- When two different metals are placed in an intraoral environment, an electrochemical reaction occurs due to the difference in their electrode potentials.
- This interaction leads to the formation of an electric current between the metals, which accelerates the corrosion process at the junction where the metals meet. This specific type of corrosion is known as galvanic corrosion.

Key points to understand include:
- Galvanic corrosion occurs when two dissimilar metals are in electrical contact in the presence of an electrolyte, such as saliva.
- Oral fluids act as electrolytes, facilitating ion movement and enabling the electrochemical reaction.
- The metal with the lower electrode potential (anode) corrodes preferentially, while the other (cathode) remains protected.
- This type of corrosion is particularly important in dentistry because it can lead to deterioration of dental restorations, causing clinical problems such as discoloration, metallic taste, or even failure of the restorative material.

In contrast:
- Pitting corrosion is localized corrosion forming small pits, often in metals like stainless steel.
- Crevice corrosion occurs in confined spaces where fluid stagnation happens.
- Uniform corrosion affects the entire exposed surface more or less evenly.

Therefore, when dealing with junctions of two different metals intraorally, galvanic corrosion is the typical concern.

Reference: Sturdevant's Art and Science of Operative Dentistry, 6th Edition, Chapter on Dental Materials, Pg. 320