INTRODUCTION The purpose of this study was to compare the torsion and bending properties of OneShape (OS; Micro Mega, Besançon, France) and WaveOne (WO; Dentsply Maillefer, Ballaigues, Switzerland) single-file systems. METHODS The torsional strength of OS size #25, 0.06 taper and WO primary size #25, 0.08 taper was measured by using a torsiometer after fixing the apical 5 mm of the instrument...

Periprosthetic femoral fractures are a common complication associated with cementless press-fit total hip arthroplasty. The use of prophylactic cerclage wire fixation has been advocated to reduce this complication. The objective of this study was to evaluate whether a double loop cerclage wire, used as adjunctive fixation, increased the peak torsional load to failure in femora implanted with pr...

The purpose of this study was to analyze the type and frequency of defects in nickel-titanium rotary endodontic files after routine clinical use, and to draw conclusions regarding the reasons for failure. All of the files (total: 378, Quantec Series 2000) discarded after normal use from a specialist endodontic practice over 6 months were analyzed. Almost 50% of the files showed some visible def...

this study compares the functional capabilities of different metacarpal fixation constructs under physiological loadings in an attempt to identify the optimal construct rather than the strongest one. one hundred and twenty-six preserved human metacarpals were mechanically tested after oblique osteotomies and internal fixation. maximum load to failure, average structural rigidity, and energy abs...

This paper presents a recent self-sampled-data control algorithm applied to nonlinear systems with actuator failures. Our approach uses the linear model of a given nonlinear system, and based on a granted actuator fault observer method, an asynchronous sampled-data fault compensator controller is then formulated. The proposed sampling rule is realized by using an event-detector monitoring signa...

The optimal management of pathologic long bone lesions remains a challenge in orthopedic surgery. The goal of the current study was to investigate the effect of defect depth on the torsional properties of the distal femur. A laterally placed distal metaphyseal cylindrical defect was milled in the cortex of the distal femur in 20 composite models. The proximal extent of the defects was constant....

INTRODUCTION The use of reciprocating movement was claimed to increase the resistance of nickel-titanium (NiTi) file to fatigue in comparison with continuous rotation. Recently 2 new brands of NiTi files have been marketed for use in a RM mode. The purpose of this study was to compare the cyclic fatigue resistance and torsional resistance of these 2 files, Reciproc and WaveOne. METHODS Cyclic...

the cadaver spine motion segment behavior under torsional load was evaluated with the disc intact, with partial anterior discectomy and with spacer insertion. the results of this study explain how anterior lumbar discectomy and interbody fusion (alif) affects the torsional stability of the motion segment. the pseudarthrosis rate of the anterior lumbar discectomy and interbody fusion (alif) is k...

OBJECTIVE Rod-screw fixation systems are widely used for spinal instrumentation. Although many biomechanical studies on rod-screw systems have been carried out, but the effects of rod contouring on the construct strength is still not very well defined in the literature. This work examines the mechanical impact of straight, 20° kyphotic, and 20° lordotic rod contouring on rod-screw fixation syst...

PURPOSE To compare tibial fracture healing in rats with or without soft-tissue attachment. METHODS The left tibias of 30 Wistar rats were osteotomised and equally randomised into 3 groups. In the avascular segmental fracture group, an 8-mm bone segment were first removed and then immediately put back. In the vascular segmental fracture group, the 8-mm bone segment was not displaced, with peri...