What is the depth of undercut for a Cobalt Chrome retentive arm clasp?

The correct depth of undercut for a Cobalt Chrome retentive arm clasp is typically 0.25 mm. This specific measurement is essential to ensure that the clasp fits accurately and retains the prosthesis securely without compromising the support and retention needed for removable partial dentures.

When designing a clasp, especially made from Cobalt Chrome, the undercut needs to be minimal to allow for flexibility in retention while maintaining overall strength. If the undercut is deeper, such as 0.50 mm or greater, it could potentially lead to difficulties in insertion or removal of the prosthesis, creating a situation where the clasp could engage too tightly, leading to discomfort or damage to the abutment teeth. Therefore, 0.25 mm is the accepted standard that balances adequate retention with patient comfort and the structural integrity of both the clasp and the underlying tooth structure.