INTRODUCTION The aim of this study was to evaluate the resistance to flexural fatigue of Reciproc R25 (VDW, Munich, Germany), WaveOne Primary (VDW, Munich, Germany), Mtwo (Sweden & Martina, Padova, Italy), and Twisted File (TF; SybronEndo, Orange, CA) instruments used in continuous rotation or in 2 different reciprocating motions. METHODS A total of 180 nickel-titanium files from 4 brands mar...

AIM To compare cyclic fatigue resistance of two geometrically similar nickel-titanium instruments, used in conditions similar to clinical use in reciprocating and continuous rotary motion. METHODOLOGY Four groups of eighteen instruments each, Reciproc(®) files sizes ISO 25 and 40 (R25 and R40) and Mtwo(®) files sizes ISO 25 and 40 (M25 and M40), were tested in reciprocating and continuous rot...

OBJECTIVE Apical extrusion of debris and irrigants during cleaning and shaping of the root canal is one of the main causes of periapical inflammation and postoperative flare-ups. The purpose of this study was to quantitatively measure the amount of debris and irrigants extruded apically in single rooted canals using two reciprocating and one rotary single file nickel-titanium instrumentation sy...

To determine whether a contraction-excitation feedback mechanism exists in human atrium, we investigated the effects of varying the atrioventricular (AV) interval from 0 to 360 msec during AV pacing at a cycle length of 400 msec on atrial pressure, size, and refractoriness in 10 patients (group 1, without supraventricular tachycardia). The same parameters were determined in another 10 patients ...

BACKGROUND Whole-body vibration (WBV) is a new type of exercise that has been increasingly tested for the ability to prevent bone fractures and osteoporosis in frail people. There are two currently marketed vibrating plates: a) the whole plate oscillates up and down; b) reciprocating vertical displacements on the left and right side of a fulcrum, increasing the lateral accelerations. A few stud...

the modern surgical endodontic treatment is a safe and predictable procedure with high success rate. however, several factors can retard or impede the proper healing process. use of a high speed handpiece during hard tissues management (osteotomy and apical resection) can potentially be one of these factors. formation of metallic debris from the surgical diamond burs, production of necrotic loc...

apical extrusion of debris and irrigants during cleaning and shaping of the root canal is one of the main causes of periapical inflammation and postoperative flare-ups. the purpose of this study was to quantitatively measure the amount of debris and irrigants extruded apically in single rooted canals using two reciprocating and one rotary single file nickel-titanium instrumentation systems.sixt...

cold rolling process of a major transformation in the form of sheet metal and a wide range of steel products are produced in this way. elastic deformation during cold rolling working rollers and the inevitable increase in the rolling force. in this study, the effect of elastic deformation during cold rolling mill rollers working on the reciprocating back and forth in tandem with the presence of...

Four patients are reported in whom alternation ofRR cycle length before reversion to sinus rhythm occurred during the administration of intravenous verapamil. In 2 of these 4 patients, alternation of cycle lengths was associated with a changing QRS morphology. It is suggested that one patient had a reciprocating tachycardia using dual AV nodal pathways. The alternating cycle lengths in response...

This case report describes a patient with the permanent form of junctional reciprocating tachycardia coexisting with atrial tachycardia. A detailed electrophysiological study established the diagnosis, and radiofrequency catheter ablation abolished both arrythmias.