Influence of rotation speed on the number of cycles to fracture engine-driven NiTi endodontic instruments

Hélio Lopes, Alessandra Ferreira, Edson Moreira, Júlio Cesar Machado

Abstract


This study evaluated the influence of rotational speed in the number of cycles required to fracture engine-
driven NiTi endodontic instruments. ProTaper Universal F3 instruments 25mm in length at 300 and 600 rpm were used in an artificial curved canal. The surfaces of fracture and the helical shaft of the fractured instruments were analyzed using a scanning electron microscope (SEM). The results indicated that the number of cycles required to cause the fracture was influenced by the speed of rotation. The morphology of the fracture surface showed ductile type characteristics and there was no plastic deformation in the helical shaft of the instruments fractured.

Keywords


velocidade de rotação; fratura por fadiga; fratura; níquel-titânio; instrumento rotatório.



DOI: http://dx.doi.org/10.18363/rbo.v65n2.p.234

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