Wear on total knee replacements (TKRs) is an important criterion for their performance characteristics. Numerical simulations of such wear has seen increasing attention over the last years. They have the potential to be much faster and less expensive than the in vitro tests in use today. While it is unlikely that in silico tests will replace actual physical tests in the foreseeable future, a ju...

Metal-on-metal (MoM) bearings have shown low-wear rates under standard hip simulator conditions; however, retrieval studies have shown large variations in wear rates and mechanisms. High-wear in vivo has caused catastrophic complications and has been associated with steep cup-inclination angle (rotational malpositioning). However, increasing the cup-inclination angle in vitro has not replicated...

In internal combustion engines it is important to manage the wear in the valve and valve seat contact in order to minimise emissions and maximise economy. Traditionally wear in this contact has been controlled by the use of a valve seat insert and the careful selection of materials for both the valve and the insert. More recently, due to the increasing demands for both performance and cost, alt...

BACKGROUND The DASCOR device has recently been introduced as an innovative nucleus replacement alternative for the treatment of low-back pain caused by degenerative intervertebral disc disease. The purpose of this study was to characterize, through a series of preclinical mechanical bench and biomechanical tests, the effectiveness of this device. METHODS A number of samples were created using...

Abrasive wear resistance of injection molded polycarbonate (PC) and polycarbonate + zinc oxide nanocomposites containing 0.5 wt% ZnO nanoparticles was determined as a function of the sliding direction with respect to injection flow. First we have performed single scratch testing under progressively increasing the load applied. Then sliding wear testing consisting of 15 successive scratches alon...

The biological significance of cobalt-chromium wear particles from metal-on-metal hip replacements may be different to the effects of the constituent metal ions in solution. Bacteria may be able to discriminate between particulate and ionic forms of these metals because of a transmembrane nickel/cobalt-permease. It is not known whether wear particles are bacteriocidal. We compared the doubling ...

Primates tend to be long-lived, and, except for humans, most primate females are able to reproduce into old age. Although aging in most mammals is accompanied by dental senescence due to advanced wear, primates have low-crowned teeth that wear down before old age. Because tooth wear alters crown features gradually, testing whether early dental senescence causes reproductive senescence has been ...

BACKGROUND All-polymer bearings involving polyetheretherketone (PEEK) have been proposed for orthopaedic applications because they may reduce stress shielding, reduce weight of the implants, reduce wear and risk of osteolysis, and prevent release of metal ions by replacing the metal articulating components. Little is known about the biotribology of all-polymer PEEK bearings, including the effec...

OBJECTIVE The main objective of this study was to evaluate the wear characteristics of fiber-reinforced dental composites. Variables under investigation include the fiber weight percent added to the matrix as well as fiber length. METHODS Dental specimens with glass fiber content of 2, 5.1, 5.7, and 7.6 wt% with fiber length of either 1.5 or 3 mm, were prepared by mixing an activated dental r...