During their service life, most biomaterials and medical implants are vulnerable to tribological damage. In addition, the environments in which they are placed are often corrosive. The combination of triobology, corrosion and the biological environment has been named 'bio-tribocorrosion'. Understanding this complex phenomenon is critical to improving the design and service life of medical implants. This important book reviews recent key research in this area.After an introduction to the topography of bio-tribocorrosion, Part one discusses different types of tribocorrosion including fatigue-corrosion, fretting-corrosion, wear-corrosion and abrasion-corrosion. The book also discusses the prediction of wear in medical devices. Part two looks at biological effects on tribocorrosion processes, including how proteins interact with material surfaces and the evolution of surface changes due to bio-tribocorrosion resulting from biofilms and passive films. Part three reviews the issue of bio-tribocorrosion in clinical practice, including dental applications and joint replacement as well the use of coatings and test methods for bio-tribocorrosion.With its international team of contributors, Bio-tribocorrosion in biomaterials and medical implants is a standard reference for those researching and developing medical devices as well as clinicians in such areas as dentistry and orthopaedic surgery. - Reviews recent research in bio-tribocorrosion and its role in improving the design and service life of medical implants - Discusses types of bio-tribocorrosion including fatigue and wear corrosion - Examines biological effects on bio-tribocorrosion processes including interaction of proteins with metal surfaces

The tribological performance of implant materials within the body where the pH can vary between 7.4 and 4.0, depending on whether the joint is infected or not, is extremely harsh and varies significantly from that experienced in other engineering environments. Three wear mechanisms that affect biomedical and, in particular, orthopaedic implants are regularly reported. These are adhesion, abrasion and fatigue. The wear mechanisms in biomedical implants, particularly hip joints, are reported to be a function of the following variables: type of materials used, contact stresses, lubricants and clearance, surface hardness and roughness, type of articulation due to motion, number of cycles, solution particle count and distribution, and tribocorrosion.

Wear can be defined as a process where interaction between two surfaces or bounding faces of solids within the working environment results in dimensional loss of one solid, with or without any actual decoupling and loss of material. Wear may accelerate corrosion that involves chemical or electrochemical reactions between materials. Both these phenomena fall under the broader category of tribocorrosion. The interactions of mechanical loading and chemical/electrochemical reactions that occur between the elements of a tribological system exposed to biological environments constitute bio-tribocorrosion science.

This chapter discusses synergistic damage mechanisms of modular implants due to mechanical stimulus and electrochemical dissolution. The influences of contact loads, plastic deformation, residual stresses, and environmental conditions are focused to illustrate mechanisms of damage and dissolution. Fretting corrosion is the most prevalent phenomenon that degrades the mechanical and chemical properties of implant materials. It has been explained as an alternating process of fracture and unstable growth of metal oxide film during fatigue contact motion in the corrosive environment. Stress-dependent electrochemical dissolution has also been identified as one of the key mechanisms governing surface degradation in fatigue contact and crevice corrosion of biomedical implants. This damage mechanism incorporates contact-induced residual stress development and stress-assisted dissolution. Understanding of the corrosion damage mechanism of metallic implants is very important in predicting the useful life of implants and optimizing the design of orthopedic implants.

Two materials (one being metal) under slight relative motion in a liquid medium are subjected to fretting corrosion. This chapter is dedicated to studying fretting corrosion of implants. After describing the most significant implants subjected to fretting, fretting corrosion is defined. Fretting corrosion is a particular degradation mechanism; it highlights the key role of passive film, crevice corrosion, etc. For demonstrating the electrochemical effect of the fretting corrosion of metal, some investigations are presented at free corrosion potential and at applied potential to measure the specific current density. Moreover, the role of proteins is investigated because they constitute the biological environment and thus play a significant role in fretting corrosion processes. Finally, results from atomic force microscopy (AFM) show the particular debris, size about 100nm. The problem of debris influence is discussed.

In the oral cavity, materials (including our natural teeth) are exposed to a complex environment, which results in simultaneous mechanical, electrochemical, and microbiological solicitations. Therefore, bio-tribocorrosion is an important cause of degradation of dental materials leading to functional and/or biological detrimental effects due to an increased release of metallic ions and wear debris. This chapter describes the main bio-tribocorrosion phenomena that occur in the oral environment, and discuss the main parameters related to both the materials and the environment affecting bio-tribocorrosion in dental applications.

Total joint replacement (TJR), or joint arthroplasty, is a widely used surgical procedure in which the entire joint is removed and replaced with a prosthetic joint. The most common types of TJR are total hip replacement (THR) and total knee replacement (TKR). The improvement and development of safer, longer lasting and better functioning implants are essential. Recent reports of potential problems caused by ion release in metal-on-metal (MoM) TJRs resulting in the formation of pseudo-tumours therefore need to be properly investigated. This chapter provides an overview of the evolution of TJR, followed by a review of the issues and the science around ion release. The potential corrosion issues and bio-tribocorrosion processes which prevail in TJRs, including orthopaedic implant materials, load-bearing joint replacement materials tribocorrosion, and protein adsorption, are also discussed.