Which property improves the ferrule effect?

Correct answer: B. A metal band (crown margin) encircling the tooth at the cervical area

• A. The core material affects core retention — not the ferrule effect, which depends on the crown preparation encircling sound tooth structure.
• B. The FERRULE EFFECT is created by the crown encircling 360° of sound tooth structure (at least 2mm of vertical tooth structure above the margin). This band resists forces that would split or fracture the tooth. The ferrule must be of adequate height and thickness to be effective.
• C. Pins/dowels in the core improve RETENTION of the core buildup — they do NOT create a ferrule effect. The ferrule is about crown margins, not the core.
• D. Depth alone does not create the ferrule — the ENCIRCLING of sound tooth structure by the crown margin at adequate height is what creates the ferrule effect.