National Dental Assisting Examining Board (NDAEB) Practice Exam

A restoration of IRM can last up to how long?

1. A few days

2. Several months

3. More than a year

4. One week

The correct answer is: Several months

IRM, or Intermediate Restorative Material, is specifically designed for temporary restorations. It is typically used in situations where a longer-term solution isn't immediately available or where a patient needs time before a more definitive procedure can be performed, such as a crown or permanent filling. The longevity of IRM can extend to several months, which is why the answer indicating this as the correct duration is accurate. The material is formulated to withstand the forces of chewing and is capable of sealing the cavity to protect the tooth from bacteria and further decay for a significant amount of time. The context of the other options reflects a misunderstanding of IRM’s capabilities. A duration of just a few days or one week would not capitalize on the material’s intended use as a long-term temporary solution. While IRM might not last beyond a year when placed under certain conditions or heavy load, it is explicitly recognized for its effectiveness in providing protection for several months. Thus, given its properties, the option stating several months aligns well with the realistic expectations for its use.