Wear mechanisms of UHMWPE under physiological conditions
In 2005 one of the giants in implant manufacturing launched the most flawed metal on metal implant. It caused a loss of billions of dollars and more than 8000 patients were forced to a revised surgery because of the high health hazard. At present, polymer on metal implants comprise of 70% of all hip and knee arthroplasty. Increased life expectancy and lower revision surgeries due to wear induced osteolysis are driving development of superior grades of UHMWPE. Since 1970s, the procedure for the development of new orthopaedic bearings initiates with screening of several candidate ... Read More
Tag: Biomaterials
Soft contact tribology is at the heart of our feelings perceived as moistness, smoothness and comfort. Although there is no standard definition, the study of friction behavior of low modulus materials could qualify as soft contact tribology. Lately, several studies have highlighted the benefits of soft contact tribology in improving our perception of feelings, through engineering the materials that we touch.
Friction (or shear stress) connects the mechanical action like touch with the psychological reaction such as smoothness feeling. A representative friction curve for the soft contacts is given in Figure 1.
Few important features in this curve are static friction ... Read More
DLC coating to neutralize fretting of dental implant componentsThe success of two-piece dental implants (Figure 1) is threatened by fretting occurring between the ceramic abutment and the titanium-based fixture. A wrong design could generate mismatches between surfaces and a poor choice of materials would result in excessive micromotions between abutment and fixture. Sliding and fretting wear cause a disproportionate ion release in the surrounding tissues, potentially giving the gingiva a greyish appearance. The lost material enlarges the existing microgaps exposing the implant to bacterial colonization and infections. The extreme consequences of these processes result in the removal of the implant ... Read More
Application of friction and wear test methods in personal and health care research has delivered consumer friendly products and improved biomaterials. In this webinar, we will discuss such cases using examples like SHAVERS (failed soft coatings), SKIN CREAM (skin friction: natural vs. synthetic), CATHETERS (superlubricity), DENTAL IMPLANTS (fretting wear) and UHMWPE (low wear coatings).