What happens when metals rub together in dental materials?

When metals rub together in dental materials, galvanism occurs due to the generation of an electric current. This phenomenon can happen when dissimilar metals come into contact, especially in the presence of saliva, which acts as an electrolyte. The metal ions are released, resulting in an electrochemical reaction that can produce a shock or a tingling sensation in the patient's mouth, known as galvanic response.

Understanding galvanism is key for dental professionals, especially when selecting materials for restorations and ensuring the comfort of patients. This is particularly relevant in cases where different metal restorations are placed in close proximity within the oral cavity, highlighting the importance of material compatibility.

This context underscores why the other options do not accurately describe the outcome of rubbing metals together in dental materials. For instance, corrosion typically involves the gradual deterioration of a material due to a chemical reaction, which is different from the immediate electrical reaction associated with galvanism. While enhanced bonding processes can occur in some contexts, they are not a direct result of metal friction. Finally, while promoting tooth decay is a significant concern in dentistry, it does not apply to the action of metals rubbing together; instead, decay is primarily caused by bacteria and acids affecting the tooth structure.