What is the recommended restoration technique for a fracture distal marginal ridge on a tooth with a huge mesio-occlusal amalgam?

The recommended restoration technique for a fracture of the distal marginal ridge, especially in a tooth that is already compromised by a large mesio-occlusal amalgam, is to use a cast restoration. A cast restoration, such as a crown, provides the necessary strength and durability to reinforce the remaining tooth structure, particularly in areas that are under significant stress and loading during function.

When a tooth has a substantial existing restoration like an amalgam, there can be concerns about the integrity of the remaining tooth structure. A cast restoration can be custom-made to fit the tooth precisely, ensuring that it covers the fractured areas adequately, including the distal marginal ridge, while restoring the tooth's function, aesthetics, and protection against further fracture.

Other techniques might be suitable in different contexts, but in the case of significant structural compromise due to prior restorations, a cast restoration is often the most reliable choice to ensure long-term success and stability of the tooth.