A comparison of root canal transportation and centering ability between WaveOne® Gold and Protaper Next® files, using microcomputed tomography

Background: The combination of NiTi alloy with rotary instrument is a turning point in clinical endodontics that helps to keep the original shape of the canal, reduce the errors such as displacement of the root apex, perforation,... This study aimed to compare the enlargement, canal transportation and centering ratio of two nickel-titanium file systems, WaveOne Gold and Protaper Next. Materials and method: In this in vitro study, forty L-shaped root canals in resin blocks curvatures 400 were divided randomly into two equal groups. The root canals of one group were prepared using Protaper Next files, and the other using WaveOne Gold files. Pre-instrumentation and post-instrumentation imaging were taken for all teeth and stacked on top of each other. The enlargement, canal transportation and centering ratio were evaluated at 1 to 9 levels from the apex. Results: In the apical and middle thỉds, canals prepared with WaveOne Gold files had a greater extension than those prepared with Protaper Next files; in coronal third, the Protaper Next group had a greater extent than the WaveOne Gold group, but the difference was not statistically significant (p > 0.05). Root canal transportation and centering ratio were no significant difference between the groups (p > 0.05). Both of groups were less centered in the canal at levels in curvature of the canal. Conclusion: Both of WaveOne Gold and Protaper Next were same in centering ability. Key words: WaveOne Gold, Protaper Next, centering ability.

BackgroundThe purpose of the current study was to inspect and compare the influence of applying continuous rotation and reciprocation motions on the cyclic fatigue resistance of Protaper Next (PTN) file (X2) and WaveOne Gold (WOG) Primary file in simulated canals. Twenty Protaper Next files(X2) and 20 WaveOne Gold Primary files were included in this study. A cyclic fatigue testing device was employed to test the cyclic resistance of each file in different motions. The testing device has an artificial custom-made stainless-steel canal with a 60° angle of curvature and a 2-mm radius of curvature. The files were randomly divided into 4 groups; group 1: PTN in continuous rotation, group 2: PTN in reciprocation, group 3: WOG in continuous rotation and group 4: WOG in reciprocation. All the instruments were rotated until fracture occurred, and the time to fracture was recorded in seconds using a digital chronometer. The number of cycles to fracture (NCF) was calculated. The data were analyzed statistically (p < .05).ResultsResults represented that when using either continuous rotation motion or reciprocating motion, WOG files showed a significantly longer time until failure than PTN files (p < 0.001). The time till fracture increased significantly, when using both types of files with a reciprocating filing motion.ConclusionWithin the confinement of this study, WOG file in reciprocation showed higher cyclic fatigue resistance than PTN in both continuous rotation and reciprocating motion. The reciprocating motion enhances both files behavior in terms of cyclic fatigue resistance.

BackgroundThis study aims to evaluate the frequency of dentinal defects after root canal preparation with the ProTaper NEXT, K3XF and WaveOne GOLD systems using microcomputed tomography.MethodsSixty permanent mandibular incisors with a single canal were selected. Inspection of the teeth was performed under a stereomicroscope (15x) to observe the presence of pre-existing cracks and fractures lines. Samples were divided into three experimental groups (n = 20): ProTaper NEXT (PTN), K3XF (K3XF) and WaveOne GOLD (WOG). Specimens were scanned through high-resolution microcomputed tomography before and after the preparation of the root canal. Subsequently, all the axial images were examined by two different methods to find possible dentinal defects. Furthermore, an analysis of each millimeter of ten apical millimeters was also performed. The absence or presence of dentinal defects was screened by 3 pre-calibrated blinded examiners.ResultsAfter analysing all 45,720 slices, dentinal defects were observed in 48,33% (22096 slices). PTN, K3XF and WOG groups represented 11,11% (5079 slices), 17,22% (7873 slices) and 20% (n = 9144) of the cross-sectional images, respectively. At 10 apical millimeters (600 slices), 33,33% (200 slices) presented some dentinal defects, representing 7,22% (43 slices), 13,33% (80 slices) and 12,77% (77 slices) of the cross-sectional images in the PTN, K3XF and WOG groups, respectively. All the dentinal defects presented in the postoperative images existed in the images prior to instrumentation.ConclusionsThere was no correlation between the preparation of a root canal using the PTN, K3XF and WOG systems and the formation of new dentinal defects.

Context:Canal shaping abilities such as canal transportation, centering ability, and preparation time are important and have to be considered before using any Nickel–Titanium file system.Aim:This in vitro study aimed to evaluate and compare the amount of canal transportation, centering ability, and time required for the shaping of severely curved canals with WaveOne Gold (WOG) Primary Reciprocating file and One Curve (OC) Rotary file using the micro computed tomography (μCT).Materials and Methods:Thirty intact mesial roots of extracted human mandibular first molars having severe curvature (25°–35°) were selected. Samples were divided into two groups. Samples in Group I and II were shaped with WOG primary reciprocating files and OC rotary files, respectively, to the working length. Time required to prepare each canal was recorded. μCT pre- and post-instrumentation scans of all samples were taken. The cross-sectional images at 3, 6, and 9 mm from the radiographic apex were selected for analysis. Statistical analysis was performed using the Kruskal–Wallis and unpaired t-test.Results:At 3 mm, OC showed statistically lower canal transportation with mean value (0.17 ± 0.10) than WOG (0.55 ± 0.42). Furthermore, OC showed statistically significant better centering ability (0.59 ± 0.25) than WOG (0.39 ± 0.20) at 3 mm level. However, the differences between both instruments were not statistical significant at 6 and 9 mm level for canal transportation and centering ratio. WOG reciprocating file required less time for canal preparation than OC file.Conclusions:OC rotary file showed less canal transportation and better canal centring ability than WOG file, during the preparation of severely curved canals. However, WOG required less time for canal preparation.

The nickel-titanium alloy used in the production of nickel-titanium files contains approx. 56% nickel and 44% titanium by weight. To improve the properties of nickel-titanium files, the manufacturers introduce some innovations in the production process. Their purpose is primarily to decrease the stiffness of the instruments while increasing the resistance to cyclic fatigue, which reduces the risk of file separation. One of the most popular processes is the heat treatment of the nickel-titanium alloy. The aim of the research was to determine the influence of the manufacturing process of rotary files on the shaping of L-shaped canals. Fifty L-shaped resin canals were instrumented (10/group) with ProTaper Universal ®, ProTaper Next®, Hyflex CM®, Hyflex EDM®, or WaveOne Gold® files, with the same apical size of 25. Each L-shaped resin canal was photographed both before and after instrumentation. Differences between the change of the working length and apical transportation were analyzed statistically. The smallest mean loss of the working length was observed after instrumentation with Hyflex CM files. Statistically significant differences in the working length were found between ProTaper Universal and Hyflex CM (p = 0.0032), ProTaper Universal and Hyflex EDM (p = 0.021), and ProTaper Universal and WaveOne Gold (p = 0.0112) files. The lowest apical transportation was noted in the case of WaveOne Gold files. In terms of apical transportation, statistically significant differences were observed between ProTaper Universal and WaveOne Gold files (p = 0.0254). Shaping Lshaped canals with the ProTaper Universal file system resulted in the greatest changes in the working length (x = 0.35 mm) and apical transportation (x = 0.034 mm). The study, with its limitations, shows that in the files whose nickel-titanium alloy was subjected to a thermal treatment process, a smaller loss of the working length and lower values of apical transportation were observed.

Objectives: One of the important objectives of root canal instrumentation is the removal of vital and/or necrotic pulp tissue, as well as dentin debris ensuring a completely clean canal environment. During the past few decades, various nickel titanium rotary endodontic file systems have been developed with high efficiency and sound safety to ensure completely clean canals. The purpose of the present study was to compare the cleaning efficacy of two different rotary file systems- ProTaper NEXT and WaveOne, using a Scanning Electron Microscope. Study Design: 60 extracted single rooted teeth with single root canals were selected for the study and access cavities were prepared. The working lengths were determined using #10/15 K files and the samples were divided into two experimental groups. Group-1: Cleaning and Shaping was performed using ProTaper NEXT rotary files following manufacturer's instructions up to size X4 (apical diameter of 0.40 mm). Group-2: Cleaning and Shaping was performed using WaveOne rotary files of size 40 (apical diameter of 0.40 mm) following manufacturer's instructions. 6 samples from each group were left uninstrumented which served as control. The radicular portion of all the samples were split buccolingually following decoronation at the cementoenamel junction. The samples were examined in the coronal, middle and apical third of the root canal under the scanning electron microscope. Results: The analysis of the results demonstrated that WaveOne (Mean debris score= 1.22) presented higher cleaning capacity of root canals when compared to ProTaper NEXT (Mean debris score= 1.58) (p value <0.05) Conclusion: Both the rotary systems WaveOne and ProTaper NEXT resulted in cleaner canals after instrumentation. However, the apical thirds of the root canals demonstrated more residual debris scores when compared to the middle and coronal thirds. Also, the WaveOne files resulted in cleaner canals than ProTaper NEXT file system.

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

To compare the centring ability and transportation of ProTaper Next (PTN), ProTaper Universal (PTU), Race 123 and RevoS using micro-computed tomography (μCT). Sixty mesial root canals of thirty mandibular molars were divided virtually into coronal, middle and apical thirds, and two reproducible reference points were marked on the external surface of the roots creating 360 measurement points. Samples were randomly allocated to four NiTi instrumentation techniques. Group 1: PTU up to F2 (n=16), group 2: PTN up to X2 (n=18), group 3: Race 123 up to T2 (n=12) and group 4: RevoS up to SU (n=14). To reproduce a clinical situation, samples were prepared on a phantom head using a surgical operating microscope. Samples were scanned pre- and postoperatively using μCT to compare and calculate the transportation and centring ratio. The data were analysed using parametric statistics. In the coronal and middle third of the root canals, there were significant differences in centring between PTN and PTU (coronal P<0.001), PTN and RevoS (coronal P<0.001), Race and PTU (coronal P<0.01), Race and RevoS (coronal P<0.01), PTN and RevoS (middle P<0.01) and Race and RevoS (P<0.05). Furthermore, there were significant differences in centring between PTN root canal preparations and other instruments in the apical third (PTN and PTU P<0.01, PTN and Race P<0.001, PTN and RevoS P<0.001). In terms of transportation, in the coronal third, there was a significant difference between PTN and PTU (P<0.05). However, there were no significant differences between the other instruments. In the middle third, significant differences were observed between PTN and PTU (P<0.05), PTN and RevoS (P<0.05), Race and PTU (P<0.05) and Race and RevoS (P<0.05). However, there were no significant differences between other systems. There was no significant difference in terms of transportation between the four systems in the apical third. ProTaper Next prepared more centred root canal shapes when compared with Race, PTU and RevoS. In the coronal and middle third of the root canals, the differences in centring between PTN and PTU/RevoS were significant. PTN root canal preparations were more centred than those achieved with all other instruments in the apical third.

Objectives: This current study was performed to evaluate the ability of two rotary filing systems; namely, FKG Dentaire NiTi files (La Chaux-de-Fonds,Switzerland) and ProTaper Next NiTi files (Dentsply Maillefer, Ballaigues, Switzerland) in preservation of canal width and degree of taper after instrumentation in root canal system. Materials and Methods: A total of sixty-four freshly extracted single-rooted first mandibular permanent human premolar teeth with single canals were selected. The teeth were then decoronated and the canals were instrumented. Teeth were then divided into two main groups, consisting of thirty-two each. Root canals were prepared using the FKG Dentaire system in the first group and the PTN (ProTaper Next) system in the second group. Degree of canal width changes and change in canal taper were measured by using the Cone-Beam Computed Tomography (CBCT) before and after root canal instrumentation. Finally, all data were collected and statistically analyzed by the aid of the paired Student's t and Chi-square test. Results: At the minimal width changes measurements, 1mm from the apex, it was found that no significant difference exists between the mean and standard deviation of pre-instrumented and post-instrumented groups using FKG system, (P=0.0756). However, a significant difference exists between the mean and standard deviation of pre- and post-instrumented groups using the PTN system, (P=0.0117). On the other hand, at the maximum width changes measurements, 7mm from the apex, it was found that a significant difference exists between the mean and standard deviation of pre- and post-instrumented groups using FKG system, (P=0.0015). While a highly significant difference exists between the mean and standard deviation of pre- and post-instrumented groups using PTN system, (P=0.0005). Conclusion: Under certain conditions of this study, FKG system appears to remove lesser dentin with more tendency to preserve the canal taper and decrease any unneeded enlargement.

Aim: To evaluate the centering ability of ProTaper Next (PTN) and 2Shape (TS) nickel—titanium (NiTi) instruments in terms of maintaining the original root canal configuration in a simulated tooth with severe curvature. Methodology: Twenty standardized simulated curved root canals were prepared to an apical size of 0.25 mm using PTN and TS (n = 10 canal/group) nickel-titanium files. A gig was constructed to enable reproducible image acquisition using a photographic camera. Pre- and post-instrumented images were recorded and superimposed using a computer software. The ability of the instruments to remain centered in the canal was determined by calculating a centering ratio at three independent points of the simulated canal: coronal, middle and apical third of the curvature, using a computer software. Statistical analysis was performed using one-way analysis of variance (ANOVA) followed by independent sample t-test at 5% significance level. Results: No significant difference was found between the two systems (p &gt; 0.05). At the apical third, the mean centering ratio was significantly higher than the centering ratio of the coronal and the middle thirds in both TS and PTN (p &lt; 0.05). Conclusions: There were no significant differences in the centering ability of the ProTaper Next and 2Shape systems in simulated severe curved canals. Both systems exhibited some degree of transportation, especially in the apical third.

To compare postoperative pain intensity between two single-file systems with different kinetics (the OneShape file with continuous rotation vs. the WaveOne Gold file with reciprocation movement) after primary molar pulpectomy. This superiority, parallel, randomized clinical trial included 164 healthy children aged 6 to 8years with asymptomatic, necrotic, maxillary primary second molars due to caries. An equal number of children were assigned to the two groups. The teeth of children in Group 1 were instrumented with the OneShape rotary system (Micro-Mega), whereas teeth of children in Group 2 were instrumented with the WaveOne Gold reciprocating system (Dentsply Maillefer). Postoperative pain intensity was assessed using a 4-point pain scale at 6, 12, 24, 48 and 72h and 1week after treatment. The parent of each participant received 6 flashcards that included four faces and a word describing each face. A chi-square test was used to compare postoperative pain intensity. The level of significance was set to 5%. Over the follow-up period, no significant difference in postoperative pain intensity was found between the two groups (p>.05). Although the absolute risk reduction maximum limit of 95% CI equal or exceeded the predetermined proportional difference of 0.15, pain intensity was inconclusive at 6, 24, and 48 hours denoting that the superiority of the OneShape single-file over the WaveOne Gold single-file could not be declared. Postoperative pain intensity associated with a rotary vs. reciprocating file system was nearly similar.

Surface alterations of instruments were investigated after single and multiple uses in the root canals. XP-endo Shaper (n=5) and WaveOne GOLD (n=5) files were used until the separation of the instruments occurred. The apical 3-mm and separated fragments were analysed by SEM to determine the changes in the instruments and the cross-sections of the separated fragments. Each group was divided into five subgroups: control, first, second, third and fourth molar. The results were reported descriptively for each group. In the XP-endo Shaper group, microcracks started to appear after the second use, and pitting and galvanic corrosion occurred after the third use. During the fourth use, microcracks propagated, resulting in ductile fracture while it happened after the third use in the second group. The single use of XP-endo Shaper and WaveOne GOLD was safe without any major changes on their surfaces. Reciprocating motion was not necessarily superior to full rotation motion.

Aim: This study compared the apical transportation and centering ratio of ProTaper Next (PTN) and XP-endo Shaper (XPS) nickel titanium (NiTi) rotary files in curved root canals using cone beam computed tomography (CBCT). Methodology: The current in vitro study involved the mesiobuccal canals of mesial roots in 44 extracted mandibular first molars that exhibited apical curvature ranging from 10° to 30°. Two experimental groups were randomly formed from the teeth (n = 22) and subjected to instrumentation with PTN and XPS. CBCT scans were performed before and after instrumentation on the teeth, and the apical transport and centering ratio were calculated at 3, 4, and 5 mm from the apex. Group comparisons were conducted using an independent t-test with a significance level set at alpha = 0.05. Results: Comparisons within groups did not reveal any statistically significant differences in the magnitude of canal transportation in the buccolingual (BL) and mesiodistal (MD) directions at any level from the apex, neither in the XPS group nor in the PTN group (p > 0.05). Canal transportation in both BL and MD directions was significantly greater in PTN than in XPS (p < 0.05). The centering ratio in the MD and BL directions was the same at 3, 4, and 5 mm from the apex in the PTN (p > 0.05) and also in the XPS (p > 0.05) groups. The centering ratio was significantly higher in XPS than in PTN (p < 0.05) except at 5 mm from the apex in the MD direction and 4 and 5 mm from the apex in the BL direction (p > 0.05). Conclusions: Both buccolingually and mesiodistally, PTN led to greater apical transport than XPS and also showed a lower centering ratio.

Objective: This study aimed to evaluate the effectiveness of photon-induced photoacoustic streaming (PIPS), XP-endo Finisher (XPF), and passive ultrasonic irrigation (PUI) for the removal of root canal filling materials from oval root canals. Background: Various adjunctive irrigation techniques following mechanical preparation have been applied to enhance removal of fillings during root canal retreatment. However, whether there is superiority of one approach over others remains controversial. Methods: Thirty extracted single-rooted teeth with oval-shaped canals were instrumented with the ProTaper Next (PTN) system and obturated with the warm vertical compaction technique. After storage at 37°C for 1 month, retreatment was performed with the PTN system up to size X4. The teeth were then randomly assigned into three groups (n = 10) that were, respectively, subjected to supplementary irrigation with different protocols: PIPS, PUI, and XPF, followed by measurement of filling material volumes using high-resolution micro-computed tomography. Results: The PTN preparation resulted in significant reductions in residual filling materials (p < 0.05), whereas PIPS, PUI, and XPF moderately improved the removal of the remnants (p > 0.05). The residual filling materials after supplementary irrigation ranged from 0.384 ± 0.181 to 0.421 ± 0.143 mm3 in oval canals. There was no significant difference in the effectiveness among the PIPS, PUI, and XPF approaches (p > 0.05). Conclusions: Mechanical preparations are useful for removing most root fillings during retreatment in oval-shaped canals. PIPS can reduce residual root-filling materials to the similar extent as PUI and XPF.

The aim of the present study was to compare the effect of etidronic acid (HEBP), NaOCl, and EDTA solutions and their combinations on cyclic fatigue resistance of NiTi RPC Blue (RPC Blue), HyFlex EDM (HEDM), and WaveOne Gold (WOG) instruments having different metallurgic characteristics at the body temperature (37°C). 100 WOG, 100 RPC Blue, and 100 HEDM NiTi files were randomly divided into 5 groups and immersed in the following solutions: group 1, distilled water; group 2, 6% NaOCl; group 3, 17% EDTA; group 4, 18% HEBP; group 5, 6% NaOCl and 18% HEBP. Then the instruments were rotated in an artificial canal until fracture occurred and the number of cycles to fracture was calculated. A univariate analysis of variance and post hoc Tukey tests were then performed for comparisons using SPSS 21.0 software with the significance level set at P < .05. In all the conditions, there was no difference between the cyclic fatigue resistance of WOG and RPC Blue files (P > .05). In the intragroup comparison, WOG, RPC Blue, and HEDM files showed significantly low cyclic fatigue resistance in group 5 compared to other groups (P < .05). Among the groups, there was no statistically significant difference in the fracture lengths (P > .05). EDTA, NaOCl and HEBP solutions did not affect the cyclic fatigue resistance of the tested files when used without combination. However, the combination of NaOCl and HEBP solutions significantly reduced the cyclic fatigue resistance of the tested files.