A patient needs a crown on a mandibular first molar with visible metal. For optimal ESTHETICS and STRENGTH in this posterior location, the BEST material is:

Zirconia (monolithic) — strongest all-ceramic, excellent for posterior esthetics
Feldspathic porcelain (brittle — not ideal for posterior high-load areas)
PFM with subgingival margin (metal will still show at margin over time)
Lithium disilicate (e.max) — good strength but less than zirconia for posterior

Show answer and explanation

Correct answer: A. Zirconia (monolithic) — strongest all-ceramic, excellent for posterior esthetics

A. Correct. For a mandibular POSTERIOR molar requiring both ESTHETICS (no metal visible) and STRENGTH (posterior high occlusal loads): ZIRCONIA (monolithic or zirconia-based) is the best choice. Zirconia has the highest flexural strength of any all-ceramic material (>900 MPa for monolithic), is tooth-colored, and withstands high occlusal forces. Monolithic zirconia in particular is ideal for posterior teeth.
B. Feldspathic porcelain is too brittle for posterior teeth under heavy occlusal loads — prone to fracture.
C. PFM with subgingival margin hides the metal junction but gingival recession will eventually reveal the metal collar. Not ideal for esthetics long-term.
D. Lithium disilicate (e.max, ~400 MPa) is excellent for anteriors and premolars but may not be strong enough for heavy posterior bruxers — zirconia is preferred for molars.

More Prosthodontics & Occlusion practice questions