HOSA Dental Terminology Practice

What is typically included in the design of an onlay?

1. It covers the entire tooth surface

2. It covers some of the occlusal tooth cusp and sidewall area

3. It is used exclusively for temporary restoration

4. It restores only the inner structure of the tooth

The correct answer is: It covers some of the occlusal tooth cusp and sidewall area

The design of an onlay is specifically intended to cover some of the occlusal tooth cusp and sidewall area. Onlays are indirect restorations that are used to repair teeth that have sustained damage due to decay or fracture. Unlike full crowns that cover the entire tooth, onlays provide a more conservative approach, targeting only the affected areas while preserving as much of the natural tooth structure as possible. This design allows for maintaining the tooth's strength and functionality, while also providing support to the cusps and preventing further damage. In contrast, covering the entire tooth surface is characteristic of full crowns, which are more extensive restorations. Temporary restorations are typically made from different materials and are not used in a permanent sense, while onlays are intended for long-term use. Restorations that focus solely on the inner structure of the tooth would classify as inlays, which do not extend to the cusps or sidewalls and are, therefore, distinctly different from an onlay's design.