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 energ...

We report on molecular dynamic calculations of combined tension–torsion of chiral single-wall nanotubes. We work within the framework of objective structures that exploits symmetry groups to enable torsion of chiral nanotubes, in addition to non-equilibrium extension. We apply the method to study the mechanical response and failure of nanotubes of various chiralities. We find that three distinc...

The most used life-line structure of the modern day is the bridges, which has been developed significantly, with the most recent introduction being of the curved bridges. They provide an aesthetic look and are also very convenient at various crossings and cross-over. However, curved bridges have been observed to have poor seismic response. Pounding between the adjacent segments, in-plane deck r...

OBJECTIVES The aim of this study was to compare the mechanical properties of various nickel-titanium (NiTi) files with similar tapers and cross-sectional areas depending on whether they were surface-treated. MATERIALS AND METHODS Three NiTi file systems with a similar convex triangular cross-section and the same ISO #25 tip size were selected for this study: G6 (G6), ProTaper Universal (PTU),...

AIMS Visual and microscopic evaluation of defects caused by torsional fatigue in hand and rotary nickel titanium (NiTi) instruments. MATERIALS AND METHODS Ninety-six NiTi greater taper instruments which were routinely used for root canal treatment only in anterior teeth were selected for the study. The files taken include ProTaper for hand use, ProTaper Rotary files and Endowave rotary files....

BACKGROUND Proximal femoral bone loss during revision hip arthroplasty often requires bypassing the deficient metaphyseal bone to obtain distal fixation. The purpose of this study was to determine the effect of stem diameter and length of diaphyseal contact in achieving rotational stability in revision total hip arthroplasty. METHODS Twenty-four cadaveric femoral specimens were implanted with...

A hybrid longitudinal-torsional ultrasonic transducer is designed and fabricated in this research. The design of the transducer was performed using the FE method with ABAQUS software, with the aim of combining the longitudinal and torsional vibration modes. The transducer horn is then fabricated using a 4-axis milling machine. The PZT stacks are employed in order to excite the transducer. The t...

Wet friction clutches play a critical role in vehicles equipped with automatic transmissions. It is unavoidable that they progressively degrade and eventually break down while the vehicles are under operational condition. To avoid unexpected failures, a proper condition monitoring tool extended with a lifetime prediction method should be implemented. In order to achieve this, appropriate parame...

BACKGROUND Owing to the complexity and magnitude of functional forces transferred to the bone-implant interface, the mechanical strength of the interface is of great importance. The purpose of this study was to determine the intraosseous torsional shear strength of an osseointegrated oral implant using 3-D finite element (FE) stress analysis implemented by in vivo failure torque data of an impl...