Page 20 - SPEMD_59-2

78 rev port estomatol med dent cir maxilofac. 2018;59(2):75-79

resistance of endodontic rotary instruments. Such a new stan- references
dard is required to introduce universally accepted testing de-
vices for experimental evaluation of products or prototypes 1. Gulabivala K, Ng Y-L. Endodontics. 4th ed. London: Elsevier
that could also simulate root canals found in real teeth in a Health Sciences; 2014.
clinical environment. In addition, a consensus between re- 2. Li UM, Lee BS, Shih CT, Lan WH, Lin CP. Cyclic Fatigue of
searchers should also be reached to find the most accurate Endodontic Nickel Titanium Rotary Instruments: Static and
Dynamic Tests. J Endod. 2002;28:448-51.
statistical analysis. 3 3. Plotino G, Grande NM, Cordaro M, Testarelli L, Gambarini G. A
In this in vitro study, instruments were tested beyond time Review of Cyclic Fatigue Testing on Nickel-Titanium Rotary
that the instrument is expected to be active at a specific level instruments. J Endod. 2009;35:1469-76.
when shaping a root canal and no lubrication was used. In 4. Lopes HP, Ferreira AA, Elias CN, Moreira EJ, de Oliveira JC,
addition, pilot experiments had indicated that lubrication with Siqueira JF Jr. Influence of rotational speed on the cyclic
various agents leaded to a higher fatigue life. 18,26 Moreover, fatigue of rotary nickel-titanium endodontic instruments. J
Endod. 2009;35:1013-6.
and although it minimizes the effect of variables, rotary tests 5. Lee MH, Versluis A, Kim BM, Lee CJ, Hur B, Kim HC.
with no axial movement showed lower fatigue resistance Correlation between experimental cyclic fatigue resistance
when compared with those obtained with dynamic tests. and numerical stress analysis for nickel-titanium rotary files.
Until now, there is no specification or international stan- J Endod. 2011;37:1152-7.
dard to test cyclic fatigue resistance of endodontic rotary in- 6. Wan J, Rasimick BJ, Musikant BL, Deutsch AS. A comparison
struments. Thus, different results may arise. of cyclic fatigue resistance in reciprocating and rotary
nickel-titanium instruments. Aust Endod J. 2011;37:122-7.
That being stated, it is important for clinicians to under- 7. Bouska J, Justman B, Williamson A, DeLong C, Qian F.
stand the mechanical differences between systems of files to Resistance to cyclic fatigue failure of a new endodontic
take advantage of the latest technology. rotary file. J Endod. 2012;38:667-9.
8. Stojanac I, Drobac M, Petrovic L, Aranackovic T. Predicting in
vivo failure of rotary nickel-titanium endodontic instruments
Conclusions under cyclic fatigue. Dent Mater J. 2012;31:650-5.
9. Parashos P, Messer HH. Rotary NiTi instrument fracture and
its consequences. J Endod. 2006;32:1031-43.
Regarding Protaper Gold RM system, F2 instrument showed su- 10. Gutmann JL, Gao Y. Alteration in the inherent metallic and
perior cyclic fatigue resistance when compared with F3. Fur- surface properties of nickel-titanium root canal instruments
®
thermore, comparing data from PTG F2 and F3 with ProTaper to enhance performance, durability and safety: a focused
Universal F2 and F3, respectively, ProTaper Gold RM showed a review. Int Endod J. 2012;45:113-28.
superior behavior on cyclic fatigue resistance, with higher 11. Shen Y, Qian W, Abtin H, Gao Y, Haapasalo M. Fatigue testing
time to fracture (PTG F2 > PTGF3 ≥ PTU F2 > PTU F3). of controlled memory wire of nickel-titanium rotary
instruments. J Endod. 2011;37:997-1001.
12. Versluis A, Kim HC, Lee W, Kim BM, Lee CJ. Flexural stiffness
and stresses in nickel-titanium rotary files for various pitch
Ethical disclosures and cross-sectional geometries. J Endod. 2012;38:1399-403.
13. Uygun AD, Kol E, Topcu MK, Seckin F, Ersoy I, Tanriver M.
Protection of human and animal subjects. The authors declare Variations in cyclic fatigue resistance among ProTaper Gold,
that no experiments were performed on humans or animals ProTaper Next and ProTaper Universal instruments at
for this study. different levels. Int Endod J. 2016;49:494-9.
14. Pérez-Higueras JJ, Arias A, de la Macorra JC, Peters OA.
Confidentiality of data. The authors declare that no patient Differences in cyclic fatigue resistance between Protaper
data appear in this article. Next and Protaper Universal instruments at different levels. J
Endod. 2014;40:1477-81.
Right to privacy and informed consent. TThe authors declare 15. Hieawy A, Haapasalo M, Zhou H, Wang ZJ, Shen Y. Phase
that no patient data appear in this article. transformation behavior and resistance to bending and
cyclic fatigue of ProTaper Gold and ProTaper Universal
instruments. J Endod. 2015;41:1134-8.
Funding 16. Tripi TR, Bonaccorso A, Condorelli GG. Cyclic fatigue of
different nickel-titanium endodontic rotary instruments.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod.
Manufacturer DENTSPLY had no influence in the present 2006;102:e106-14.
study and authors deny any conflicts of interest. The financial 17. Fife D, Gambarini G, Britto LR. Cyclic fatigue testing of
support was provided by both Faculdade de Medicina Dentá- ProTaper NiTi rotary instruments after clinical use. Oral Surg
ria da Universidade de Lisboa and Faculdade de Ciências e Oral Med Oral Pathol Oral Radiol Endod. 2004;97:251-6.
Tecnologias da Universidade Nova de Lisboa. 18. Ullmann CJ, Peters OA. Effect of cyclic fatigue on static
fracture loads in ProTaper Nickel-Titanium rotary
instruments. J Endod. 2005;31:183-6.
19. Wolcott S, Wolcott J, Ishley D, Kennedy W, Johnson S, Minnich
Conflict of interest S, Meyers J. Separation incidence of Protaper rotary
instruments: a large cohort clinical evaluation. J Endod.
The authors have no conflicts of interest to declare. 2006;32:1139-41.