Search

Copyright of Acta Odontologica Latinoamericana: AOL is the property of Acta Odontologica Latinoamericana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: One of the most important steps in endodontic treatment is the preparation of a uniform space, the use of endodontic irrigant and creating space for the endodontic filling. Therefore, improving endodontic treatment techniques is one of the most important tasks of modern dentistry. The success and effectiveness of endodontic treatment is largely determined by the quality of chemo-mechanical root canal treatment. In recent years there has been a major emphasis on the use of rotary mechanical instrumentation systems, namely the use of nickel-titanium (NiTi) alloys, which due to their properties represent a favorable flexibility in the instrumentation of difficult anatomies. Material and methods: 20 patients were examined and treated. They were divided into 2 groups: for the treatment of 6 patients was applied the Protaper Universal rotary system. In the second group of 14 patients to whom mechanical instrumentation was applied, were 7 patients following the Protaper Next and the other 7 Dc Taper with different pulpal and periodontal diseases. Results: Mechanical instrumentation was performed on different nosological entities, the prevalence being acute pulpitis. Among instrumented teeth, the prevalence was on the side of pluriradicular teeth. Conclusions: The practical application of different NiTi rotary systems has to be determined individually, as each clinical case has its own practical properties. But the success of an endodontic treatment depends not only on the rotary instruments used and, on the method, chosen, but also on the practitioner’s experience, detailed knowledge of the properties and step-by-step instrumentation protocols.

Purpose: This study aimed to investigate the canal transportation and instrumentation time of pediatric rotary files with or without a glide path. Methods: Fifty simulated resin blocks were randomly assigned to one of five experimental groups (n = 10): Group K is a K-type hand file (control), group P is a Kiddy files rotary system, group OP is a One G glide path file and a Kiddy files rotary system, group F is an AF baby tooth file (AFB) rotary system, and group OF is a One G glide path file and an AFB rotary system. The instrumentation time was recorded after preparing simulated canals. Image J software was used to calculate canal transportation at various canal levels. Results: The group K had the longest preparation period (p < 0.05) and the greatest apical transportation scores (0.35 ± 0.23). It was followed by groups F (0.18 ± 0.26), OF (0.03 ± 0.09), OP (0.03 ± 0.03), and P (0.02 ± 0.01). The difference between the K and P groups, the K and OP groups, and the F and P groups was statistically significant (p < 0.05). Conclusion: Using a glide path during canal preparation by rotary systems could reduce procedural errors. For root canal preparation, Kiddy files with or without a glide path may be advised. [ABSTRACT FROM AUTHOR]

Copyright of Aydin Dental Journal is the property of Aydin Dental Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Successful outcome of pulp therapy depends on good chemomechanical preparation of the canals. This is completed with the help of various upcoming rotary and hand files. However, during this preparation, there might be an apical extrusion of the debris which may result in postoperative complications. The aim of this study was to evaluate and compare the number of debris apically extruded during canal preparation using two different pediatric rotary file systems and conventional hand file systems in primary teeth. 60 primary maxillary central incisors that were extracted due to trauma or untreated dental caries with no signs of resorption were taken. Canal preparation was executed using three different file systems: Group A: Group A hand K file system, Group B Kedo S Plus, Group C Kedo SG Blue. For each of these files using the Myers and Montgomery model, the pre- and post-weight of the eppendorf tube was assessed to quantify the number of apical debris. The maximum extrusion of apical debris was noticed with the Hand K-file system. The least debris was noticed in the Kedo S Plus file system. Statistical analysis revealed that there were highly significant differences in apical extrusion and debris when comparing hand files and rotary files and also between the two rotary files used. Apical debris collection is an unavoidable outcome of canal instrumentation. Among the file systems compared, rotary files had lesser extrusion when compared to hand files. Among the rotary files, Kedo S plus showed normal extrusion compared to SG Blue. [ABSTRACT FROM AUTHOR]

Background: Manual or mechanized instruments can be used for root canal preparation. Manual instrumentation using K‐files is widely used in primary teeth, but there are many limitations. Mechanized root canal preparation can lead to easy access to all canals, decrease instrumentation time, and result in more funnel‐shaped root canals, resulting in a more predictable uniform paste fill. Aim: This study aimed to evaluate the shaping ability and instrumentation time of VDW.ROTATE™ and EdgeTaper Platinum™ during the preparation of resin‐printed primary molars. Hand K‐files were used as a reference for comparison. Design: Sixty‐six resin‐based maxillary second primary molars, obtained from extracted tooth cone‐beam computed tomography (CBCT) image and printed on a three‐dimensional printer, were divided into three groups: VDW.ROTATE™, EdgeTaper Platinum™, and K‐files. The specimens were scanned using CBCT imaging before and after root canal preparation. Images were registered using a dedicated software, and changes (Δ) in the canal area, volume, and untouched canal surface were calculated. Instrumentation time was evaluated. Data were statistically analyzed using the SPSS program. Results: There was no significant difference among the tested file systems for Δ canal volume and area (p >.05). VDW.ROTATE™, however, showed significantly lower untouched canal surface area than other systems in all roots (p <.001). The VDW.ROTATE™ was found to be significantly faster (6.47 ± 0.39 min) than EdgeTaper Platinum™ (7.71 ± 0.73 min) and K‐files (8.22 ± 0.72 min), (p <.05). Conclusions: The shaping ability and the instrumentation time were directly influenced by the root canal instrumentation system used during the preparation of resin‐printed primary molars, with VDW.ROTATE™ being the faster system and associated with the lower amount of untouched canal surface area. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of our study is to examine in vitro the amount of debris extrusion from the apical after root canal preparation with different rotary instruments. Materials and Methods: In present study, 60 single root single-canal lower premolar human teeth were used. The teeth were randomly selected and divided into 4 main groups (n=15). Root canals are shaped by using 2Shape, One Curve and XP-3DEndo Shaper working in rotational motion and WaveOne Gold working reciprocal motion. Later, the weight of each eppendorf tube was weighed on a precision scale and the amount of debris extrusion from the apical was determined with 10ˉ4 precision by subtracting the empty weight of the tube. Since the parametric test assumptions were fulfilled in the evaluation of the data obtained regarding the amount of debris extrusion from the apical of file systems by loading them into the SPSS 22.0 program, One-Way Variance analysis was used and the level of error was taken as 0.05. Results: When the amount of debris extrusion from the apical is ordered from high to low, it was seen that there are 2Shape, One Curve, XP-Endo Shaper, WaveOne Gold. However, the difference between study groups was not statistically significant (p> 0.05). Conclusions: Considering the results obtained in terms of debris extrusion from the apical about the new generation files with different metallurgy, kinematics, structural features, designs and different configurations that we used ın present study, it was seen that these systems would not show any difference in terms of the effect of debris on the success of endodontic treatment.

Successful outcome of pulp therapy depends on good chemomechanical preparation of the canals. This is completed with the help of various upcoming rotary and hand files. However, during this preparation, there might be an apical extrusion of the debris which may result in postoperative complications. The aim of this study was to evaluate and compare the number of debris apically extruded during canal preparation using two different pediatric rotary file systems and conventional hand file systems in primary teeth. 60 primary maxillary central incisors that were extracted due to trauma or untreated dental caries with no signs of resorption were taken. Canal preparation was executed using three different file systems: Group A: Group A hand K file system, Group B Kedo S Plus, Group C Kedo SG Blue. For each of these files using the Myers and Montgomery model, the pre- and post-weight of the eppendorf tube was assessed to quantify the number of apical debris. The maximum extrusion of apical debris was noticed with the Hand K-file system. The least debris was noticed in the Kedo S Plus file system. Statistical analysis revealed that there were highly significant differences in apical extrusion and debris when comparing hand files and rotary files and also between the two rotary files used. Apical debris collection is an unavoidable outcome of canal instrumentation. Among the file systems compared, rotary files had lesser extrusion when compared to hand files. Among the rotary files, Kedo S plus showed normal extrusion compared to SG Blue.

This study aimed to evaluate the preservation of periradicular dentin and the enlargement of the apical canal of mandibular molars with TruNatomy (Dentsply Sirona, Ballaigues, Switzerland) and ProTaper Gold (Dentsply Sirona) instruments. Twenty mandibular molars were scanned in a micro–computed tomographic device, anatomically paired, and distributed into 2 groups (n = 10). In the ProTaper Gold group, mesial and distal canals were prepared up to F2 (25/.08v) and F3 (30/.09v) instruments, whereas in the TruNatomy group, mesial and distal canals were enlarged up to the prime (26/.04v) and medium (36/.03v) instruments, respectively. After a new scan, the surface area, volume, unprepared areas, transportation, percentage of dentin removal, and dentin thickness parameters were calculated. Data were compared between groups using the Mann-Whitney test, the Student t test, and the nonmetric multidimensional scaling test with alpha set at 5%. No difference was found between groups regarding unprepared canal areas and the reduction of dentin thickness (P >.05). Transportation was lower than 0.1 mm in all groups, and statistical differences were observed only at the apical third of the mesiobuccal canal with lower values in the TruNatomy group. ProTaper Gold removed more dentin than TruNatomy at the coronal level of mesial roots (1.8% and 1.0%, respectively) (P <.05). TruNatomy and ProTaper Gold were efficient for performing canal preparation in mandibular molars. The tested systems were similar in terms of untouched canal walls and remaining dentin thickness and slightly different in the apical transportation of mesial canals and the percentage of dentin removal at the coronal third but without clinically significant errors. [ABSTRACT FROM AUTHOR]

Purpose: Pulpectomy may be indicated in restorable primary teeth exhibiting irreversible pulpitis or pulpal necrosis. The purpose of this study was to compare the cleaning and shaping efficacy of NiTi systems (Reciproc® Blue and MTwo®) with manual stainless-steel instrumentation in primary molars using micro-CT analysis. Methods: Fifty-seven maxillary second primary molars were scanned using micro-CT. Teeth with three divergent roots were divided randomly (n = 15) according to instrument type (K file, MTwo®, and Reciproc® Blue). Teeth with root fusion were instrumented manually as a separate group (n = 12). Pre- and post-instrumentation micro-CT images were superimposed, and the instrumentation area (IA) and procedural complications were recorded. Results: No statistically significant differences in IA between file systems was observed in the non-fused teeth. The mean IA of fused roots was significantly lower than in the non-fused distobuccal (p = 0.003) and palatal (p < 0.001) roots. The root segment had a significant effect on IA (p < 0.001) and the highest mean IA was observed in the apical third. Manual instrumentation had fewer procedural complications compared with rotary systems. Conclusion: No differences were determined in the cleaning and shaping effectiveness of all systems in non-fused teeth. Uninstrumented areas (> 60%) occurred in both non-fused and fused primary teeth with fewer procedural complications observed after manual instrumentation. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the influence of large apical preparations with Reciproc (REC), Hyflex CM (HCM) and Twisted File Adaptive (TFA) systems using micro‐computed tomography (MCT). Ninety mesiobuccal (MB) and distobuccal (DB) root canals of maxillary molars (n = 45) were scanned using MCT before and after the shaping procedures. The root canals (n = 15) were prepared until REC 40.06, HCM 40.04 and TFA 35.04. The root canal transportation (RCT), centring ability (CA), change in volume of the root canal and at different levels (VC), remaining dentine thickness (RDT), removal of dentine wall (RDW) and working time (WT) were evaluated. Data were analysed using the Kruskal–Wallis and Dunn tests, and the one‐way ANOVA and Tukey tests with a level of significance set at 5%. No significant difference among the instruments was found regarding the RCT, CA, RDT, RDW and WT (P > 0.05), in larger apical preparations in curved MB and straight DB canals of maxillary molars. [ABSTRACT FROM AUTHOR]

The remaining filling material after retreatment can harbor bacteria and organic tissues that can influence the outcome of the therapy., Aim: The aim of this study was to evalúate, by micro-CT, the amount of filling material remaining in the root canal after its removal using WaveOne Gold or ProDesign RT., Material and Method: Forty human mandibular canines were instrumented with the ProTaper Next system up to the X2 instrument (25.06) and filled with gutta-percha cones and AHPlus. Teeth were divided into 2 groups (n=20): WaveOne Gold 25.07 (WOG) and ProDesign RT 25.08 (PRT) for filling removal, after which they were scanned in a micro-CT device to quantify the volume of remaining filling material. The data were subjected to log 10 transformation, Student 's t-test was performed to account for multiple observationsper sample, significance was set at 5%., Results: Student 's t-test showed that there was no difference between the two systems regarding the volume of remaining filling material in the thirds: apical (p = 0.392), middle (p = 0.065), or cervical (p = 0.918)., Conclusión: Remaining filling material was present in all groups and both systems were similar in removing root filling material in mandibular canines., Competing Interests: The authors declare no potential conflicts of interest regarding the research, authorship, and/or publication of this article., (Copyright© 2024 Sociedad Argentina de Investigación Odontológica.)

Eshaghali Saberi,1 Bita Aramesh2 1Department of Endodontics, Oral and Dental Disease Research Center, Dental School, Zahedan University of Medical Sciences, 2Department of Endodontics, Dental School, Zahedan University of Medical Sciences, Zahedan, Iran Background: This ex vivo study aimed to compare transportation of the mesiobuccal root canal of mandibular first molars instrumented with ProTaper, Race and Sendoline rotary systems using cone beam computed tomography (CBCT). Materials and methods: Forty-five mesiobuccal canals of mandibular first molars were randomly divided into three groups of 15. Root canals in each group were instrumented with the ProTaper, Race or Sendoline rotary system according to the manufacturers’ instructions. Root canal preparations were performed by one operator, while root canal wall measurements were made by another operator blinded to the group allocation of teeth. The pre- and post-chemomechanical preparation CBCT scans were obtained and evaluated at 3, 6 and 9 mm levels from the apex. The amount of root canal transportation at these levels was calculated. Data were analyzed using SPSS version 17 via Mann–Whitney and Kruskal–Wallis tests. P0.05), but ProTaper showed the least and Sendoline caused the most canal transportation in the coronal third. Conclusion: ProTaper, Race and Sendoline rotary systems are not significantly different in terms of canal transportation. Although all rotary files cause root canal transportation, ProTaper and Race showed the least amount of canal transportation in the coronal and apical thirds, respectively. Keywords: canal transportation, ProTaper, Race, Sendoline, rotary systems, cone beam computed tomography

Introduction: Biomechanical preparation (BMP) of root canal damages the root dentin which becomes a gateway to dentinal cracks and thereby causing failure of the treatment. Therefore, there is a need of best instruments to minimize the failure of endodontic treatment. Aims and Objective: The objective of this study is to compare the incidence of cracks observed in the root dentin after root canal preparation with three different rotary instrument systems. Material and Methods: Seventy-five freshly extracted permanent maxillary incisors were randomly selected. Teeth were divided into five groups (n = 15), Group 1 – Untreated (negative control group), Group 2 – BMP done with nickel–titanium K-files (positive control group), Group 3 – BMP done with ProTaper Universal files, Group 4 – BMP done with ProTaper Next files, and Group 5 – BMP done with HyFlex EDM files. Roots were sectioned horizontally at 2 mm, 4 mm, and 6 mm from the apex. All slices were then viewed under stereomicroscope. All findings were analyzed using Chi-square test. Observations and Results: In the apical third, Group 5 had maximum number of fracture cases while Group 4 had lesser number and Group 3 had the least. In the middle third, Group 3 had maximum number of fracture cases while Group 4 and Group 5 showed lesser number of fractures. In the cervical third, Group 3 and Group 4 showed equal and maximum number of fracture cases. Group 5 showed no fracture cases. Group 1 and Group 2 showed no fracture cases in all the root sections. Conclusion: Conventional hand instrumentation is the best as compared to rotary instrumentation. However, rotary systems render various benefits with an acceptable success in comparison to the conventional hand instrumentation. In our study, we found that HyFlex EDM rotary system was the best with least number of fracture as compared to other systems used.

Background: Root canals of primary teeth are commonly prepared with endodontic files that are originally manufactured for permanent teeth. Aim: This micro‐computed tomography (micro‐CT) study evaluated and compared the changes in root canal morphology after preparation with different conventional and rotary files in primary teeth and young permanent teeth. Design: Seventy‐two extracted primary and permanent molars were selected and randomly assigned to three subgroups according to the file systems used (n = 12/each). After pre‐scanning of teeth with micro‐CT, root canals were prepared with One Shape and Revo‐S rotary systems and conventional endodontic files. After rescanning procedure, changes in canal volume, surface area, uninstrumented surface area, and apical transportation were evaluated. Mann‐Whitney U test, Kruskal‐Wallis test, and Conover's multiple comparison test were used for statistical analysis (P =.05). Results: Instrumentation with rotary files resulted in significantly greater volume and surface area of root canals and less uninstrumented areas (P <.001) than with manual files (P <.001). Primary molars showed significantly less apical transportation than permanent teeth (P <.001). Conclusions: Preparation of canals with rotary files could be a viable alternative to conventional files in primary teeth. Regardless of the file system used, uninstrumented areas still exist in both primary teeth and permanent teeth. [ABSTRACT FROM AUTHOR]

In the last two decades, an increase in large rotary machines/systems has been witnessed. To ensure safe operation of these systems especially due to extreme stress caused by centrifugal forces as well as the wind or water loadings, regular structural health monitoring (SHM) of the unbalanced parameters, particularly at the blade tips is necessary. For this, the use of non-contact sensors provides the most appropriate approach; however, millimetric out-of-plane deflection monitoring using non-contact sensors at distances >1 m has not been comprehensively addressed for rotary systems, like wind turbines. This study presents a modelling environment to simulate radar returns to analyse rotary systems. Employing Sammon mapping as a dimensionality reduction procedure in conjunction with 2D visualisation, the study demonstrates the characterisation of dynamic deflection parameters using a fast, portable ground-based interferometric radar (GBR). Comparisons between the GBR results with those of a Leica AR20 GPS indicate a divergence ±12.79 mm. The study utilises SHM framework to acquire, normalise, extract, and validate GBR signals within an SHM framework for structures under test or for deflection validation of the new system. Further, it contributes to the non-contact structural fatigue damage detection during design, testing, and operating stages of rotary structures blade tips.

In the last two decades, an increase in large rotary machines/systems has been witnessed. To ensure safe operation of these systems especially due to extreme stress caused by centrifugal forces as well as the wind or water loadings, regular structural health monitoring (SHM) of the unbalanced parameters, particularly at the blade tips is necessary. For this, the use of non-contact sensors provides the most appropriate approach; however, millimetric out-of-plane deflection monitoring using non-contact sensors at distances >1 m has not been comprehensively addressed for rotary systems, like wind turbines. This study presents a modelling environment to simulate radar returns to analyse rotary systems. Employing Sammon mapping as a dimensionality reduction procedure in conjunction with 2D visualisation, the study demonstrates the characterisation of dynamic deflection parameters using a fast, portable ground-based interferometric radar (GBR). Comparisons between the GBR results with those of a Leica AR20 GPS indicate a divergence ±12.79 mm. The study utilises SHM framework to acquire, normalise, extract, and validate GBR signals within an SHM framework for structures under test or for deflection validation of the new system. Further, it contributes to the non-contact structural fatigue damage detection during design, testing, and operating stages of rotary structures blade tips. [ABSTRACT FROM AUTHOR]

Abstract Introduction The aim of this study was to assess the frequency of root crack formation caused by the use of manual instrumentation, 2 rotary systems, and 1 reciprocating system using light-emitting diode transillumination. Methods One hundred fifty mandibular premolars were randomly divided into 5 groups (n = 30): control 1, no intervention; control 2, instrumented with hand files; group 3, instrumented with ProTaper Universal rotary files (Dentsply Maillefer, Ballaigues, Switzerland); group 4, instrumented with OneShape rotary files (Micro-Mega, Besancon, France); and group 5: instrumented with the WaveOne reciprocal system (Dentsply Maillefer, Ballaigues, Switzerland). After root canal preparations, the roots were sectioned at 3, 6, and 9 mm from the apex with water irrigation. The slices were inspected under a stereomicroscope with light-emitting diode transillumination from the buccal, lingual, mesial, and distal directions at ×40 magnification to determine the presence/absence of cracks (dentinal defects). The chi-square test was used to analyze the data. Results There was a significant difference among the groups in crack frequency (P <.05). The 2 single systems had significantly higher cracks than the other 3 groups. At 3 mm from the apex, there were significantly more cracks in groups 4 and 5 than in groups 1, 2, and 3 (P <.05). At 6 mm from the apex, no significant difference was noted (P >.05). At 9 mm from the apex, the frequency of cracks in group 3 was significantly higher (P <.05). Conclusions According to the results, using rotary instrumentation can result in some dentinal defects, and single-file systems, regardless of motion type, can cause significantly higher crack formation in the apical third of root canals. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to compare instrumentation time and cleaning efficacy of manual instrumentation and two rotary systems in the preparation of primary molar root canals. Materials and Methods: The teeth were randomly divided into three experimental groups, Group 1 K-file (n = 30), Group 2 Mtwo (n = 30), Group 3 WaveOne (n = 30), and one control group (n = 30). The root canals were prepared using one of the three file systems followed by clearing the teeth with different demineralizing solutions. The instrumentation time in each root canal was measured by a chronometer. The results were statistically evaluated using Kruskal–Wallis tests.Results: In the coronal third, WaveOne showed more ink removal and the difference found was highly significant (P < 0.0001). In the middle third of the root canal, WaveOne performed better than Mtwo and K-file (P < 0.005). At the apical level, there was no statistical difference between the three systems. WaveOne was found to take significantly (P < 0.0001) less time than Mtwo and K-file. Conclusion: WaveOne took less time and showed better cleaning efficacy when compared to other instrumentation techniques, especially in coronal and middle one-third.

Endodontic management of 3-rooted maxillary premolars is a challenge due to their complex anatomy and narrow root canal walls. This study aimed to evaluate, by microcomputed tomography (pCT), the apical enlargement and centering ability promoted by hand, rotary, and reciprocating instrumentation in 3-rooted maxillary premolars. Eighteen teeth were divided into 3 groups (n = 6) according to the preparation technique: crown-down hand, rotary, and reciprocating instrumentation. Instruments with similar apical diameters were used (25 and 40 mm for buccal and palatal canals, respectively). Centering ability and canal enlargement were evaluated through the comparison of gCT images obtained before and after instrumentation. Distances of 0, 2, 4, and 6 mm from the apical stop were considered. Differences between canal areas before and after instrumentation were calculated. In addition, distances between the original canal center and the prepared canal center at the apical stop were measured in both the mesiodistal and buccopalatal directions. Significant differences in enlargement areas and centering ability among the techniques were determined using 2-way analysis of variance and Tukey post hoc test (P < 0.05). Root canal enlargement was similar for all techniques. Excessive enlargement was observed in only a few specimens, and root perforation did not occur. Some specimens presented untreated canal areas. In mesiobuccal and distobuccal roots, reciprocating instrumentation promoted more centered preparations than hand instrumentation when measured in the mesiodistal direction (P < 0.05). There were no other statistically significant differences. The results established that hand, rotary, and reciprocating techniques presented similar safety margins for instrumentation of the apical third of 3-rooted maxillary premolars. Reciprocating instrumentation presented some advantages over hand preparation regarding centering ability. [ABSTRACT FROM AUTHOR]

Because of increasing demands for using rotating systems with high accuracy and in high speed applications, in addition to the specific condition of rotating systems, it is necessary to analyze these rotating systems characteristics. Tolerance analysis is a useful tool for estimating effects of dimensional and geometrical errors of effective parameters on functional characteristics in a mechanical system. Unlike other mechanical systems, besides the dimensional and geometrical errors, the accuracy of the rotary systems performance directly depends on the flexibility of parts and Non Repetitive Run-Out (NRRO) errors. In this paper, a new method is proposed for static and dynamic tolerance analysis of the rotary systems with the dimensional and geometrical errors, the flexibility effects, and the NRRO errors based on the tolerance zone model. First, using the small degrees of freedom concept, the dimensional and geometrical errors and the NRRO error are modeled in the tolerance zone. Then, based on a new strategy, the performance-assembly functions of the system for modeling the error propagation of the rotary system in the static and dynamic conditions are extracted. Then, using the proposed equations, sensitivities of the requirements such as the end of shaft position and the main natural frequency to tolerances are computed. To illustrate applicability of the proposed method, a rotary system is considered as a case study. Monte Carlo simulations are used for validation of the computational results from proposed method. [ABSTRACT FROM AUTHOR]

Introduction This single-blind, randomized controlled trial aimed to evaluate whether foraminal enlargement (FE) with a continuous rotary system during endodontic treatment causes more postoperative pain than nonforaminal enlargement (NFE). Methods Seventy qualified patients were randomized into 1 of 2 groups in a 1:1 ratio using a series of random numbers: the FE group and the NFE group. The patients were followed up for 7 days to evaluate between-group differences in the outcome measures. The study participants were selected from among patients who had necrosis and apical periodontitis in the maxillary or mandibular molar teeth. The primary outcome was to assess postoperative pain severity, and the secondary outcome was to evaluate analgesic consumption during the follow-up period. Pain severity was evaluated for the first 7 days using a visual analog scale (VAS). The VAS consisted of a 100-mm line. Pain severity was assessed as no pain (0–4 mm), mild pain (5–44 mm), moderate pain (45–74 mm), and severe pain (75–100 mm). The quality of life of patients during the follow-up period was assessed using a quality of life scale. The Student t test was used to identify statistically significant differences between the study groups ( P < .05). Results A significant difference was noted in postoperative pain in the first 2 days; the FE group experienced more pain than the conventional NFE group ( P < .05). In the FE group, 12 and 11 patients (34% and 31%) had severe postoperative pain (VAS score, >74 mm) on the first day and second day, respectively. VAS pain scores between the groups were not different ( P > .05) on other days. No significant difference was found in analgesic consumption between the groups ( P > .05). Conclusions On the basis of the VAS results, this randomized controlled trial indicates that FE causes more pain on the first 2 days after an endodontic treatment. [ABSTRACT FROM AUTHOR]

Aims: The purposes of this study were to evaluate the efficacy of two rotary systems (RaCe and ProTaper) compared with hand files, in the removal of gutta percha during retreatment. Retreatment time, amount of apically extruded debris, and procedural errors were also evaluated. Materials and Methods: Forty extracted mandibular premolars were instrumented to size 30 and obturated with lat-eral condensed gutta percha. Then teeth were randomly divided into four groups, 10 teeth each. Re-moval was performing with chloroform and one of the following techniques: (I) Hedstrom and K-files, (II) Hedstrom and hand ProTaper, (III) Rotary ProTaper, and (IV) RaCe. Retreatment times, apically extruded debris, and broken instrument were recorded. The root split longitudinally viewed under ste-reomicroscope at (10 X) photograph are taken, and then the area of remaining filling material and whole area of the canal were measured using SigmaScan software. Data were analyzed statistically using one way ANOVA and Tukey test. Results: The two rotary systems left significantly less remain-ing filling material, faster, and produce less amount of apically extruded debris compared to hand files. There was no significant difference between the two rotary systems, but there was significant differ-ence between the two hand files regarding the amount of remaining filling materials. Only RaCe exhib-its no fracture instruments during retreatment. Conclusions: The two rotary systems were found to be effective and faster in removing gutta percha during endodontic retreatment.

The use of rotary instrumentation had gained universal interest, therefore, providing a high level of competence in using these new systems is a major concern of most dental medical schools. This study evaluates the quality of root canal cleaning and shaping achieved by undergraduate students in using rotary Ni-Ti endodontic instruments compared to postgraduate students. We used 60 single rooted extracted teeth, assigned to two study groups that were evaluated based on histological criteria. The presence of debris inside the root canal was assessed and the recordings were statistically evaluated (p<0.05). There was a statistically significant difference between the levels of root canal cleaning and shaping recorded in the study groups. The endodontic performance in using rotary Ni-Ti systems by undergraduate students was not satisfactory, compared to postgraduate students. Therefore, the evaluation of dental curriculum in our school would be necessary in order to improve the undergraduate training in Endodontology. [ABSTRACT FROM AUTHOR]

INTRODUCCIÓN: el objetivo de este estudio in vitro fue comparar el grado de transportación de los canales radiculares utilizando tres técnicas de instrumentación rotatoria: HERO Shaper, ProTaper Universal y RaCe. MÉTODOS:se seleccionó una muestra de treinta canales vestibulares de molares humanos superiores con ángulo de curvatura entre 25 y 35° con conductos finos y formación radicular completa que fue dividida en tres grupos arbitrarios de diez conductos cada uno, los que fueron preparados por los sistemas de instrumentación rotatoria HERO Shaper, ProTaper Universal y Race respectivamente, todos hasta el diámetro # 30 a la longitud de trabajo, utilizando el motor Endo-Mate TC NSK con control de torque y velocidad controlada. Se tomaron radiografías previas y posteriores a la instrumentación, las que fueron digitalizadas con escáner Agfa Duoscan T1200 a resolución de 2.400 dpi en escala de grises, luego mediante el método de morfometría lineal utilizando el sistema computacional para imágenes digitales NIH ImageJ se hicieron un total de 12 mediciones por canal, 4 para el ancho total radicular, 4 para la pared cóncava y 4 para la pared convexa, todos a 1, 2, 4 y 6 mm, respectivamente, desde el vértice radiográfico del conducto. Los datos obtenidos fueron analizados mediante eálisis estadístico no paramétrico Mann Whitney Rank Sum y Kruskal Wallis para muestras independientes. RESULTADOS: se observa transportación del canal radicular hacia la pared cóncava al utilizar el sistema ProTaper Universal, siendo estadísticamente significativa. (p = 0,01). CONCLUSIÓN: el sistema rotatorio ProTaper Universal produce mayor número de transportaciones al compararlo con los sistemas RaCe y HERO Shaper.INTRODUCTION:the objective of this in vitro study was to compare the degree of transportation of root canals using three rotary systems: HERO Shaper, ProTaper Universal, and Race. METHODS:a sample of thirty buccal root canals of upper molars with curvatures between 25 and 35° was divided into three random groups of ten canals each, which were then instrumented by using the rotary systems HERO Shaper, ProTaper Universal, and Race respectively, all to a diameter # 30 to the working length, using the motor NSK Endo-Mate TC to control torque and speed. Radiographs were taken before and after mechanical instrumentation, and they were scanned with DuoScan Agfa T1200 scanner at a resolution of 2400 dpi gray scale. Afterwards, by the method of lineal morphometry and using the computer system for digital images NIH imageJ, a total of 12 measurements per root canal were done: 4 for the total root width, 4 for the concave wall and 4 for the convex wall, all at 1, 2, 4 and 6 mm respectively from the radiographic apex of the canal. The data were analyzed by using the Mann Whitney Rank Sum and Kruskal Wallis nonparametric statistical analysis for independent samples. RESULTS:Transportation was observed from the root canal to the concave wall when the ProTaper Universal system was used, being statistically significant (p = 0,01). CONCLUSION:the ProTaper Universal rotary system produced the greatest number of transportations when compared with HERO Shaper and RaCe systems.

OBJECTIVE: The efficiency of rotary, manual and ultrasonic root canal instrumentation techniques was investigated in proximally flattened root canals. MATERIAL AND METHODS: Forty human mandibular left and right central incisors, lateral incisors and premolars were used. The pulp tissue was removed and the root canals were filled with red die. Teeth were instrumented using three techniques: (i) K3 and ProTaper rotary systems; (ii) ultrasonic crown-down technique; and (iii) progressive manual technique. Roots were bisected longitudinally in a buccolingual direction. The instrumented canal walls were digitally captured and the images obtained were analyzed using the Sigma Scan software. Canal walls were evaluated for total canal wall area versus non-instrumented area on which dye remained. RESULTS: No statistically significant difference was found between the instrumentation techniques studied (p

OBJECTIVE: The aim of this study was to evaluate the biomechanical preparation of flattened root canals using the following systems: Endo-Eze AET stainless steel oscillatory instruments (Ultradent) and RaCe rotary NiTi instruments (FKG Dentaire). MATERIAL AND METHODS: Twenty extracted human mandibular incisors were randomly assigned to two groups: Group 1 - Instrumentation with oscillatory Endo-Eze AET files (oscillatory technique); Group 2 - Instrumentation with rotary NiTi RaCe files (rotary technique). The teeth were decoronated, had their apices and coronal openings sealed with sticky wax and were embedded in crystal-clear orthophtalic polyester resin. The roots were sectioned transversally with diamond discs at 10 mm (middle third) and 5 mm (apical third) from the apex and the segments were reassembled for instrumentation. The sections were photographed before and after root canal instrumentation and evaluated with respect to whether the original root canal shape was modified by instrumentation. To evaluate the differences in the root canal shape before and after biomechanical preparation, scores were given regarding the instruments touch on the intracanal walls. RESULTS: In middle third of the root canals instrumented with the rotary system, there was a change in the original canal anatomy (p0.05). CONCLUSION: Under the tested conditions, Endo-Eze oscillatory system yielded the instrumentation of all flattened root canal walls, maintaining the canal original shape throughout the biomechanical preparation, and was more effective than RaCe rotary system.

OBJECTIVE: to investigate the influence of three different rotary systems for cervical flaring on establishment of the real working length. MATERIAL AND METHODS: Thirty mandibular first molars were submitted to conventional endodontic access and initial working length measurement, followed by irrigation/suction of the pulp chamber with 5% sodium hypochlorite. Teeth were randomly divided into 3 groups (n=10) and cervical flaring of the mesiobuccal canals were performed using one of the following instrument systems: Group 1 - Gates-Glidden burs; Group 2 - Orifice Openers; Group 3 - La Axxess system. Two subsequent numbers of instruments of each rotary system were used and the final working length was recorded. A digital calyper was used to record the working length, in millimeters, to investigate a possible discrepancy between initial and final measurements. RESULTS: Analysis of variance (Anova) na Tukey test revealed statistical difference between Group 1 and Groups 2 and 3 (p£ 0.05). CONCLUSIONS: all groups presented shorter working length after cervical flaring; groups prepared with instruments La Axxes and Orifice Opener presented the best results among the systems studied.OBJETIVO: determinar a influência de três sistemas distintos de instrumentos rotatórios para alargamento cervical na determinação do comprimento real de trabalho. MATERIAL E MÉTODOS: Trinta primeiros molares inferiores foram submetidos ao acesso endodôntico convencional e odontometria inicial pelo método visual, utilizando-se para irrigação/aspiração da câmara pulpar o hipoclorito de sódio a 5%. Procedeu-se a ampliação cervical dos canais mésio-vestibulares empregando-se diferentes alargadores cervicais. De acordo com o sistema de ampliação cervical empregado, as 30 amostras foram divididas aleatoriamente em 3 grupos de 10 dentes cada. No Grupo 1 as brocas de Gates-Glidden foram utilizadas para a ampliação cervical; no Grupo 2, Orifice Openers foram empregados; e, no Grupo 3, foi usado o sistema La Axxess. Foram utilizadas em ordem crescente, duas numerações do sistema rotatório correspondente a cada grupo e, após, realizou-se a odontometria final. A leitura das duas tomadas odontométricas foi realizada com paquímetro digital, em milímetros, considerando-se duas casas decimais para averiguar a provável discrepância entre ambas as tomadas. RESULTADOS: a análise de variância (ANOVA) e o teste de Tukey (p£ 0,05) demonstraram diferença estatística entre o Grupo 1 e os Grupos 2 e 3. CONCLUSÕES: todos os grupos apresentaram encurtamento do comprimento de trabalho após alargamento cervical; os grupos preparados com instrumentos La Axxes e Orifice Opener apresentaram os melhores resultados.

Introduction The aim of this ex vivo study was to evaluate the removal of filling material after using CM-wire, M-wire, and nickel-titanium instruments in both reciprocating and rotary motions in curved canals. Methods Thirty maxillary lateral incisors were divided into 9 groups according to retreatment procedures: Reciproc R25 followed by Mtwo 40/.04 and ProDesign Logic 50/.01 files; ProDesign R 25/.06 followed by ProDesign Logic 40/.05 and ProDesign Logic 50/.01 files; and Gates-Glidden drills, Hedström files, and K-files up to apical size 30 followed by K-file 40 and K-file 50 up to the working length. Micro–computed tomography scans were performed before and after each reinstrumentation procedure to evaluate root canal filling removal. Statistical analysis was performed with Kruskal-Wallis, Friedman, and Wilcoxon tests ( P < .05). Results No significant differences in filling material removal were found in the 3 groups of teeth. The use of Mtwo and ProDesign Logic 40/.05 rotary files did not enhance filling material removal after the use of reciprocating files. The use of ProDesign Logic 50/.01 files significantly reduced the amount of filling material at the apical levels compared with the use of reciprocating files. Conclusions Association of reciprocating and rotary files was capable of removing a large amount of filling material in the retreatment of curved canals, irrespective of the type of alloy of the instruments. The use of a ProDesign Logic 50/.01 file for apical preparation significantly reduced the amount of remnant material in the apical portion when compared with reciprocating instruments. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to compare the efficacy of hand file, nickel titanium rotary instrument, and two reciprocating instruments for removing gutta-percha and sealer from the root canals. Materials and Methods: Eighty-eight mandibular premolar teeth were used. The root canals were shaped and filled with guttapercha and a resin-based sealer. The specimens were divided into four groups according to the technique by which the root filling material was removed: Group 1 — Wave One; Group 2 — Reciproc; Group 3 — ProTaper; and Group 4 — Gates-Glidden burs and stainless steel hand file. Then teeth were split longitudinally and photographed. The images were transferred to a computer. The ratio of remaining filling material to the root canal periphery was calculated with the aid of ImageJ software. Statistical analysis was performed using Kruskal–Wallis and Mann–Whitney tests. Results: A significant difference was found among all groups (P < 0.001). The WaveOne group demonstrated significantly less remaining filling material. The greatest amount of filling material was found in specimens where gutta-percha was removed with Gates-Glidden burs and stainless steel hand file. Conclusion: The reciprocating files were found to be significantly more effective in removing the filling material from the canal walls compared to the rotational file and hand file. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the apical displacement produced by different rotary nickel-titanium instruments, testing the hypothesis that rotary systems with nickel-titanium instruments produce lower mean values of apical displacement than stainless steel hand instruments. A total of 100 maxillary permanent first molars were selected for the study. The mesiobuccal roots were sectioned at the top cervical third and embedded in blocks of self-curing resin. The specimens were randomly divided into 5 groups and the root canals were prepared using the following nickel-titanium instruments: Group 1 - Quantec system 2000 (Analytic Endodontics, Mexico); Group 2 - Pro-File T.0.04 (Dentsply/Maillefer, Switzerland); Group 3 - Pro-File Series 29 T.0.04 (Dentsply Tulsa, Switzerland); Group 4 - Pow-R T.0.02 (Moyco-Union Broach, USA). Specimens in Group 5 were prepared using stainless steel hand instruments Flexofile (Dentsply/Maillefer, Switzerland). All root canals were previously submitted to cervical preparation using Orifice Shaper instruments #1, 2, 3 and 4 (Dentsply/Maillefer, Switzerland). After odontometry, the remaining root canal was shaped employing increasingly larger instruments, so that the final instrument corresponded to Quantec #9, Pro-File Series 29 #6, and #35 for the other groups. Specimens in Groups 1 to 4 were prepared using an electric handpiece with 16:1 reduction at 350 rpm. The specimens in Group 5 were manually prepared. Apical displacement was measured and recorded by means of radiographic superimposition on a specific desk. Statistical analysis (ANOVA) of the results revealed that all groups presented apical displacements. Considering only the nickel-titanium instruments, Group 4 showed the lowest mean value while Groups 2 and 3 produced the highest mean apical displacement values (pO objetivo deste trabalho foi avaliar o deslocamento apical produzido por diferentes instrumentos de níquel-titânio acionadas a motor testando a hipótese de que os sistemas rotatórios que usam instrumentos de níquel-titânio produzem valores médios de deslocamento apical menores que as limas manuais de aço inox. Foram utilizados 100 primeiros molares permanentes superiores, cujas raízes mesiovestibulares foram separadas e incluídas em blocos de resina autopolimerizável. Os corpos de prova foram divididos aleatoriamente em 5 grupos e os canais radiculares preparados com instrumentos de níquel-titânio: Grupo 1 - sistema Quantec 2000 (Analytic Endodontics, México); Grupo 2 - Pro-File T.0.04 (Dentsply/Maillefer, Suíça); Grupo 3 - Pro-File Série 29 T.0.04 (Dentsply Tulsa, Suíça); Grupo 4 - Pow-R T.0.02 (Moyco-Union Broach, EUA); e Grupo 5 (limas manuais) - limas manuais de aço inox Flexofile (Dentsply/Maillefer, Suíça). Todos os canais mesiovestibulares foram submetidos a um preparo cervical prévio utilizando-se instrumentos Orifice Shaper números 1, 2, 3 e 4 (Dentsply/Maillefer, Suíça). Realizada a odontometria, o restante do canal radicular foi modelado a partir dos instrumentos do menor para o maior calibre de tal ordem que o instrumento final de preparo correspondeu ao número 9 para o Quantec, número 06 para o Pro-File Série 29 e o número 35 para os demais grupos. Nos grupos de 1 a 4 foi utilizado motor elétrico com contra-ângulo de redução de 16:1 numa velocidade de 350 rpm. No grupo 5 o preparo foi realizado manualmente. A análise dos resultados (ANOVA), obtidos pela sobreposição radiográfica numa plataforma especifica, demonstraram que todos os grupos apresentaram deslocamentos apicais, sendo que o menor valor médio foi verificado no grupo 4 e os maiores valores médios foram observados nos grupos 2 e 3 (p

Introduction: An overlooked but important part of successful root canal treatment is a straight-line access (SLA). The purpose of this in vitro study was to compare the efficacy of IntroFile and PreRaCe rotary instruments with Gates Glidden (GG) drills in gaining SLA by cone-beam computed tomography (CBCT). Methods and Materials: A total of forty five extracted mandibular first molars were selected and mounted in dental like arches. Subsequently, they were randomly classified into three groups (n=15). After preparation of a standard access cavity, orifices of the mesiobuccal canal was reached and a #10 file was inserted to explore the canals until the file tip was visible at the apex. Then, preoperative CBCT images were taken. SLA was gained in three groups; group 1, FlexMaster's IntroFile (FM); group 2, PreRaCe (RC) and group 3, GG. Again, the first binding file at the working length (WL) was placed in the canal and postoperative CBCT images in similar positions were taken. The pre/post operative morphology of the canal was evaluated for changes. Data was analyzed using the one-way ANOVA and post-hoc Bonferroni analysis. Results: The average amount of reduction in coronal canal curvature in FM, RC and GG groups was 2.43±1.79, 3.17±2.05 and 8.7±3.45, respectively. This descending trend was statistically significant. The difference between pre/post SLA changes in FM and RC groups was significant compared to GG group, while there were no significant differences between RC and FM. Conclusion: GG drills produced extraordinary results in reducing coronal curvature of the canal and achieving SLA. They are also more effective than nickel-titanium (NiTi) rotary instruments in canals with coronal curvature. [ABSTRACT FROM AUTHOR]

Copyright of Revista ADM is the property of Asociacion Dental Mexicana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Statement of problem: Microorganisms are essential for the development of periradicular diseases and are one of the major causative factors associated with endodontic treatment failures. Different instruments and preparation techniques have been developed in Endodontics to eliminate or reduce intracanal bacteria. Purpose: The aim of this study was to compare the amount of remaining E. faecalis in the apical third of root canals following instrumentation with Profile, Race and FKG files. Materials and Methods: Ninety freshly extracted mandibular single canal premolars were selected. A horizontal groove was made circumferentially around the roots at a depth of 0.5 mm and a distance of 5 mm from the anatomic apex. All the equipments were sterilized overnight by ethylene oxide gas. Root canals, inoculated with E. faecalis suspension, were prepared using Profile, Race or FKG instruments in a step-back technique. Master apical file, amount of irrigant for each canal and working length were similar in all specimens groups. Following preparation, the apical portions of the roots were separated from the previously made grooves and were sampled by sterile paper points. Statistical analysis was performed using ANOVA and Duncan’s multiple range tests. Results: Profile was significantly more effective in eliminating E. faecalis as compared to Race. A significant difference was not observed between FKG and the other two studied instrumentation techniques. Conclusions: Neither of the methods could completely eliminate E. faecalis from the root canals.

Introduction: the objective of this in vitro study was to compare the degree of transportation of root canals using three rotary systems: HERO Shaper, ProTaper Universal, and Race. Methods: a sample of thirty buccal root canals of upper molars with curvatures between 25 and 35º was divided into three random groups of ten canals each, which were then instrumented by using the rotary systems HERO Shaper, ProTaper Universal, and Race respectively, all to a diameter # 30 to the working length, using the motor NSK Endo-Mate TC to control torque and speed. Radiographs were taken before and after mechanical instrumentation, and they were scanned with DuoScan Agfa T1200 scanner at a resolution of 2400 dpi gray scale. Afterwards, by the method of lineal morphometry and using the computer system for digital images NIH imageJ, a total of 12 measurements per root canal were done: 4 for the total root width, 4 for the concave wall and 4 for the convex wall, all at 1, 2, 4 and 6 mm respectively from the radiographic apex of the canal. The data were analyzed by using the Mann Whitney Rank Sum and Kruskal Wallis nonparametric statistical analysis for independent samples. Results: Transportation was observed from the root canal to the concave wall when the ProTaper Universal system was used, being statistically significant (p = 0,01). Conclusion: the ProTaper Universal rotary system produced the greatest number of transportations when compared with HERO Shaper and RaCe systems. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: To determine whether increased apical enlargement would result in a complete preparation of curved canals and to progressively assess shaping quality using multiple microcomputed tomography (MCT) scans. Methods: Ninety root canals with a curvature of 25° to 50° were selected. Five MCT scans, 1 preoperative and 4 postoperative, were acquired from each canal. Canal preparation was performed up to size 50 using 3 techniques, nickel-titanium (NiTi) hand files, Mtwo (VDW, Munich, Germany), and ProTaper (Maillefer, Ballaigue, Switzerland), by experienced operators in a dental mannequin so as to simulate the clinical conditions. At a level of 1 mm short of the working length, 2 parameters were evaluated in each of the 4 postoperative acquisitions: the percentage of the prepared outline and the amount of dentin removed (the prepared area). Results: Statistically, there was no significant difference between the 3 systems used regarding the prepared outline. The maximum prepared outline was achieved by the use of NiTi hand files (63%; confidence interval [CI], 54%–73%), whereas Mtwo and ProTaper amounted to 58% (CI, 50%–66%) and 60% (CI, 51%–70%), respectively. In contrast, the dentin area removed by ProTaper was significantly higher than that of Mtwo and NiTi hand files. Conclusions: Increased apical enlargement of curved canals did not result in a complete apical preparation, whereas it did lead to the unnecessary removal of dentin. [Copyright &y& Elsevier]