ABSTRACT
All metallic implants electrochemically corrode to some extent. This is disadvantageous for two main reasons: (1) the process of degradation reduces the structural integrity and (2) degradation products may react unfavorably with the host. Metallic implant degradation results from both electrochemical dissolution and wear, but most frequently occurs through a synergistic combination of the two [1,2]. Electrochemical corrosion processes include both generalized dissolution uniformly affecting an entire surface and localized areas of a component. Locally these areas tend to be at both identifiable areas relatively shielded from the environment (e.g., crevice corrosion) and at random sites on the surface (e.g., pitting corrosion). In the past, these electrochemical and other mechanical processes have interacted to cause premature structural failure and accelerated metal release (e.g., stress corrosion cracking, corrosion fatigue, and fretting corrosion). Current clinical questions persist regarding the degree to which elevated local and systemic metal concentrations and particulate corrosion products persist in peri-implant tissues.
