The aim of the study was to evaluate mechanical behavior of implants inserted in three substrates, by measuring the pullout strength and the relative stiffness. 32 implants (Master Porous-Conexao, cylindrical, external hexagon, and surface treatment) were divided into 4 groups (n = 8): pig rib bone, polyurethane Synbone, polyurethane Nacional 40 PCF, and pinus wood. Implants were installed with...

In this paper, the inelastic damage process in Engineered Cementitious Composites (ECC) in the high stress concentration zone adjacent to the head of an embedded anchor under tensile load was examined experimentally and numerically. An FEM model together with a tensile strain-hardening material model of ECC was developed to simulate the damage process leading to final failure. Experimental obse...

An important concept in bone mechanics is that osteons influence mechanical properties in several ways, including contributing to toughness and fatigue strength by debonding from the interstitial matrix so as to "bridge" developing cracks. Observations of "pulled out" osteons on fracture surfaces are thought to be indicative of such behavior. We tested the hypothesis that osteon pullout varies ...

Copper wires have been attracting much attention for Large Scale Integration (LSI) bonding because of their excellent mechanical and electrical properties, in addition to their low material cost. The ends of these wires are usually joined to pads or through-holes on a printed circuit board, and lead-free soldering is one of the popular bonding methods. Since the deformation resistance of solder...

OBJECTIVES This study aims to assess five different cortical screw types using artificial femurs, under equated testing conditions. MATERIALS AND METHODS We investigated the maximum force needed to cause deformation at screw-bone interface using fourth generation composite femurs by conducting separate pullout tests for each screw type. We normalized obtained results with traditional methods ...

Patients with pathologic hip fractures or impending pathologic proximal femur fractures are at a high risk for developing bone cement implantation syndrome during cemented femoral arthroplasty. Comorbid conditions of patients who sustain these fractures, including cardiopulmonary compromise and permeable, highly vascular bone related to metastatic disease, put them at risk for sudden death. Red...

Tenotomy of the long head of the biceps tendon (LHBT) is gaining popularity in shoulder surgery. We evaluated biomechanical and histological changes after tenotomy in a rabbit LHBT tenotomy model to confirm that autotenodesis is a phenomenon that occurs after the procedure. Twenty-three rabbits were included. The right shoulder was harvested from 10 randomly selected rabbits. The shoulders were...

Cancellous screws are designed to optimize fixation in metaphyseal bone environments; however, certain clinical situations may require the substitution of cortical screws for use in cancellous bone, such as anatomic constraints, fragment size, or available instrumentation. This study compares the biomechanical properties of commercially available cortical and cancellous screw designs in a synth...

Frontal plane humeral elevation effects on the pullout strength of suture anchors used in rotator cuff repair The rotator cuff offers the stabilizing forces necessary for fine arm movement. The most common injury to the rotator cuff is the partial or full thickness tear of the supraspinatus tendon, which attaches the humerus to the scapula on the superior side, due to an acute or chronic injury...

Structural biological materials such as bone, teeth or mollusk shells draw their remarkable performance from a sophisticated interplay of architectures and weak interfaces. Pushed to the extreme, this concept leads to sutured materials, which contain thin lines with complex geometries. Sutured materials are prominent in nature, and have recently served as bioinspiration for toughened ceramics a...