An overview of modern endodontics Niti system

Brazilian oral research, 2018

The introduction of automated instrumentation in endodontics represented a major advance in progress for this specialty, with improvements in the quality and predictability of root canal preparation and a significant reduction in procedural errors. In recent years, endodontic instruments have undergone a series of changes brought about by modifications in design, surface treatments, and thermal treatments. In addition, new movements have also been incorporated to offer greater safety and efficiency, optimizing the properties of the NiTi alloy, especially through eccentric rotary motion. An understanding of the mechanical properties of these new NiTi instruments and their effect on the clinical performance of root canal preparation is essential if dental practitioners are to select the instruments that provide optimal clinical outcomes, especially in curved or flattened canals. The objective of this literature review is to present and discuss the characteristics of the NiTi alloys us...

Australian Endodontic Journal, 1998

Scant information could be found in the dental literature on the hardness or strength of the materials in nickel-titanium (NiTi) root canal instruments. Hardness testing is a convenient method for examining these products and strength properties can be deduced from strength-hardness data. The Vickers Hardness was determined for NiTi root canal files and reamers from five manufacturers for sizes 15, 25 and 40. Significant differences in hardness were found between manufacturers, with values ranging from 296 to 349. Some differences were found between the different sizes from each manufacturer, but these were generally not statistically significant. These values obtained for NiT instruments are lower than the softest stainless steel files previously examined (296–347 cf. 403–651), and below the hardness required for many cutting instruments (550–650). The values obtained suggest that NiTi instruments may not be as sharp as, and become blunt more easily than, stainless steel instruments. The strengths are expected to be in the lower range of those for stainless steel instruments.

International Endodontic Journal, 2012

Gutmann JL, Gao Y. Alteration in the inherent metallic and surface properties of nickel-titanium root canal instruments to enhance performance, durability and safety: a focused review.

Materials, 2022

The current study aimed to compare the F1 endodontic instruments from five different heat-treated rotary systems regarding their design, metallurgical properties, and mechanical performance. Five F1 root canal shaping instruments (ProTaper Gold [PTG], Premium Taper Gold, Go-Taper Flex, EdgeTaper Platinum, and Super Files Blue)—plus, a conventional ProTaper Universal (PTU)—which were evaluated regarding their design, nickel/titanium ratio, phase transformation temperatures, microhardness, cyclic fatigue, and torsional and bending strengths. Mood's median test was used for the statistical comparison with a significance set at 5%. The instruments were similar regarding the nickel/titanium ratio and overall design. Go-Taper Flex had the closest transformation temperatures to PTG. PTU and Go-Taper Flex had the highest microhardness (408.3 and 410.5 HVN). The time to fracture of Super Files Blue was three and seven times higher than PTG and PTU, respectively. No difference was observe...

Applied Sciences, 2021

In modern endodontics, nickel-titanium (NiTi) rotary instruments are used on a large scale for root canal shaping. Nevertheless, the separation of an instrument is a serious concern during shaping. The aim of this study is to determine and compare the torsional fracture characteristics of three types of NiTi endodontic instruments, each with different cross-section designs and movements performed during root canal shaping: Endostar E3 (Endostar, Poldent Co. Ltd., Warsaw, Poland); Reciproc R25 (VDW, Munich, Germany); and Protaper Next X2 (Dentsply Maillefer, Ballaigues, Switzerland). Fifteen instruments are used in this study, divided in three groups (n = 5): Group Endostar, Group Reciproc and Group Protaper. For testing, each instrument is used to shape five simulated root canals, following which its torsional stress to failure is measured. The fracture lengths of all three groups are roughly between 2 and 3 mm from the tip. Higher values of the moment of torsion in fracture, and sm...

applied sciences, 2023

Abstract: This article aims to explore the importance of multimethod research in assessing the performance of nickel-titanium (NiTi) endodontic instruments. The review highlights the limitations of relying solely on measurements obtained through a narrow set of mechanical tests and acknowledges the challenge of replicating real-world working conditions in controlled laboratory settings. While achieving a perfect simulation may be difficult, the focus should be on developing research strategies that provide a superior understanding of outcomes. The multimethod research, which combines qualitative and quantitative methodologies, offers a promising solution to address this challenge effectively. By integrating nonquantifiable data with quantitative measurements, researchers may overcome the limitations of individual methodologies and gain deeper and more comprehensive insights into instrument performance. This multimethod approach enables a more accurate interpretation of results, enhancing the validity of the methodology. Therefore, conducting a comprehensive analysis of various competencies displayed by NiTi systems is essential for a comprehensive understanding of their characteristics, including cyclic fatigue, torsional and bending resistance, cutting efficiency, microhardness, design analysis, element composition, phase transformation temperatures, shaping ability, and additional methodologies that can address specific inquiries. By combining qualitative and quantitative methodologies in a multimethod approach, researchers can enhance their ability to answer research questions and provide valuable insights for clinical practice.

Over the decades, a wide array of nickel-titanium (NiTi) instruments has been introduced for shaping root canals. Each generation of instruments has had something new to offer and has been intended to improve upon previous generations. Many variables and physical properties influence the clinical performance of NiTi rotaries. Ultimately, clinical experience, handling properties, safety, and case outcomes should decide the fate of a particular instrument design. This review article summarizes the metallurgical and mechanical properties of NiTi endodontic instruments and the design features of each generation, with a special focus on the latest generation of NiTi instruments. Experimental and clinical evaluations of the performance of NiTi instruments in endodontic treatment are discussed.

Quintessence International, 2010

The introduction of nickel-titanium (Ni-Ti) to endodontics almost two decades ago 1 has dramatically changed the way root canal preparation is performed, in both general and specialist practices. The perceived most significant advantage lies in the predictability with which a desired shape is achieved. 2 Possibly more important, the use of rotary instruments requires attention to detail, eg, regarding the efficacy of antimicrobial regimes that further contribute to successful endodontic therapy. Then, cases of varying degrees of difficulty can be successfully treated, with excellent long-term outcomes (Fig 1). Not every instrument system is suitable for every clinician, and not all cases lend themselves to rotary preparation, mainly because of varying degrees of experience and complexity. Moreover, rotary instruments may break rather unexpectedly; if they are cleaned and sterilized for reuse, issues of corrosion and persistent contamination may come into play. 3 Therefore, knowledge of both clinical guidelines for and metallurgical properties of Ni-Ti rotary instruments is critical for their successful use. 2,4,5 A recent survey indicated that US-based endodontists are knowledgeable about Ni-Ti instrument usage but are still concerned about issues such as breakage and the quality of the canal shape. 6 Therefore, this review is intended to summarize most recent trends in Ni-Ti technology, instrument design, and usage parameters. This is hoped to provide clinicians a knowledge base for evidence-based practice, thus maximizing the benefits from the selection of Ni-Ti rotary instruments for root canal treatments. NICKEL-TITANIUM METALLURGY AND MANUFACTURING Nickel-titanium alloy, first developed for the US Navy, 7 is in principle highly resistant against corrosion, and, more important, it is superelastic and has a shape memory. The latter two properties stem from an atomic arrangement that is different from conventional alloys such as stainless steel. The atoms in steel can move against each other by a small specific amount before plastic deformation occurs (Fig 2); in contrast, Ni-Ti exists reversibly in two conformations, martensite and austenite, depending on ambient temperature (see Fig 2a) and external tension (see Figs 2b and 2c).

American journal of dentistry

The growing use of NiTi rotary instruments in dental practice demands a good understanding of their concept of alloy and design in relation to improved properties and inherent limitations. Nickel titanium's super elasticity allows more centered canal preparations with less transportation and a decreased incidence of canal aberrations. Furthermore, the production of files with increased taper became possible. This is of special importance because of concerns on the achievement of adequate irrigation and close adaptation of the filling material during endodontic treatment. Unique shaft and tip designs should permit the use of a rotary handpiece allowing different tactile awareness. On the other hand, special attention is paid to maximize cutting efficiency and cutting control throughout instrumentation. NiTi rotary instruments are generally used in a crown-down approach and a continuous reaming motion. Consequently, rounder root canal preparations, with less straightening and a smaller amount of apical extrusion is achievable. In spite of their increased flexibility, separation is still a concern with NiTi files. The phenomenon of repeated cyclic metal fatigue and the variable of torsional loading are two important factors in instrument fracture. However, with awareness of the appropriate manipulation and special attention to the equipment used, NiTi systems are safe with a minimal incidence of instrument failure. (Am J Dent 2001;14:324-333).

World Journal of Dentistry, 2015

In the last decade, nickel-titanium (NiTi) rotary canal instruments have proved to be valuable for root canal therapy because of their exceptional ability to shape root canals with potentially fewer procedural complications. The purpose of this clinical update article is to bring clinicians up to date with the current and popular endodontic rotary NiTi instrument systems. How to cite this article Jain P, Nayan S, Keswani E, Pawar S. Clinical Update on Nickel-Titanium Rotary Instruments. World J Dent 2015;6(2):97-103.