Biotribological Characteristics of Cutting-Edge Materials in Medical Applications: A Review

Implantable medical devices and their associated materials constitute a cornerstone of modern medical science, addressing physical and aesthetic needs while ensuring biocompatibility and optimal performance. This review explores the intricate relationship between biotribology, material selection, and device efficacy, such as advancements in high-performance polymers like PEEK (polyetheretherketone), noting that they exhibit wear rates reduced by up to 48% compared to traditional materials, with coefficients of friction as low as 0.01 under dry conditions. Emphasis is placed on specific compositions and resultant microstructures that lead to enhanced tribological performance and biocompatibility. For example, the elastic modulus and nano-hardness of Bis-GMA/TEGDMA composites increased from 9.2 GPa and 420 MPa for 20% micro-sized hydroxyapatite to 16.8 GPa and 608 MPa for 20% micro-sized tricalcium phosphate reinforcement, indicating that the lower values in hydroxyapatite-containing composites can be attributed to its larger particle size compared to tricalcium phosphate. In cardiovascular devices, surface modifications, such as TiO2/TiN coatings, have shown to extend wear resistance, with coated artificial heart valves enduring over 38 million cycles without wear, while non-coated valves exhibited significant abrasion after 18 million cycles. Additionally, innovative designs in artificial joints and dental implants focus on mitigating fretting wear and improving stability through material optimization and surface treatments. This review highlights the importance of biotribological principles in the design of modern medical devices, vital in future advancements and improved patient outcomes.