Mtwo System Research Articles

The Effect of Different Obturation Techniques Using Different Root Canal Sealers on the Residual Filling Material After Retreatment Procedures.

This study aimed to compare the effect of different obturation techniques with root canal sealers on the residual filling material after retreatment using SEM. Sixty (60) single rooted mandibular premolars were selected and instrumented with rotary files using the Mtwo system up to file size 30/.05 taper. The samples were randomly divided to two groups based on the type of sealer and three sub-groups (n=10) based on the obturating technique used. The root fillings were removed using the PTUR system files and the specimens were longitudinally sectioned while digital images were obtained from the root canals with SEM. The time required to reach working lenght were recorded. There was no difference in terms of the smear score when comparing both sealer and obturation technique groups in the apical third. Smear scores were significantly affected by the type of sealer and obturation technique in the medium and coronal thirds of root canals (p<0.05). Higher smear scores were obtained with GFB than AH Plus (p<0.05). The time required to reach working length with GFB was longer than AH Plus (p<0.05). Residual filling material was observed in all samples, regardless of the root canal sealer or the obturation technique used. There was a significantly lower smear scores in the AH Plus groups as compared to the GFB.

The effect of sealer type and obturation technique on the fracture resistance of endodontically treated roots.

This study evaluated the effect of sealer type with various obturation techniques on the fracture resistance of root filled teeth. Eighty mandibular premolars were collected, and root canals of 70 of them were prepared by Mtwo system up to 40/04. Thirty teeth were obturated using TotalFill BC sealer, and 30 using AH Plus sealer, with one of the obturation techniques (N = 10), namely cold lateral compaction (CLC), warm vertical compaction (WVC), and single cone (SC). Ten teeth were left without obturation as a positive control, and the other 10 teeth were not prepared serving as a negative control. Teeth were stored for 3weeks, and the crowns were separated and the roots were subjected to fracture test using a universal testing machine. Data was analyzed by ANOVA followed by Tukey's test. Fracture resistance of the TotalFill groups was significantly higher than the AH Plus groups in each obturation technique, and SC had the highest fracture resistance regardless of sealer used (P < 0.05). Obturation of the root canal by TotaFill BC sealer increased the calcium/phosphorous ratio in the dentin of the root. Obturation with TotalFill BC sealer improved the fracture resistance of the roots more than AH Plus sealer, and obturation with SC resulted in higher fracture resistance than CLC and WVC. Obturation of the root canal with Bioceramic sealer with single cone obturation technique could reduce the incidence of vertical root fracture.

Optimization of endodontic root canal treatment in pediatric dentistry (a systematic literature review)

Early loss of primary teeth is an important problem in pediatric dentistry. One of the most difficult aspects during treatment of the complications of caries in primary teeth is the duration of treatment. The introduction of rotary nickel-titanium systems made endodontic treatment in primary teeth easier and faster. Thereby, the aim of the present work was to conduct a systematic review with elements of the network meta-analysis and an indirect comparison of different rotary endodontic systems in terms of the time spent for endodontic treatment in primary tooth canals using the common comparator «manual treatment with K-files». Seven articles were included in the final analysis, which revealed statistically significant heterogeneity of the included data from laboratory randomized controlled trials (ProTaper/K-file: I2 = 85; p = 0.00001 and Mtwo/K-file: I2 = 95; p = 0.00001). A systematic review of the articles revealed a trend toward designating the Mtwo (VDW) system as the least time-consuming mechanical root canal preparation in primary teeth.

Post-Endodontic Pain after Root Canal Treatment of Symptomatic Teeth with Mtwo and Safe Sider Multiple File Systems: A Randomized Clinical Trial

Background: Considering the increasing popularity of rotary files among dental clinicians and the emergence of several types of rotary systems, clinical trials are necessary to compare these systems from various aspects. Objectives: This study compared post-endodontic pain following the use of Mtwo and Safe Sider multiple file system. Methods: A total of 150 maxillary and mandibular molars with symptomatic irreversible pulpitis were selected. Their root canals were randomly instrumented with hand files, Mtwo and Safe Sider instruments. The severity of postoperative pain was assessed using a Visual Analog Scale (VAS) at 6, 12, 24, 48 and 72 hours. The data were analyzed using repeated measures ANOVA. P&lt;0.05 was considered statistically significant. Results: The mean postoperative pain score significantly decreased in all three groups over time. The mean pain score at 12 and 24 hours post-treatment was significantly higher in the Safe Sider group compared to the other two groups. At 6, 48 and 72 hours, no significant difference was noted in the severity of pain among the three groups. Conclusions: Postoperative pain is significantly higher at 12 and 24 hours following endodontic treatment with Safe Sider compared to the conventional hand instruments and Mtwo system.

Shaping ability of reciprocating and rotary systems in oval-shaped root canals: a microcomputed tomography study.

This study compared the shaping ability of single-file reciprocating (WaveOne Gold) and multifile rotary (Mtwo) systems on mandibular oval-shaped canine root canals, using microcomputed tomography (micro-CT). Thirty mandibular canines were scanned by micro-CT and assigned to one of two groups (n=15) according to the system used for root canal preparation: WaveOne Gold or Mtwo. After preparation, the teeth were rescanned, and the percentage of untouched canal area, apical transportation and centering ability were analyzed. The data was evaluated using Kruskal and Mann- Whitney tests (p<0.05). No difference was found in percentage of unprepared canal area between groups in the entire root canal or the apical third, or in centering ability (p>0.05). WaveOne gold had less canal transportation than MTwo at the 5 mm section (p<0.05). WOG and Mtwo systems presented similar shaping ability and centering ability in oval-shaped canals. However, WOG presented less transportation than Mtwo at 5 mm from the apex.

Real-time co-site optical microscopy study on the morphological changes of the dentine’s surface after citric acid and sodium hypochlorite: a single-tooth model

BackgroundTo this day, the effects of sodium hypochlorite and chelating agents on the smear layer and on the dentine’s surface, remain not fully examined. The study is aimed to analyze the dentine's surface treated with 40% citric acid and 5.25% sodium hypochlorite according to two irrigation protocols.Materials and methodsThe study employed a computer-controlled Nikon Eclipse LV100 optical microscope. Ten roots split longitudinally with canals prepared mechanically using the MTwo system to a size of 40/04 were observed. The root halves were divided into two study groups, one half in each of the groups. According to two irrigation protocols, the dentine's surface was irrigated with 40% citric acid and 5.25% sodium hypochlorite, separated with water. Dentine surface was observed in a fixed place and photographed in 500 × magnification after each irrigation stage. The obtained images were then analyzed using computer software (NIS-Elements AR, GIMP-2.6, ImageJ 1.45s).ResultsVarious speed of removal of the smear layer and varied morphological changes of the dentine's surface were observed in both examined groups. Double irrigation of the dentine with citric acid for 30 s resulted in complete removal of the smear layer, and double irrigation for 60 s resulted in increased mean diameter of the dentine tubules (degradation of the dentine's surface).ConclusionsDouble alternating irrigation with citric acid and sodium hypochlorite for 30 s yielded satisfactory results, while double irrigation for 60 s resulted in increased mean diameter of the dentine tubules. A real time assessment of the dentine’s surface changes after both tested solutions can improve understanding of the phenomena that occur during the irrigation and as a result it might help to improve clinical outcomes in root canal treatment.

Shaping efficiency of XP-endo shaper and Mtwo instruments in long oval root canals: A micro-CT study.

This study evaluated the shaping ability of XP-endo Shaper and Mtwo systems in long-oval-shaped canals of extracted human mandibular molars using micro-computed tomography (micro-CT). Images recorded before and after preparation were evaluated for morphometric measures regarding increase in canal volume, dentin removed, surface area, untouched walls and structure model index (SMI). Data were statistically analysed using the Mann-Whitney test with 5% of significance. On both groups, the root canal preparation significantly increased all analysed parameters (P > 0.05). There was no statistical difference between XP-endo Shaper and Mtwo systems in the increase of the canal volume (30.50%-27.82%), in volume of dentin removed (2.77%-2.40%), in the increase of the canal surface area (11.30%-8.86%), in canal untouched surfaces (9.57%-8.51%) and in the SMI (2.59%-2.68%), respectively. XP-endo Shaper and Mtwo systems showed similar shaping efficiency and were not able to completely prepare the walls of long-oval-shaped canals of extracted human mandibular molars.

Could the Calcium Silicate-Based Sealer Presentation Form Influence Dentinal Sealing? An In Vitro Confocal Laser Study on Tubular Penetration.

Dentinal tubule penetration influences root canal treatment sealing. The aim of this study was to compare dentinal penetration of two clinical presentations of silicate-based sealers using confocal laser. Sixty single-rooted human teeth from 50–70 year-old patients extracted for orthodontic/periodontal reasons were used. Canals were prepared using Mtwo system up to 35/0.04, with 5.25% NaOCl irrigation and final irrigation using 17% EDTA. Teeth were randomly assigned into study groups (ni = 20): EndoSequence BC sealer (ES, group 1), BioRoot RCS (BR, group 2); and a control group (nc = 20) with AH Plus (AHP). Root canals were obturated with 35/0.04 gutta-percha (single-cone technique). The samples were obtained from apical, middle, and coronal thirds. Dentinal tubule penetration depth and percentage of penetration around the canal perimeter were measured. The statistical analysis was performed using Mann Whitney U test and Wilcoxon t-test (95% confidence interval). ES exhibited a significantly higher penetration than AHP in apical and middle thirds (p < 0.05), and in middle and coronal thirds relative to BR (p < 0.05). The percentage of penetration around the canal perimeter was significantly higher for ES compared to BR in all thirds, but only in the apical third for AHP (p < 0.05). The pre-mixed silicate-based sealer exhibited better penetration than the powder/liquid one.

Evaluation of surface characteristics of new rotary nickel-titanium instruments - SEM-EDS analysis

Introduction. Modern endodontic procedure implies the use of rotary Ni-Ti instruments during chemomechanical treatment of root canals. The aim of this study is to analyze the surfaces of new (unused) rotary endodontic instruments using the SEM-EDS method and determine how frequently manufacture defects or impurities appear on their working surfaces. Material and method. Five new different sets of rotary endodontic Ni-Ti instruments were included in this study: K3, Mtwo, ProTaper Universal, HyFlex and BioRaCe. The working part of endodontic instrument was analyzed using SEMEDS method (magnifications ?150 to ?2000), which determined the morphological characteristics of the instrument surface and chemical composition of the found impurities. Statistical analysis was performed using the Fisher?s test (p &lt; 0.05). Results. The results of SEM-EDS analysis showed that there is no new instrument without defects on its surface. The most common defects were observed in K3 (27.43%) and ProTaper Universal group (27.21%) and the least were in BioRaCe instruments (7.67%). The most common type of defect in tested instruments was fretting. In addition, the presence of debris and metal strips was found on all instruments, while corrosion of the working part was observed only in K3, ProTaper Universal and Mtwo systems in a small percentage. Conclusion. Based on the results of this research, it can be concluded that manufacturing defects were noticed in all examined instruments. The most common defect is pitting. Impurities such as debris and metal strips have also been registered. No organic debris was observed on electropolished surface of BioRaCe instruments, but a small percentage of other types of defects were registered.

Shaping ability of two root canal instrumentation systems in oval-shaped canals: A microcomputed tomography study.

The objective was to evaluate the shaping ability of XP-endo Shaper and Mtwo systems in oval-shaped canals preparation by microcomputed tomography (micro-CT) along the entire canal. The volume, surface area and percentage of unprepared area were evaluated by image processing in entire canal and apical third (5mm). Apical transportation and centring ability were evaluated at 3, 5 and 7mm from the apex. Forty single-canal oval canines were paired in two groups (n=20) according to the instrumentation system: XP-endo Shaper and Mtwo. The teeth were scanned by micro-CT before and after instrumentation, using a thermal vat at 37°C. The XP-endo Shaper system was more effective in the instrumentation of oval-shaped canals when compared to Mtwo system, resulting in greater volume increases and lower percentage of unprepared canals walls in apical region. Regarding apical transportation and centring ability, no statistical difference was observed.

Evaluation of Penetration Depth of Sodium Hypochlorite Into Dentinal Tubules After Passive Ultrasonic Irrigation Compared to Er;Yag Laser Activation. An In-Vitro Study

Objectives: The aim of this study was to compare penetration depth of sodium hypochlorite into dentinal tubules after passive ultrasonic agitation or ER; YAG activated irrigant.Materials and Methods: Twenty-four single rooted human mature mandibular premolars were decoronated and accessed. After locating the apex and determining the working length, preparation of root canal was done up to #35 file using Mtwo system and with 5.25 NaOCl irrigation. Teeth were then sealed apically with wax and submerged in a crystal violet dye for 48 hours to stain dentin. NaOCl Irrigation was activated with either Ultrasonic or ER;YAG laser. Specimens were sectioned longitudinally and depth of bleached zone was evaluated under a stereomicroscope 40X.Results: Penetration depth was significantly higher in overall root canal in ultrasonic group than ER; YAG laser group (P=.000). In ER;YAG Laser group, the highest penetration depth was in the coronal third followed by middle and third, with significant difference between apical third and both middle and coronal thirds (P=.009, .003 respectively), and no significant difference between middle and coronal thirds (P=.083). Highest penetration depth was seen in middle third for no significant deference in penetration depth between the three thirds of the root canal activated with Ultrasonic (P=.664). Conclusion: ultrasonic activation can lead to more NaOCl penetration into dentinal tubules than activation with ER;YAG.

Shaping Ability of Reciproc R25 File and Mtwo System Used in Continuous and Reciprocating Motion

Nickel-titanium (NiTi) instruments were designed to be used in continuous rotation mode with controlled speed and torque and a sequence of different sizes. The reciprocating motion was purposed to improve cyclic fatigue of rotary instruments if compared to the conventional rotation. The purpose of this work was to compare the shaping ability of Reciproc R25, Mtwo #25/0.06 used as a single file, and Mtwo sequence used in reciprocating motion and in continuous rotation. Forty-eight endodontic training resin blocks ISO 15, 2% taper, 7 mm radius, and a 60° angle of curvature were shaped with four different protocols. Group I (Rrsf) was shaped with Reciproc R25 used as a single file in a reciprocating motion. Group II (Mrsf) was shaped with Mtwo #25/0.06 used as a single file in a reciprocating motion. Group III (MSrec) was shaped with Mtwo sequence in reciprocating motion, and finally, group IV (MSrot) was shaped with the Mtwo sequence used in continuous rotation. Preoperative and postoperative images of the simulated canals were taken under standardized conditions and combined exactly. The amount of resin removed was determined at both the inner and outer sides of the canal curvature. The ability of the instruments to remain centered in the canal was determined by calculating a centering ratio. These data were analyzed statistically using two factors analysis of variance (ANOVA) with Bonferroni correction (Bonferroni post-hoc test). Group Rrsf produced a greater enlargement of the canal, especially on the outer side, in the apical and middle third (p < 0.05). Group MSrot produced a lower enlargement in the middle third (p < 0.05). Group Rrsf displayed a lower centering ratio in the apical third (p < 0.05). Group MSrot displayed a lower centering ratio in the coronal third (p < 0.05). The shaping of simulated canals using a sequence of instruments in continuous rotation resulted in a more centered preparation of the apical third. The reciprocating motion for all tested instruments produced a bigger enlargement of the canals. Reciprocating movement results in a more pronounced canal enlargement but appears to be less respectful of the original canal curvature and produces more apical transportation than a sequence of rotary NiTi files with the same ending apical size.

Evaluation of the amount of apically extruded debris using different root canal instrumentation systems

The purpose of this study was to evaluate the amount of apically extruded debrisusing 5 types of nickel–titanium endodontic instruments (Hand ProTaper, RotaryProTaper, Rotary Mtwo, RECIPROC and WaveOne). Seventy-five freshly extractedmandibular premolar teeth were used in this study. All teeth were shortened to alength of 14mm. The specimens were randomly divided into five groups (each groupcontaining 15 samples) according to the type of instrumentation systems used. GroupI: instrumented by hand ProTaper system (Hand technique). Group II: instrumentedby rotary ProTaper system. Group III: instrumented by rotary Mtwo system. Group1V: instrumented by single file RECIPROC system. Group V: instrumented by singlefile WaveOne system. Debris extruded from the apical foramen was collected intopre-weighed glass vials. The difference between the weights of vial (pre-weight andpost-weight) represented the weight of debris extruded from apical foramen duringcanal preparation. The results showed that all groups induced extrusion of debris,Mtwo group (III) has statistically the lowest mean value of apically extruded debris incomparing with all other groups, followed by rotary ProTaper (II), hand ProTaper (I),and WaveOne (V) groups respectively. While the RECIPROC group (IV) hasstatistically highest mean value.

Evaluation of the amount of apically extruded debris using different root canal instrumentation systems

The purpose of this study was to evaluate the amount of apically extruded debrisusing 5 types of nickel–titanium endodontic instruments (Hand ProTaper, RotaryProTaper, Rotary Mtwo, RECIPROC and WaveOne). Seventy-five freshly extractedmandibular premolar teeth were used in this study. All teeth were shortened to alength of 14mm. The specimens were randomly divided into five groups (each groupcontaining 15 samples) according to the type of instrumentation systems used. GroupI: instrumented by hand ProTaper system (Hand technique). Group II: instrumentedby rotary ProTaper system. Group III: instrumented by rotary Mtwo system. Group1V: instrumented by single file RECIPROC system. Group V: instrumented by singlefile WaveOne system. Debris extruded from the apical foramen was collected intopre-weighed glass vials. The difference between the weights of vial (pre-weight andpost-weight) represented the weight of debris extruded from apical foramen duringcanal preparation. The results showed that all groups induced extrusion of debris,Mtwo group (III) has statistically the lowest mean value of apically extruded debris incomparing with all other groups, followed by rotary ProTaper (II), hand ProTaper (I),and WaveOne (V) groups respectively. While the RECIPROC group (IV) hasstatistically highest mean value.

Root canal adaptation and intra-tubular penetration of three fiber-post cementation systems

BackgroundTo measure the penetration of three bonding systems for the luting of fiber glass posts in endodontically treated teeth, using confocal laser scanning microscopy (CLSM).Material and MethodsA total of 30 maxillary incisors were shaped with the Mtwo system and filled with gutta-percha and Top Seal cement. The sample was divided into three groups (ni=10) according to the bonding system used to cement the posts: Group 1 (Prime&Bond NT and Rebilda DC with a total-etch technique); Group 2 (Futurabond DC and Rebilda DC with a dentin self-etch technique); and Group 3 (BisCem self-adhesive cement). Rhodamine B was added to the bonding systems to allow visualization by CLSM. Three 1-mm thick cross-sections were obtained of each root at a distance of 2, 5 and 8 mm from the coronal limit of the root. The specific software of the CLSM system was used to measure the percentage of the root canal perimeter showing penetration of the bonding system in the dentinal tubules, together with the maximum depth of penetration. Comparison between groups were made by Kruskal Wallis test, and comparison two by two groups with Mann-Whitney U-test.ResultsDepth of penetration of the resin tags, were distributed from greater to lesser depth as follows: BisCem > Prime&Bond NT > Futurabond DC. BisCem showed significantly greater penetration in the middle and apical thirds than the rest of the systems (906.14±67.42 and 699.27±76.26 µm, respectively). The percentage perimeter exhibiting penetration in the coronal third was significantly greater with BisCem versus Futurabond DC (56.08±7.24 and 44.38±5.23%, respectively). No significant differences were recorded in the middle and apical thirds among the three systems.ConclusionsBisCem resulted in greater depth of intratubular penetration at all studied levels. The percentage perimeter of the canal showing penetration was similar for all the bonding systems. Key words:Fiber post luting, sealer adaptation, confocal laser scanning microscope.

Counterclockwise or clockwise reciprocating motion for oval root canal preparation: a micro-CT analysis.

To evaluate oval root canal preparation using one or two instruments in counterclockwise or clockwise reciprocating motion. The radiographic diameter of mandibular human incisors was evaluated, and oval canals were selected (2≤Diameter Ratio≤4). Fifty-seven teeth were assigned to root canal preparation (n=19): Reciproc 40 (R40) in a counterclockwise reciprocating motion; Mtwo size 40, .06 taper (M 40.06) in a clockwise reciprocating motion or Mtwo size 20, .06 taper and size 40, .06 taper (M 20/40.06) in a clockwise reciprocating motion. Mtwo instruments were coupled to an ENDO DUAL motor, turning 150° clockwise and 30° counterclockwise. Scanning was performed before and after root canal preparation using a SkyScan 1176 micro-computed tomography. Volume, percentage of debris and percentage of uninstrumented surface were analysed in the entire root canal and in each third of the canal. Data were compared using anova and Tukey's tests or Kruskal-Wallis and Dunn tests. The Reciproc and Mtwo systems using different kinematics were associated with a similar increase in root canal volume. Additionally, both system had similar percentage of uninstrumented surface (P>0.05). Mtwo size 20, .06 taper and size 40, .06 taper was associated with significantly lower debris (P<0.05) in the middle third (0.56%) when compared to R40 (1.31%) and M size 40, .06 taper (1.54%). The conventional reciprocation motion for R40 and the clockwise reciprocation motion for Mtwo resulted in similar root canal preparations. Less remaining debris was present in the middle third when two instruments with different diameters were used.

A Comparative evaluation of three different Ni-Ti rotary files using Crown Down technique. An Exvivo study using C T scan

Objective: This ex-vivo study evaluated and compared the canal transportation of the prepared root canals and centering ratio maintained by Mtwo, Protaper and Twited Ni-Ti rotary files using Crown-Down technique.Materials and Method: Thirty non-carious extracted permanent human maxillary central incisors without any fracture and having Vertucci type I canal configuration were selected. The teeth were divided into 3 groups each group comprising of ten teeth. All the teeth were mounted on a wax block and pre instrumented canal CT Scan was performed. Access cavity preparation was done in group samples and canal was prepared using crown down technique by Mtwo, Protaper and Twisted NiTi Rotary file systems for the respective groups. Image analysis was done at 9 levels to access transportation and centricity ratio from pre and post instrumented CT scan images. The results showed that Software program determined the volume of pre and post instrumented canals.Results: The Canal transportation occurred least in root canals prepared by Twisted files, followed by canals prepared by Mtwo files and Protaper files. Centricity ratio was maintained the best in root canals prepared by twisted files.Conclusion: Within the parameters of this study, canals prepared by Twisted Files showed a well centered preparation and maintained the original shape of the root canal without any aberrations.Bangladesh Journal of Medical Science Vol.16(2) 2017 p.212-218

Automatic Electronic Device Used for the Evaluation of Cyclic-Fatigue Resistance of Nickel-Titanium Instruments

The aim of this study was to evaluate the cyclic-fatigue fracture of different Nickel-Titanium motor-driven rotary instruments (ProTaper® Universal, ProFile®, and Mtwo® systems) in artificial canals by means of an Automatic Electronic Device (AED). The study was performed using Nickel-Titanium instruments 25/0.06 evaluated in canals with a 45-degree curvature and 2-mm radius. The analyses evaluated two parameters: fracture by cyclic fatigue, and time of fracture; in addition, the length of separated fragment was evaluated. Medians and range values were calculated for each group. Data were analyzed by the Kruskall–Wallis and Mann–Whitney U tests to determine statistical difference. The ProFile motor-driven rotator system exhibited highest resistance to fracture due to cyclic fatigue and highest fracture time compared with the ProTaper and Mtwo systems (p &lt;0.05). The equipment proposed in this study (AED) demonstrated efficiency for recording information, automation, scheduled work times and durations, cycle number, time of fracture, pressure changes and, principally control of the human factor.

Automatic Electronic Device Used for the Evaluation of Cyclic-Fatigue Resistance of Nickel-Titanium Instruments

The aim of this study was to evaluate the cyclic-fatigue fracture of different Nickel-Titanium motor-driven rotary instruments (ProTaper® Universal, ProFile®, and Mtwo® systems) in artificial canals by means of an Automatic Electronic Device (AED). The study was performed using Nickel-Titanium instruments 25/0.06 evaluated in canals with a 45-degree curvature and 2-mm radius. The analyses evaluated two parameters: fracture by cyclic fatigue, and time of fracture; in addition, the length of separated fragment was evaluated. Medians and range values were calculated for each group. Data were analyzed by the Kruskall–Wallis and Mann–Whitney U tests to determine statistical difference. The ProFile motor-driven rotator system exhibited highest resistance to fracture due to cyclic fatigue and highest fracture time compared with the ProTaper and Mtwo systems (p &lt;0.05). The equipment proposed in this study (AED) demonstrated efficiency for recording information, automation, scheduled work times and durations, cycle number, time of fracture, pressure changes and, principally control of the human factor.

The root canal shaping ability of WaveOne and Reciproc versus ProTaper Universal and Mtwo rotary NiTi systems

Aim: The aim of this study is to compare the root canal shaping ability of two reciprocating instruments: WaveOne and Reciproc versus two rotary instruments – ProTaper Universal (PTU) and Mtwo. Materials and Methods: A total of 160 simulated root canals in resin blocks were constructed with two curvatures located at two positions creating four different combinations: 20°/8 mm, 20°/12 mm, 40°/8 mm, and 40°/12 mm. Canals were prepared using continuous rotation (PTU and Mtwo) or reciprocating (WaveOne and Reciproc) instruments according to the manufacturer's recommendations. Each system was used to prepare 10 canals of each shape. Each file or a set of files was used to prepare one canal. Using Image Analysis Software, pre- and post-instrumentation matching images were superimposed and analyzed for canal width and transportation. Instrument fractures, time of preparation, and change in working length were also recorded. The effect of instrument and canal type on shaping ability were analyzed using two-way ANOVA test followed by post hoc Pearson Chi-square test and sum of squares test at level of significance 5%. Results: The largest mean canal width and transportation values were associated with the Mtwo system (P Conclusions: Continuous rotation and reciprocating files were safe and maintained the original canal anatomy. However, continuous rotation instruments have a higher tendency for canals transportation and aberrations, especially with larger curvatures. Reciprocating files were faster than continuous rotation files in shaping simulated root canals in resin blocks.