Abstract
To aim of this study is to evaluate the cyclic fatique resistance of two different Ni-Ti rotary files Protaper Next and Fantadental V-Taper Gold at angle of 60 degrees in a metal block. This study was done with 7 files in each group including Protaper Next #25(Group 1) and Fantadental V-Taper Gold files#25(Group 2). The files were tested in artificial 600 curved canal on computer (CNC) machined metal block at a constant body temperature at 36.5 degrees. Each file rotated in a 360 motion with 350 rpm speed and 2.5 Ncm torque (Xsmart plus, Dentsply) until files were fractured. The time elapsed during rotation were recorded and the length of fractured part of the instruments measured for each file. Mann-Whitney U test was used to compare two independent groups. Kruskal-Wallis test was conducted to compare time and length among groups. The time periods and the length of the fractured parts of the instruments in each group: Group1 Protaper Next #25 10:05±0,76 sec (n=7); Group2 Fanta V-Taper Gold#25: 24:02±0:36 sec /(n=7).There was significant difference observed between cyclic fatigue of Group1 Protaper Next Files#25 and Group2 Fanta V-Taper Gold Files#25. No significant differences between groups were apparent regarding length of the fractured part. Keywords: Cyclic Fatique, Protaper Next,V-Taper Gold.
Highlights
NiTi rotary instruments are popular among clinicians because of their high flexibility and elasticity when compared with stainless steel files
Removing the fractured segment of the file, which is inside the root canal, is usually a difficult process, and the amount of residual dentin tissue significantly decreases while taking the instrument outside the canal.As a result, the prognosis of endodontic treatment might be negatively affected.[3]
All Studies showed that 70% of file fractures in curved root canals were caused by cyclic fatigue during shaping procedures.[5]
Summary
NiTi rotary instruments are popular among clinicians because of their high flexibility and elasticity when compared with stainless steel files. Nickel-titanium (NiTi) file fracture during root canal preparation is one of the most frequently seen complications.[1,2] Removing the fractured segment of the file, which is inside the root canal, is usually a difficult process, and the amount of residual dentin tissue significantly decreases while taking the instrument outside the canal.As a result, the prognosis of endodontic treatment might be negatively affected.[3] Cyclic fatigue occurs when all parts of NiTi file rotates continuously in the curved root canal.[4] At that point, flexion and tension cycles occur until file is broken. All Studies showed that 70% of file fractures in curved root canals were caused by cyclic fatigue during shaping procedures.[5] To avoid this unwanted situation, many investigations and renovations were done on metallurgical, chemical and mechanical properties of NiTi alloys to make files resistant to fracture.[6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
