Clinical Update on Nickel-Titanium Rotary Instruments

BMC Oral Health

Background To investigate the complications associated with the use of nickel titanium rotary instruments (NiTi-RIs) for root canal treatments (RCTs), in Saudi Arabia dental practice, and to explore the influencing factors. Methods After obtaining an ethical approval, two pilot studies were conducted to formulate the final questionnaire. The sample size was measured taking into consideration 60% expected response rates and confidence level of 99.9%. The questionnaire was emailed to 600 general dentists (GDs) randomly selected from the dental register and all of the endodontists (175). The email’s introduction clarified objectives of the study and guaranteed that all of the collected information would remain confidential. A reminder was sent after 10 weeks. The data were collected and analyzed using the chi-squared test at a 0.05 significance level. Results With a 51% overall response rate, 71.9% off the respondents used NiTi-RIs. The majority (83.1%) experienced complications while ...

International Endodontic Journal, 2005

Guelzow A, Stamm O, Martus P, Kielbassa AM. Comparative study of six rotary nickel-titanium systems and hand instrumentation for root canal preparation. International Endodontic Journal, 38, 743-752, 2005. Aim To compare ex vivo various parameters of root canal preparation using a manual technique and six different rotary nickel-titanium (Ni-Ti) instruments (FlexMaster, System GT, HERO 642, K3, ProTaper, and RaCe). Methodology A total of 147 extracted mandibular molars were devided into seven groups (n ¼ 21) with equal mean mesio-buccal root canal curvatures (up to 70°), and embedded in a muffle system. All root canals were prepared to size 30 using a crown-down preparation technique for the rotary nickel-titanium instruments and a standardized preparation (using reamers and Hedströem files) for the manual technique. Length modifications and straightening were determined by standardized radiography and a computer-aided difference measurement for every instrument system. Post-operative cross-sections were evaluated by light-microscopic investigation and photographic documentation. Procedural errors, working time and time for instrumentation were recorded. The data were analysed statistically using the Kruskal-Wallis test and the Mann-Whitney U-test. Results No significant differences were detected between the rotary Ni-Ti instruments for alteration of working length. All Ni-Ti systems maintained the original curvature well, with minor mean degrees of straightening ranging from 0.45°(System GT) to 1.17°( ProTaper). ProTaper had the lowest numbers of irregular post-operative root canal diameters; the results were comparable between the other systems. Instrument fractures occurred with ProTaper in three root canals, whilst preparation with System GT, HERO 642, K3 and the manual technique resulted in one fracture each. Ni-Ti instruments prepared canals more rapidly than the manual technique. The shortest time for instrumentation was achieved with System GT (11.7 s). Conclusions Under the conditions of this ex vivo study all Ni-Ti systems maintained the canal curvature, were associated with few instrument fractures and were more rapid than a standardized manual technique. ProTaper instruments created more regular canal diameters.

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...

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).

BMC Oral Health

Background: To establish the extent of using nickel titanium rotary instruments (NiTi-RIs), to identify reasons for using / not using NiTi-RIs, to explore usage modalities and to identify factors and measures that can increase implementation of NiTi-RIs in general dental practice. Methods: Two pilot questionnaires were conducted on academic staff members at College of Dentistry, Taibah University, general dentists (GDs) and endodontists to finalise the questionnaire. A sample size was calculated considering the expected and minimum accepted response rates (60 and 48%, respectively) and a 99.9% Confidence Level. The online-questionnaire was sent to 600 GDs and all endodontists (175) working in Saudi Arabia. A reminder was emailed after 10 weeks to encourage non-respondents to complete the questionnaire. Responses, were collected and converted into numerical data which were analysed using the Chi-square test (p = 0.05). Results: Significantly most respondents (71.9%) used NiTi-RIs (p < 0.001); with more endodontists (96.9%) than GDs (60%). Most users (62.5%) had been using NiTi-RIs for More than 3 years (p < 0001). The trend of using NiTi-RIs increased as participants' experience and the number of root-canal treatments performed per week increased (p = 0.021). While most respondents (45.3%) used NiTi-RIs because of faster root-canal preparation, the majority of non-users (85.3%) didn't do so because of high cost. The highest proportion (43.3%) reported better undergraduate education as the most important factor that can significantly increase NiTi-RIs usage. The majority (91.8%) prepared glide-path before using NiTi-RIs; especially with stainless steel hand-files (63.3%). Conclusions: NiTi-RIs are relatively well adopted in Saudi dental practice. However, better education, especially during undergraduate training and lower cost can increase their usage. Overall, clinicians showed good awareness of NiTi-RIs usage aspects which reflected on usage modalities.

Iranian endodontic journal, 2013

Disinfection and subsequent obturation of the root canal space require adequate mechanical enlargement of the canals. The purpose of this in vitro study was to compare the shaping ability of Mtwo, RaCe and Medin rotary instruments during the preparation of curved root canals. Sixty mesiobuccal root canals of mandibular molars with severe curvatures between 25-35(°) and radius of 4-9 mm were randomly divided into three groups of 20 canals each. Using pre- and post-instrumentation radiographs, straightening of the canal and the apical transportation were determined with AutoCAD software. The data were analyzed using Chi square, analysis of variance, and post-hoc tests and the significance level was set at P&lt;0.05. Mtwo instruments maintained the canal curvature significantly better than Race and Medin instruments (P&lt;0.05). There was significant difference between the rotary instruments for iatrogenic transportation of the major foramen (P&gt;0.05). Under the conditions of this in...

Journal of dentistry and oral care, 2017

Introduction: The purpose of the present study was to evaluate comparatively the efficiency of two rotary Nickel Titanium (NiTi) file systems in instrumentation of simulated curved canals performed by undergraduate dental students and general dentists. Methodology: Twenty undergraduate dental students and 20 dentists participated in this study. After an introductory lecture, two simulated curved root canals in resin blocks with the same size and geometry were prepared by each participant, using the ProTaper Next or iRace file systems. The preparation time was recorded, and each participant received a questionnaire for self-assessment and evaluation of the difficulty of the systems. Blocks were collected, coded, photographed digitally, and evaluated microscopically. The status of the apical foramen of the simulated root canals was classified as intact, blocked or instrumented. The shape of root canal was evaluated further for the presence of zipping or transportation. T-test and Fisher's exact test were used for statistical analysis of the collected data (p < 0.05). Results: The mean time for instrumentation with the ProTaper Next system by the group of students was significantly greater than that prepared by the group of dentists. The time for instrumentation was significantly greater for the ProTaper Next system than that for the iRace system prepared by the group of students, while no significant difference was seen in the group of dentists between instrumentation with the two rotary systems. In general, no significant differences were observed between the two systems in terms of technical quality of instrumentation. In the group of students, significantly greater number of canals with blocked apical foramen were produced with ProTaper Next than the iRace system, while the number of over-instrumented canals was significantly greater with the iRace system. In the group of dentists, significantly greater number of canals with blocked apical foramen with the iRace than the ProTaper Next system was seen, while the number of over-instrumented canals was significantly greater with the ProTaper Next system. Conclusion: No significant difference in the technical quality of simulated curved canal preparation was detected between the ProTaper Next and iRace rotary Ni-Ti files systems. Although no difference in the occurrence of procedural errors produced by the in experienced students or experienced dentists groups was noticed, the types of procedural errors in relation to the used rotary files system were different between the two groups of participants.

International Endodontic Journal, 2004

Parashos P, Messer HH. Questionnaire survey on the use of rotary nickel^titanium endodontic instruments by Australian dentists.

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2010

The aim of this study was to compare the shaping ability of 4 nickel-titanium rotary techniques and 1 hand technique in simulated S-shaped curved root canals. Study design. Seventy-five simulated double-curved resin root canals were divided into 5 groups (n ϭ 15). The canals were compared at 12 different levels and at 3 different times: before preparation and after preparation to master apical 25 and 35. Data were statistically analyzed by performing 2-by-2 comparisons with the Tukey parametric test of variance analysis using a confidence interval of 95%. Results. All of the 75 resin blocks presented transportation of the root canals by transforming the apical curvature into a straight zone and straightening the first curvature. When increasing the diameter from 25 to 35, both curvatures were straightened. Conclusions. Based on the conditions of this study, we can say that the flexibility of the instruments is inversely related with the transportation of the root canals, and that in the double-curved root canals, the apical curvature is always straightened. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:e136-e144)

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.