Why are amalgam margins important?

• A. Margin adaptation
• B. Require ideal thickness throughout restoration
• C. For color matching
• D. To simplify finishing

Answer: (B)

The key idea is that the margin must have ideal thickness throughout the restoration because bulk at the edges is essential for both strength and a durable seal. Amalgam relies on adequate material thickness to withstand biting forces and to be properly condensed into a tight, continuous margin. When margins are too thin, the edge is prone to fracture, marginal breakdown, and microleakage, which can lead to recurrent decay and restoration failure. Maintaining uniform, sufficient thickness around the entire margin helps ensure the restoration remains sealed, resists functional stresses, and finishes cleanly. Margin adaptation and finishing ease matter, but they don’t replace the need for enough bulk to support a lasting margin.