What material is commonly used for prefabricated provisional crowns?

Polycarbonate is commonly used for prefabricated provisional crowns because of its favorable properties that make it ideal for providing temporary restorations. This material is strong yet lightweight, allowing for durability during the time the provisional crown is in place. Additionally, polycarbonate crowns can be easily customized to match the patient's natural tooth color, which is important for aesthetic reasons. They also have a good polishability, contributing to improved appearance and patient acceptance.

While other materials like steel, composite resin, and aluminum may have their specific applications in dentistry, they do not possess the same combination of aesthetics and functionality for temporary crowns. Steel, for example, is typically used in applications where strength is paramount but lacks the aesthetic appeal of polycarbonate. Composite resin is more commonly used for other types of restorations rather than prefabricated temporary crowns, and aluminum does not offer the necessary esthetic qualities required in this context. Therefore, polycarbonate stands out as the most suitable option for prefabricated provisional crowns.