Which of the following is a tooth-related factor affecting clasp retention?

Which of the following is a tooth-related factor affecting clasp retention?

• A. How far the clasp terminus is placed from the height of contour in the same angle of gingival convergence
• B. Angle of gingival convergence
• C. Clasp length
• D. Clasp cross sectional form

Answer: (B)

Retention from a clasp comes from engaging a tooth undercut created by the tooth’s shape. The angle of gingival convergence describes how the tooth walls tilt toward the gum. When a tooth converges more toward the gingiva (a steeper, more acute angle), the accessible undercut on the tooth is deeper, which provides greater grip for the clasp and hence greater retention. If the tooth is flatter with less convergence, the undercut is shallower and retention is reduced. So this angle is a tooth-related factor because it stems from the tooth’s natural morphology, directly influencing how well a clasp can grab onto the tooth. The other options involve how the clasp is designed or placed rather than the tooth’s inherent shape.

Retention from a clasp comes from engaging a tooth undercut created by the tooth’s shape. The angle of gingival convergence describes how the tooth walls tilt toward the gum. When a tooth converges more toward the gingiva (a steeper, more acute angle), the accessible undercut on the tooth is deeper, which provides greater grip for the clasp and hence greater retention. If the tooth is flatter with less convergence, the undercut is shallower and retention is reduced. So this angle is a tooth-related factor because it stems from the tooth’s natural morphology, directly influencing how well a clasp can grab onto the tooth. The other options involve how the clasp is designed or placed rather than the tooth’s inherent shape.