Components of a Removable Partial Denture (RPD) Practice Test 2026 - Free Removable Partial Denture Exam Questions and Study Guide

Approaching the retentive undercut from the gingival direction means using an infrabulge clasp. Infrabulge clasps engage undercuts from below the height of contour, so the retention is provided by portions that come up from the gingival side to grip the undercut. This is in contrast to suprabulge clasps, which approach from above the survey line and engage the undercut from the occlusal/incisal direction. The term infrabulge specifically describes the path of insertion relative to the tooth’s height of contour, which is why it’s the correct choice for a gingival-direction approach.