الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 101 |  |  |
| | | from | 101 | | |
Abstract
This study was intended to compare the cyclic fatigue resistance of three different rotary NiTi systems; GT series X (GTX), TF and Revo-s rotary nickel-titanium files in simulated curved canals, and also compare the cyclic fatigue of GTX, TF and Revo-s rotary nickel-titanium files after clinical use. Size #30 TF, GTX, and Revo-S with 0.06 taper were tested in a cyclic fatigue testing device that evaluated cycles to failure of rotary instruments in a simulated canal with 45 ºdegrees of curvatures and 5 mm radius of curvature. The number of rotations until fracture was recorded for each instrument. Results showed a statistically significant difference (p < 0.05) between the new GTX, TF and Revo-S NiTi instruments. New TF instruments showed a significant increase in the mean number of cycles to failure when compared with the new GTX and Revo-S instruments. GTX instruments showed a significant increase in the mean number of cycles to failure when compared with Revo-S instruments. The used TF instruments showed a statistically significant difference in the mean number of cycles to failure (p < 0.05) when compared with the used GTX and Revo-S instruments. No statistically significant difference (p > 0.05) was noted between the used GTX and Revo-S instruments. Comparison between new instruments and used instruments showed a statistically significant difference (p˂ 0.05) between the new and used GTX, TF and Revo-S NiTi instruments. The new manufacturing processesof the TF appeared to offer greater resistance to cyclic fatigue in a simulated canal model.