Efficacy of EDDY, ultrasonic activation, XP-endo Finisher and needle irrigation on the removal of mTAP from artificially created grooves in root canals.

This study analysed the effect of needle irrigation (NI), passive ultrasonic irrigation (PUI), EDDY and the use of the XP-endo Finisher (XPF) on the removal of modified triple antibiotic paste (mTAP) from artificially created grooves in root canals. Forty-eight maxillary incisors were prepared up to size 50, with a standard groove on one surface of the root canal wall and filled with mTAP. Re-attached roots were analysed based on the activation techniques applied for 180 s with 5 ml 3% sodium hypochlorite. The results showed that EDDY was more effective at removing mTAP than PUI, XPF and needle irrigation (P < 0.05), whereas XPF and PUI were significantly more effective than needle irrigation. (P < 0.05). No significant difference in mTAP removal was observed between XPF and PUI (P > 0.05). These findings suggest that the removal of mTAP can be more efficiently achieved with EDDY than with XPF, PUI or NI.

Cyclic fatigue resistance of VDW.ROTATE and Reciproc Blue nickel-titanium files at root canal temperature.

Background. This study aimed to compare the VDW.ROTATE instruments with the Reciproc Blue instruments in different kinematics in terms of the cyclic fatigue resistance. Methods. Sixty instruments, 40 VDW.ROTATE and 20 Reciproc Blue instruments, were divided into three groups (n=20): VDW.ROTATE was used in both continuous rotation and reciprocation, and Reciproc Blue was used in reciprocation only. The cyclic fatigue resistance test was carried out in an artificial canal (60°, r=3 mm) at an intracanal temperature of 35±2°C until fracture, and the time to fracture was recorded in seconds. The data were analyzed statistically using Kruskal-Wallis and Tamhane's T2 tests (P<0.05). Results. DAll the reciprocating motion groups resulted in a longer mean duration to failure than the continuous rotation motion group (P<0.05). Conclusion. It was observed that the Reciproc Blue instruments had higher cyclic fatigue resistance than VDW.ROTATE instruments (P<0.05). Recent studies have shown that reciprocal movement increases cyclic fatigue resistance compared to rotational movement. The VDW.ROTATE instrument, which has a similar size, design, and alloy as the Reciproc Blue instrument, can also be used by clinicians in reciprocating motion with endo motors capable of reciprocating in different directions. However, even if the cyclic fatigue resistance increases by using VDW.ROTATE instruments in reciprocation, the cyclic fatigue resistance is lower than Reciproc Blue instruments.

Comparison of the cyclic fatigue resistance of ProGlider, PathGlider and One G path-finding instruments.

Background . The aim of the present study was to compare the cyclic fatigue resistance of novel nickel titanium rotary pathfinding instruments. Methods . Twenty instruments were selected for each file system. A simulated stainless steel root canal, with a 90° angle of curvature and a curvature radius of 3 mm, was used for cyclic fatigue test of the ProGlider (#16, progressive taper: 0.02‒ 0.085), PathGlider (#15, taper: .03), and One G (#14, taper: .03) instruments. Statistical analyses were performed with oneway ANOVA (P=0.05). Post hoc Tukey tests were used to determine any statistically significant differences between the groups. Results . The ProGlider instruments exhibited significantly more cyclic fatigue resistance than both PathGlider and One G instruments (P<0.001). One G instruments had significantly more resistance to fracture than PathGlider instruments (P<0.05). Conclusion . ProGlider instruments had better cyclic fatigue resistance than PathGlider and One G instruments.

Effect of ProTaper Gold, Self-Adjusting File, and XP-endo Shaper Instruments on Dentinal Microcrack Formation: A Micro-computed Tomographic Study.

INTRODUCTION: The aim of the present study was to evaluate the frequency of dentinal microcracks observed after root canal preparation with ProTaper Universal (PTU; Dentsply Tulsa Dental Specialties, Tulsa, OK), ProTaper Gold (PTG; Dentsply Tulsa Dental Specialties), Self-Adjusting File (SAF; ReDent Nova, Ra'anana, Israel), and XP-endo Shaper (XP; FKG Dentaire, La Chaux-de-Fonds, Switzerland) instruments using micro-computed tomographic (CT) analysis. METHODS: Forty extracted human mandibular premolars having single-canal and straight root were randomly assigned to 4 experimental groups (n = 10) according to the different nickel-titanium systems used for root canal preparation: PTU, PTG, SAF, and XP. In the SAF and XP groups, the canals were first prepared with a K-file until #25 at the working length, and then the SAF or XP files were used. The specimens were scanned using high-resolution micro-computed tomographic imaging before and after root canal preparation. Afterward, preoperative and postoperative cross-sectional images of the teeth were screened to identify the presence of dentinal defects. For each group, the number of microcracks was determined as a percentage rate. The McNemar test was used to determine significant differences before and after instrumentation. The level of significance was set at P ≤ .05. RESULTS: The PTU system significantly increased the percentage rate of microcracks compared with preoperative specimens (P < .05). No new dentinal microcracks were observed in the PTG, SAF, or XP groups. CONCLUSIONS: Root canal preparations with the PTG, SAF, and XP systems did not induce the formation of new dentinal microcracks on straight root canals of mandibular premolars.

Efficacy of XP-endo finisher and TRUShape 3D conforming file compared to conventional and ultrasonic irrigation in removing calcium hydroxide.

The aim of this study was to compare the efficacy of the XP-endo Finisher and TRUShape 3D Conforming File to conventional and ultrasonic irrigation techniques for removing calcium hydroxide from artificially created grooves on root canals. The study used 32 human mandibular premolar teeth, which were decoronated and instrumented up to ProTaper Universal F5 (Dentsply Maillefer; Ballagiues, Switzerland). The teeth were split longitudinally, two standardised grooves were prepared in the apical and coronal portions and filled with calcium hydroxide. Each tooth was reassembled with wax. The samples were stored at 100% humidity at 37°C for 1 week, after which the specimens were grouped and irrigated using needle irrigation, ultrasonic irrigation, XP-endo Finisher via continuous irrigation or TRUShape 3D Conforming File via continuous irrigation. Two calibrated observers scored the amount of calcium hydroxide remaining, and the data were statistically analysed using the Kruskal-Wallis and Mann-Whitney U-tests, (P < 0.05). Needle irrigation had the poorest scores (P < .001), while the XP-endo Finisher, TRUShape 3D Conforming File via continuous irrigation and ultrasonic irrigation groups had similar results in removing calcium hydroxide.

Comparison of cyclic fatigue resistance between different NiTi instruments with 4% taper.

The aim of this study was to make a comparison between the cyclic fatigue (CF) resistance of F360, twisted files (TF), FlexMaster (FM) and RaCE instruments with 4% taper. A total of 40 instruments were evaluated 8 mm from the tip. A stainless steel block with a simulated canal of 1.5 mm diameter, and a 60° angle of curvature was tested using CF testing. One-way ANOVA and posthoc Tukey's test (P < 0.05) were used. The F 360 files showed the highest CF resistance while the TF files had greater CF resistance than the FM and RaCE (P < 0.05). There was no significant difference between the FM and RaCE (P > 0.05). F360 instruments with a double S cross-section had the highest CF resistance among the group. The TF led the NiTi rotary files to be more resistant to fatigue than the FM and RaCE instruments.

Influence of Instruments Used in Root Canal Preparation on Amount of Apically Extruded Debris.

The aim of the present study was to compare the effects of ProTaper Gold, WaveOne Gold, ProTaper Universal, and WaveOne instruments on the amount of apically extruded debris. Eighty mandibular premolar teeth with straight root canals were selected and assigned to four groups (n = 20). The root canals were instrumented using ProTaper Gold, WaveOne Gold, ProTaper Universal, and WaveOne systems. Eppendorf tubes containing apically extruded debris were weighed three times, and mean values were calculated. The net mass of the extruded debris was calculated by subtracting the initial mass from the final mass. The groups were compared using one-way analysis of variance and Tukey's post hoc tests at a significance level of P < 0.05. The PTG group extruded less debris than the PTU group, and the WOG group extruded less debris than the WO group (P < 0.05). All the instrumentation systems tested in the present study were associated with apical extrusion of debris.

Micro push-out bond strength of resin cement in roots exhibiting the butterfly effect.

The aim of this study was to determine the bond strength of resin cement in root sections with or without butterfly effect. Fifteen single-rooted human maxillary central incisors were decoronated and prepared up to size 40. After post space preparation, the resin cement was placed into the post space and the fiber posts were luted. 1 mm thickness slices were obtained and the presence of the butterfly effect was recorded. A push-out test was then used to measure the bond strength between the resin cement and root dentin. Data were analyzed using independent samples of t and χ(2) tests (p = 0.05). The sections exhibiting butterfly effect showed higher push-out bond strength values than those of without butterfly effect (p < 0.05). Butterfly effect can influence the push-out bond strength. Thus, this phenomena should be taken into account, when push-out bond strength test is performed. Root sections exhibiting butterfly effect resulted in higher push-out bond strength values to root sections without butterfly effect.