Effect of various single file systems on microcrack formation in root canals: Scanning electron microscope study

Background: In endodontics, the three processes of biomechanical preparation, disinfection, and obturation are each essential. The electron microprobe and scanning electron microscope (SEM) allowed for the detection and identification of the smear layer and debris. The purpose of the current investigation was to use a scanning electron microscope to evaluate the relative merits of two single-file systems, the reciprocating WaveOne and the continuous motion F360 files, in the cleaning and contouring of root canals in removed teeth. Materials and method: The 50 central maxillary permanent teeth Data was gathered from the Oral and Maxillofacial Surgery Division at Sri Ganganagar's Maharaja Ganga Singh Dental College and Research Centre for a number of reasons. Group A followed the manufacturer's guidelines for using the WaveOne instrument, whereas Group B utilised the F360. Reciprocating motion WaveOne system (group A) and continuous motion F360 system (group B) root canals were scored at three levels: coronal third, middle third, and apical third (group B). SPSS version 22 was used for the data analysis. The data were examined using the chi-square test and the one-way analysis of variance. Results: A greater quantity of smear layer was found in the apical third, whereas better results were achieved in the coronal and middle thirds. When compared to the F360 file system, the WaveOne file system is subpar when it comes to clearing the canal of debris. While both groups showed a large amount of debris in the apical third, outcomes were somewhat better in the coronal and middle thirds. Conclusion: The WaveOne and F360 file systems were both more effective in removing trash from the coronal and middle thirds of the disc than they were from the apical thirds. In comparison to the continuous motion F360 file system, WaveOne files demonstrated a statistically significant reduction in the amount of debris cleared from root canals in all three root zone thirds (coronal, middle, and apical). The reciprocating action of the WaveOne file system, in contrast to the continuous motion of the F360 file system, resulted in more extensive cleaning of the root canal smear layer in the coronal and middle thirds and less thorough cleaning in the apical thirds of the canal.

Objectives: The aim of this study was to compare the shaping ability of four different single-file systems; WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), Reciproc (VDW), OneShape (Micro Mega), and F360 (Komet Brasseler, Lemgo, Germany). Stainless steel K-file (KSS) (Dentsply Maillefer, Ballaigues, Switzerland) was used as a control during the preparation of simulated root canals. Materials and Methods: Eighty L-shaped canals in resin blocks were prepared to an apical size of 25 using one of the five groups (each group = 16). A series of pre- and post-operative images were taken by a digital camera (EOS 650D. Canon) and superimposed on two different layers. The amount of resin removed from both the inner and the outer sides of the canal were measured at five different points: orifice, half way of the orifice, beginning of the curvature, apex of the curve, and the apical end. The amount of resin removed by each system was measured using image analysis software. Canal aberrations and the preparation time were also recorded. The data were statistically analyzed by using analysis of variance, Tukey's post hoc, and Chi-square tests. Results: There are significant differences between all single files and KSS in time for preparation (P Conclusion: Within the limitation of this study, NiTi instruments are superior to stainless steel K-files in their shaping ability. All single-file systems maintained root canal curvature well and were safe to use. Canals prepared with the F360 and OneShape systems were better centered compared with the Reciproc and WaveOne systems.

Background The apically extruded debris [AED] is an unwanted complication during root canal preparation, especially in curved canals. Purpose This study aimed to assess the impact of the glide path on the quantity of AED during root canal preparation with three different single-file systems with improved alloy technology in extremely curved canals. Materials and Methods One hundred and twenty maxillary teeth with severe curvature [25°-45°] were randomly assigned to six groups [n=20]. No glide path was created in three groups, whereas in the remaining three groups, a glide path was established in the mesiobuccal canals. Root canal instrumentation of the mesiobuccal canals was performed using three single-file systems: Reciproc Blue [RCB], WaveOne Gold [WOG], and TruNatomy [TN]. AED was collected in pre-weighed Eppendorf tubes, which were subsequently stored in an incubator at 37 °C for two weeks. The weight of the dry extruded debris was determined by subtracting the pre-instrumentation weight from the post-instrumentation weight of the Eppendorf tubes. Statistical analysis was conducted using the Kruskal-Wallis test followed by Dunn’s post-hoc test with Holm correction [p<0.05]. Results RCB and WOG without glide path extruded significantly more debris than other groups [p<0.05]. The canal preparation required significantly less time in teeth with a glide path than the teeth without a glide path [p<0.05]. Conclusion Within the limitations of this in vitro study, all tested instruments caused debris extrusion. A glide path significantly reduced the amount of AED and the preparation time. TN files extruded less debris compared with RCB and WOG.

Factor that should be considered in the use of irrigation is the loss of the smear layer on root canal walls. Therefore the prepared root canal can be irrigated using materials, such as EDTA 17% and 2,5% NaOCl and of extract Acanthus ilicifolius 7,5% and 10%. To determine the potential of extract Acanthus ilicifolius leaves as an alternative of root canal irrigation in removing smear layer at a concentratiom of 7,5% and 10%. The type of this study is a laboratory experimental with post-test only control group design. The total sample is 24 teeth samples that have been prepared and irrigated consisting of four groups. 6 samples for irrigation 7,5% extract Acanthus ilicifolius, 6 samples for irrigation 10% extract Acanthus ilicifolius, 6 positive control samples for combination 2,5% NaOCl and EDTA 17%, and 6 negative control samples. Shooting tool used to observe the cleanliness level in the walls of the root canal is a Scanning Electron Microscope (SEM). Data were analyzed using Kappa statistics, followed by Kruskal wallis analysis test and continued with Mann-Whitney analysis. Acanthus ilicifolius 7.5% and 10% extracts can remove the smear layer when compared with the negative control group. The combination of 2.5% NaOCl and 17% EDTA is better in smear layer removal compared to 7.5% and 10% Acanthus ilicifolius extracts. Acanthus ilicifolius was able to clean the smear layer on the root canal and can be used as an alternative root canal irrigation.

The aim of this study was to evaluate the efficiencies of the self-adjusting file (SAF) system, passive ultrasonic irrigation (PUI), and conventional irrigation (CI) in removing calcium hydroxide (CH) from root canals. Fifty-one mandibular premolars were used. After root canals were instrumented and filled with a CH paste, 45 teeth were randomly assigned to three experimental groups according to CH removal technique: SAF system, PUI, or CI. The remaining 6 teeth served as positive and negative controls. All samples were evaluated by scanning electron microscopy (SEM) and scored. None of the techniques removed CH completely. However, results at coronal, middle and apical thirds showed that PUI technique was significantly more effective than SAF and CI in removing CH dressing residues from root canal walls.

Background/purposeRoot fractures after endodontic treatment are a serious complication, and it often causes tooth loss, several studies have found a correlation between root canal preparation and filling, and the possibility of root fracture. Therefore, this study aimed to evaluate the root fracture resistance of the endodontically treated mandibular premolars after preparing and filling by EndoSequence Bioceramic (BC), EndoSequence BC HiFlow, and AH Plus (AHP).Materials and methodsThe study sample consisted of 75 single-rooted and single-canal mandibular premolars, they were randomly distributed into five groups: Group I: root canals preparation and fillings with AHP sealer; Group II: root canals preparation and fillings with EndoSequence BC sealer; Group III: root canals preparation and fillings with BC HiFlow sealer; Group IV (Negative Control): without root canals preparation; and Group V (Positive Control): canals preparation without root canals filling. A glide path was established by #10 hand K-file, then the crowns were cut, and the canals were prepared and filled. All teeth were restored with glass ionomer cement and kept in an incubator at 37°C for a week. All samples were placed within acrylic bases and a vertical force was applied using a Testometric machine and the fracture resistance force was recorded.ResultsEndoSequence BC and BC HiFlow groups showed slightly better fracture resistance (494.440, 496.960 N respectively) than AHP group (492.680 N). However, no statistically significant difference was found between the two groups (P-value >0.05). The greatest mean fracture force was observed in the positive control group (736.040 N) with statistically significant difference between the other groups (P-value <0.01) and the least mean fracture force was shown in the negative control group (318.040 N) with statistically significant difference between the other groups (P-value <0.01).ConclusionBased on this in vitro study, the use of EndoSequence BC, BC HiFlow, and AHP enhanced the fracture resistance in root-filled single-rooted premolar teeth. While, the application of EndoSequence BC, BC HiFlow, and AHP did not increase the fracture resistance of roots compared to that of unprepared root canals.

Objective: This study aimed to examine the effects of three distinct file systems with two motion types—rotary and reciprocation—on the development of dentinal microcracks after root canal preparation using a stereomicroscope. Methods: Sixty mandibular molars with a curvature of 30° were decoronated and divided into three groups (Vortex Blue, Mtwo, and ProTaper Next) and two subgroups (rotary and reciprocating motions). The samples were then instrumented with the files, dyed with 1% methylene blue dye, and sectioned horizontally at 3, 6, and 9 mm from the root apex. The dentinal microcracks were inspected using a stereomicroscope at 40× magnification. One-way analysis of variance and post hoc Tukey tests were used to perform statistical analysis. Results: Crack formation was statistically significant at the 6-mm and 9-mm levels from the root apex in both motions (p &lt; 0.05). Among all the file system, Vortex Blue caused the highest dentinal microcracks in both motions at 6 mm from the root apex. Conclusion: The reciprocating motion resulted in fewer dentinal microcracks than the rotary motion. All file systems caused significant dentinal microcracks at the curvature of the root canal during both motions. Dentinal microcrack formation was not significant at the root apex.

Introduction: Knowledge on shaping ability of advanced Nickel Titanium (NiTi) rotary instruments holds a great significance in the field of endodontics. Root canal shaping systems should maintain the original canal anatomy and thereby, reduce the risk of iatrogenic errors. Aim: To compare and evaluate the canal transportation, centering ability and time taken for preparation of curved root canals after instrumentation with F6 SkyTaper, Navigator EVO and One Shape file systems using Cone Beam Computed Tomography (CBCT) imaging. Materials and Methods: This was an in vitro study conducted in the Department of Conservative Dentistry and Endodontics, I.T.S Centre for Dental Studies and Research, Ghaziabad, Uttar Pradesh, India in July 2020. Thirty mesiobuccal canals of extracted mandibular molars with an angle of curvature between 20 to 40 degrees were selected and divided into three groups (n=10 into each group): F6 SkyTaper (group I), Navigator Evo (group II) and One Shape (group III). Canals were biomechanically prepared till size 30/6%; scanned using CBCT, before and after instrumentation to evaluate shaping ability at 3 mm, 5 mm, 7 mm and 9 mm from the apex. The results were subjected to statistical analysis using Analysis of variance (ANOVA) and Bonferroni post-hoc test with level of significance set at p-value &lt;0.05. Results: Out of three file systems selected, Navigator EVO showed significantly least canal transportation (0.222) (p-value &lt;0.05) and highest centering ability (0.535) as compared to F6 SkyTaper and One Shape. Overall, F6 SkyTaper and One Shape showed comparable results with respect to canal transportation and centering ability. The F6 Skytaper showed the fastest preparation (75.72 sec) of canals while Navigator EVO took the maximum time (307.046 sec). Conclusion: Navigator EVO showed superior shaping ability in curved canals than single file systems, although the time taken was the least with F6 SkyTaper.

Ni-Ti alloy remnants after root canal preparation with Ni-Ti engine-driven files: a preliminary report

The purpose of this ex vivo study was to evaluate the biomechanical preparation and obturation of root canals using ProTaper, WaveOne, Reciproc and Self-Adjusting File systems. It was evaluated: 1) area, perimeter, roundness, major diameter, minor diameter, surface area, volume and SMI after biomechanical preparation, using microcomputed tomography (TC), 2) percentage volume of voids in the obturation material by means of TC, 3) bond strength (BS) and type of failure after the pushout test, and 4) the analysis of the interface dentin / filling material using scanning electron microscopy (SEM). One-hundred human mandibular canines were scanned in the SkyScan 1174v.2 device. After preparing the coronal third of the canals, the teeth were divided into 4 groups (n=25), according to the biomechanical preparation system used: ProTaper, WaveOne, Reciproc, and Self-Adjusting File (SAF). After the second TC, eigthteen specimens of each group were assigned to two groups (n=9), according to the obturation technique: the Modified Continuous Wave of Condensation Technique and the technique recommended by the manufacturer. The remaining seven specimens of each group were used as negative and positive controls. After scanning, the obturated specimens were sectioned perpendicularly to its long axis into 1-mm slice thickness of the coronal, middle and apical thirds. The bond strength (BS) was performed by the push-out test and, after dislodgments, the failures were observed in a digital microscope. The specimens were processed for SEM analysis to observe bonding interface formation and resin tag density using a four-step scale method. Overall, the analysis of the biomechanical parameters showed that the most significant changes in the root canal occurred in the ProTaper group and WaveOne groups. Reciproc results were in an intermediate level and smaller changes were observed in the SAF group (ANOVA, p<0.05). In the coronal third, the Modified Continuous Wave of Condensation Technique showed a lower percentage volume of voids than the technique recommended by the manufacturer (Kruskal-Wallis test, p<0.05). After the push-out test, the analysis indicated the mean BS (MPa) was significantly higher in specimens filled by the manufacturer's technical than the Modified Continuous Wave of Condensation Technique (t test for independent samples, p<0.05). The adhesive failures were frequent in all groups. The Modified Continuous Wave of Condensation Technique showed the highest percentage of adhesive failure in dentin while in the technique recommended by the manufacturer, mixed failure was predominant. Overall, in SEM analysis, no tags were observed in most of the specimens filled by the Modified Continuous Wave of Condensation Technique. When present, they were small and irregularly distributed. The specimens filled by the technique recommended by the manufacturer showed long and well-distributed tags, especially in the apical third (Friedman test, p<0.05). It was concluded that all systems promoted root canal changes after the biomechanical preparation, the obturation technique recommended by the manufacturer resulted in a higher volume of voids in the coronal third and BS of the Modified Continuous Wave of Condensation Technique group.

Thermal and microstructural events resulting from KTP laser use during root canal preparation were investigated in 30 extracted single-rooted human teeth. In the first section of this study, thermal events occurring on the root surfaces of 18 teeth during and after exposure of the root canal were measured using thermography. A variety of parameters were used to determine settings that would be effective without causing thermal damage to the periodontal ligament. In the second section of the study, root canals of 12 teeth exposed to KTP laser irradiation at parameters derived from section 1 were evaluated using Scanning electron microscopy. KTP laser application at a power setting of 3 W, an exposure time of 2 s, and a frequency of 5 Hz, applied five times, removed smear layer and debris from the root canal surface at temperatures below the thermal injury threshold for periodontal tissue.

This in vitro study compared and assessed two endodontic handpieces during the preparation of root canals in extracted human teeth. Eighty extracted human teeth, with single root canals, were divided into eight matched groups. They were prepared using Shaper files activated by the MM1500 Sonic Air handpiece (Micro-Mega, Besançon, France) or Excalibur files activated by the W & H Excalibur 969 handpiece (W & H, Bürmoos, Austria). The files were 21 mm or 25 mm in length. When preparing the canals, the files were used either in line with or perpendicular to any canal curvature. Preparation of the canals was carried out using the techniques described in the manufacturers' literature. A variety of parameters were used to compare the handpieces, including canal preparation time, deformation or fracture of instruments, loss of canal length, weight loss from the prepared teeth and the overall postpreparation canal shape. A microradiographic technique was used to produce a tracing record of the pre- and postpreparation canal shape. Both handpieces provided an efficient and easy method of preparing and shaping the root canal with little operator fatigue. The MM1500 Sonic air handpiece took significantly more time (P < 0.001) to prepare the canals than the Excalibur. Few aberrations in the shapes of prepared canals were created by either handpiece. No endodontic file fractured but a few of them were permanently deformed. The effects of two variables--file length and the plane of use of the file--on performance of the handpieces, were also assessed.

Aim: The aim of this study was to compare the efficacy of 980 nm diode laser and QMix 2in1 solution (DENTSPLY Tulsa Dental Specialties) alone and in combination, for smear layer removal from the root canals. Background: Smear layer is an amorphous layer formed on root canal walls following instrumentation. This layer should be removed as it can harbor bacteria and bacterial products and prevents the penetration of intracanal medicaments into the dentinal tubules. Irrigation agitation techniques have been proposed recently to remove smear layer from root canals more efficiently. The diode laser has the potential for irrigant activation and studies are needed to establish their efficacy for smear layer removal especially from apical thirds of canals. Methods: Forty extracted single-rooted permanent human teeth were used. Root canals were prepared to full working length using manual K-files (MANI) till 40K. Prepared teeth were divided into four groups (n=10): Group 1, no irrigation; Group 2, QMix 2in1 solution; Group 3, diode laser; Group 4, QMix 2in1 in combination with a diode laser. The roots were split longitudinally and prepared for scanning electron microscopic (SEM) investigation. The split roots were examined for remaining smear layer at the coronal, middle, and apical portion of each canal under a scanning electron microscope (JSM5910, JEOL, Japan) at 1000x magnification. Results: Smear layer removal was scored according to Guttman rating system for remaining smear layer scores (Gutmann et al.). Diode laser in combination with QMix solution had the least smear layer scores. Conclusions: Diode laser irradiation in combination with QMix 2in1 solution effectively removes smear layer from apical thirds of root canals.

This study aimed to evaluate and compare the quality of matching single-cone obturation using three different single-file systems—WaveOne® Gold (Dentsply Sirona, Bensheim, Germany), Reciproc® blue (VDW GmbH, Munich, Germany), and Procodile® (Komet Medical, Gebr. Brasseler GmbH &amp; Co. KG, Lemgo, Germany). The evaluation focused on the percentage of gutta-percha-filled areas (PGFAs), sealer-filled areas (PSFAs), and unfilled areas (PUAs) across three different sections of curved and straight root canals. Sixty extracted human teeth were categorized into six groups. Based on radiographically determined root canal curvature, thirty curved and thirty straight root canals were prepared using the single-file systems according to the manufacturers’ instructions and obturated with matching gutta-percha cones using AH-Plus sealer. A total of 180 sections were evaluated digitally under the microscope and the results were statistically analyzed. The mean gutta-percha percentages for Reciproc® blue, Procodile®, and WaveOne® Gold were 83%, 82%, and 80%, respectively. No significant (p &gt; 0.05) and relevant (ηp2 &lt; 0.10) differences were found in the proportion of form-fitting gutta-percha cones between the systems in all sections. Similarly, canal anatomy showed no significant influence (p &gt; 0.05). Ex vivo, all three systems showed comparable filling quality in all sections of curved and straight canals. Therefore, it can be concluded that all three file systems, in combination with their corresponding gutta-percha points, might be reliable methods for root canal obturation. Reciproc® Blue, Procodile®, and WaveOne® Gold consistently achieved comparable obturation results across various root configurations and levels of the root canal.

The objective of the study was to examine whether argon laser has a property to remove debris and smear layer from root canal walls. Twelve endodontically treated human maxillary molar teeth with three root canals were divided into two groups of six teeth. The first group was left unlased as a control; in the second group the root canals were irradiated by argon laser (laser parameters were set at 1 W and pulse duration and pulse frequency fixed at 0.05 s and 5 Hz). After the usual root canal preparation and lasing had been carried out, the teeth were decoronated, bisected longitudinally, observed with a scanning electron microscope and evaluated as to how clean the surfaces of root canal walls were. In most cases control teeth presented surfaces with debris covering the root canals, obscuring the dentinal tubules. Only 1 of 18 specimens was free of debris. In the lased group, root canal surfaces free of debris and vaporized pulpal tissue remnants were observed in 13 of 18 specimens. The results showed significant statistical differences between the control group and the lased groups (P < 0.001). These results suggested that argon laser irradiation has an efficient cleaning effect on instrumented root canal surfaces.