Flexible Files Research Articles

Comparative Analysis of Cyclic Fatigue Resistance of NeoEndo Flex Vs Protaper Gold Rotary Files: An In-Vitro Study

Background: During the endodontic process, cleaning and shaping are essential steps. The fracture of nickel-titanium (NiTi) tools is a procedural issue that significantly impedes therapy in normal endodontic therapy. Efficient and reliable endodontic therapy requires rotary NiTi files that demonstrate superior cyclic fatigue resistance to prevent file separation within the canal. This study aimed to investigate the in-vitro cyclic fatigue resistance of two commonly used rotary NiTi files: NeoEndo Flex file and ProTaper Gold file. Methods: The cyclic fatigue tests were carried out by determining the lifespan of each file type in a controlled environment mimicking a curved root canal. A total of 30 files (15 NeoEndo Flex and 15 ProTaper Gold) were subjected to continuous rotation until fracture occurred. The numbers of cycles until failure (NCF) were recorded for statistical comparison. Results: The ProTaper Gold files showed significantly higher NCF, indicative of stronger cyclic fatigue resistance when compared to NeoEndo Flex files (p < 0.05). The variance in fatigue resistance is attributable, in part, to differences in alloy composition and proprietary heat treatment processes. Conclusion: ProTaper Gold rotary NiTi files exhibited enhanced cyclic fatigue resistance in comparison to NeoEndo Flex, suggesting that they may be the preferred choice for clinical procedures where greater stresses are anticipated on the file. However, clinicians should balance file strength with other clinical factors when choosing the appropriate file for endodontic treatment.

CBCT Comparison of the Remaining Dentin Thickness Following Biomechanical Teeth Preparation using Edge Endo X7, Hero Gold, and Neo Endo Flex Rotary File Systems: An In-vitro Study

Introduction: Success in endodontics depends on canal preparation, disinfection, and obturation. Cleaning and shaping play a pivotal role in successful endodontic therapy. An important factor in preventing procedural mishaps and further complications is the quantity of dentine removed during instrumentation because the fracture resistance of the root is directly influenced by the amount of dentine that remains after instrumentation. Aim: To evaluate and compare the remaining dentine thickness of the root canal after instrumentation with three different rotary file systems using Cone Beam Computed Tomography (CBCT) imaging. Materials and Methods: Thirty permanent extracted, singlerooted teeth were collected. The samples were decoronated at the level of the Cementoenamel Junction (CEJ). A preinstrumentation CBCT scan was taken. Access opening and working length were determined. The samples were randomly assigned to three groups: Group I - Edge Endo X7, Group II- Hero Gold, Group III - Neo-endo flex files. Biomechanical preparation was carried out using the respective files. To evaluate the remaining dentine thickness, a comparison was made with the pre-instrumentation CBCT scan. Statistical analysis was performed using One-way ANOVA. Results: Upon inter-group comparison of the pre-instrumentation group, no significant difference (p≥0.05) was observed. Postinstrumentation, it was noted that the remaining dentine thickness in Group I (p≤0.05) at the apical third was significantly less than in Group II (p=0.007) and Group III (p=0.042). Maximum preservation of dentine was seen with Hero gold files, whereas the minimum preservation of dentine was seen with Edge Endo X7. Conclusion: Hero gold files exhibited less removal of dentine apically, whereas Edge Endo X7 showed more removal of dentine apically

Hyflex CM and EDM from Shape Memory to Control Memory.

The new era in endodontics has been established with the introduction of nickel titanium (NiTi) alloys, and later on the automation of mechanical preparation. By changing the phase transformation temperatures of NiTi alloy, the manufacturers alter the phase composition to have a NiTi with new mechanical properties. These mechanical properties can be achieved either by thermal, mechanical treatments or both. Moreover, many machining procedures (e.g. twisting, electrical discharge machining), were developed. The higher flexibility of thermomechanically treated NiTi alloys was found as the main advantages of these alloys with the improvement of cyclic fatigue resistance when compared to conventional NiTi. Austenitic alloys have superelastic properties due to stress-induced martensite transformation and consequently try to springback to their original shape after distortion. In contrast, the martensitic instruments have ability to reorientation of martensite variants when heated. So these instruments easily deformed and show a shape memory effect. Moreover, the use of martensitic alloy results in more flexible files, with an increased cyclic fatigue resistance compared with austenitic alloy. So, continued development in the manufacturing treatment of NiTi alloys has resulted in the producing of controlled memory (CM) wire. These materials do not possess superelastic properties at neither room nor body temperature. This article reviews the development process, features and properties of Hyflex file and Hyflex EDM file made from CM wire. Keywords: NiTi alloy, CM wire, Hyflex EDM, Heat treated NiTi

Life span of Neoendo Flex and ProTaper Next rotary files with reciprocating motion in single-rooted teeth.

Cleaning and shaping represent a vital step in the endodontic procedure. In routine endodontic therapy, the fracture of nickel-titanium (NiTi) instruments is a procedural problem creating a major obstacle to therapy. This study examines the life span of one Neoendo Flex and ProTaper Next (PTN) rotary file using reciprocating motion and compares the time required by both file systems for canal preparation. One hundred maxillary permanent central incisors were selected. In that, fifty teeth are utilized in a reciprocating motion (RM) with the PTN file (n = 25) and Neoendo Flex file (n = 25). To check fractured resistance and the overall root canal preparation time, fifty more teeth are employed in continuous motion (CM) with canals prepared using PTN (n = 25) and Neoendo Flex (n = 25). All canals are prepared following the sequence of respective files. Later, the fracture mechanism of the files was inspected using a scanning electron microscope. In an RM motion, both PTN and Neoendo Flex files can be used in a minimum of 25 canals in single-rooted teeth. Statistical analysis using the Mann-Whitney U-test showed no significant difference in total time taken by PTN and Neoendo Flex in both motions. Within the limitation of this study, the RM was found to be better than CM with less incidence of instrument fracture.

Compare of the Frequency of Instrument Fracture of Endodontic File Using Rotary Pro Tapers and HY Flex Series

Objective: To compare the frequency of instrument fracture of endodontic file using Rotary Pro Tapers and EDM Hy Flex series. Study Design & Setting: This experimental in vitro study was conducted at Institute of Dentistry Liaquat University of Medical and Health Sciences Jamshoro. Subjects and Methods: Data was prospectively collected from extracted human teeth. A total of 66 canals were included. Simple descriptive statistics were used to present demographic data, along with frequency and percentages to present qualitative variables. It was decided to perform a post-stratification chi square test taking a p-value of less than 0.05 as significant. Results: A total of 66 canals (33 each endodontic file using Rotary Pro Tapers and EDM Hy Flex series) were included. Mean endodontic file in group A and B was 1.28±0.14 mm and 0.58±0.08 mm. Comparison of instrument separation in endodontic file using Rotary Pro Tapers and Hy Flex series showed separation of 09 (27.3%) and 02 (6.1%) respectively. Conclusion: Based on the results of this study, Protaper files generated much more stress than EDM Hy Flex files, but comparisons of instrument separation between the two instruments showed that the latter performed better overall. Keywords: Root canal treatment, Endodontic file, Rotary Pro Tapers and Rotary EDM Hy Flex.

In-vitro study quantitative evaluation of apically extruded debris during canal preparation using three different motions of hand files

This study aimed to evaluate the quantity of apically extruded debris during the bio-mechanical preparation of the root canal treatment. Fifteen extracted premolars with single root canal were collected and divided into three groups for this study. Hand protaper files (reaming motion), K files (watch-wind motion), and K flex files (balanced force technique) were used. The irrigant and debris were collected in pre-weighed (using analytic scale) empty microtainer bottles. The microtainers were kept in an incubator at 700C for 4 days for complete drying and then weighed of dry debris was recorded. Statistical analysis: Data was treated for the mean values of the weight and analysed using kruskall-wallis test at a significance of 0.05. All the three motions of hand files extruded debris. Watch wind motion showed the lowest mean value whereas reaming showed the highest. There were no significant difference between the reaming motion, watch wind motion and balanced force technique (p <0.05). The study revealed that the amount of extruded debris from the apical foramen was comparatively least in watch wind motion among all the three motions in terms of the mean weight but there is no significance difference between the three Groups.

Effectiveness of antimicrobial photodynamic therapy as an adjunct to mechanical instrumentation in reducing counts of Enterococcus faecalis and Candida albicans from C-shaped root canals.

The aim was to assess the effectiveness of antimicrobial photodynamic therapy (aPDT) as an adjunct to mechanical instrumentation (MI) in reducing Enterococcus faecalis (E faecalis) and Candida albicans (C albicans) counts from C-shaped root-canals. Teeth with C-shaped canals as identified on cone beam computed tomographic images were included. Following incubation with E faecalis and C albicans, samples were divided into 4 groups a four follows: Group-1: MI with adjunct aPDT; Group-2: aPDT alone; Group-3: MI alone; and Group-4: no treatment. The pulp chambers of these teeth were exposed and coronal pulp was mechanically derided using sterile endodontic excavators. Using flexible files, all canals were debrided up to size #30K-files with intermittent irrigation with 2.5% sodium hypochlorite irrigation. In Groups 1 and 3, methylene-blue was injected in all canals and aPDT was performed using a 600nm diode laser. Sample-size estimation was done on data from a pilot investigation and group-comparisons were done using one way analysis of variance and Bonferroni post-hoc adjustment tests. P < .05 was considered statistically significant. Sixty periodontally hopeless mandibular second molars with C-shaped canals were included. There was a statistically significant reduction CFU/mL of E faecalis (P < .001) and C albicans (P < .001). At post-operative microbial assessments in Group-1. There was no difference CFU/mL of E faecalis and C albicans at post-operative microbial assessments in Groups 2-4. MI with adjunct aPDT is more effective in reducing count of E faecalis and C albicans from C-shaped root canals.

Effect of autoclaving on the cyclic fatigue resistance of nickel-titanium rotary instruments: An in vitro study.

Aim:The aim of the study is to determine the effect of autoclaving on the cyclic fatigue resistance (CFR) in respect to three different rotary nickel-titanium (NiTi) systems.Methods:Three rotary NiTi files with different manufacturing process were selected and arranged into three groups. Group 1: Neolix Neoniti files (n = 15), Group 2: Edge Files (n = 15), Group 3: NeoendoFlex files (n = 15). Each group was then subdivided into three subgroups containing 5 samples each based on the number of cycles of autoclaving (0, 1, 5 cycles). The instruments were subjected to autoclave without usage. The files of size 25, taper 6%, and 25 mm length were taken. After the autoclaving cycles, the files were rotated in cyclic fatigue testing device with simulated canal curvature of 60° until file separation. Time taken for the instrument separation (in minutes) was multiplied by the number of rotations per minute to attain the mean number of cycles to failure for every file. The obtained results were subjected to statistical analysis using two-way ANOVA and Newman–Keuls multiple post hoc procedures.Results:Neolix Neoniti files exhibited the maximum CFR (98.80) than EdgeFiles (80.47) and Neoendo Flex files (41.80) (P = 0.0001). Reduction in CFR was observed with increase in the number of cycles of autoclaving (i.e., 0, 1, 5 cycles).Conclusion:Autoclaving has a negative influence on the CFR of the rotary NiTi files used. Neolix Neoniti files exhibited greater CFR than EdgeFiles and Neoendo Flex files.

COMPARATIVE EVALUATION OF RADICULAR DENTINE THICKNESS IN DANGER ZONE OF MANDIBULAR FIRST MOLAR AFTER INSTRUMENTATION WITH TWO DIFFERENT ROTARY SYSTEMS USING CBCT - AN INVITRO STUDY

Introduction: The mandibular first molar poses a series of anatomic challenges such as multiple canals, isthmuses, lateral canals, and apical ramifications. Additionally, the distal surface of mesial root presents a thin zone, which is 4-6 mm cervical to canal orifice with a thin area of dentin termed as “danger zone,” as it increases the risk of perforation of furcal dentin during mechanical instrumentation.&#x0D; Aim: To measure the amount of the dentin removed after biomechanical preparation with XP-Endoshaper and Neoendo flex files in the danger zone of the mandibular first molar using CBCT.&#x0D; Methodology: Twenty-four mandibular first molars, the mesial roots of which presented a curvature of 20-30 degrees, were selected using the Schneider method. Samples were instrumented with Neoendo rotary file system (n=12) and XP-Endoshaper rotary single file system (n=12). The samples were scanned using CBCT before and after instrumentation. The analyzed parameter includes the remaining dentin thickness at the danger zone of the mandibular 1st molar. The obtained data were subjected to statistical analysis.&#x0D; Results: There was no significant difference in remaining dentine thickness between the two rotary systems (p &gt; 0.05).&#x0D; Conclusion: XP-Endoshaper revealed better results than Neoendo rotary files. However, both rotary file systems showed no significant difference in the remaining dentin thickness in the danger zone of the mandibular first molar.&#x0D; Keywords: Danger zone, Remaining dentine thickness, XP EndoShaper, NeoEndo, CBCT.

Postoperative Pain with Hand, Reciprocating, and Rotary Instrumentation Techniques after Root Canal Preparation in Primary Molars: A Randomized Clinical Trial.

ABSTRACTAimThe purpose of this randomized clinical trial was to evaluate the intensity and duration of postoperative pain after pulpectomy of primary teeth using three preparation techniques.Materials and methodsA total of 60 patients were randomly allocated to three groups of 20 patients each, according to the root canal instrumentation techniques used. In group I, the teeth were prepared using manual NiTi K flex files till size 35. In group II, the teeth were prepared using NiTi K flex files till size 35 in reciprocating motion. In group III, the teeth were prepared using Kedo-S pediatric rotary files. After root canal preparation, the canals were obturated with endoflas paste and were restored permanently with composite filling material. The intensity and duration of postoperative pain were evaluated after 6, 12, 24, 48, and 72 hours, using a four-point pain-intensity scale.ResultsThere was a statistically significant difference among the groups, wherein the postoperative pain was more in NiTi K flex files used in reciprocating motion followed by manual NiTi K flex files and Kedo-S pediatric rotary files.ConclusionPostoperative pain was more with NiTi K flex files in reciprocating motion and was less with Kedo-S rotary files after root canal preparation in primary maxillary molars.How to cite this articleJeevanandan G, Ravindran V, Subramanian EMG, et al. Postoperative Pain with Hand, Reciprocating, and Rotary Instrumentation Techniques after Root Canal Preparation in Primary Molars: A Randomized Clinical Trial. Int J Clin Pediatr Dent 2020;13(1):21–26.

Effect of three different rotary file systems on dentinal crack formation – A stereomicroscopic analysis

Background: This study is aimed to analyze and compare the formation of dentinal cracks after root canal preparation with three different rotary file systems using a stereomicroscope. Materials and Methods: Forty extracted human mandibular premolars were selected and divided into three experimental groups and a control group of 10 each. The root canals were prepared in the experimental groups. Group I: ProTaper Gold files (PTG), Group II: Neo Endo flex files, and Group III: Waldent Wal flex files. No preparation was done in the control group (Group IV). The roots were sectioned at 3, 6, and 9 mm from the apex, and the surfaces were examined under a stereomicroscope. The data were analyzed using the Chi-square test. Results: There were no cracks in the control group. Neo Endo flex showed maximum cracks at 3 mm level, which was statistically significant compared to other groups (P 0.05). Conclusion: All the rotary files that were tested produced dentinal cracks. Neo Endo flex files group was associated with more number of cracks than PTG and Waldent Wal flex files group. The apical section of samples showed significantly higher defects compared to the middle and coronal sections.

Detection of Dentinal Microcracks in Radicular Dentin after Shaping with XP-endo Shaper, Neoendo Flex Files, and Hero Shaper Using Scanning Electron Microscope: An In Vitro Study.

ABSTRACTThe study aimed to compare the extent of dentinal microcracks in the radicular dentin using hand K files and various types of rotary nickel-titanium (NiTi) file systems. Forty mandibular incisor teeth (human) were grouped for the study. The root apices were closed, and the canals were straight (<5°). The samples were divided into four groups (n = 10). Group 1—Hand K file system (SybronEndo, SA), Group 2—XP-endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland), Groups 3—Neoendoflex file (Neoendo, Orikam, India), and Group 4—Hero Shaper files (Micro-Mega, Becacon, France). Sectioning was done at 3, 6, and 9 mm from the apex, perpendicular to the long axis using a diamond disc under water coolant. The cut samples were then observed through a scanning electron microscope at ×50 enlargement. The control group showed no microcracks except one sample in the coronal third, which was less significant. The difference in the amount of crack detected on comparing the different groups was significant. In the experimental groups, XP-endo Shaper group showed significantly less number of cracks than the Neoendo flex, and Hero Shaper groups. Within the limitations of this study, all the system, except hand K files, produced remarkable dentinal microcracks. Least cracks were seen in canals instrumented with XP-endo Shaper. It can also be noted that single file system causes less number of microcracks.

Comparative evaluation of dentinal crack formation after root canal preparation with Neoendo Flex and Mani Silk files: An in vitro study.

Context:Neoendo Flex and Mani Silk are recently launched nickel–titanium (NiTi) rotary files. Dentinal cracks and file separation remain a critical problem in the endodontic domain.Aim:The aim was to evaluate and compare the incidence of dentinal crack formation after root canal preparation with Neoendo flex and Mani silk files.Materials and Methods:Thirty-six extracted single-rooted premolars with straight, single root canals were selected for the study. The specimens were randomly assigned to three groups, with 12 samples in each group. The root canal preparation for the three groups was done with hand K-file, Mani Silk, and Neoendo Flex files, respectively, following which the specimens were horizontally sectioned at 3, 6, and 9 mm from the apex. Sectioned samples were viewed under a stereomicroscope to determine the presence or absence of dentinal cracks. The data were analyzed using one-way ANOVA and Chi-square test.Results:Hand K-files and Mani Silk files produced a lesser number of cracks than Neoendo Flex files; however, the difference was not statistically significant among the three file groups at 3 mm and 6 mm (P > 0.05). A statistically significant difference between the groups was seen at 9 mm, where Mani Silk files produced fewer cracks than K files and Neoendo Flex files (P = 0.007). Overall, Neoendo Flex significantly produced more cracks than Mani Silk and hand K-files (P = 0.0029).Conclusions:Both hand K files and NiTi rotary instruments may cause dentinal cracks. Neoendo Flex files tend to produce more dentinal cracks than Mani silk and K-file.

Assessment of the shaping ability of different reciprocating systems in simulated curved root canals using micro-computed tomography

Aim: To analyze the shaping ability of Unicone (Medin), Wave One (Dentsply Maillefer) and Reciproc (VDW) reciprocating systems through the use of micro-computed tomography (MCT) in simulated curved canals. Methods: The shaping time, the centering ability and the changes in canal volumes of these systems were measured. Sixty artificial root canals with a curvature range of 30 0 in resin blocks, were scanned pre and postoperatively by MCT. The resin blocks were divided into four groups (n=15) and the root canals were shaped using three reciprocating systems and Ni-Ti Flex files (Dentsply Maillefer) for the control group. The data were analized using the software CTAnalyser and the Shapiro-Wilks test with p<0.05 indicating a statistically significant difference. Results: The results showed statistically significant difference (p<0.05) between the reciprocating and manual instruments regarding the shaping time. There was not statistically significant difference between the reciprocating systems used in this study. In the cervical portion of the canal, the Unicone system showed the highest volume increase of the reciprocating systems. No statistically significant diferences regarding the centering ability of the reciprocating systems were found. Conclusions: In comparison to the manual preparation technique, the reciprocating instruments provided a faster shaping of the simulated root canals and similar centering ability. Lastly, concerning the volume increase of the root canal portions, statistically significant differences in the cervical portion of the root canals were observed, identifying the highest values for the Unicone group within the reciprocating systems. Lastly, the reciprocating systems provided an adequate centering ability.

A Comparison of Time Needed for Instrumentation of Simulated Curved Canals by Using Different Files

Background : A more flexible file was needed for instrumentation of curved canals using step back enlargement technique Ni-Ti files has been shown to be exceptionally elastic , having a lower bending moment and lower permanent set after torsion with similar gauge stainless steel files . Aim of the study: is to compare the time needed to prepare curved resin simulated root canals with Ni-Ti, S.S., and SS K-Flex files using a step –back enlargement technique. Materials and methods: 30 simulated root canals were constructed using size 20 silver points as a mold, then divided into 3 groups: group 1: Canals instrumented with SS K – files, group 2: Canals instrumented with stainless steel K- flex files. And group 3: Canals instrumented with Ni – Ti files. Results: The comparison between the three groups using ANOVA and T- test, showed a significant difference in time needed to fully instrument the canals. CONCLUSION: Ni- Ti files required more time to instrument the canals than other files.

Intra-canal calcium hydroxide removal by two rotary systems: A comparative study.

Aim:The presence of calcium hydroxide (Ca(OH)2) in the root canal interferes with the apical root canal sealing and may result in periapical lesions in the long run. The present study was aimed to compare the efficacy of two rotary systems of Race and Mtwo in the removal of Ca (OH)2 aqueous-based from distobuccal canals of human maxillary molars.Materials and Methods:A total of 44 distobuccal root canals of human maxillary molars were randomly distributed into two groups of 20 canals each and two control groups. Specimens in each group were instrumented with similar master apical rotary (MAR) and flexible files according to the manufacture's guidelines. The Ca (OH)2 paste was placed in canals using # 20 lentulo and radiographs were taken from the two dimensions. The roots were incubated for 1 week at 37°C and 100% humidity and Ca (OH)2 was removed from canals by MAR, afterward. Then, the roots were longitudinally split in halves by diamond disk and chisel without entering the root canals. Photos were taken from the canals’ walls by a stereomicroscope with × 10 magnification. Next, according to a defined scoring system, photos were scored by four endodontists, so that scores 1 and 2 (nonvisible remnants or scattered remnants of Ca(OH)2) were considered as acceptable and scores 3 and 4 (distinct mass or densely-packed mass of Ca(OH)2) were regarded as nonacceptable.Results:The obtained findings indicated that in coronal, middle, and apical portions of the root canal, 45, 60, and 65% of Mtwo specimens and 40, 50, and 55% of specimens prepared by the Race system acquired an acceptable score (1 and 2), respectively. Moreover, the results showed no significant difference between the two groups (P > 0.05).Conclusions:Both Mtwo and Race rotary systems with acceptable removal efficiency (score 1 and 2) were similarly able to remove Ca(OH)2

Design and Simulation about Linkage of Caterpillar Beach Cleaner’s Graps

To improve the security of linkages, it is necessary to validate the mechanism. Through the Pro/E software the link mechanism was created and carried out pre-processing in ANSYS to get a flexible linkage files, then imported to ADAMS to build rigid-flexible coupled body and proceeded dynamic simulation, finally outputted the boundary load files to ANSYS to calculate the stress and strain of linkage mechanism. The results showed that the linkages to meet the safety of the design.

Dynamical Simulation Model of Auger Miner's Working Mechanism Based on Virtual Prototyping Technology

In order to do research on dynamic characteristics of auger miner’s working mechanism, three-dimensional entity model was built by software Pro/E, some components of working mechanism were made flexible and corresponding Modal Neutral Files were created by software ANSYS. Through the date exchange among Pro/E, ANSYS and ADAMS, dynamical simulation model of working mechanism was built in ADAMS environment. ADAMS/vibration, a plugin in ADAMS, can solve the dynamical simulation model and obtain dynamic characteristics of working mechanism. The establishment of the model can lay the foundation for the research on dynamic characteristics of working mechanism. The resolved results of the model can provide reference for structural design and performance improvements of working mechanism.

Evaluación in vitro de la exactitud del localizador apical miniapex (sybronendo)

The purpose of this study was to determine the accuracys grade of the mini apex locator in the location of the CDC when this it indicates the measure of 0.0mm, confirmed with the SEM. 84 root canals were taken from permanent extracted lower first molars for periodontics of prostodontics reasons this were separated of the distal roots, cut them to level of the enamel-cementum joint, with a carbide disk to low speed, to later on the COE was made using gates glideen burs # 2y 3, irrigating each one of them with NaOCl to 5.25% and later they were introduced sybronendo K flex files #0.8, 10, or 15 depending of the root canal diameter. The Asakos method was used for determine the work's length, followed step was to fit the files inside of the root canal with fluid resin, subsequently to proceeded to cut the filess handle with a and to observe the position of the D0 of the file with respect to the CDC with the SEM with a magnification of 400X. The results show that in the 85.7 %( 52 roots canals) of the samples the D0 of the file was between 0.0 -0.5mm of the CDC and the 14.3 %( 12 root canals) was for under of the CDC. Test showed no significant differences between measurements demonstrated like that the accuracy of Mini Apex locator in determining the working length of root canals during endodontic treatment.

Curved canals: Ancestral files revisited

The aim of this article is to provide an insight into different techniques of cleaning and shaping of curved root canals with hand instruments. Although a plethora of root canal instruments like ProFile, ProTaper, LightSpeed etc dominate the current scenario, the inexpensive conventional root canal hand files such as K-files and flexible files can be used to get optimum results when handled meticulously. Special emphasis has been put on the modifications in biomechanical canal preparation in a variety of curved canal cases. This article compiles a series of clinical cases of root canals with curvatures in the middle and apical third and with S-shaped curvatures that were successfully completed by employing only conventional root canal hand instruments.