Which type of dental materials are soft, moldable, and set hard within cavities?

The correct answer is composites because they are specifically designed to be soft and moldable when applied, allowing for easy adaptation to the cavity's contours. Once the composite material is placed within a cavity, it undergoes a curing process—often through light activation—that causes it to harden and bond effectively to the tooth structure. This characteristic makes composites highly effective for use in restorative dentistry, particularly for aesthetic repairs and fillings in posterior teeth.

Other types of materials do not share these specific properties. Permanent prosthetic restorations, for example, refer to more rigid structures like crowns or bridges that are fabricated outside the mouth before being placed, whereas composites are molded in place. Pre-constructed filling materials generally come in predefined shapes and sizes, requiring additional shaping to fit, which does not align with the idea of moldability at the time of placement. Temporary cements, while also soft and moldable before setting, serve a different function as they are typically used for temporary restorations and are not intended for permanent application.