## **Core Concept**
The question pertains to dental materials, specifically the composition of low copper alloys used in dentistry. These alloys are often used for making dental amalgams. The key components of dental amalgams include mercury, silver, tin, copper, and zinc. The percentage of tin in these alloys is crucial for their properties and durability.

## **Why the Correct Answer is Right**
In low copper alloys, which typically contain less than 6% copper, tin plays a significant role in the formation of the gamma-2 phase, which is a tin-mercury phase. This phase is important for the strength and clinical performance of the amalgam. The correct percentage of tin in low copper alloys is around 14%, as it helps in achieving a balance between the strength, corrosion resistance, and handling properties of the amalgam.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option suggests a lower percentage of tin, which might not provide the optimal properties for low copper alloys.
- **Option B:** This is the correct answer; hence, it is not incorrect but rather the standard for low copper alloys.
- **Option C:** This option suggests a higher percentage of tin, which could potentially alter the phase composition and properties of the amalgam in a less desirable way.
- **Option D:** This option also suggests a different percentage, which does not align with the standard composition for low copper alloys.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the gamma-2 phase, which is influenced by the tin content, can affect the clinical performance of dental amalgams. Low copper amalgams have a higher gamma-2 phase content compared to high copper amalgams, which can make them more prone to corrosion and less durable over time.

## **Correct Answer:** .