Ni-Ti K-files Research Articles

Determination of correlation between the quality of obturation and postoperative pain following root canal preparation with rotary and manual file systems in the primary molars-A comparative randomized clinical trial

To determine the correlation between the quality of root canal obturation and postoperative pain following root canal preparation with rotary and manual file systems in the primary molars. A total of 150 primary molars requiring pulpectomy were selected from children aged 4–7 years. The selected teeth were divided into three groups: Kedo-S (KS), HERO Shapers (HS) and Manual Files (MF)-of 50 teeth each. In groups KS, HS, and MF, root canal instrumentation was carried out with Kedo-S pediatric rotary files, HERO Shaper rotary files, and manual NiTi K-files, respectively. Root canal obturation was carried out with zinc oxide eugenol cement using an engine-driven Lentulo spiral. The quality of the root filling was radiographically assessed immediately after obturation. The postoperative pain was evaluated at time intervals of 6, 12, 24, 48, 72 h, and 1 week. The quality of obturation was superior in the root canals instrumented with rotary file systems compared to manual files. There was decreased postoperative pain with the use of rotary file systems as compared to manual files. In all three groups, postoperative pain decreased over time. The use of rotary file systems resulted in a higher percentage of optimal root canal filling with lesser postoperative pain than the manual file system. The overfilled root canals were not associated with significant postoperative pain.

Evaluation of the clinical efficiency of rotary and manual files for root canal instrumentation in primary teeth pulpectomies: A comparative randomized clinical trial

Aim: To evaluate and compare the instrumentation time, obturation time, quality of obturation, and clinical and radiological success of pulpectomized teethfollowing root canal preparation of primary molars with rotary and manual file system. Methods: A total of 150 primary molars requiring pulpectomy were selected from children aged four to seven years. These teeth were divided into three groups of 50 teeth each. In Groups 1, 2, and 3, cleaning and shaping were carried out with Kedo-S pediatric rotaryfiles, HERO Shaper rotary files, and manual NiTi K-files, respectively. Obturation was carried out with zinc oxide eugenol cement and an engine-driven Lentulo spiral. The instrumentation and obturation times were recorded. A radiographic assessment of thequality of the root filling was carried out immediately after obturation. Finally, the pulpectomized teeth were clinically and radiographically evaluated over a two-year period. Results: The mean instrumentation times for Groups 1, 2, and 3 were 14.56 ± 2.89 min, 17.93 ± 3.51 min, and 29.00 ± 2.08 min, respectively. The mean obturation times for Groups 1, 2, and 3 were 8.11 ± 1.7 min, 7.93 ± 1.3 min, and 9.64 ± 17.61 min, respectively. The mean difference in the quality of obturation was not statistically significant in primary molars instrumented with Kedo-S pediatricand HERO Shaper rotary file systems (p = 0.16). However, this mean difference was significant when compared between primary molar instrumented with rotary file systems and manual NiTi files (p = <0.001). At two years, the clinical success rate was 100% and the radiological success rates were 95.3%, 97.9%, and 89.5% in Groups 1, 2, and 3, respectively. Conclusions: The rotary file systems took significantly less instrumentation and obturation time than the manual NiTi files. There were no significant differences in obturation quality or success rates after two years.

Computed Tomography Assessment of Canal Centering Ability Using Hand and Rotary Instruments - an In Vitro Study

Abstract Aim: The present in vitro study aims to evaluate canal preparation comparing centering ability of ProTaper, Mtwo, Wave One, Hand Ni-Ti K-files using Computed Tomography(CT). Materials and Methods: Sixty extracted permanent teeth were selected and decoronated at 11 mm from the apical end. Samples were randomly divided into 4 groups as ProTaper, Mtwo, Wave One, Hand Ni-Ti K-files. Teeth were scanned by CT Scanner. Sectioning was started at 1 mm from the apex up to coronal orifice. Nine levels at 1 mm each were chosen for evaluation in the Computed Tomography. The canals were prepared and a post instrumentation scan was again taken. The pre and postoperative CT images were superimposed at all nine levels. The canal centering ability was calculated. Statistical data was evaluated using One Way Analysis Of Variance test. Results: Amongst the rotary and reciprocal groups the best canal centering ability at the apical third was seen with Wave one. All the three groups behaved similarly in the middle and coronal thirds of the root canal. Conclusion: Keeping in mind the importance of apical third preparation and consistent behaviour in all directions, Wave One may be considered by far the best in the apical third.

Micro-computed tomography evaluation of root canal preparation using rotary system and hand instrument in young permanent molars

The aim of this study was to evaluate the shaping potentials of the ProTaper system and nickel-titanium (Ni-Ti) hand-files using micro-computed tomography (μCT) in young permanent teeth. Thirty-second permanent molar teeth extracted from patients 15 to 18 years of age were divided into two groups with 15 samples of each. Group I: were instrumented using the traditional step-back technique by Ni-Ti K-files. Group II were instrumented using the crown-down technique by ProTaper rotary instruments. Before and after root canal preparation, the μCT data were analyzed for the canal volume changes, the percentage differences between these volumes and unprepared surface area ratio of the total surfaces. At all root canals in both groups, the difference between the percentage of the root canal volume before-after preparation was significant (P 0.05). There was no difference between the systems in terms of shaping ability. Considering the shortening session time of the child patient ProTaper system appeared to be beneficial.

A Comparison of Canal-centering ability of Two Nickel-Titanium Rotary Systems with Nickel Hand Instrumentation with Stainless Steel Hand Instrumentation in 10 to 25° Curved Canals using Kuttler's Cube.

ABSTRACT%Aims: The purpose of this study was to compare the canal centering abilities of rotary nickel-titanium (NiTi) files (ProFile 0.04 and 0.06 and Lightspeed LSX) and NiTi hand K-files in 10° to 25° curved canals. This was compared with the canal centering ability of stainless steel hand K-files using Kuttler's endodontic cube.Settings and design: The teeth with a 10° to 25° of clinical mesiodistal curvature were used for this study. Each tooth was immersed in methylene blue dye for a period of 10 seconds, as recommended by Kuttler.Materials and methods: The study sample comprised of 60 intact freshly extracted single rooted human mandibular premolars. The radiographs were traced on a tracing paper and the canal curvature was determined according to methodology introduced by Schneider.Statistical analysis used: The statistical package SPSS PC + (Statistical package for social service, Version 4.01) was used for analysis.Results: Overall, Lightspeed LSX instruments showed superior canal centering ability and performed better than Profile series, hand NiTi K-files and hand stainless steel K-files.Conclusion: The endodontic cube can be used as an effective method for analyzing the canal-centering ability of different endodontic instruments. Both the NiTi rotary instruments showed superior canal-centering ability than NiTi and stainless steel hand K-files.How to cite this article: Swarnkar A. A Comparison of Canal-centering ability of Two Nickel-Titanium Rotary Systems with Nickel Hand Instrumentation with Stainless Steel Hand Instrumentation in 10 to 25° Curved Canals using Kuttler's Cube. Int J Clin Pediatr Dent 2014;7(3):157-162.

Shaping Potential of Manual NiTi K-File and Rotary ProTaper and Analyzing the Final Outcome of Shaped Canals using CT

To assess and compare the shaping potential of manual NiTi K-files and Rotary ProTaper instruments in narrow canals using CT. To assess the shaping potential of manual NiTi K-files and Rotary ProTaper and analyzing the final outcome of shaped canals using CT and determining different variables, like • Working time • Change in volume • Change in cross-sectional area. From a pool of fifty freshly extracted permanent maxillary molars (1st and 2nd), 30 were selected with curvatures (20 to 40°) (Schneider 1971). Tissue fragments and calcified debries were removed from the teeth by scaling. The teeth were then stored in normal saline until used. All the mesiobuccal canals were scanned by CT to obtain preinstrumented images. Teeth were scaled and stored in normal saline. This study was divided in two groups with 15 samples each. GROUP I (PROTAPER ROTARY): Canals were instrumented with Protaper Rotary instruments using crown down technique according to manufacturer's instructions. GROUP II (NITI K-FILE): Were instrumented by NiTi K-files using step back technique with a quarter turn/pull motion. EVALUATIONS OF WORKING TIME: Comparative evaluations of working time was done for both the experimental groups. CT ANALYSIS AND MEASUREMENTS: The samples were analyzed and evaluated for: • Postinstrumentation change in volume. • Postinstrumentation change in cross-sections area. From the observations and statistical analysis carried out in this study, it was found that: There was a statistically significant difference between all the parameters judged for the present study that is: 1. Instrumentation with ProTaper Rotary system took significantly less time than instrumentation with manual NiTi K-file. 2. Change in the canal volume following instrumentation with ProTaper Rotary was significantly greater than that produced by manual NITi K-file. 3. a. Change in cross-section area at 2 and 3 mm from the apex was significantly greater with manual NiTi K-file as compared to ProTaper Rotary. b. Change in cross sections at 4.5, 6 and 7.5 mm from the apex with ProTaper Rotary was significantly greater than that produced by manual NITi K-file. This clearly establishes that there is a drastic difference in the shaping ability of manual and Rotary NiTi instruments used with step back and crown down technique respectively with the rotary instrumentation being faster and producing greater changes in the canal anatomy.

The effectiveness of a self‐adjusting file to remove residual gutta‐percha after retreatment with rotary files

To test the efficacy of a two-stage retreatment method in which the Self-Adjusting File (SAF) is used to remove root canal filling residue left in the canal after using ProTaper Universal retreatment files. One of the curved mesial canals of 25 extracted mandibular molars was instrumented up to ProTaper F2, followed by NiTi K-files up to size 45 and filled. Radiographs of these canals served as a pre-treatment control, which was later compared with those of the same canals after each stage of the retreatment procedure. Stage 1 consisted of ProTaper Universal D1-D3 retreatment files, which were used to remove the bulk of root filling material, followed by stage 2 in which a SAF file was applied to remove the remaining root canal filling residue. The amount of the radiopaque material in each third of the canal was evaluated before and after each stage, using bucco-lingual and mesio-distal radiographs. The amount of residue was expressed as the per cent of the root canal filled area, as measured in the pre-treatment control. The difference between the control and results of the first and second stages of retreatment was analysed using the Wilcoxon signed-rank test. Radiopaque residue was present after the use of the ProTaper Universal rotary files in 7.8 (± 12.9)%, 12.9 (± 13.9)% and 34.7 (± 22.8)% of the coronal, mid-root and apical areas, respectively. Following the supplementary application of the SAF, the amounts of residue were reduced to 2.6 (± 3.7)%, 4.1 (± 5.7)% and 6.7 (± 9.4)% of the coronal, mid-root and apical canal areas, respectively (P < 0.01 for the coronal and mid-root and P < 0.001 for the apical third). No system removed the root filling materials entirely. The use of the SAF after rotary instrumentation using ProTaper Universal retreatment files resulted in a significant reduction in the amount of filling residue in curved canals of mandibular molars.

CT evaluation of canal preparation using rotary and hand NI-TI instruments: Anin vitrostudy

Background:Controlled, uniformly tapered radicular preparation is a great challenge in endodontics. Improper preparation can lead to procedural errors like transportation of foramen, uneven dentine thickness, stripping of root canal, formation of ledge, zip, and elbow in curved canals. These procedural errors and their sequel can adversely affect the prognosis of treatment.Aim/Objectives:The present in vitro study aims to evaluate canal preparation based on the following factors: canal transportation, remaining dentine thickness and comparing centering ability between hand Ni-Ti K files and ProTaper rotary Ni-Ti instruments using computed tomography (CT).Materials and Methods:For evaluation, 30 mesiobuccal roots of maxillary molars were selected. Of these, 15 roots were distributed into two groups where Group 1 included hand instrumentation with Ni-Ti K-files; and Group 2 comprised ProTaper NiTi rotary system. Pre instrumentation and post instrumentation three-dimensional CT images were obtained from root cross-sections that were 1 mm thick from apex to the canal orifice; scanned images were then superimposed and compared.Result:It was observed that the manual technique using hand Ni-Ti K-file produced lesser canal transportation and maintained greater dentine thickness than the rotary ProTaper technique at middle and coronal third and this difference was statistically significant. No significant difference was seen with regard to canal transportation and remaining root dentine at apical levels. With regard to centering ratio, no significant difference was seen between both the groups at all levels.Conclusion:ProTaper should be used judiciously, especially in curved canals, as it causes higher canal transportation and thinning of root dentine at middle and coronal levels. None of the groups showed optimal centering ability.

Study of the Progressive Changes in Canal Shape After Using Different Instruments by Hand in Simulated S-Shaped Canals

This study analyzed the progressive changes in canal shape after the use of different instruments by hand in simulated S-shaped canals. Forty simulated canals with double curvatures, 30 degrees coronally and 20 degrees apically, were randomly divided into four groups and prepared with stainless steel K-files, the ProTaper for hand use (PHU) system, NiTi K-files, and the combination of PHU and NiTi K-files, respectively, by hand. All canals were scanned pre-and postoperatively. Each postinstrumentation image was superimposed with the preoperative one in a computer. The amount of material removed after every instrument was measured at 14 points. Statistical analysis was performed using an analysis of variance (ANOVA) test at alpha=0.05. All four instruments straightened the S-shaped canals, except the combination of PHU (S1, Sx, and S2) and NiTi K-files, which created a continuous funnel shape. There was a significant difference in the amount of material removed between S2 and F1 of the PHU system (p<0.05), and the finishing files of PHU created the same transportation as the stainless steel instruments with the same tip size (p>0.05).

Analysis of Ni-Ti versus stainless steel instrumentation in resin simulated canals

This study compared step-back preparations in curved canals of resin blocks using nickel-titanium K-files and stainless steel K-files. Forty canals in resin blocks were cross-sectioned at 3 levels: 1 to 2 mm from the apical foramen, middle of the curve, and coronal. Direct digital computer images were recorded before and after instrumentation. Superimposition of the images combined with digital subtraction computer software allowed direct measurement of area instrumented, distance of transportation, and shape analysis. Time for instrumentation was recorded. Results showed Ni-Ti files to cause significantly less transportation and remain more centered at the apical level (p < 0.05). Area removed by instrumentation was significantly greater for stainless steel files at the middle level (p < 0.05). Cross-sectional shape of the instrumented canal was not significantly different (p < 0.05). It took significantly longer to prepare a canal with Ni-Ti K-files in resin blocks compared to stainless steel (p < 0.05). Resin simulated canals showed similar results compared to canals in extracted roots using an identical methodology.