A patient wants extractions and immediate implants. Teeth #7, #8, #9 have fractured/dislodged crowns with very short clinical crowns; tooth #10 has a crown. Most likely reason the previous restorations failed?

Correct answer: B. Retention

• A. Support resists vertical seating forces; it is not the primary issue when crowns repeatedly dislodge.
• B. Correct. Very short clinical crowns provide inadequate axial wall height and surface area, so the restorations lack RETENTION (resistance to dislodgement along the path of insertion) — hence repeated loss of the crowns.
• C. Stability resists lateral/tipping forces; the recurring dislodgement points to retention rather than stability.
• D. Marginal defects cause leakage/recurrent caries, not the wholesale dislodgement seen with short preparations.