BACKGROUND Complete removal of old filling material during root canal retreatment is fundamental for predictable cleaning and shaping of canal anatomy. Most of the retreatment methods tested in earlier studies have shown inability to achieve complete removal of root canal filling. Therefore the aim of this investigation was to assess the efficacy of three different rotary nickel titanium retrea...

BACKGROUND AND AIMS The purpose of this study was to compare several parameters of root canal preparation using two different rotary Nickel-Titanium instruments: Pro-Taper (Dentsply Maillefer, Ballagigues, Switzerland) and Hero-Shaper (Micro Mega, Besancon, France). METHODS Twelve extracted maxillary premolars were randomly divided into two groups and embedded into a muffle system. All root c...

AIM To compare the shaping ability of four different nickel-titanium rotary instruments during the preparation of curved root canals in extracted teeth. METHODOLOGY A total of 80 root canals with curvatures ranging between 25° and 39° were divided into four groups of 20 canals. Based on radiographs taken prior to instrumentation, the groups were balanced with respect to the angle and the radi...

AIM To evaluate the cyclic fatigue fracture resistance of engine-driven F2 ProTaper instruments under reciprocating movement. METHODOLOGY A sample of 30 NiTi ProTaper F2 instruments was used. An artificial canal was made from a stainless steel tube, allowing the instruments to rotate freely. During mechanical testing, different movement kinematics and speeds were used, which resulted in three...

introduction : to evaluate the efficacy of niti mechanical rotary instrumentation and hedstrom file for gutta-percha/sealer removal computed tomography (ct) was utilized in vitro . materials and methods: thirty extracted human single rooted teeth, each with a single canal were selected. the samples were decoronated with a double faced diamond disk to have 17-mm root; teeth roots were instrument...

AIM The aim of this study was to measure the increase in root canal surface area and canal transportation after biomechanical preparation at 1, 3, and 5 mm short of the apex with three different rotary systems in both continuous rotary and reciprocating rotary motions. MATERIALS AND METHODS Sixty freshly extracted human mandibular molars with mesial root canal curvatures between 20° and 30° w...

Following didactic instruction, most aircrew are able to experience some of the disorientating illusions and limitations of the orientational senses in a variety of ground-based devices. In order to reinforce instruction in spatial disorientation (SD) within the environment in which they operate, British Army Air Corps helicopter pilots also receive an airborne demonstration of the limitations ...

INTRODUCTION The aim of this study was to compare several metallurgic properties of Neoniti instrument with four other commonly used endodontic rotary files. METHODS AND MATERIALS Neoniti A1 (25/0.08), RaCe (25/0.06), Mtwo (25/0.06), Twisted file (25/0.06) and ProTaper Next X2 (25/0.06) were examined by differential scanning calorimetry (DSC) before and after heat treatment at 500°C. X-ray di...

Statement of the Problem File fracture can interfere with cleaning and shaping of the canal and compromise periradicular healing. Autoclave sterilization may prone the files to fracture. Purpose The purpose of the present study was to determine the effect of autoclave sterilization on the cyclic fatigue resistance of Hero642 rotary instrument in two curvatures of 45 and 60 degrees. Material...