According to GV Black, all pits and fissures are included in the prep, gingival margin is extended ___________, cavity width depends on margin placement but is midway between __________ and ____________.

• A. Supragingivally; cusp tip and depth of fissure
• B. Subgingivally; cusp tip and crest of enamel
• C. Subgingivally; cusp tip and gingival margin
• D. Subgingivally; depth of fissure and cusp tip

Answer: (D)

In GV Black’s approach to pit-and-fissure occlusal preparations, the finish line and width are set by specific anatomic landmarks to ensure complete removal of affected tissue while preserving tooth structure. The gingival margin is extended subgingivally, so the margin finishes on sound tooth structure beyond the fissure area rather than closer to the sulcus. The cavity width, determined by where the margin is placed, should be midway between the depth of the fissure and the cusp tip. This central position between how deep the fissure runs and how tall the cusp is helps create a balanced prep that removes demineralized material without unnecessarily weakening the marginal ridges, and it supports proper resistance and retention for the future restoration. Choosing a supragingival margin or placing the margin at the crest of enamel would not align with this geometry, and using gingival margin as one of the width determinants would misplace the walls relative to the fissure anatomy.