omparison between a Novel Nickel-Titanium Alloy and 08 Nitinol on the Cyclic Fatigue Life of ProFile 25/.0 otary Instruments

kel R ckelroot c istry, b tanium o s manu erior r memo nal shape ( eased f 2 taper w ) ( C files o while m the U nickelt cyclic f . The p d in the l ults in e rque s reas a P istance t ese two t separ ( S namic t s the m out a d tors a dimp d elong instrum al and is a lic f aper of i en well r ument b exceeded i on and, s to have s sufficient t t its tip. P bstract roFile 25/.04 instruments manufactured from thr ariants of Nitinol (1A, 1B & 2AS) were compared tock production ProFile 25/.04 instruments and fati ested to failure. Cyclic fatigue testing was perfor y rotating instruments at 300 RPM in a simulated oot canal with 5 mm radius and 90° curve unt trument separation. Time to failure was record orsion testing was undertaken by clamping 3 mm ach instrument tip between brass plates and rota t at 2 RPM until failure. Data were recorded for t nd angle at fracture. Statistical differences were found ith nickel-titanium variant 1B (M-WireTM NiTi) ne 00% more resistant to cyclic fatigue than stock Pr 5/.04 (P .001). Torsion testing found difference etween all 508 Nitinol groups and M-WireTM P .001). ProFile 25/.04 files manufactured fro -WireTM NiTi have significantly greater resistance yclic fatigue while maintaining comparable torsio roperties. (J Endod 2008;34:1406 –1409)