Since the introduction of nickel titanium (NiTi) to field endodontics, it paved way for fast and reliable root canal instrumentation. Rotary instruments are solely manufactured from NiTi alloy, due its favorable mechanical physical properties such as flexibility cutting efficiency. The main problem with rotary is their high fatigue susceptibility, unexpected incident instrument separation insid...

Numerical modeling of microstructure evolution in various regions during uniaxial compression and canning compression of NiTi shape memory alloy (SMA) are studied through combined macroscopic and microscopic finite element simulation in order to investigate plastic deformation of NiTi SMA at 400 °C. In this approach, the macroscale material behavior is modeled with a relatively coarse finite el...

Benign prostatic hyperplasia (BPH) remains an incompletely understood disease, mostly striking old men. In fact, 40% of men over 50 show evidence of BPH [1]. The main consequence of BPH is an uncontrolled growth of prostate epithelial and stromal tissues. Eventually, this may lead to an acute urinary retention (AUR) [2], calling for an emergency treatment. Today, the first line treatment consis...

Ball-on-disk sliding wear tests were conducted on martensitic NiTi shape memory alloy against an alumina counter ball. The wear features and coefficients of friction of the samples subjected to different loads and sliding cycles were investigated to reveal the degradation process of the NiTi surface. Three stages of degradation were identified, namely, a near-zero wear stage, a transition wear ...

NTRODUCTION The goals of root canal therapy are to remove infected and necrotic pulpal tissue remnants, shape the root canal system to facilitate irrigation and medication and adequate sealing using obturation materials. 1 Rotary instruments enhance the quality of obturation by providing conical shape to the root canal. Nickle titanium (NiTi) alloy instruments inherent flexibility that allows t...

The oxidation of Ti terminated NiTi surfaces is investigated with density functional theory. The surfaces considered are (001) and (110) of the austenite phase (B2) and (010) of the martensite phase (B19’). The favored adsorption sites for atomic oxygen are fourfold hollow on B2 (001), and twofold bridged between two surface Ti atoms on B2 (110) and B19’ (010). Adsorption of one oxygen molecule...

This paper presents the development of an endoscopic continuum robot for surgical obesity treatment using a transgastric approach. This proposed transgastric gastroplasty approach performs suturing and resizing of a stomach from inside, aiming at further reducing postoperative complications by avoiding the use of skin incisions. The presented design can be inserted into the stomach in a folded ...

As a non-line-of-sight surface modification technique, chemical treatment is an effective method to treat porous NiTi with complex surface morphologies and large exposed areas due to its liquidity and low temperature. In the work described here, three different chemical processes are used to treat porous NiTi alloys. Our results show that H(2)O(2) treatment, NaOH treatment, and H(2)O(2) pre-tre...

Objectives The friction between the brackets and orthodontic wire during sliding mechanics inflicts difficulties such as decreasing the applied force and tooth movement and also the loss of anchorage. Therefore, many studies have focused on the factors that affect the friction. The purpose of this study was to assess the effect of 0.05% sodium fluoride mouthwash on the friction between orthodon...