Overview of instrumentation used in endodontics

The fundamentals of root canal therapy include thorough cleaning, suitable shape, and total root canal filling. There are numerous tools at our disposal to help us achieve these goals. A complicated range of files, filling techniques, and modern materials have been designed to speed up the process, increase its dependability, and enable the clinician to properly treat challenging patients and intricate anatomies. Hand instruments include barbed broaches, reamers, and files such as K-file, K-flex file, Flexofile, and Hedstrom files. Nickel-titanium alloys have been used to replace stainless steel in the production of endodontic equipment. Compared to stainless steel tools, these lead to more straightening of canal curvature, centering, tapering, and leading to a superior preparation. In an effort to speed up preparation of canals and lessen operator fatigue, a wide variety of electric power-run tools have been created like reciprocating handpieces, rotary NiTi files and handpieces. Accurate root canal length measurement is crucial to the effectiveness of root canal therapy. Radiography and the application of an electronic apex locator are the two methods used most frequently to confirm canal length. Instruments needed for filling canals are dependent on the procedure chosen to fill the root canal. Hand or finger spreader with a pointed tip are used in lateral condensation; hand or finger pluggers with blunt, flat ends are employed in vertical condensation; thermomechanical compaction uses an engine-powered compactor, thermoplasticized injectable gutta-percha and gutta-percha carrier devices. Careful use of canal preparation, sterilization, and obturation techniques, together with the appropriate instrument selection and use, can significantly increase the likelihood that endodontic procedures will be successful.

Evaluation of glide path preparation and shaping ability of two nickel-titanium engine driven systems in moderate curved root canals / 上海交通大学学报（医学版）

Objective:To evaluate the clinical application effect of two nickel-titanium engine driven systems on moderate curved root canals. Methods:Ninety mesial root canals with moderate curvature of extracted human first mandibular permanent molar were randomly divided into three groups: M3 PRO Group, MTwo group and K group. The glide path was firstly prepared by using #10/04 file in M3 PRO group and MTwo group and #10 file in K group respectively.Then the preparation of root canals up to #25 was performed according to the instruction manual in each different group using standardized technique. All data including time required in glide path preparation, shaping preparation, total root canals preparation and changes of working length in root canal were recorded and analyzed statistically by using Analysis of Variance (ANOVA) and LSD-t tests (P<0.05). Results:Root canal glide path preparation time: MTwo group showed significantly less preparation time while M3 PRO group exhibited significantly the longest preparation time. There was significant difference between MTwo group and M3 PRO group (P=0.001). Root canal shaping preparation time: M3 PRO group showed significantly less preparation time while K group exhibited significantly the longest preparation time. Both MTwo group and M3 PRO group showed significantly less preparation time than K group (P=0.004, P=0.001), but there was no significant difference between MTwo group and M3 PRO group (P=0.573). Total root canal preparation time: MTwo group showed the shortest time while K group exhibited the longest time. There were significant differences between MTwo group, M3 PRO group and K group (P=0.004, P=0.033), but no significant difference between MTwo group and M3 PRO group (P=0.451). Changes of root canal working length: There were significant differences among the three groups (P=0.037, P=0.037, P=0.000). M3 PRO group showed a minimal change while K group exhibited significant changes. Conclusion:MTwo nickel-titanium engine driven system with #10/04 file preform a high efficiency in glide path preparation, whilst M3 PRO nickel-titanium engine driven system show less changes in working length. Under the circumstances where the total time required for root canal preparation is not significant, M3 PRO nickel-titanium engine driven system is more suitable for root canal preparation in moderate curved root canals.

Comparision of the shaping and cleaning ability of Reciproc,OneShape and ProTaper rotary instrument in oval-shaped canal of extracted teeth / 实用口腔医学杂志

Objective:To investigate the shaping and cleaning ability of Reciproc(RE),OneShape(OS)and ProTaper(PT)in oval-shaped root canal preparation.Methods:The canals of 57 distal roots of mandibular first molars were randomly divided into 3 groups and prepared by RE,OS and PT respectively.The preparation time was recorded.After instrumentation,all root canal walls were examined under SEMand evaluated by scores of debris and smear layer.The 3D data and images of the roots of pre-and post-preparation were con-structed by Micro-CT scanning.Results:Group RE and OS showed lower scores of debris and smear layer than those in group PT at the apical level(P <0.05),and less preparation time (P <0.05).Before and after preparation,the changes of root canal morphological pa-rameters (including volume,surface,area,major diameter and minor diameter)in OS group were less than those in group RE and PT(P<0.05).The changes of canal curvature in group PT was larger than that in group RE and OS (P <0.05).Conclusion:RE and OS are more effective than PT in debridement and faster in root canal preparation.RE and OS can maintain the centering of original canal better than PT in the apical part of the root canal.The shaping ability of OS is weaker than that of RE and PT.

Comparison of canal transportation and centering ability of hand Protaper files and rotary Protaper files by using micro computed tomography

Introduction and objective: The aim of the present study was to compare root canal preparation with rotary ProTaper files and hand ProTaper files to find a better instrumentation technique for maintaining root canal geometry with the aid of computed tomography. Material and methods: Twenty curved root canals with at least 10 degree of curvature were divided into 2 groups of 10 teeth each. In group I the canals were prepared with hand ProTaper files and in group II the canals were prepared with rotary ProTaper files. Image analysis was performed at four levels 4mm, 6mm, 9mm, and 12mm from the root apex to assess changes in canal transportation and centering ratio using computed tomography (CT). Results: Data suggest that rotary ProTaper files presented the best outcomes for both variables evaluated. Rotary ProTaper files caused lesser transportation and remained better centered in the canal than hand ProTaper files. Conclusion: The canal preparation in natural teeth with rotary Protaper files showed lesser transportation and better centering ration than hand ProTaper files.

Endodontia mecanizada: a evolução dos sistemas rotatórios contínuos: [revisão] / Mechanized endodontic: the evolution of continuous rotary systems: [review]

Introdução: Nenhuma fase do tratamento endodôntico vivenciou significativa evolução como a instrumentação, graças ao desenvolvimento expressivo dos instrumentos rotatórios contínuos, o que justifica a necessidade de estudos a respeito do assunto. Objetivo: O objetivo deste trabalho foi realizar um levantamento bibliográfico sobre a evolução dos sistemas rotatórios contínuos, abordando as características individuais, o mecanismo de ação, a técnica de preparo, as vantagens e desvantagens de cada sistema, assim como as correções de possíveis falhas existentes. Revisão de literatura: Por meio de comparação, analisaram-se na revisão de literatura, de maneira geral, os principais fatores que envolvem a utilização dos sistemas rotatórios, como: limpeza e modelagem, habilidade na remoção de smear layer e debris, transporte apical, extrusão apical de debris, perda de comprimento de trabalho, formação de zips, degraus e perfurações, taxa de deformações e fraturas de limas e tempo de preparo do canal radicular. Conclusão: Concluiu-se que os sistemas ProTaper Universal, K3, Hero, MTwo e Race são os mais representativos no momento atual, e os sistemas BioRace e Twisted Files, os mais promissores, pois estudos a seu respeito ainda precisam ser realizados.

Introduction: None phase of endodontic treatment has showed significant evolution as the instrumentation, due to the expressive development of the rotary files, what justifies the need of studies regarding this matter. Objective: The aim of this study was to carry a review about the evolution of continuous rotary systems, showing individuals features, action mechanism, shaping technique, advantages and disadvantages of each system and corrections of possible failures. Literature review: Through comparison, the main factors regarding the use of rotary systems were analyzed in general in the literature review, such as cleaning and shaping, ability to remove smear layer and debris, apical transportation, apical extrusion of debris, loss of working length, zips formation, stairs and perforations, file deformations and fractures? rate and working time for root canal shaping. Conclusion: It was concluded that the systems ProTaper Universal, K3, Hero, Race and MTwo are the most representative in the actual moment. The systems BioRace and Twisted File are the most promising because studies about them still need to be accomplished.

Reduction of Broach Rotation for Versys Fibermetal Tapered Stem during the Femoral Canal Shaping / 대한정형외과연구학회지

PURPOSE: Inaccurate femoral canal shaping can result in post-operative complications in hip arthroplasty. We addressed the amount of broach rotation during shaping of the femoral canal and compared it with respect to newly designed broaches which were modified to minimize the rotation. MATERIALS AND METHOD: we designed the broaches that had canal guide which restricts the broach motion such that it is always aligned with the femoral axis while the broach machines the metaphyseal bone. Conventional broaches and the modified broach applied to 5 pair of fresh-frozen cadaver femurs and its spatial motion was measured with motion tracker. Rotations in coronal, saggital and frontal plane during the final 10 mm of broach advance were measured. RESULTS: 2.4..of axial rotation was occurred during final 10 mm advance of broach in the conventional method, which was the largest component of the rotation. Rotation of the broach during machining was decreased to 37% (p=0.075) and 25% (p=0.042) in the sagittal plane and coronal plane, respectively, by proposed method. CONCLUSION: The canal guide in the proposed method significantly reduced the rotation of the broach without any extra incision or measurement devices, resulting in increased accuracy in the femoral canal shaping.

Shaping ability assessment of Hero 642 in curved canals / 实用口腔医学杂志

Objective: To evaluate shaping ability of nickel-titanium rotary instruments (Hero 642) in curved root canals. Methods:The computer assistant measure system of simulated root canal was used for quantitative analysis of root shape in eight simulated root canals during nickel-titanium rotary instruments (Hero 642) shaping process. Results:Nickel-titanium rotary instruments (Hero 642) could keep the curved angles in simulated canals very well. The cutting of Hero 642 in curved root canals was balanced and there was almost no transportation of canals central lines when the simulated canals were prepared to 0.02 taper 25~# and 30~# files. Conclusion:Nickel-titanium rotary instruments (Hero 642) has good shaping ability. In preparation of highly curved canals, the master apical file (MAF) may be Hero 642 0.02 taper 30# files.

Application of computer-added measure system in the practice training of root canal therapy / 实用口腔医学杂志

Objective:To test the validity of the computer-added measure system in pre-clinical practice training of root canal treatment with resin transparent tooth models.Methods:Two groups of students prepared resin transparent tooth models in three ways.Transparent root canal preparation was conducted by the first group, blind root canal preparation and blind followed by transparent preparation were conducted by the second group. Resin transparent tooth models were scanned frontally and laterally before and after the preparation. The computer-added measure system was used to evaluate the effect of instrumentation. The data was analyzed by SPSS 10.0 software.Results:It was helpful to understand the change of root canal shape and the problems in instrumentation by using the computer-added measure system with resin transparent tooth models in pre-clinical practice training. The transparent preparation resulted in lower frequency of the preparation defects(P