Titanium (Ti) is an inert metallic element with the atomic number 22. It is alloyed with other elements to create strong, lightweight materials like titanium alloy Ti6Al4V, a titanium alloy composed of 90% titanium, 6% aluminum, and 4% vanadium. These alloys have been widely used in dentistry and surgery for their biocompatibility, mechanical strength, and corrosion resistance. A key feature of titanium implants is their ability to osseointegrate with bone, creating a stable connection between the implant and the surrounding bone tissue. Titanium naturally forms a protective oxide layer during implant placement, enhancing its corrosion resistance. However, continuous exposure to the oral environment poses challenges that may lead to its degradation and corrosion. This process releases metal ions, microparticles, and nanoparticles into the surrounding tissues, triggering local and systemic inflammatory reactions. Alongside bacterial infection and mechanical wear, this corrosion can exacerbate peri-implant inflammatory diseases, such as mucositis and peri-implantitis, potentially leading to implant failure. This chapter explores the mechanisms of titanium implant corrosion, risk factors accelerating the process, the role of titanium hypersensitivity in response to corrosion by-products, as well as its effects on implant success. Furthermore, it explores how corrosion contributes to peri-implant inflammation and affects the surrounding peri-implant tissues. It also highlights strategies to minimize corrosion, including the use of innovative materials in implant coatings and surface treatments, and concludes by discussing potential future research directions.