Which amalgam material helps provide structural support for a fixed restoration?

The core buildup is specifically designed to provide structural support for a fixed restoration. When a tooth is significantly decayed or damaged, a core buildup is necessary to create a stable base for a crown or other prosthetic device. This procedure involves adding material to the remaining tooth structure to ensure there is enough support and retention for the final restoration.

While pins and posts can also be used in restorative dentistry, their primary function is different. Pins are used to retain a restoration in cases where there is insufficient tooth structure, whereas posts are utilized in endodontically treated teeth to retain a buildup. However, neither pin nor post systems is intended to serve as the primary structural support themselves; rather, they aid in securing the core buildup.

Therefore, while all the choices listed can be involved in facilitating a dental restoration, the core buildup is uniquely important for providing the necessary structural support for fixed restorations.