Hand Instrumentation Techniques Research Articles

Comparative Evaluation of GC Gold Label IX with GC Gold Label IX Extra and GC Gold Label Hybrid in Cavitated Lesions Prepared by Hand Instrumentation Technique in Primary Molars: An In Vivo Study.

The purpose of the present study was to compare the clinical efficacy of GC Gold Label IX, GC Gold Label IX Extra, and GC Gold Label Hybrid in occlusal surface cavities in primary molars prepared by hand instrumentation technique. Ninety primary molars were selected from the children according to the inclusion and exclusion criteria. The selected teeth were randomly allocated into the following three groups, with 30 teeth in each group, according to the restorative material used: group I: GC Gold Label IX, group II: GC Gold Label IX Extra, and group III: GC Gold Label Hybrid. Occlusal cavities were prepared using hand instruments. Caries removal efficacy was verified using caries detector dye. The restorative materials were mixed and condensed into the prepared cavities. The restorations were assessed using modified United States Public Health Service (USPHS) evaluation criteria at 1, 3, and 6 months. The results were tabulated and statistically analyzed using the Chi-squared test. No significant difference was found in terms of color match, marginal discoloration, marginal integrity, surface roughness, and secondary caries, but a significant difference was observed in terms of retention and anatomic form between group I and group III. GC Gold Label Hybrid exhibited better clinical performance with respect to GC Gold Label IX and comparable clinical performance with respect to GC Gold Label IX Extra. GC Gold Label Hybrid is a newly developed glass ionomer cement (GIC), and its clinical performance needs to be studied. Mittal M, Bajaj N, Bhola M, et al. Comparative Evaluation of GC Gold Label IX with GC Gold Label IX Extra and GC Gold Label Hybrid in Cavitated Lesions Prepared by Hand Instrumentation Technique in Primary Molars: An In Vivo Study. Int J Clin Pediatr Dent 2024;17(5):570-575.

Evaluation of Papacarie®, Carie-Care™, BRIX3000™ and conventional hand instrumentation for caries removal in primary teeth: a randomized control study.

In the current odontological era, carious lesions are removed while tooth tissue is preserved. Most of these ideals are met by chemomechanical caries removal (CMCR) methods, which are easy and comfortable to use, differentiate and eliminate infected tissues, minimize pressure, vibration and heat, and are cost-effective. This study examines the efficacy of commercially available CMCR agents, namely Papacarie®, Carie-Care™ and BRIX3000™, and a conventional hand instrumentation method for caries removal in deciduous molars in terms of time consumption, ease of application, and pain perception. For this randomized clinical trial, 120 children aged 4 to 9 years were selected and randomly allocated to four groups of 30 patients each. Time consumption, ease of application, and pain perception were evaluated at three intervals: pre-, during- and post-caries removal, using Wong-Baker FACES (WBF) Pain Rating Scale and the Face, Legs, Activity, Cry, Consolability (FLACC) scale. The results showed that among the compared materials and conventional hand instrumentation technique, Carie-Care™ was statistically found to be the least time-consuming with a p-value of 0.019, have the least pain perception with a p-value of 0.02, and was clinically the best with respect to manipulation and handling. While all three CMCR agents aid in the removal of carious tissue, Carie-Care™ was the most effective based on time consumption, pain perception and simplicity of administration.

An Apprise on Root Canal Preparation Procedures and How to Evade Procedures Errors in Endodontics A New Assessment

Background: Effective root canal treatment involves cleaning and shaping root canals using a range of instrumentation procedures and techniques. The aim of this review was to provide an update on root canal hand instrumentation techniques and how to overcome iatrogenic errors. Purpose: Purpose of this review was to provide an update on root canal hand instrumentation techniques commonly used in endodontics, including how to overcome iatrogenic errors and optimize the quality of endodontic treatment outcomes. Methods: A comprehensive search was carried out using multiple databases, PubMed, Medline, Google scholar, and Scopus, to identify relevant studies addressing the objective of this study and to summarize the current evidence to readers. Results: The hybrid technique is a commonly used approach that combines the benefits of both the crown-down and step-back techniques and was reported to be one of the best techniques to produce an optimal root canal preparation outcome. Hand-instrument manipulation using the balanced forced technique is also favored as it rapidly and safely permits removal of canal contents allowing irritants and medications to reach deep inside canal spaces. Conclusion: The use of hand files is still recommended for initial canal negotiation and preparation and is essential for the correction of procedural errors. This study provided an update on several hand instrumentation techniques commonly used in endodontics. The correct and safe application of these techniques can prevent iatrogenic procedural errors from occurring which optimizes the quality of treatment outcome.

Incidence and Intensity of Pain Following Endodontic Treatment by Different Instrumentation Techniques in Teeth With Periapical Lesion.

This study was carried out to compare the effectiveness of hand and rotary instrumentation techniques on postoperative pain in asymptomatic necrotic premolars with periapical lesions and instrumented by a modified step-back technique using a K file, crown down by continuous rotary motion technique using ProTaper Universal (Dentsply Mailefer, Ballaigues, Switzerland), and with the reciprocation technique using WaveOne (Dentsply Sirona, Charlotte, NC, USA). For this study, 66 premolars with single roots and canals were chosen. The procedure was completed in a single visit. Following access opening, the working length was initially determined using an apex locator and then confirmed after inserting K file #10 by radiograph. The canal was cleaned and shaped using a grouping system. After the masterapical preparation, the canal was dried by paper point and obturated with gutta-percha and AH plus sealer, an epoxide-amine resin pulp canal sealer. In order to confirm the obturation, a radiograph was taken. After that, a permanentrestoration material was used to seal the access cavity. Following that, patients to whom the visual analog scale (VAS) had already been explained were contacted by phone at six, 12, 24, and 48 hours. In this study, compared to a stainless steel instrumentation technique, WaveOne instrumentation caused more noticeable pain. The results of the current study showed that, on average, postoperative pain scores decreased over the course of the 12to 48-hour period, reaching a minimum or a maximum at 48 hours (p<0.01). Postoperative pain was produced by all instrumentation methods used in the study. In comparison to ProTaper and WaveOne, instrumentation using the modified step-back technique with K files caused less pain, especially over the course of a 24-hour period.

Self-assessment of hand instrumentation skills in pre-doctoral students using painted typodont teeth

This study was conducted to determine if a hand instrumentation exercise on painted typodont teeth is a useful guided self-assessment tool for predoctoral students compared to artificial calculus on typodont teeth. Four (4) artificial calculus typodont teeth and four (4) painted typodont teeth were scaled by 69 fourth year dental students in fall of 2015 in their dental licensure board preparation course. Selected typodont teeth were free of calculus and instead painted. Students were asked to participate voluntarily in the survey for their perception of the new exercise and self-assessment of their hand instrumentation skill. The same set of survey questions were given after scaling artificial calculus and after painted teeth on mounted dental hygiene models on Simulation Manikins. Forty-four (44) students participated in the survey. The survey revealed that students felt significantly more familiar with overall hand instrumentation techniques after painted tooth exercise than calculus typodont teeth exercise. However, their responses showed statistically less confidence in their skill level in overlapping strokes, adequate force and correct finger grasp than traditional calculus typodont teeth. Students found the painted teeth exercise helpful in advancing their practical skills and spatial and anatomical arrangement (p &amp;#60; 0.05). For experienced predoctoral students, the painted typodont tooth exercise provided a more detailed, targeted self-assessment and better practical skill advancement than a traditional calculus typodont exercise.

Radiographic assessment of endodontic mishaps in an undergraduate student clinic: a 2-year retrospective study.

ObjectivesThe aim of this study was to compare the occurrence of instrumentation and obturation related endodontic procedural mishaps following the use of either, stainless steel hand or engine-driven rotary instrumentation techniques.MethodsFrom a computerized hospital database, a total of 730 dental patient records who had received endodontic treatment by undergraduate dental students between August 2018 to September 2020 were retrieved. The inclusion criteria were primary (non-surgical) endodontic treatment on permanent teeth with complete radiographic records. Following record screening, a final sample of n = 475 dental records were included. Radiographic records were evaluated for both instrumentation and obturation related mishaps. The data was analysed using multiple logistic regression analysis (α = 0.05).ResultsEngine-driven rotary instrumentation resulted in a significant decrease in the overall occurrence of instrumentation related endodontic mishaps by 40% compared to hand instrumentation (Odds Ratio = 0.59 [0.36–0.97], p = 0.04). In particular, rotary instrumentation decreased ledge formation, perforation and obturation related mishaps, with minimal effect on the limitation of zipping.ConclusionThe use of rotary instrumentation techniques may reduce the incidence of instrumentation and obturation endodontic mishaps in the undergraduate dental clinic.

Quality of root canal treatment performed by undergraduate students using nickel-titanium reciprocating versus hand instruments.

To compare the technical quality of root canal treatment (RCT) depending on the incidence of procedural errors performed by undergraduate students using nickel-titanium reciprocating and conventional hand instrumentation techniques, and to assess the impact of case difficulty and localization of the teeth (maxillary or mandibular molars). Dental records and periapical radiographs of molars that were treated with either hand or reciprocating WaveOne (WO) instruments were evaluated retrospectively. The technical quality of RCTs, the incidence of ledge formation, perforation, instrument fracture, overinstrumentation, underfilling, overfilling, inadequate root canal filling, and the effects of case difficulty and tooth localization were compared using the chi-square test with a significance of 5% (α=0.05). While overinstrumentation was more frequent in the WO group (247 teeth), the incidence of inadequate root canal fillings was higher in the hand instrumentation group (245 teeth) (p<0.01). No significant difference was observed in the incidence of other procedural errors (p>0.05). The number of teeth with acceptable technical quality in preparation and obturation was 172 (69.6%) in the WO group, whereas it was 142 (58%) in the hand instrumentation group, presenting a significant difference between the instrumentation techniques (p<0.01). Higher technical quality rates were observed with WO instrumentation in the high difficulty category and in maxillary teeth (p<0.01). Higher technical quality in preparation and obturation can be achieved with WO reciprocating instruments and file-matched greater tapered gutta-percha cones. No significant difference was observed between the groups in the incidence of procedural errors except for overinstrumentation and insufficient root canal filling. WO instrumentation and obturation with file-matched greater tapered gutta-percha cones provided better technical quality in the high difficulty category and in maxillary teeth.

An Update on Root Canal Preparation Techniques and How to Avoid Procedural Errors in Endodontics

Background:Effective root canal treatment involves cleaning and shaping root canals using a range of instrumentation procedures and techniques. The aim of this review was to provide an update on root canal hand instrumentation techniques and how to overcome iatrogenic errors.Methods:A comprehensive search was carried out using multiple databases, PubMed, Medline, Google scholar, and Scopus, to identify relevant studies addressing the objective of this study and to summarize the current evidence to readers. Keywords,i.e., endodontics, root canal preparation, hand instrumentation, techniques and procedural errors, as well as, MeSH terms,i.e. “endodontics”, “instrumentation”, “root canal preparation” were used to conduct our comprehensive search.Results:The hybrid technique is a commonly-used approach that combines the benefits of both the crown-down and step-back techniques and was reported to be one of the best techniques to produce an optimal root canal preparation outcome. Hand-instrument manipulation using the balanced forced technique is also favoured as it rapidly and safely permits removal of canal contents allowing irrigants and medications to reach deep inside canal spaces.Conclusion:The use of hand files is still recommended for initial canal negotiation and preparation and is essential for the correction of procedural errors. This study provided an update on several hand instrumentation techniques commonly used in endodontics. The correct and safe application of these techniques can prevent iatrogenic procedural errors from occurring which optimizes the quality of treatment outcome.

Incidence and Severity of Postoperative Pain Following Root Canal Treatment in Nonvital Pulps with Hand and Rotary Instrumentation Techniques in Chhattisgarh Population.

Aim:To evaluate the incidence and severity of postoperative pain following root canal treatment in nonvital pulps with hand and rotary instrumentation techniques in Chhattisgarh population.Materials and Methods:Sixty asymptomatic single-canaled nonvital teeth were selected and were divided into two groups of 30 each. Group I: 30 single-canalled teeth were treated in a single visit and prepared with hand file system. Group II: 30 single-canaled teeth treated in a single visit and prepared with K3-rotary file system. Group I and II were divided into two subgroups of 15 each (Group IA, IB and Group IIA, IIB) which were irrigated with 2% chlorhexidine and 5.25% sodium hypochlorite, respectively. The patients were recalled at 24, 48, and 72 h and at 1 week to record the incidence and severity of postoperative pain by using visual analog scale.Results:Results showed low incidence and severity of postoperative pain following a single-visit treatment with rotary instrumentation when compared to hand instrumentation technique. No statistical significant difference was observed between the groups at different time intervals, i.e., at 24, 48, and 72 h and at 1 week. The use of recent endodontic techniques and devices reduces the postoperative pain.Conclusions:Postoperative pain after root canal treatment ranged from mild to severe and it can happen even after high-standard root canal treatment. There is low incidence and severity of postoperative pain following a single-visit treatment with rotary instrumentation when compared to hand instrumentation technique.

Scanning Electron Microscopic and Dye Penetration Evaluation of Hand Instrumentation Techniques on Formation of Smear Layer in Root Canal Preparation: An In vitro Study.

Aims and Objectives:The present study was undertaken for evaluating various hand instrumentation techniques with different instruments in the formation of smear layer.Materials and Methods:One hundred and seventy-five extracted mandibular molars were collected and were cut at cementoenamel junction. Afterward, the distal roots were separated. Working length was determined, and roots were divided into five equal groups with 35 roots in each group as follows: Group A: K-type files with conventional step-back technique, Group B: Canal Master U instrument with clockwise–counterclockwise rotation, Group C: Flex-R® files with clockwise–counterclockwise rotation, Group D: FlexoFiles® with conventional step-back technique, and Group E: Nickel titanium files with conventional step-back technique. Biomechanical preparation was done according to their respective groups. The teeth in various groups were scanned under scanning electron microscope and scoring was done. All the results were analyzed by SPSS software version 17.0.Results:Scanning electron microscopic results indicated that apparently there seems to be a significant difference in the scoring of the smear layer between each group at all the three levels, but the difference was statistically nonsignificant. Microleakage was present in all the samples. Nonsignificant results were obtained while comparing the microleakage in between different the groups. However, microleakage was highest in Group D.Conclusion:The amount of smear layer is maximum at the apical third and lesser in the middle third followed by the coronal third in all the groups. All the samples showed microleakage to a varying extent.

Clinical differences of hand and rotary instrumentations during biomechanical preparation in primary teeth-A systematic review and meta-analysis.

The hand and rotary instruments are used for cleaning and shaping of root canals during biomechanical preparation in primary teeth. To determine clinical differences of hand versus rotary root canal instrumentation in primary teeth. Comprehensive searches were made in four electronic databases [MEDLINE (via PubMed), EMBASE, Google Scholar, and The Cochrane Central Register of Controlled Trials] till March 2020, and prospective studies that met the inclusion criteria were included. The primary outcome was instrumentation time, whereas the secondary outcomes were quality of obturation, obturation time, and clinical and radiographic success. From 604 screened studies, eleven studies qualified for meta-analysis. The random-effect model and generic inverse variance approach were used for meta-analysis. There was significant decrease in instrumentation time [MD-5.00minutes (95% CI: 3.05-6.94), P<.00001, moderate evidence quality] and obturation time [MD-0.43minutes (95% CI: 0.15-0.71), P=.003, low evidence quality] with rotary instrumentation. Optimal quality of obturation was achieved in significantly more number of teeth [risk ratio (RR)=0.71(95% CI: 0.53-0.95),P=.02, moderate to high evidence quality] with rotary instrumentation. Similar clinical and radiographic success was observed in hand and rotary instrumentation techniques. Significant reduction in instrumentation time of five minutes was observed using rotary instrumentation with moderate quality evidence.

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.

Substance P and Calcitonin gene-related peptide expression in human periodontal ligament after root canal preparation with Reciproc Blue, WaveOne Gold, XP EndoShaper and hand files.

To quantify Substance P (SP) and Calcitonin gene-related peptide (CGRP) expression in healthy human periodontal ligament from premolars after root canal preparation with Reciproc Blue, WaveOne Gold, XP EndoShaper and hand files. A total of 50 human periodontal ligament samples were obtained from healthy mandibular premolars where extraction was indicated for orthodontic reasons. Prior to extraction, 40 of these premolars were equally divided into four groups, and root canals were prepared using four different systems: Reciproc Blue, WaveOne Gold, XP EndoShaper and a hand instrumentation technique. The remaining 10 healthy premolars were extracted without treatment and served as a negative control group. All periodontal ligament samples were processed, and SP and CGRP were measured by radioimmunoassay. The Kruskal-Wallis test was used to establish significant differences between groups and LSD post hoc comparisons were also performed. Greater SP and CGRP values were found in the hand instrumentation group, followed by the XP EndoShaper, WaveOne Gold and the Reciproc groups. The lower SP and CGRP values were for the healthy periodontal ligament group. The Kruskal-Wallis test revealed significant differences between groups (P<0.05). Post hoc Least Significant Difference (LSD) tests revealed significant differences (P<0.05) in SP and CGRP expression between all the comparisons except for the Reciproc Blue and WaveOne Gold group (P>0.05). All the root canal preparation techniques tested increased SP and CGRP expression in human periodontal ligament, with hand files and XP EndoShaper instruments being associated with greater neuropeptide release compared to Reciproc Blue and WaveOne Gold files.

Volumetric analysis of hand, reciprocating and rotary instrumentation techniques in primary molars using spiral computed tomography: An in vitro comparative study.

Objective:This present study was conducted to analyze the volumetric change in the root canal space and instrumentation time between hand files, hand files in reciprocating motion, and three rotary files in primary molars.Materials and Methods:One hundred primary mandibular molars were randomly allotted to one of the five groups. Instrumentation was done using Group I; nickel-titanium (Ni-Ti) hand file, Group II; Ni-Ti hand files in reciprocating motion, Group III; Race rotary files, Group IV; prodesign pediatric rotary files, and Group V; ProTaper rotary files. The mean volumetric changes were assessed using pre- and post-operative spiral computed tomography scans. Instrumentation time was recorded. Statistical analysis to access intergroup comparison for mean canal volume and instrumentation time was done using Bonferroni-adjusted Mann–Whitney test and Mann–Whitney test, respectively.Results:Intergroup comparison of mean canal volume showed statistically significant difference between Groups II versus IV, Groups III versus V, and Groups IV versus V. Intergroup comparison of mean instrumentation time showed statistically significant difference among all the groups except Groups IV versus V.Conclusion:Among the various instrumentation techniques available, rotary instrumentation is the considered to be the better instrumentation technique for canal preparation in primary teeth.

Evaluation of Dentin Defect Formation during Retreatment with Hand and Rotary Instruments: A Micro-CT Study.

The purpose of this study was to compare the incidence and longitudinal propagation of dentin defects after gutta-percha removal with hand and rotary instruments using microcomputed tomography. Twenty mandibular incisors were prepared using the balanced-force technique and scanned in a 19.9 μm resolution. Following filling with the lateral compaction technique, gutta-percha was removed with ProTaper Universal Retreatment (PTUR) or hand instruments. After rescanning, a total of 24,120 cross-sectional images were analyzed. The numbers, types, and longitudinal length changes of defects were recorded. Defects were observed in 36.90% of the cross sections. A total of 73 defects were comprised of 87.67% craze lines, 2.73% partial cracks, and 9.58% fractures. No significant difference in terms of new defect formation was detected between the retreatment groups. The apical and middle portions of the roots had more dentin defects than the coronal portions. Defects in three roots of the PTUR instrument group increased in length. Under the conditions of this in vitro study, gutta-percha removal seemed to not increase the incidence of dentin defect formation, but the longitudinal defect propagation finding suggests possible cumulative dentinal damage due to additional endodontic procedures. Hand and rotary instrumentation techniques caused similar dentin defect formation during root canal retreatment.

Kedo-S Paediatric Rotary Files for Root Canal Preparation in Primary Teeth - Case Report.

Nickel-Titanium (Ni-Ti) instrument are widely used for root canal preparation in permanent tooth compared to primary teeth. Hand instrumentation technique remains the conventional method for root canal preparation in primary teeth. The time taken for root canal preparation with the conventional method is more resulting in patients and clinicians fatigue. Recently Ni-Ti rotary files designed for permanent tooth has been used for root canal preparation in primary teeth. Using rotary instruments for primary tooth pulpectomies resulted in better and predictable root canal filling. This article presents case reports of pulpectomy treatment performed using Kedo-S an exclusive paediatric Ni-Ti rotary files. The advantages and disadvantages in use of Ni-Ti rotary files in primary teeth are discussed in this article.

Effectiveness of hand and Mtwo™ instruments in preparing oval-shaped root canals: in vitro study

Objective: This study evaluated through stereomicroscopy the effectiveness of hand and rotary instrumentation techniques, either isolated or combined, in the preparation of oval-shaped root canals. Materials and method: Thirty single-rooted human mandibular incisors were selected. After endodontic access and coronal preflaring, teeth were mounted in a modified Bramante muffle and then sectioned transversely at 3 and 6 mm from the root apex. Images of each section were made under a stereomicroscope at 30× magnification. Teeth were reassembled in the muffle and divided into three groups (n=10) according to the root canal preparation technique: GI - rotary preparation with Mtwo™ basic sequence (10/.04; 15/.05; 20/.06; 25/.06), followed by Mtwo™ complementary instruments (30/.05; 35/.04; 40/.04); GII - rotary preparation with Mtwo™ basic sequence, complemented by hand instruments (#30, #35 and #40); GIII - hand instrumentation using the conventional technique (#10 to #40). All instruments were used in brushing motion. The muffles were separated again so that new images of each section could be obtained. The following parameters were evaluated in pre- and postoperative images: root canal area; perimeter; mesiodistal (MD) and buccolingual (BL) diameters; and mesial (M) and distal (D) wall thickness. Next, the values measured in post- and preoperative images were subtracted forcomparison of experimental groups. Data were analyzed using the Kruskal-Wallis test (α=0.05). Results: No significant difference between groups was observed for all parameters. Conclusion: There was no difference among hand, rotary, or combined instrumentation; all techniques were able to increase root canal area, perimeter, and diameter in MD and BL directions. Moreover, the amount of dentin wearon proximal root canal walls was similar for all tested groups.

An in vitro study to determine fracture resistance of tooth roots after different instrumentation techniques

Aim: The aim was to study the influence of rotary and hand instruments techniques on the susceptibility of the root to fracture. Materials and Methods: Forty extracted human maxillary permanent first and second molars without any defects were selected as sample. Teeth were randomly divided into four groups of ten teeth in each group. Palatal canals were instrumented depending on the instrumentation techniques used in the groups. Group 1: 0.02 taper K-files and Gates Glidden drills (Mani Inc., Japan); group 2: Hand ProTaper (Dentsply-Maillefer, France); group 3: Rotary ProTaper (Dentsply-Maillefer, France); and group 4: Endowave (J. Morita, Japan). After instrumentation, palatal roots were resected and apical 7 mm sectionally obturated. Obturated roots were embedded in putty impression material and mounted on Universal testing machine (Lloyd instruments, UK). Vertical load was applied by means of a spreader inserted into the canal and load at fracture was recorded for each tooth. Fractured roots were embedded in self-cure resin, sectioned horizontally, and viewed under operating microscope to determine the direction of fracture line: Maximum and minimum remaining dentin thickness was measured at coronal, middle, and apical thirds. Statistical analysis of data was accomplished by one-way ANOVA and post-hoc tests with Tukey honest significant difference. Results: Mean fracture loads was 20.6 ± 3.8 kg (group 1), 9.5 ± 2.4 kg (group 2), 8.4 ± 1.4 kg (group 3), and 13.4 ± 3.1 kg (group 4). There was statistical significance in the values between group 1 and groups 2, 3, and 4 (P Conclusion: Preparation of canals with a conventional hand instrumentation technique using 0.02 taper K-files showed highest fracture resistance with least amount of dentin removed at all levels followed by Endowave, ProTaper Hand, and Rotary files.

Effectiveness of Three Rotary Niti Instruments and Hand Instrumentation in Removing Gutta Percha from Root Canals: an in vitro Study

Abstract Objectives: The study aimed to assess variation in the remaining filling material by radiographic analysis and the time taken for retreatment system, with H-files; the ProTaper Universal Retreatment System; Mtwo retreatment system and the SybronEndo K3. Methods: 120 human mandibular premolars with single straight root canals were prepared with rotary twisted files (up to size 40/0.04) using the crown down technique and filled by cold lateral condensation and the radiographs were taken. After one week, teeth were divided into four groups (n = 30). Gutta-percha was removed using H-files, the ProTaper Universal Retreatment System, Mtwo system and the K3 System. After retreatment radiographs were taken for each sample and the remaining material was calculated for each canal third. Results: Rotary NiTi instruments were significantly faster than the hand instrumentation technique in performing the retreatment. In radiographic analysis there was significant difference in between the groups for coronal third in ProTaper group and for apical third in H-file group. Conclusions: In the radiographic analysis the ProTaper Universal System left less filling material in the coronal third and the H-files left less filling material in apical third as compared to other groups. Rotary instruments worked faster than H files.

Scanning Electron Microscopic Evaluation of Residual Smear Layer Following Preparation of Curved Root Canals Using Hand Instrumentation or Two Engine-Driven Systems.

Introduction:In this experimental study, the amount of smear layer (SL) remnants in curved root canals after chemomechanical instrumentation with two engine-driven systems or hand instrumentation was evaluated. Methods and Materials:Forty-eight mesiobuccal roots of mandibular first molars with curvatures ranging between 25 and 35 degrees (according to Schneider’s method) were divided into three groups (n=16) which were prepared by either the ProTaper Universal file series, Reciproc single file system or hand instrumentation. The canals were intermittently irrigated with 5.25% NaOCl and 17% (ethylenediaminetetraacetic acid) EDTA, followed by distilled water as the final rinse. The roots were split longitudinally and the apical third of the specimens were evaluated under 2500× magnification with a scanning electron microscope (SEM). The mean scores of the SL were calculated and analyzed using the non-parametric Kruskal-Wallis and Mann-Whitney U tests. Results:The mean scores of the SL were 2.00±0.73, 1.94±0.68 and 1.44±0.63 µm for the ProTaper Universal, Reciproc and hand instrumentation, respectively. Mean score of SL was significantly less in the hand instrumentation group than the ProTaper (P=0.027) and Reciproc (P=0.035) groups. The difference between the two engine-driven systems, however, was not significant (P=0.803). Conclusion:The amount of smear layer in the apical third of curved root canals prepared with both engine-driven systems was similar and greater than the hand instrumentation technique. Complete cleanliness was not attained.