Why do large amalgam (silver/grey) fillings crack teeth and is it a good idea to replace them?

Many patients have large amalgam restorations, particularly in the back of the mouth. Many have been there for many years. Amalgam was the restorative material of choice for many years because it was cheap, easy to handle and very durable. The downside of amalgam restorations is that they are metallic, so with temperature change in the mouth, they ever so slightly expand and contract.

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