Curved Canals Research Articles

Comparative Evaluation of the Cyclic Fatigue Resistance of WaveOne Gold in Reciprocation, ProGlider in Rotary Motion, and Manual Files in a Reciprocating Handpiece Within Simulated Curved Canals: An In Vitro Study.

Aim This study compares the cyclic fatigue resistance of glide path files versus manual files used with a reciprocating handpiece in simulated curved canals, specifically evaluating WaveOne Gold Glider, ProGlider, stainless steel (S.S.) K files, nickel-titanium (NiTi) K files, and Flexo K files. Materials and methods Seventy-five instruments were divided into five groups of 15. Simulated canals with a 45° angle and a 5 mm radius of curvature were created using laser micromachining on S.S. blocks. A reciprocating endodontic handpiece (TEP-ER10, NSK, Japan) was used for the manual files and an X-Smart Plus endo motor for the rotary files. The time to fracture was recorded via videography. Statistical analysis was performed using analysis of variance (ANOVA) and post-hoc Tukey tests. Results Flexo files exhibited the highest mean cyclic fatigue resistance (1690.33 ± 456.97 seconds), followed by WaveOne Gold Glider (872.13 ± 210.08 seconds), NiTi K files (760.73 ± 163.86 seconds), S.S. K files (707.60 ± 257.98 seconds), and ProGlider (371.00 ± 66.02 seconds). Fragment length differences were statistically insignificant among the groups. ANOVA showed significant differences in cyclic fatigue resistance but not in fragment length. Conclusion Flexo files showed superior cyclic fatigue resistance, making them ideal for glide path formation. NiTi and S.S. K files with a reciprocating handpiece performed similarly to WaveOne Gold Glider, providing a cost-effective alternative to rotary systems, especially in resource-limited areas. ProGlider had the lowest resistance, highlighting the advantage of reciprocating motion in enhancing durability.

Micro-CT Evaluation of Centering Ability and Canal Transportation of Protaper Ultimate and RevoS+ Rotary File Systems in Simulated Curved Canals

Purpose
 A successful root canal preparation is to remove infected dentin and pulp tissue and to obturate the canal three-dimensionally. This study aimed to compare the centering ability of Protaper Ultimate and RevoS+ rotary file systems in curved canals of printed mandibular first molars by using micro-computed tomography (micro-CT). 
 Materials and Methods
 In this in-vitro study, 16 mandibular molar teeth were printed from resin with 45° mesial root curvature. Root canal preparation was performed according to the specified groups, either Protaper Ultimate or RevoS+. The pre-and post-preparation images were repositioned in all three spatial planes by DataViewer. All images were imported into the CTAn software for the calculation of the centering ability and transportation values. 
 Results
 The results showed no significant differences between the Protaper Ultimate and RevoS+ groups in terms of the centering ratio in the most inclined part of the canal. There were also no significant differences between the groups in canal transportation. (p>0.05)
 Conclusions
 Protaper Ultimate and RevoS+ rotary file systems showed similar ability in centering ratio and canal transportation in curved canals from printed mandibular molars.

Cone-beam Computed Tomographic Analysis of Apical Transportation and Centering Ratio of TruNatomy and V-taper 2H NiTi Rotary Systems in Curved Canals: An In Vitro Study

Cone-beam Computed Tomographic Analysis of Apical Transportation and Centering Ratio of TruNatomy and V-taper 2H NiTi Rotary Systems in Curved Canals: An In Vitro Study

Preparation Activities of Different Ni-Ti File Systems in Curved Canals

Preparation Activities of Different Ni-Ti File Systems in Curved Canals

In-Vitro study to Assess Effect of a Glide Path on Canal Transportation and Centering Ratio in Double Curved canals.

Objective: In endodontic treatment, creating a glide path became one of the recommended essential principles to obtain a safe preparation as possible; so the aim of the research is to evaluate the efficiency of the R-Pilot system in glide path preparation within the double curved canals.Study design: A laboratory study to assess the efficiency R-Pilot mechanical patency system on the shape marinating of the canal. Those criteria were used to evaluate the change in the original shape of the canal, Canal Transportation and Centering Ratio. The data were analyzed using SPSS V.13 program and the correlation between the variables were defined using descriptive statistics and inductive statistical tests (chi-square, T Student for independent samples, ANOVA).Results: no significant difference between the two glide path creation systems was found in terms of the deviation amount from the canal centric. whereas, between the R-Pilot system and the manual preparation, significant difference was found in the preserving rate of the canal centric at both the coronal area and the entire canal.Conclusion: glide path creation in the previously mentioned methods with confirmation on the importance of the mechanical patency in terms of speed, Reducing the effort and burden imposed on the practitioner compared to the use of manual files. XP Endo shaper had lower deviation values and more ability to save the shape and centric of the canal.

Comparative Evaluation Of Apical Transportation and Canal Centering Ability Of Various NickelTitanium Rotary Systems In Curved Canals Using Cone-Beam Computed Tomography: An In Vitro Study

Comparative Evaluation Of Apical Transportation and Canal Centering Ability Of Various NickelTitanium Rotary Systems In Curved Canals Using Cone-Beam Computed Tomography: An In Vitro Study

Comparison of Canal Transportation and Centering Ability of ProGlider and WaveOne Gold Glider in Curved Canals

Objectives The aim of this study was to compare the volume variation and maintenance of the root canal position when using the ProGlider 16.02 (PG) and the WaveOne Gold Glider 15.02 (WOGG) file systems for glide path preparation. Materials and Methods Twenty-four moderately curved mesiobuccal canals of maxil-lary first molars were selected and randomly divided into two groups: PG and WOGG. The selected teeth were scanned using microtomography before and after root canal preparation to assess centralization and linear transport at 1, 3, 5, and 7 mm from the apical foramen. Statistical Analysis The data were analyzed with the Mann–Whitney U test. The level of significance was 5%. Results There were no significant differences in volume variation or root canal transport ( p > 0.05). There was a significant difference in the centralization of the root canal at 3 mm from the foramen ( p < 0.05). Conclusions WOGG and PG instruments presented similar results regarding the root canal volume increase and transport. WOGG caused higher decentralization at 3 mm from the apical foramen.

Root Canal Preparation and Enlargement Using Thermally Treated Nickel-Titanium Rotary Systems in Curved Canals

IntroductionThe purpose of this study was to evaluate root canal preparation and apical enlargement of curved canals using rotary heat-treated and heat/surface-treated systems by micro–computed tomographic imaging. MethodsCurved mesial root canals (n = 48) of mandibular molars (20°–40°) were prepared using ProDesign Logic (PDL; Easy Equipamentos Odontológicos, Belo Horizonte, MG, Brazil) 25/.01 and 25/.06 or HyFlex EDM (HFEDM) 10/.05, HyFlex CM 20/.04, and HFEDM 25/.08. Apical enlargement was performed using PDL 40/.05 or HFEDM 40/.04. Scanning (9 μm) was performed before and after preparation and after apical enlargement using micro–computed tomographic imaging. Volume, percentage of volume increase, debris, untouched root canal surface, and centering ability were analyzed. Statistical analysis was performed using Mann-Whitney, Wilcoxon, and unpaired t tests (α = .05). ResultsHFEDM promoted a higher volume increase of the root canals than PDL after preparation and after apical enlargement (P < .05). The apical enlargement promoted a significant decrease in debris and untouched surface in both groups (P < .05). The percentage of debris and untouched surface were similar between HFEDM and PDL after preparation and after apical enlargement (P > .05). Both systems promoted centered canals (P > .05). ConclusionsHFEDM instruments promoted greater volume of the root canal than PDL. However, the cleaning ability of the instruments was similar. The apical increase up to size 40 with both instruments provided less debris and untouched surfaces and allowed centralization of the curved root canals.

Management of Separated Instruments in Apical Third of Extremely Curved Canals: A Case Report

This report describes the case of a 23 years old male patient who presented with the chief complaint of pain in mandibular right lower first molar tooth. Detailed clinical and radiographic examination revealed acute pulpitis in lower right second premolar and first molar teeth. During root canal instrumentation, a rotary instrument separated at the apical third of mesiobuccal canal. After careful assessment, it was decided to bypass the instrument and obturate the root canal space with warm vertical compaction using thermoplasticized gutta percha and resin based sealer materials. After considering the curvature of canal, thin root of tooth and location of broken instrument in the apical third of canal space, attempts of instrument removal were ruled out as a treatment option for the patient. Bypassing the broken instrument fragment with pre-curved hand files of small sizes was chosen as a predictable treatment option since it is not associated with removal of excessive remaining dentin from the roots of the teeth. Hence, teeth do not become weak and risk of post-operative root fracture is minimized. Due to successful bypassing and preparation of root canal space beyond broken instrument, canal was shaped, cleaned and disinfected adequately. Decision of instrument bypassing or removal should be taken with extreme care. Bypassing the instrument in apical third of root canal space with thin rooted teeth is the most conservative and practical approach, and objectives of adequate shaping and cleaning of canals can be achieved successfully without compromising remaining tooth structure.

Comparative Evaluation of Root Canal Transportation by Three NiTi Single-File Systems in Curved Canals: A Cone Beam Computed Tomography Study.

Introduction This study is aimed at evaluating root canal transportation in the mesiobuccal canal of mandibular first molars prepared with One Shape, Reciproc, and M-One nickel titanium (NiTi) single-file rotary systems using cone beam computed tomography (CBCT). Materials and Methods In this ex vivo study, CBCT scans of 45 extracted human mandibular first molars with 20–40° curvature were obtained. The teeth were randomly divided into three groups (n=15) for preparation of the mesiobuccal canal with One Shape, Reciproc, and M-One rotary systems according to the manufacturers' instructions. CBCT scans were obtained again after canal preparation. Changes caused by preparation in the coronal, middle, and apical thirds were determined on CBCT scans and analyzed using the Kruskal–Wallis test at P ≤ 0.05 level of significance. Results No significant difference was noted in the amount of canal transportation among the three groups (P > 0.05). M-One caused greater transportation in the apical third compared with Reciproc and One Shape, and One Shape caused greater transportation in the coronal third compared with other groups, although its magnitude was less than 0.3 mm. Conclusion Reciproc, One Shape, and M-One are not significantly different in terms of canal transportation.

Cyclic Fatigue Life of Two Single File Engine-Driven Systems in Simulated Curved Canals.

Introduction:This study aimed to evaluate the cyclic fatigue resistance of two single file engine-driven instruments, Reciproc and NeoNiTi, in simulated root canals. Methods and Materials: Two groups of 15 NiTi endodontic instruments with an identical tip size of 0.25 mm were tested: Reciproc R25 (group A) and NeoNiTi A1 (group B). Cyclic fatigue testing was performed in a stainless steel artificial canal. The simulated canals had a 60° angle and 5-mm radius curvature. The Reciproc instruments were operated using the preset program on torque control electric motor specific for the Reciproc instruments, while the NeoNiTi instruments were operated using the manufacturer recommendation. All instruments were rotated until fracture occurred, and the number of cycles to fracture (NCF) and the length of the fractured tip were recorded and registered. Means and standard deviations of NCF and fragment length were calculated for each system and data were subjected to Student’s t test (P<0.05). Results:A statistically significant difference (P<0.05) was noted between Reciproc and NeoNiTi instruments. NeoNiTi A1 instruments were associated with a significantly higher mean NCF as compared to Reciproc R25 instruments (833±176 vs. 318±87 NCF). There was no significant difference (P>0.05) in the mean length of the fractured fragments between the instruments. Conclusion:NeoNiTi instruments were associated with a significantly higher cyclic fatigue resistance than Reciproc instruments.

Comparison of the Shaping Ability of Various Nickel Titanium File Systems in Simulated Curved Canals

Comparison of the Shaping Ability of Various Nickel Titanium File Systems in Simulated Curved Canals

An In vitro Comparison of Apically Extruded Debris Using Reciproc, ProTaper Universal, Neolix and Hyflex in Curved Canals.

Introduction:As a consequence of root canal preparation, dentinal chips, irrigants and pulp remnants are extruded into preradicular space. This phenomenon may lead to post endodontic flare-ups. The purpose of this study was to compare the amount of extruded debris with four endodontic NiTi engine-driven systems. Methods and Materials:Sixty mesiobuccal roots of maxillary molars with 15-30˚ curvature were divided randomly into four groups (n=15). Each group was instrumented up to apical size of 25 using Reciproc, ProTaper Universal, Neolix and Hyflex. Bidistilled water was used as irrigant and extruded debris was collected in pre-weighted Eppendorf tubes. Tubes were stored in incubator for drying the debris. Extruded debris were weighted in electronic microbalance with accuracy of 0.0001 g. The raw data was analyzed with one way analysis of variance (ANOVA) and Tukey’s HSD post hoc test. Level of significance was set at 0.05. Results:The debris extrusion with Reciproc files was significantly higher than the other groups (P<0.05). Hyflex significantly extruded less debris than other files (P<0.05). There was no significant difference between ProTaper Universal and Neolix regarding the amount of extruded debris (P=0.98). Conclusion:All systems extruded debris during the instrumentation. Reciproc system significantly extruded more debris. Caution should be taken when interpreting the results of this study and applying it to the real clinical situation.

Glide Path Management with Single- and Multiple-instrument Rotary Systems in Curved Canals: A Micro–Computed Tomographic Study

IntroductionSecuring a reproducible glide path before instrumentation is recommended to maintain the original geometry of the root canal system and to prevent file separation. Mechanical glide path management systems have been introduced to expedite this step. The aim of this study was to compare apical transportation, canal volume increase, and working time during glide path management with ProGlider (PG; Dentsply Tulsa Dental Specialties, Tulsa, OK) and PathFiles (PF, Dentsply Tulsa Dental Specialties). MethodsForty curved mesial canals of mandibular molars were randomly allocated into 2 experimental groups (n = 20) according to the glide path management system: PG or PF. A glide path was achieved according to the manufacturers' protocol. Micro–computed tomographic analysis was performed to assess apical transportation at 1, 3, and 5 mm and volume increase. The time required to achieve the glide path was measured. ResultsThe overall apical transportation mean values (± standard error) were 13.33 ± 3.37 μm for PG and 19.21 ± 4.4 μm for PF (P > .05). The mean (± standard error) volume increase values were 0.49 ± 0.06 mm3 for PG and 0.48 ± 0.06 mm3 for PF (P > .05). A statistically significant difference in the working time was found between the groups (P < .0001) where the mean (± standard error) values for time were 7.38 ± 1.73 seconds for PG and 20.61 ± 5.54 seconds for PF. ConclusionsSimilar apical transportation and volume increase occurred during glide path management with PG single-file and PF multi-file systems; however, PG achieved glide path faster than PF.

Evaluation of the Shaping Characteristics of ProTaper Gold, ProTaper NEXT, and ProTaper Universal in Curved Canals

IntroductionThis study evaluated the shaping characteristics of the ProTaper Gold system (PTG; Dentsply Maillefer, Ballaigues, Switzerland) and compared it with that of the ProTaper Next (PTN, Dentsply Maillefer) and ProTaper Universal (PTU, Dentsply Maillefer) systems using micro–computed tomographic imaging. MethodsTwenty-four mandibular first molars with 2 separate mesial canals were matched anatomically using micro–computed tomographic scanning (SkyScan1174v2; Bruker-microCT, Kontich, Belgium) with a voxel size of 19.6 μm. Canals were prepared with PTG, PTU, or PTN rotary systems to F2 or X2 instruments, respectively, and scanned again. Coregistered images were evaluated for 2- and 3-dimensional morphometric measurements of canal transportation, centering ability, untouched canal walls, and remaining dentin thickness. Data were statistically compared using Kruskal-Wallis and 1-way analysis of variance tests (α = 5%). ResultsOverall, PTN showed significantly higher percentage values of static voxels than PTG and PTU systems (P < .05). Surface area, perimeter, and minor diameter were higher in the PTG and PTU groups than in the PTN group (P < .05). No difference was observed in form factor, roundness, major diameter, aspect ratio, or structure model index (P > .05). PTG (0.11 ± 0.05 mm) and PTN (0.09 ± 0.05 mm) produced significantly less transportation than PTU (0.14 ± 0.07 mm) (P < .05), and the percentage decrease in dentin thickness was significantly lower for PTG (22.67 ± 2.96) and PTN (17.71 ± 5.93%) (P ≥ .05) than PTU (29.93 ± 6.24%) (P < .05). ConclusionsPTG and PTN produced less transportation and maintained more dentin than PTU. PTN had less canal wall contact than PTG and PTU, but all file systems were able to instrument moderately curved mesial root canals of mandibular molars without clinically significant errors.

FINITE ELEMENT ANALYSIS OF STRESS DISTRIBUTION ON CANAL WALLS WHILE PREPARATION OF CURVED CANALS

Objective: The aim of this study is to determine stress evaluation of root canal wall during shaping curved canals with ProTaper and HeroShaper systems by using three-dimensional finite element universal. Methods: The geometries of the ProTaper Universal and HeroShaper Ni-Ti rotary systems’ selected files were created using three-dimensional finite element modelsThe three-dimensional FEA model within a curved canal was established by integrating a simulated canal and natural tooth. A micro-focus CT scanner was used to scan the models. After integration and modification a final three-dimensional model with a smooth surface and mostly centered canal was established. The stresses on the instrument during simulated shaping of a root canal were analyzed numerically by using a three-dimensional finite element package, LS-DYNA, taking into account the nonlinear mechanical behavior of the nickel-titanium material. Stress distribution in the instruments and the canal walls was recorded during simulated shaping. Results: With ProTaper file system, stress concentrations were determined towards the outer aspect of the curvature in the apical portion of the canal but in HeroShaper system stress was more concentrated in the middle portion of the canal and were less than ProTaper model. Conclusion: HeroShaper files cut more efficiently and generated less stress on the canal walls than ProTaper files because of their possitive rake angle. It was observed that there was stress concentration towards the outer aspect of the curvature in the apical portion of the canal with the ProTaper file system. This shows us that these files are more feasible for apical transportation. Key words: Curved canals, HeroShaper, ProTaper, finite element analysis, stress

The Influence of Apical Seat Diameter On The Quality Of Obturation In Curved Canals

Australian Endodontic NewsletterVolume 20, Issue 1 p. 29-30 The Influence of Apical Seat Diameter On The Quality Of Obturation In Curved Canals Ross Applegarth, Ross Applegarth 9th Floor, Watkins Medical Centre, 225 Wickham Terrace, Brisbane, QLD. 4000Search for more papers by this author Ross Applegarth, Ross Applegarth 9th Floor, Watkins Medical Centre, 225 Wickham Terrace, Brisbane, QLD. 4000Search for more papers by this author First published: April 1994 https://doi.org/10.1111/j.1747-4477.1994.tb00435.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume20, Issue1April 1994Pages 29-30 RelatedInformation