Depassivation is the loss or the removal of the surface oxide layer of a metal. Since metals will corrode in certain environments, including when in the presence of water, the chemical process of passivation is used to add a protective metal oxide layer to combat this characteristic. Metals are frequently used in dental work in creating crowns, fillings, bridges, and other dental implants or prostheses. These metal-based dental structures are exposed to saliva—a water-based substance—as well as digestive enzymes and acids from foods and the digestive tract. All of these substances can lead to corrosion and therefore metal dental components undergo passivation prior to use. When depassivation takes place, this protective oxide coating is lost, and the metal is once again susceptible to deterioration. This corrosion can lead to several complications including failure of the component, an infection in the tissues of the mouth, or the need for more expansive dental work.