Although human dentin is known to be susceptible to failure under repetitive cyclic fatigue loading, there are few reports in the literature that reliably quantify this phenomenon. This study seeks to address the paucity of fatigue data through a systematic investigation of the effects of prolonged cyclical loading on human dentin in an environment of ambient temperature Hank's balanced salt so...

AIM To compare the cyclic fatigue resistance of new generation OneShape and WaveOne instruments when used with different kinematics. METHODOLOGY An artificial canal, made of stainless steel with an inner diameter of 1.5 mm, a 60° angle of curvature and a curvature radius of 3 mm, was used for cyclic fatigue test of new generation OneShape and WaveOne instruments. Groups were as follows (n = 2...

BACKGROUND Mechanical failure of femoral stems at the modular junction of revision hip arthroplasty systems has been reported only infrequently. In the current study, the cause of six stem fractures, which occurred in vivo, was analyzed with use of clinical data and failure analysis. METHODS Six patients with a fracture at the mid-stem junction of a modular revision hip implant were identifie...

BACKGROUND Premature failure of either the nail and/or locking screws with unstable fracture patterns may lead to angulation, shortening, malunion, and IM nail migration. Up to thirty percent of all unreamed nail locking screws can break after initial weight bearing is allowed at 8-10 weeks if union has not occurred. The primary problem this presents is hardware removal during revision surgery....

OBJECTIVES To compare the fatigue life of Tango-Endo, WaveOne GOLD, and Reciproc NiTi instruments under static model via artificial canals with different angles of curvature. MATERIALS AND METHODS Reciproc R25, WaveOne GOLD Primary, and Tango-Endo instruments were included in this study (n = 20). All the instruments were rotated in artificial canals which were made of stainless steel with an ...

Abstract: Thermal fatigue is a stochastic process often showing considerable scatter even in controlled environments. Due to complexity of thermal fatigue, there is no a complete analytical solution for predicting the effect of this property on the life of various components, subjected to severe thermal fluctuations. Among these components, one can mention car cylinder, cylinder head and pi...

Since the sub-axis of machine tool spindles subjected to fatigue loading, the effects of different surface heat treatments on fatigue behavior of 16MnCr5 steel have been investigated in the current work. After the test specimens were prepared from the steel, the surface heat treatments; carburizing, carbonitriding and a practical type of treatment involving the first nitriding then carburizing ...