Which type of clasp is appropriate for an undercut of 0.02 mm?

The appropriate choice for a 0.02 mm undercut is the wrought wire clasp. Wrought wire clasps are made from flexible materials, which allow them to adapt to slight changes in undercuts. Their ability to provide retention without being overly rigid makes them ideal for situations where a minimal undercut is present, such as 0.02 mm.

Wrought wire is also known for its resilience and ability to withstand forces without deforming, making it suitable for a retentive component in removable partial dentures. This flexibility can accommodate the intricacies of oral anatomy and offers better comfort for the patient, thus making it a favored option in prosthetics where precise fit and retention are essential.

In contrast, other types of clasps may not be as adaptable to such a small undercut. A cast clasp is typically more rigid and may not provide the necessary retention in this scenario. Flexible clasps are usually designed for greater undercuts or for more versatile applications, while metal clasps may not have the same degree of flexibility required for such a slight undercut.