The problem was in the manner that PTFE is able to maintain its low coefficient of friction. A thin film of PTFE is continuously transferred to the opposing material. In the TMJ implants, surrounding tissue quickly became overwhelmed by wear particles. Both types of material exhibit problems when implanted. Bioprosthetic valves often fail due to calcification which can result in mechanical malfunctions and vascular obstructions.
Bioprosthetic valves are also prone to mechanical fatigue.
Cyclic loading can result in cracking followed by catastrophic failure. Coating mechanical valves with pyrolytic carbon has become very popular due to its excellent resistance to clotting. Pyrolytic carbon is currently being studied to assess its resistance to fatigue. Scientist, working together with engineers, continue to develop biomaterials that will enhance life for everyone and help us enjoy longer, more prosperous days. For Your Information ChE in Everyday Life ChE in Medicine Alternative Energy Proc.