What is amalgam commonly used for in dentistry?

Amalgam is a widely accepted material in dentistry primarily used for filling cavities, especially in posterior teeth. This is due to its durability and strength, making it ideal for areas that experience significant chewing pressure. The composition of amalgam includes a blend of metals, such as mercury, silver, tin, and copper, which contributes to its longevity and resistance to wear.

When a tooth is decayed, the affected material is removed, and the cavity is cleaned to prepare for the filling. Amalgam fills the cavity securely, restoring the tooth's function and protecting it from further decay. Its ability to bond well with tooth structure and its aesthetic acceptance—though less favorable than tooth-colored materials in visible areas—makes it particularly suitable for molars and premolars where appearance is less critical.

The other choices present alternatives to dental procedures but are not relevant for the role of amalgam. For example, whitening teeth involves procedures that do not utilize amalgam; treating gum disease focuses on periodontal health rather than restorations; and aligning misaligned teeth employs orthodontic treatments rather than cavity fillings. Thus, the correct answer highlights the specific application of amalgam in maintaining dental health by effectively filling cavities.