“…There are many approaches to the improvement in mechanical stability (hardness, elastic modulus), tribological behavior (wear resistance), or adhesive (roughness of surface) properties of the polyethylene. The most popular ones are the reinforcement with carbon nanotubes [9], graphene [10], kaolin or zeolite fibers [11,12]; filling of silver [13], zirconium/titanium/hafnium [14], alumina nanoparticles [15], or surface modification by argon plasma [16], chemical etching, electrostatic spraying techniques [17,18], and ultraviolet grafting [19]. On the other hand, many studies are focused on altering physical and chemical properties of the UHMWPE to increase wear resistance, using gamma-irradiated cross-linking [20,21], which correlates with decreases in wear.…”