OBJECTIVES The aim of this study was to compare the mechanical properties of various nickel-titanium (NiTi) files with similar tapers and cross-sectional areas depending on whether they were surface-treated. MATERIALS AND METHODS Three NiTi file systems with a similar convex triangular cross-section and the same ISO #25 tip size were selected for this study: G6 (G6), ProTaper Universal (PTU),...

The enormous demands for metal implant have given rise to a search for cheap material with good bio-tolerability and resistance to corrosion. Although stainless steel has these properties and is widely used for this purpose, its long term application is still a concern. The corrosion resistance of stainless steel depends on the passive layer. Herein, chemical surface treatment, including passiv...

Effects of anti-asthmatic drugs on airway resistance and plasma level of cyclic AMP were investigated in guinea pigs sensitized and non-sensitized with egg-albumin. Histamine increased airway resistance in the both groups of guinea pigs, and guinea pigs sensitized with egg-albumin were more sensitive to histamine. Anti-asthmatic drugs inhibited dose-dependently the increase of airway resistance...

OBJECTIVE The objective of this study is to compare the cyclic fatigue resistance of nine types of endodontic instruments of nickel-titanium. MATERIALS AND METHODS Five files of 25 mm of length of each group: Reciproc (RC) R25; WaveOne (WO) Primary; Unicone (UC) L25 25/0.06; K3XF 25/0.06; ProTaper Universal F2 (PTF2); ProTaper Next X2 (PTX2); Mtwo 25/0.06; BioRaCe 25/0.06; One Shape L25 25/0....

This study compared the cyclic fatigue resistance of OneShape (OS) instrument which used continuous rotation with WaveOne (WO) instrument which used reciprocating motion. OS size 25, 0.06 taper and WO primary size 25, 0.08 taper were used in simulated canals with 45°, 60°, and 90° angles of curvature until fracture. The number of cycles to fracture (NCF) was recorded to evaluate cyclic fatigue ...

Comparative Evaluation of Cyclic Fatigue Resistance Two Single-file Rotary Instruments in Simulated Stainless Steel Curved Canals

BACKGROUND Inhaled nitric oxide produces potent pulmonary vasodilation by activating soluble guanylate cyclase and increasing smooth muscle cell concentrations of cyclic guanosine monophosphate. However, responses are often nonsustained, and clinically significant increases in pulmonary vascular resistance have been noted on its acute withdrawal. In vitro and in vivo data suggest that inhaled n...

AIM To compare the cyclic fatigue resistance of HyFlex CM, Twisted Files (TF), K3XF, Race, and K3, and evaluate the effect of autoclave sterilization on the cyclic fatigue resistance of these instruments both before and after the files were cycled. METHODOLOGY Five types of NiTi instruments with similar size 30, .06 taper were selected: HyFlex CM, TF, K3XF, Race and K3. Files were tested in a...