title: Fatigue resistance of engine-driven rotary nickel-titanium instruments produced by new manufacturing methods.
abstract: The aim of the present study was to investigate whether cyclic fatigue resistance is increased for nickel-titanium instruments manufactured by using new processes. This was evaluated by comparing instruments produced by using the twisted method (TF; SybronEndo, Orange, CA) and those using the M-wire alloy (GTX; Dentsply Tulsa-Dental Specialties, Tulsa, OK) with instruments produced by a traditional NiTi grinding process (K3, SybronEndo). Tests were performed with a specific cyclic fatigue device that evaluated cycles to failure of rotary instruments inside curved artificial canals. Results indicated that size 06-25 TF instruments showed a significant increase (p < 0.05) in the mean number of cycles to failure when compared with size 06-25 K3 files. Size 06-20 K3 instruments showed no significant increase (p > 0.05) in the mean number of cycles to failure when compared with size 06-20 GT series X instruments. The new manufacturing process produced nickel-titanium rotary files (TF) significantly more resistant to fatigue than instruments produced with the traditional NiTi grinding process. Instruments produced with M-wire (GTX) were not found to be more resistant to fatigue than instruments produced with the traditional NiTi grinding process.
authors.affiliation: La Sapienza University, Rome, Italy. ggambarini@tin.it
authors.forename: Gianluca
authors.initials: G
authors.lastname: Gambarini
authors.forename: Nicola Maria
authors.initials: NM
authors.lastname: Grande
authors.forename: Gianluca
authors.initials: G
authors.lastname: Plotino
authors.forename: Francesco
authors.initials: F
authors.lastname: Somma
authors.forename: Manish
authors.initials: M
authors.lastname: Garala
authors.forename: Massimo
authors.initials: M
authors.lastname: De Luca
authors.forename: Luca
authors.initials: L
authors.lastname: Testarelli
mesh_terms: D003722:Dental Alloys; D003762:Dental Instruments; D003799:Dental Stress Analysis; D008669:Metallurgy / Q000379:methods; D009532:Nickel; D018915:Root Canal Preparation / Q000295:instrumentation*; D014025:Titanium
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium