Resin composites were first introduced as anterior restorative materials, but are more and more used in posterior teeth, as amalgam replacements. Nowadays the so-called ‘condensable’ composites are frequently used in posterior teeth. These materials are subjected to high values of contact and mastigatory loads, loading rates and sliding distances. In such contact conditions, wear is the major f...

Dislocation remains a common cause of failure after total hip arthroplasty. The limitations of existing approaches to address instability have led to the development of powerfull options: constrained liners, dual mobility and large heads. These implant-related options have proven to be very efficient, but have raised concerns.With constrained liners, restricted range of motion (ROM) is responsi...

Surface morphology and wear characteristics of five dental composites subjected to accelerated aging were investigated. Aging conditions caused degradation of the surface as evidenced by the formation of microcracks and the exposure and loss of filler particles. Wear parameters such as track width, transition load and mode of surface failure caused by single-pass sliding were influenced by agin...

in this research, our attempt is to monitor tool wear through the chip formations, forces, and temperature of edge of drill while drilling in superalloy plate to optimizes effective parameters, which lead to facilitate machining process to, improved tool life, and enhance the productivity. in this study, inconel718 superalloy material, and cemented coated carbide tool was selected for investiga...

The significant costs insert on mineral processes due to mill liner wear including the labor costs, price of material and shut down periods. Therefore, the study of this phenomenon is economically important to optimize the mill operating conditions and liner profile design to decrease the wear rate. There is no appropriate and applicable research on impact wear evaluation of mill liners. In the...

Polyethylene (PE) wear is the limiting factor for the longevity of a conventional total knee arthroplasty (TKA). Excessive wear leads to loosening and eventual implant failure. The aim of our in vitro study was to investigate wear of a PE tibial insert on a rotating platform as compared to the same insert fixed to the tibial baseplate and articulating with a similar femoral component. All tests...

Ultra-high molecular weight polyethylene wear particles have been implicated as the major cause of osteolysis, implant loosening and late aseptic failure in total hip arthroplasties in vivo. This study initially screened 22 carbon-carbon composite materials as alternatives for UHMWPE in joint bearings. New bearing materials should satisfy certain criteria--they should have good wear properties ...

A retrieval analysis has been performed on 50 polyethylene inlays of cementless screw ring implants (Mecring, Mecron, Berlin, Germany) to investigate the failure mechanism of this specific open cup hip arthroplasty design that has shown a high clinical failure rate. Design-specific damage modes like rim creep, collar fatigue, and backside wear were assessed. Furthermore, the inlays were measure...

statement of problem: as a physical property, wear resistance of the materials used in the fabrication of orthodontic retainers play a significant role in the stability and long term use of the appliances. objectives: to evaluate the wear resistance of two commonly used materials for orthodontic retainers: acropars op, i.e. a polymethyl methacrylate based material, and 3a-gs060, i.e. a polyethy...