Topographic changes in NiTi rotary instruments after the clinical use.

This study compared the transportation and centering ability of ProTaper Next (PTN) and WaveOne Gold (WOG) files in curved permanent teeth using micro-computed tomography (μCT). Twenty-four molar teeth with curved roots were divided randomly into two equal groups. The root canals of one group was prepared using PTN files, and the other using WOG files. Pre-instrumentation and post-instrumentation μCT imaging were taken for all the teeth. The dentine thickness of the pre-and the post-instrumentation cross sections was measured at eight different points at three levels: 3, 5 and 7mm from the apex, by two dentists using image analysis software. The data were analysed using one-way ANOVA, at a 5% significance level. The transportation in both groups was within the range accepted in the literature. The WOG file exhibited significantly less root canal transportation compared with the PTN file (p=0.001). The WOG file showed a significantly (p<0.001) higher mean centering ratio of 0.4286 when compared to that of PTN at 0.2448. Using a novel technique to measure canal transportation, this study found that the WOG and PTN systems were both suitable for preparation of curved molar root canals, but the WOG showed significantly less canal transportation and better centering ability than the PTN system.

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.

Objectives: The aim of this study was to compare the apical debris extrusion after using three different single-file systems. Materials and Methods: Mesial roots with curved canals of extracted mandibular molar teeth were randomly divided into three experimental groups according to preparation techniques: the XP-endo Shaper, WaveOne Gold, and One Curve. Previously weighed Eppendorf tubes were used to collect the debris which was placed in a 35°C hot water bath. The weight of the empty tube was subtracted from the final weight after instrumentation and recorded as the amount of extruded debris. The data were analyzed using the Kruskal–Wallis test at a 5% level of significance and compared all groups. Results: XP-endo Shaper presented less debris extrusion than WaveOne Gold and One Curve (P < 0.05). There was no significant difference between the WaveOne Gold and the One Curve files (P > 0.05). Conclusions: All the tested file systems caused debris extrusion. XP-endo Shaper caused less debris extrusion than WaveOne Gold and One Curve files.

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.

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.

Introduction The aim of this study was to evaluate the efficacy of new rotary NiTi instrument XP endo SHAPER (XPS) used with conventional irrigation protocol on the root canal cleaning in the apical area. Material and methods The research was conducted in vitro on 40 extracted single-rooted teeth divided into the four groups. Instrumentation in the first group was performed using iRa Ce NiTi rotary instruments, in the second group the same instruments were used plus XP endo FINISHER (XPF) for smear layer removal. In the third group, canal instrumentation was done using new instrument XPS, and in the fourth XPS instruments plus XPF was used. During the instrumentation 2% NaOCl solution was used for rinsing canals. The SEM analysis of the cleaning quality in the apical third of the canal was performed on longitudinal root cross-sections and standardized microphotography with a 2000x magnification. Results The thickest smear layer in the apical third was recorded in the first group (iRa Ce) NiTi instruments (2.12), and somewhat less in the group with the new XPS instrument (1.95). An identical and somewhat smaller amount of smear layer was registered in the second and fourth groups where XPF was used with the final irrigant (1.64) (p<0.001). Conclusion The application of only one instrument (XPS) in the canal enabled efficient cleaning of a very complex apical third. Cleaning was more efficient when XPF was used with final irrigant after the canal instrumentation.

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.

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.

Aim To evaluate dentinal microcrack formation on root canals instrumented, continuously in the body temperature, with XP-endo shaper (XPES) and ProTaper Universal (PTU), by means of microcomputed tomographic (micro-CT) analysis. Methodology. Nineteen mesial roots with two separate canals (Vertucci Type IV) of extracted mandibular molars were used in this study. The root canals (N = 38) were divided into 2 groups. Group 1 (n = 19): all MB canals were instrumented with XPES. Group 2 (n = 19): all ML canals were instrumented with PTU. All roots were scanned with micro-CT before and after instrumentation. Two precalibrated examiners evaluated the cross-sectional images of each sample with DataViewer program. The dentinal microcracks (complete and incomplete) were counted in each third of the root for the preinstrumentation and the postinstrumentation images. Wilcoxin signed-rank and Mann–Whitney U tests were used for statistical analysis at a significance level of P < 0.05. Results The number of microcracks increased significantly (P < 0.05) after instrumentation with XPES in the middle and cervical thirds. The number of microcracks increased significantly (P < 0.05) after instrumentation with PTU in the cervical third only. There was no significant difference between the groups in the cervical and apical thirds. In the middle third, the XPES induced more incomplete microcracks than PTU (P < 0.05). Conclusion Within the limitations of this study, there was no significant difference in the dentinal microcrack formation between XPES and PTU in the apical and cervical thirds of the root. However, XPES instrumentation induced more incomplete microcracks than PTU in the middle third of human roots.

The present study evaluated the effectiveness of XP-Endo Finisher (XPF) associated with XP-Endo Shaper (XPS) or Reciproc Blue (RB) files in the reduction of Enterococcus faecalis in oval-shaped root canals. Eighty mandibular incisors with single oval-shaped root canals were contaminated with E. faecalis for 10 days at 37°C with centrifugation on alternate days. The teeth were randomly assigned to eight experimental groups (n=10) as follows: G1 – XP-Endo Shaper, G2 – XP-Endo Shaper + XP-Endo Finisher, G3 – Reciproc Blue, and G4 – Reciproc Blue + XP-Endo Finisher. Chemomechanical preparation was performed with saline solution (NaCl) or 2.5% sodium hypochlorite (NaOCl). Microbial reduction was assessed by colony forming units (CFU/mL) count before (S1) and after (S2) CMP by using sterile paper points. ANOVA, Tukey’s test and Bonferroni’s post-hoc tests were used at 5% significance level. Bacteria were present in all initial samples (P&gt;.05). All instrumentation techniques reduced bacteria, irrespective of the irrigating solution (P&lt;.05). With the use of NaCl, Reciproc Blue was more effective than XP-Endo Shaper (P=.035). The association of XP-Endo Finisher improved the cleaning efficacy of both systems (P=.239). With the use of NaOCl, XP-Endo Shaper and Reciproc Blue presented similar effectiveness (P=.779). XP-Endo Finisher enhanced the bacterial reduction of both systems tested (P&lt;.05). The use of NaOCl improved the CMP, irrespective of the instrumentation technique used (P&lt;.05).

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.

The XP-endo Shaper and Its Impact on Posttreatment Discomfort: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

This in vitro study aimed to assess the performance of ProTaper Universal Retreatment (PTUR), Reciproc Blue (RB), and XP-endo Shaper (XPS) system in the removal of bioceramic root canal filling. Forty-five human single-rooted mandibular premolars were prepared up to 30/.04 and filled with Endosequence BC sealer and BC points before being assigned into three groups (n=15). The root canal fillings were removed until reaching predetermined working length (WL) with PTUR in group 1, RB in group 2, and XPS in group 3. During the removal of the filling material, apically extruded debris was collected in pre-weighed Eppendorf tubes, and operation time was recorded with a digital chronometer. Reaching the WL and maintaining apical patency were evaluated separately. The data were statistically analyzed using Kruskal Wallis and Mann Whitney U tests. The mean amount of extruded debris was highest in the PTUR group, although all instruments caused apical extrusion of debris. The mean time for reaching WL was longest for RB and shortest for XPS, with significant differences among the groups (p<0.05). Although the difference was not significant (p=0.799), in the PTUR group the WL was reached in 93.3% of the samples, which was higher than other groups (86.7%). All tested systems caused a certain amount of debris extrusion. XPS was associated with less extrusion while regaining more rapid access to the periapical area than PTUR and RB.

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.

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.