HOSA Dental Terminology Practice

What is the primary function of an onlay?

1. To replace missing teeth entirely

2. To cement onto the prepared site covering some occlusal tooth cusp

3. To restore the aesthetic balance of a complete arch

4. To provide a temporary fix for dental emergencies

The correct answer is: To cement onto the prepared site covering some occlusal tooth cusp

An onlay is a type of indirect restoration that is specifically designed to restore a tooth that has suffered damage or decay. The primary function of an onlay is to cement onto a prepared site, covering some of the occlusal tooth cusp while preserving as much of the natural tooth structure as possible. This is particularly beneficial for teeth that have sustained significant but not complete loss of structure, allowing for both functional restoration and protection against further decay or fracture. Unlike a complete crown, which covers the entire tooth, an onlay is more conservative and maintains some of the original tooth structure. This can be particularly advantageous in terms of preserving tooth vitality. Other options do not accurately represent the function of onlays. They are not meant to replace missing teeth entirely, as that would typically be the role of dental implants or bridges. Onlays do not restore the aesthetic balance of a complete arch; rather, they focus on individual teeth. Additionally, while onlays can address issues leading to discomfort, they are not used as temporary fixes; those are usually accomplished with temporary crowns or dressings. Thus, option B captures the essential role of onlays in restorative dentistry.