Nickel titanium, also know as nitinol, is a prototypical shape memory alloy, property intimately linked to phase transition in the microstructure, which allows meso/macroscopic sample shape...

The biomaterials used to maintain or replace functions in the human body consist mainly of metals, ceramics or polymers. In orthopedic surgery, metallic materials, especially titanium and its alloys, are the most common, due to their excellent mechanical properties, corrosion resistance, and biocompatibility. Aside from the established Ti6Al4V alloy, shape memory materials such as nickel-titani...

BACKGROUND Orthodontic wires are the corner stones of the science and art of orthodontics and they remain in the patient's mouth for a prolonged period of 18-24 months. It is but natural to expect that they will undergo some biodegradation when in the oral environment during that period. This study aims to compare the biodegradation characteristics of four different orthodontic wires, stainless...

Orthodontic mechanotherapy encompasses the use of several archwires during speci c stages of treatment. Metallic orthodontic appliances consist of bands, arch wires, ligature wires, hooks, tubes, brackets, and springs are daily used in orthodontic practices for the correction of malocclusions in patients ( Oh et al. , 2004 ; Verstrynge et al. , 2006 ; Sabane et al. , 2009 ). One of the most im...

The nickel-titanium (Ni-Ti) alloys used in endodontics contain 56% Ni and 44% Ti. The 2 unique features related to clinical dentistry (i.e., shape memory effect and superelasticity) are due to the transition from austenite to martensite in Ni-Ti alloy. When a superelastic Ni-Ti alloy undergoes a low tensile loading, normal elastic behavior occurs. In fact, at higher tensile loads, the elastic s...

since the introduction of engine-driven nickel-titanium (niti) instruments, attempts have been made to minimize or eliminate their inherent defects, increase their surface hardness/flexibility and also improve their resistance to cyclic fatigue and cutting efficiency. the various strategies of enhancing instrument surface include ion implantation, thermal nitridation, cryogenic treatment and el...

Recently, people devote to the development of beta titanium alloys which have better biocompatibility because of the addition of Mo, Nb, Ta, Zr, Sn, et al. In this paper, the effects of heat treatment and cold roll deformation on the mechanical properties of the Ti-11.3Mo-6.6Zr-4.3Sn alloy (TMZS) are investigated by tensile test. The results show that the excellent combination of strength and d...

objectives: the aim of this in-vitro study was to evaluate the effect of topical fluoride on surface of cast titanium and nickel-chromium. materials and methods: thirty-nine rectangular specimens of titanium (grade 2) and 39 rectangular specimens of nickel-chromium were cast in equal dimensions and divided into three groups of 13 samples each. group one specimens of titanium and nickel-chromium...

In this study, the feasibility of predicting surface integrity and residual stresses by using elastoviscoplastic finite element simulations and temperature-dependent flow softening constitutive material modeling is investigated. A friction determination method is proposed to identify friction coefficients in presence of tool flank wear. Serrated and cyclical chip formation has been simulated fo...

This study compared vertical and passive fit of one-piece cast frameworks made with 3 different materials: commercially pure titanium (CP Ti - G1), cobalt-chromium alloy (Co-Cr - G2) and nickel-chromium-titanium alloy (Ni-Cr-Ti - G3). Fifteen frameworks were obtained simulating bars for fixed prosthesis in a model with 5 implants. The passive and vertical fit of the framework interface was meas...