Evaluation of the Impact of Raw Materials on the Fatigue and Mechanical Properties of ProFile Vortex Rotary Instruments

doi:10.1016/j.joen.2011.11.004

Journal of Endodontics

Volume 38, Issue 3, March 2012, Pages 398-401

https://doi.org/10.1016/j.joen.2011.11.004 Get rights and content

Abstract

Introduction

In this in vitro study, raw materials (including stainless steel, conventional superelastic nickel-titanium [NiTi], M-Wire NiTi, and Vortex Blue NiTi) were used to create ProFile Vortex designed 25/.06 instruments and subject these instruments to testing for fatigue resistance, torsional properties, flexibility, and Vickers microhardness. The comparative results in this study will enable the clinician’s understanding of the performance of these materials for better choices in application during endodontic procedures.

Methods

Cyclic fatigue testing was performed by rotating files in an artificially constructed stainless steel canal with a 5-mm radius and a 90° angle of curvature at 500 rpm. Torsional properties and flexibility in bending were assessed according to specification ISO 3630-1. Vickers microhardness was measured on the cross section of instruments with 300-g load and 15-second dwell time.

Results

There were significant differences in the average fatigue life and flexibility for instruments made of different materials (P < .05). Vortex Blue was ranked first in both fatigue and flexibility, followed by M-Wire, superelastic wire, and stainless steel. For torsional strength and microhardness, stainless steel and M-Wire were ranked first and second, respectively. There was no statistically significant difference between superelastic wire and Vortex Blue. Vortex Blue showed the greatest distortion angle at break, whereas the other 3 materials showed comparable degree of rotation in the torque test.

Conclusions

Under the limitations of this study, NiTi shape memory alloy appeared to be a superior material option compared with stainless steel for its use in the application of endodontic rotary instruments. Vortex Blue and M-Wire offered functional advantages over conventional superelastic NiTi. Vortex Blue showed improved fatigue resistance and flexibility compared with ProFile Vortex M-Wire.

Section snippets

Materials and Methods

Instruments with identical geometric design and different raw materials were used to minimize or negate the potential influences that specific file designs might have on the outcomes of this study. On the basis of the design of ProFile Vortex instrument 25/.06 (tip size 25, taper 0.06, 25 mm in length), 4 different raw materials were selected, including 302 stainless steel (S-S), conventional superelastic NiTi (SE-wire), M-Wire NiTi (M-Wire), and prototype Vortex Blue NiTi (Blue).

Results

The means and standard deviations of test results on fatigue life, peak torque, angle of rotation, flexibility, and Vickers microhardness are shown in Table 1.

Discussion

File design such as size/taper, cross-sectional geometry, and pitch/helical angle has a great influence on file properties; therefore, instruments with identical geometric design but different raw materials were used to eliminate this influence in the present study. Significant variations exist in the raw materials used in the fabrication of endodontic instruments; therefore, it is important for clinicians to understand the differences and the properties of these materials to take advantage of

Conclusion

Under the limitations of this study, NiTi shape memory alloy appeared to be a superior material option compared with stainless steel for its use in the manufacturing and application of endodontic rotary instruments. Vortex Blue NiTi and M-Wire offered functional advantages over conventional superelastic NiTi. Vortex Blue showed improved fatigue resistance and flexibility compared with ProFile Vortex M-Wire.

Acknowledgments

The authors thank Marcie Littleton and Chris Miller from Dentsply Tulsa Dental Specialties for their support in instrument preparation and testing.

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Supported by Dentsply Tulsa Dental Specialties.

Yong Gao, Kevin Wilkinson, Randall Maxwell, and Dan Ammon are affiliated with Dentsply Tulsa Dental Specialties. James L. Gutmann is professor emeritus of Baylor College of Dentistry at Texas A&M Health Science Center and is currently a consultant with Dentsply Tulsa Dental Specialties.

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Basic ResearchEvaluation of the Impact of Raw Materials on the Fatigue and Mechanical Properties of ProFile Vortex Rotary Instruments

Abstract

Introduction

Methods

Results

Conclusions

Section snippets

Materials and Methods

Results

Discussion

Conclusion

Acknowledgments

J Endod

J Endod

J Endod

Oral Surg Oral Med Oral Pathol Oral Radiol Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

Basic Research
Evaluation of the Impact of Raw Materials on the Fatigue and Mechanical Properties of ProFile Vortex Rotary Instruments