What characterizes direct restorations in dentistry?

Direct restorations in dentistry are characterized by being applied in a single appointment. This involves placing materials directly into the cavity or prepared tooth structure right in the dental office during the patient's visit. For example, materials such as dental composites and glass ionomer are commonly used for direct restorations. The dentist prepares the tooth, applies the restorative material, shapes it, and hardens it, all in one sitting. This process is efficient and allows for immediate restoration of function and aesthetics.

In contrast, the other options involve processes that typically require more than one visit or outside fabrication. Indirect restorations, such as crowns and bridges, are prepared outside the mouth, which necessitates additional appointments for both taking impressions and placing the final restoration. Therefore, the nature of direct restorations is distinguished by the immediacy and convenience of their application within a single visit.