At the scale of 1–10 µm, bone is constituted by the ultrastructure, which is composed of collagen fibres and extrafibrillar spaces. At the scale of several hundred nanometres, mineralized bone is composed of elementary components such as hydroxyapatite, cylindrically shaped collagen molecules and water. implant surface, biomaterial, implant geometry).īone is a strong and lightweight composite multi-scale anisotropic material which presents a hierarchy of microstructures. aseptic conditions during surgery, surgical and loading protocol) and to the implant manufacturers (e.g. behaviour, bone quality), to the surgeons (e.g. Another difficulty arises from the fact that the implant's success depends on multi-factorial aspects related to the patients (e.g. Moreover, the presence of an interface complicates the situation. Predicting implant failure is difficult because bone is a complex multi-scale medium evolving as a function of time through remodelling phenomena. ![]() The surgical success of implant surgeries depends on the evolution of the biomechanical properties of the bone–implant interface (BII), which remains difficult to determine in vivo. Modern orthopaedic and dental implant treatments aim at a rapid, strong and long-lasting attachment between implant and bone tissue.ĭespite their routine clinical use, implant failures still occur and remain difficult to anticipate as the reasons for implant losses remain unclear. Implants and articular prostheses have led to important progress in the repair of joint degeneration (hip, knee…) and in maxillofacial surgery (to restore missing teeth or support craniofacial reconstructions). Implanting biomaterials within bone tissue to restore the functionality of the treated organ has become a common technique in orthopaedic and dental surgery. Population ageing and the occurrence of road traffic, sports and work accidents are the main reasons for the increasing interest of the research community in studying the osteoarticular system. A better understanding of the phenomena occurring at the BII will lead to (i) medical devices that help surgeons to determine an implant's stability and (ii) an improvement in the quality of implants. Eventually, the influence of the implant's properties, in terms of both surface properties and biomaterials, is investigated. The experimental multi-modality approaches used to determine the microscopic biomechanical properties of periprosthetic newly formed bone tissue are also reviewed. ![]() Then, the different mechanical methods that have been employed to derive the macroscopic properties of the BII will be described. ![]() The main characteristics of the BII and the determinants of implant stability are first introduced. The aim of this review article is to provide more insight on the current state of the art concerning the evolution of the biomechanical properties of the BII as a function of the implant's environment. The success of an implant depends on its stability, which is determined by the biomechanical properties of the bone–implant interface (BII). However, there remain risks of failure which may have dramatic consequences. It is concluded that these are the most promising methods found so far to rank the cohesion characteristics of lasma sprayed coatings.In recent decades, cementless implants have been widely used in clinical practice to replace missing organs, to replace damaged or missing bone tissue or to restore joint functionality. ![]() Some correspondence was found between most of the techniques/methods studied, but erosion and abrasion with large, hard particles and scratch testing on both top surfaces and cross-sections provided the best correlation. Bending was carried out, in ambient conditions, using test equipment small enough to be placed in the SEM, in order to observe the progressive cracking behavior and failure of the coatings. Controlled scratching was carried out on both top- and cross-section, with the cross-sectional scratching done inside a scanning electron microscopy (SEM). Methods of characterisation have included assessment of the coatings resistance to open tribo-system wear by dry particle erosion and abrasion on the one hand, and their resistance to mechanical failure during controlled scratch testing and tensile fracture in four-point bending, on the other. Several chromia and alumina-titania coatings, as well as a sintered bulk alumina, have also been studied for comparison and reference purposes. The integrity, and especially, the cohesive strength of alumina plasma-sprayed coatings prepared from a range of precursor powders of different size and crystallinity has been investigated by several different methods.
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