BACKGROUND This in vitro study compared the shaping ability of RaCe, FlexMaster, and ProFile rotary nickel-titanium instruments in severely curved root canals of extracted teeth. MATERIAL AND METHODS Sixty maxillary molars with curvatures ranging from 25° to 65° were embedded in a muffle system and portioned into five horizontal sections (thickness 1.2 mm), starting from the apex. Canals were...

introduction: rotary nickel-titanium (niti) instruments are thought to allow shaping of narrow, curved root canals more efficiently and more effectively than stainless steel hand instruments. however, the continued search for even more effective and safer instruments has resulted in new rotary systems being introduced on a regular basis. the aim of this study was to compare shaping parameters o...

objectives: the purpose of this study was to evaluate the resistance to fatigue failure of five different nickel-titanium rotary files in three different curved trajectories. materials and methods: a total of 150 neoniti a1, race 25.06, mtwo 25.06, twisted file 25.06 and protaper next x2 files with the tip size of 25 were tested (n=30 for each group). three groove types simulating curved canals...

Background and Aim:Root canal preparation with rotary instruments may cause dentinal cracks leading to tooth fracture. The aim of this study was to compare three different rotary systems ProTaper, RaCe and Niti Tee on formation of dentinal cracks following root canal preparation. Materials and Methods: In this experimental study, 50 extracted mandibular first molars were selected. Teeth having ...

OBJECTIVE To determine variation in post-instrumentation working length and root area in the following rotary systems: ProTaper, RaCe, Mtwo and K3. STUDY DESIGN A sample of 40 resin blocks with double curvature (at 14 and 16 mm) and a 33 degrees angle was used. Working length was verified with a digital measure using a number 10 K file. The specific sequence for each rotary system was followe...

introduction: the most important aims of root canal preparation are the removal of vital pulp tissue, remaining necrotic debris and infected dentin, eliminating the bulk of bacteria present in the root canal system. the aim of this study was to compare the cleaning efficacy of hand k-flexofiles and rotary race and k3 instruments in root canal preparation. materials and methods: a total of 60 si...

Canal preparation is one of the most important stages of endodontic therapy, and various techniques have been applied for it. The present study was conducted to compare the quantity of debris extruded from the apical foramen during canal preparation during the manual technique and with the use of three rotary systems (Profile, Race, FlexMaster). One hundred single-rooted premolars were divided ...

We report on the first encapsulated rotary ball bearing mechanism using silicon microfabrication and stainless steel balls. The method of capturing stainless steel balls within a silicon race to support a silicon rotor both axially and radially is developed for rotary micro machines and MEMS ball bearing tribology studies. Initial demonstrations show speeds up to 6.8 krpm without lubrication, w...

introduction: retreatment is performed in teeth with unsuccessful root canal therapy or persistent apical lesion. the most important factor for achieving successful retreatment is thorough cleaning and reshaping. niti files and rotary instruments are widely used for the removal of obturatants. this study compared the ability of mtwo and d-race retreatment systems to remove residual gutta-percha...