We have investigated the crystallization of amorphous equiatomic NiTi thin films sandwiched between two protective silicon nitride barrier films using optical, atomic force, and transmission electron microscopy. Crystallite nucleation occurs homogeneously inside the NiTi films because small composition shifts at the interfaces between NiTi and surrounding layers suppress heterogeneous nucleatio...

Nickel-titanium (NiTi) shape-memory alloys (SMAs) have been used in the manufacture of orthodontic wires due to their shape memory properties, super-elasticity, high ductility, and resistance to corrosion. SMAs have greater strength and lower modulus of elasticity when compared with stainless steel alloys. The pseudoelastic behavior of NiTi wires means that on unloading they return to their ori...

An access device using a combination of a compression coil spring made of NiTi shape memory alloy (SMA) and NiTi superelastic strips has been developed. Particular consideration is given to the application of the concept in transanal endocopic microsurgery (TEM), but it could be used in other procedures where tissue expansion is required. In TEM, it could realize the gasless dilation of the rec...

When deposited at room temperature, sputtered NiTi thin films are amorphous and need to be crystallized before they can be used as a functional material. We present the results of an annealing study on substrate-constrained NiTi shape memory thin films. Amorphous films of a NiTi shape memory alloy were deposited by UHV sputtering. Films of thickness 1.0 μm were grown on (100) Si wafers both wit...

This work studies the effect that argon and nitrogen atmospheres have on structure, phase composition, cytocompatibility, functional properties of porous NiTi alloys obtained by self-propagating high-temperature synthesis. Porous in atmosphere (NiTi-(N)) are characterized brittle interstitial phases Ti4Ni2O(N) appearance a finely dispersed TiNi3 comparison with alloy an (NiTi-(Ar)). An increase...

Resistance to cyclic flexural fatigue failure is an important feature of rotary nickel-titanium (NiTi) instruments. The aim of this study was to evaluate the cyclic flexural fatigue failure resistance of RevoS Shaper Universal rotary NiTi files and to compare it to two other rotary NiTi files with similar size and taper, the Hero Shaper and the ProFile. Fifteen each of Revo-S Shaper Universal, ...

INTRODUCTION The objective of this study was to assess tracheal reactivity after the deployment of different self-expandable metal stents (SEMS). MATERIAL AND METHODS Forty female New Zealand rabbits were divided into four groups. Three groups received three different SEMS: steel (ST), nitinol (NiTi), or nitinol drug-eluting stent (DES); the fourth group was the control group (no stent). Sten...

AIM To determine whether the following can be sterilized by autoclaving - endodontic sponges, rotary nickel-titanium (NiTi) instruments within endodontic sponges, and rotary NiTi instruments with rubber stoppers. METHODOLOGY Sixty-four samples of eight different endodontic sponges (n = 512) were placed into brain heart infusion broth (BHI) for 72 h. An aliquot of this was then spread onto hor...

procedural accidents and obstacles to normally routine therapy, at almost any stage of treatment. One of these procedural problems is intracanal instrument fracture. Fractured root canal instruments may include endodontic files (Figure 1) and Gates Glidden burs. Instruments are made from nickel titanium (NiTi), stainless steel or carbon steel. Fracture often results from incorrect use or overus...