysis showed that PTU and WO did not produce significantly different amounts of apically extruded debris: SMD -0.26, Z = 0.50 (P > 0.05). PTU produced lower amounts of apically extruded debris than WO: SMD =-4.98, Z = 2.79 (P < 0.05). However, results were significantly heterogeneous among all the included studies (I2 = 97%). No significant difference was found between PTU and WO in the amounts of apically extruded debris: SMD = 0.47, Z = 1.06 (P > 0.05). Conclusion: Currently available evidence shows that PTN can produce lower amounts of apical debris than WO (P < 0.05). Moreover, the amounts of apically extruded debris produced by PTU and WO are not significantly different (P > 0.05). Nevertheless, given the limited number of studies reviewed, a definitive conclusion cannot be reached. [ABSTRACT FROM AUTHOR]

Background: Endodontic therapy treats inside of the tooth and its success is based upon the triad of thorough canal debridement, effective disinfection, and obturation of the canal space. Thus, one of the most important steps is biomechanical preparation, which is the key stage of endodontic treatment with a predictive success factor if performed properly. Aim: The aim of the study is to evaluate and compare the cleaning efficiency of different file systems in terms of remaining dentin thickness. Materials and Methods: A total of thirty permanent extracted anterior teeth were taken for the study and was divided into three groups – Group I – Manual Protapers, Group II – Rotary Mtwo, and Group III – Reciprocating WaveOne file systems. Pre-cone-beam computed tomography (CBCT) scan was taken followed by biomechanical preparation by the respective file groups. Post-CBCT scan was taken and the pre- and post-CBCT scans were compared for remaining dentin thickness. Data were analyzed with ANOVA (P = 0.001). Statistical Analysis Used: ANOVA test was used in this study. Results: Protaper showed minimum reduction in dentin thickness followed by Mtwo and WaveOne showed maximum reduction in dentin thickness, but the intergroup comparison was found to be highly insignificant. Conclusion: WaveOne is a highly recommended rotary endodontic instrument which does not cause significant lowering in remaining dentin thickness after biomechanical preparation. [ABSTRACT FROM AUTHOR]

Introduction The purpose of this study was to evaluate the effect of sodium hypochlorite (NaOCl) and EDTA solutions on the cyclic fatigue resistance of WaveOne (WO) and WaveOne Gold (WOG) nickel-titanium reciprocating files. Methods A hundred WO (25/.08), and 100 WOG (25/.07) were randomly divided into 5 groups: group 1, no immersion; group 2, immersion in 5.25% NaOCl at 37°C ± 1°C for 5 minutes; group 3, immersion in 5.25% NaOCl at 37°C ± 1°C for 10 minutes; group 4, immersion in 17% EDTA at 37°C ± 1°C for 5 minutes; and group 5, immersion in 17 % EDTA at 37°C ± 1°C for 10 minutes. Then, the instruments were reciprocated in an artificial canal until fracture occurred, and the time to fracture was recorded. The data were statistically analyzed using 1-way analysis of variance and the Student t test via SPSS 21.0 software (IBM Corp, Armonk, NY) with the significance level set at P < .05. Results The cyclic fatigue resistance of the WOG was statistically higher than the WO in all the conditions tested ( P < .05). There was no statistically significant difference among the different conditions tested in terms of cyclic fatigue resistance for both WO and WOG files ( P > .05). Among the groups, there was no significant difference in the fracture lengths ( P > .05). Conclusions Within the limitations of the present study, it was determined that NaOCl and EDTA solutions did not have any effect on the cyclic fatigue resistance of WO and WOG files. [ABSTRACT FROM AUTHOR]

Background/purpose Reciprocating single-file systems are the latest nickel-titanium instruments and little information is available concerning the shaping ability of these new systems. Comparison of these single-file systems with well-known rotary multi-file systems is necessary. The purpose of this study was to compare the shaping ability of single-file system (WaveOne, WO) versus multiple-file system (ProTaper Next, PTN) in severely curved canals. Materials and methods A total of 20 severely curved canals were prepared with WO or PTN. Micro-computed tomography was used to scan the specimens before and after instrumentation. Differences between two groups in canal surface area, volume, Structure Model Index (SMI), thickness, straightening, the ratio of uninstrumented surface area and canal transportation were evaluated. Results The outline of the canals after preparation showed smooth taper in both groups. Canal surface area, volume, SMI, Thickness and canal curvature were significantly increased after preparation in both groups, and no significant difference was found between groups. At apical third, canals prepared with WO showed larger values of transportation compared with those in PTN group in the direction of main curvature. Approximately 29–34% of the root canal surface remained uninstrumented after preparation and no significant difference was noticed between groups. Conclusion Both of the two instrument systems maintained the original outline of the canals well. The canals prepared with PTN had less transportation and were better centered in the apical region. [ABSTRACT FROM AUTHOR]

Aim: The current study compared the fracture resistance of samples instrumented by two rotary files and a reciprocating file, obturated with gutta-percha and AH Plus. Materials and Methods: A total of 60 freshly extracted mandibular premolar teeth with single roots and single canals were acquired and decoronated at or below the cementoenamel junction. The samples were randomly divided into four groups (n = 15). Group 1 control (noninstrumented/obturated), and for Groups 2–4 root canal instrumentation was done by EndoStar E5 (EE5), ProTaper NEXT (PTN), and WaveOne, respectively. Following instrumentation, the samples were obturated using gutta-percha cones and AH Plus sealer using lateral compaction. A week later, vertical load was applied to the specimen's canal in each group until fracture. The loads required for fracture were recorded and statistically analyzed. Results: The mean loads required to fracture (Newton; N) for the four groups were; 388.54 (±29.93), 310.35 (±26.05), 328.40 (±20.67), and 278.54 (±34.16). The loads exhibited highly significant difference (P < 0.0001; analysis variance). The following Tukey's post hoc test confirmed, both samples in Groups 2 and 3 required similar loads for fracture (P > 0.05) and significantly higher than Group 4 (P < 0.01). Conclusion: The samples instrumented by EE5 and PTN exhibit similar fracture resistance. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to evaluate surface topography of WaveOne Gold (WOG) and WaveOne (WO) files using SEM before and after use. Methods: Twelve primary files from each system were scanned for surface defects before instrumentation at 100x and 750x. Each file was planned ti be used to instrument six root canals and then examined under SEM after preparing one, three and six canals at same magnifications. Data were scored and statistically analyzed using Mann Whitney and Friedman tests (p≤ 0.05). Results: Surface defects were detected in both study groups with higher values in WOG group before use. Surface defects significantly increased in both WO and WOG groups after use. WOG group showed significantly greater defects including metal strips, pitting, craters, micro-cracks and blunt edges (p≤ 0.05). Conclusion: WaveOne Gold file has a different metallurgy due to it's gold finish that does not enhance it's resistance to surface defects during clinical use. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Dental Science / Arquivos em Odontologia is the property of Universidade Federal de Minas Gerais, Faculdade de Odontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)