کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
3167435 | 1199364 | 2010 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Cyclic fatigue resistance of ProTaper Universal instruments when subjected to static and dynamic tests Cyclic fatigue resistance of ProTaper Universal instruments when subjected to static and dynamic tests](/preview/png/3167435.png)
ObjectiveThis study evaluated the number of cycles to fracture of ProTaper Universal S2 instruments when subjected to static and dynamic cyclic fatigue tests.Study designProTaper Universal S2 instruments were used until fracture in an artificial curved canal under rotational speed of 300 rpm in either a static or a dynamic test model. Afterward, the length of the fractured segments was measured and fractured surfaces and helical shafts analyzed by scanning electron microscopy (SEM).ResultsThe number of cycles to fracture was significantly increased when instruments were tested in the dynamic model (P < .001). Instrument separation occurred at the point of maximum flexure within the artificial canals, i.e., the midpoint of the curved canal segment. SEM analysis revealed that fractured surfaces exhibited characteristics of the ductile mode. Plastic deformation was not observed in the helical shaft of fractured instruments.ConclusionsThe number of cycles to fracture ProTaper Universal S2 instruments significantly increased with the use of instruments in a dynamic cyclic fatigue test compared with a static model. These findings reinforce the need for performing continuous pecking motions during rotary instrumentation of curved root canals.
Journal: Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology - Volume 110, Issue 3, September 2010, Pages 401–404