Which of the following is a suprabulge member used for extracoronal retention?

Which of the following is a suprabulge member used for extracoronal retention?

• A. Ring clasp
• B. Basic cast circumferential clasp
• C. I-bar
• D. T-bar

Answer: (D)

Suprabulge retention relies on a retentive element that projects above the height of contour to engage an undercut from above, rather than encircling the tooth from below. The T-bar fits this description because its retaining component is a bar that sits on the tooth’s facial/buccal surface above the height of contour, supported by a vertical stem from the rest seat. The crossbar engages the undercut from above, providing extracoronal retention without wrapping entirely around the tooth. This design offers reliable retention with relatively easy insertion/removal and better hygiene compared with more encircling forms.

Suprabulge retention relies on a retentive element that projects above the height of contour to engage an undercut from above, rather than encircling the tooth from below. The T-bar fits this description because its retaining component is a bar that sits on the tooth’s facial/buccal surface above the height of contour, supported by a vertical stem from the rest seat. The crossbar engages the undercut from above, providing extracoronal retention without wrapping entirely around the tooth. This design offers reliable retention with relatively easy insertion/removal and better hygiene compared with more encircling forms.