Which component of amalgam acts as a liquid binder?

The component of amalgam that acts as a liquid binder is mercury. In dental amalgam, mercury is used to mix with powdered metals such as silver, copper, and tin, resulting in a pliable material that can be shaped and packed into cavities. Mercury's liquid state is essential for creating a homogeneous mixture, allowing the metal particles to bond effectively and harden into a durable restoration after it sets.

The presence of mercury is crucial because it facilitates the chemical reaction that forms the final solid amalgam, providing the material with its unique properties—strength, durability, and resistance to wear. Without mercury, the other components would not be able to effectively combine and achieve the desired physical properties necessary for dental restorations.