AIM The aim of the present study was to compare the resistance to cyclic fatigue of Hyflex® (Coltene-Whaledent, Allstatten, Switzerland) size 40 taper.04 nickel titanium instruments used in continuous rotation versus the use with a reciprocating motion. The null hypothesis was that different file motions had no influence on the lifetime of instruments subjected to a cyclic fatigue test. METHO...

Due to its pseudo elastic behavior, the nickel-titanium (nitinol) alloy has been used in the manufacture of endodontic instruments in recent years, being especially useful for curved canals preparation. Extensive research has been carried out to improve the wear resistance of the nitinol instruments without create modifications in the bulk of the files. The purpose of this work was to measure t...

Cyclic fatigue of nickel-titanium, engine-driven instruments was studied by determining the effect of canal curvature and operating speed on the breakage of Lightspeed instruments. A new method of canal curvature evaluation that addressed both angle and abruptness of curvature was introduced. Canal curvature was simulated by constructing six curved stainless-steel guide tubes with angles of cur...

INTRODUCTION Instrument separation is a serious concern in endodontics. Stainless steel instruments usually deform before they separate whereas Nickel Titanium instruments do not show any sign of deformation. AIM of the present study was to compare the cyclic rotations needed to fracture three different rotary nickel titanium endodontic instruments namely Profile, K3 Endo, RaCe in simulated c...

The aim of this in vitro study using implants and abutments was to examine traces left by various cleaning instruments and to determine the quantity of substance removal. The implants and relevant abutments were Screw-Vent implants (Dentsply), titanium plasma-coated full-screw implants (Straumann), and standard Brånemark implants (Nobel Biocare). The instruments used were titanium curettes, Gra...

BACKGROUND This in vitro study compared the shaping ability of RaCe, FlexMaster, and ProFile rotary nickel-titanium instruments in severely curved root canals of extracted teeth. MATERIAL AND METHODS Sixty maxillary molars with curvatures ranging from 25° to 65° were embedded in a muffle system and portioned into five horizontal sections (thickness 1.2 mm), starting from the apex. Canals were...

introduction: file fracture is one of the main procedural mishaps in endodontic treatment. the aim of this in vitro study was to compare the fracture rate of three niti rotary systems; hero 642, mtwo and flexmaster in artificial canals. methods and materials: in this study, bovine long bone was used. after primary preparation of bones, longitudinal sections with 4-cm diameter were cut and encod...

Since the introduction of nickel-titanium alloy to endodontics, there have been many changes in instrument design, but no significant improvements in the raw material properties, or enhancements in the manufacturing process. Recently, a new method to produce nickel-titanium rotary (NTR) instruments has been developed, in an attempt to obtain instruments that are more flexible and resistant to f...