The tensile strength of dental amalgam is
**Core Concept**
The tensile strength of dental amalgam is a measure of its resistance to deformation and failure under tensile forces, which is crucial for withstanding the masticatory forces in the oral environment. Dental amalgam is a mixture of mercury, silver, tin, and other metals that harden to form a solid material. The properties of dental amalgam are influenced by its composition, microstructure, and the technique used for its placement.
**Why the Correct Answer is Right**
The tensile strength of dental amalgam is primarily influenced by the formation of a strong silver-tin matrix, which provides the framework for the amalgam restoration. The addition of copper to dental amalgam can also enhance its tensile strength by promoting the formation of a more robust silver-tin matrix. The mercury content in dental amalgam plays a crucial role in facilitating the formation of the silver-tin matrix by dissolving the silver and tin particles and allowing them to coalesce into a stronger structure. The resulting amalgam restoration must withstand the constant forces of mastication and should exhibit adequate tensile strength to prevent fracture and failure.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not accurately reflect the tensile strength of dental amalgam, which is influenced by the formation of a strong silver-tin matrix and the presence of copper.
**Option B:** This option is incorrect as it underestimates the tensile strength of dental amalgam, which is capable of withstanding significant forces in the oral environment.
**Clinical Pearl / High-Yield Fact**
A key factor influencing the tensile strength of dental amalgam is the addition of copper, which enhances the formation of a strong silver-tin matrix. Adequate mixing and placement of dental amalgam are also critical to achieving optimal tensile strength.
**Correct Answer: C. 30-40 MPa**