The function of copper added to 2nd generation amalgam is to:
**Core Concept**
The addition of copper to 2nd generation amalgam is a modification aimed at improving the physical properties of the material. The primary goal is to enhance the corrosion resistance and durability of the amalgam, particularly in the oral environment.
**Why the Correct Answer is Right**
Copper acts as a corrosion inhibitor by forming a thin layer of copper oxide on the surface of the amalgam. This layer protects the underlying amalgam from corrosion by oxygen, which can lead to the degradation of the material. The mechanism of action involves the formation of a copper oxide film that prevents the diffusion of oxygen ions into the amalgam, thereby reducing the corrosion rate.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because copper does not directly affect the setting reaction of the amalgam. The setting reaction is primarily influenced by the interaction between mercury and the alloy particles.
**Option B:** This option is incorrect because copper does not enhance the fluoride release from the amalgam. Fluoride release is more closely related to the type of alloy used and the presence of other elements like tin.
**Option C:** This option is incorrect because copper does not directly affect the biocompatibility of the amalgam. While copper has antimicrobial properties, its primary function in amalgam is to improve the physical properties.
**Clinical Pearl / High-Yield Fact**
One key aspect to remember is that the addition of copper to amalgam does not eliminate the need for proper oral hygiene and regular dental care. Corrosion can still occur if the amalgam is exposed to high oxygen levels or if the patient's oral environment is not well-maintained.
**Correct Answer: C. To improve corrosion resistance.**