Basic ResearchBehavior of Nickel-Titanium Instruments Manufactured with Different Thermal Treatments
Section snippets
Materials and Methods
PTU F1-SE NiTi wire, PV–M-Wire, VB-specific thermal processes, and TYP shape memory technology (all size 25/.06) were evaluated. These instruments have similar design features such as the diameter at 3 mm from the tip and a triangular cross-section avoiding major geometry influences on the test results 19, 25, 26, 27.
Flexibility was determined using a testing apparatus (Analogica, Belo Horizonte, MG, Brazil) built according to the pertinent specification ISO 3630-1 (28). Twelve instruments of
Results
Bending moments (MB) obtained in the tests are summarized in Figure 1. The flexibility for TYP was significantly higher than that for the other 3 groups (P < .0001). This parameter was also significantly higher for VB compared with PV and PTU (P < .0001) and PV compared with PTU (P = .034).
The results of the torsion tests are shown in Figure 2 and indicate that the torsional resistance (Fig. 2A) of TYP and PTU, measured in terms of maximum torque, was significantly lower than that of PV (P
Discussion
Significant variations exist in raw materials used in the fabrication of endodontic instruments; therefore, it is important for clinicians to understand their differences to take advantage of the latest technology and facilitate good choices to meet anatomic challenges. In a comparison of instruments produced by twisting with those of a geometrically similar NiTi system produced by a grinding process, it was observed that the different manufacturing methods used for producing these instruments
Acknowledgments
Supported in part by Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG No. CDS–22008/12), Belo Horizonte, MG, Brazil, contributing to an exchange scholarship for Érika Sales Joviano Pereira at University of the Pacific, Arthur A. Dugoni School of Dentistry; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes), Brasília, DF, Brazil; and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brasília, DF, Brazil.
Dr Ove A. Peters serves as a consultant
References (33)
- et al.
Comparison between a novel nickel-titanium alloy and 508 Nitinol on the cyclic fatigue life of ProFile 25/.04 rotary instruments
J Endod
(2008) - et al.
Cyclic fatigue analysis of a new generation of nickel titanium rotary instruments
J Endod
(2009) - et al.
An in vitro comparison of torsional stress and cyclic fatigue resistance of ProFile GT and ProFile GT Series X rotary nickel-titanium files
J Endod
(2009) - et al.
Effects of raw material and rotational speed on the cyclic fatigue of ProFile Vortex rotary instruments
J Endod
(2010) - et al.
Current challenges and concepts of the thermomechanical treatment of nickel-titanium instruments
J Endod
(2013) - et al.
Mechanical behavior of M-wire and conventional NiTi wire used to manufacture rotary endodontic instruments
Dent Mater
(2013) - et al.
The effect of three rotational speed settings on torque and apical force with Vortex rotary instruments in vitro
J Endod
(2011) - et al.
Blue treatment enhances cyclic fatigue resistance of Vortex nickel-titanium rotary files
J Endod
(2014) - et al.
Comparison of the mechanical behavior between controlled memory and superelastic nickel-titanium files via finite element analysis
J Endod
(2013) - et al.
Metallurgical characterization of M-Wire nickel-titanium shape memory alloy used for endodontic rotary instruments during low-cycle fatigue
J Endod
(2012)