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...

The objective of this work was to study materials subjected to external loading where alternative deformation mechanisms are available to generate strains. In the case of shapememory and superelastic NiTi, these mechanisms are twinning and stress-induced phase transformation, respectively. Superelastic NiTi (51.0 at.% Ni) reinforced with 0, 10 and 20 vol.% TiC particles was fabricated by Hot Is...

In this work, two new low-bandgap electron acceptors NITI-SeS and NITI-SSe that use electron-rich 2-alkylselenopheno[3,4-b]thiophene 2-alkylselenopheno[2,3-c]thiophene with different quinoidal-resonance effect as π-bridges to link the weak electron-donating indenoindene core strong electron-accepting INCN-2F terminal are designed synthesized. has a selenium atom in main ring shows an obviously ...

Frictional resistance is an important counterforce to orthodontic tooth movement during sliding mechanics. This study was carried out to evaluate the effect of ceramic bracket and ceramic bracket with metal slot -archwire‐ ligation combinations on “resistance to sliding” during simulated canine retraction on typodont model. The frictional resistance was tested between Ceramic brackets (3MUNITEK...

Chemomechanical preparation of the root canal includes both mechanical instrumentation and antibacterial irrigation, and is principally directed toward the elimination of micro-organisms from the root canal system. A variety of instruments and techniques have been developed and described for this critical stage of root canal treatment. Since their introduction in 1988, nickel-titanium (NiTi) ro...

The last decade has been witness to phenomenal growth in endodontic technology. The introduction of these new technologies has resulted in endodontics becoming easier, faster and most importantly, better. Principal among these is Nickel Titanium (NiTi) rotary instrumentation that results in consistent, predictable, and reproducible shaping. The purpose of this article is to review the design fe...

NiTi instrument separation is a serious concern in endodontic therapy. The analysis of NiTi files after torsional fracture reveals that the majority of torsional separations occur in the last mm. of the files and in the files with lower taper and/ or diameter. Consequentely, the tip of the smaller files presents the higher risk of torsional fracture and should be protected using low torque moto...

Since the end of the nineteenth century, automated root canal instrumentation has been available, but systems had many problems. The challenges of increased canal blockage, instrument breakage, and insufficient canal debridement were related to the use of stainless steel instruments and have been dramatically improved with the introduction of nickel-titanium (NiTi) files. The first useable NiTi...