PFM Failure Mode — NDEB AFK MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: E — Porcelain fracture (chipping)
Porcelain fracture (chipping/delamination) is the most common mode of failure of PFM restorations. It can be cohesive (within the porcelain body) or adhesive (at the metal-porcelain interface). Contributing factors include inadequate tooth reduction (thin porcelain), occlusal prematurities, bruxism, poor framework design (unsupported porcelain), and residual stresses from the firing process. Minor chips can be repaired intraorally with composite bonding; extensive fractures require crown replacement.
Reference: Shillingburg – Fundamentals of Fixed Prosthodontics, 4th ed., 2012