HOSA Dental Terminology Practice

What type of dental restoration is described as a solid casted or milled restoration covering some occlusal tooth cusp and side wall area?

1. Onlay

2. Full crown

3. Jacket crown

4. Three-quarter crown

The correct answer is: Onlay

An onlay is a specific type of dental restoration that is designed to cover one or more cusps of a tooth while also extending onto the side walls. This type of restoration is typically used when there is significant decay, damage, or wear to a tooth that cannot be adequately addressed with a simple filling. The onlay is crafted to fit the unique anatomy of the tooth, providing strength and support where it's most needed. Since it extends over some of the tooth's major surfaces, such as the occlusal surface (the top where the biting occurs) and the side walls, it offers better protection and functionality compared to a filling alone. In comparison, a full crown completely encases the entire tooth, providing a different level of coverage and restoration. A jacket crown, also known as a porcelain crown, is typically used for anterior teeth and does not provide the same coverage as an onlay. A three-quarter crown covers most of the tooth but leaves the front portion exposed, unlike an onlay that specifically covers the cusps and sides for enhanced structural integrity. This specificity in function and design is why an onlay is identified as the correct answer in this context.