Restorative & Materials · single question
Which dental material has the HIGHEST flexural strength?
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Correct answer: A. Zirconia (Yttria-stabilized tetragonal zirconia polycrystal — Y-TZP)
Flexural strength (modulus of rupture) of dental ceramics: Feldspathic porcelain: ~60-70 MPa; Leucite-reinforced ceramic (IPS Empress): ~120-160 MPa; Lithium disilicate (IPS e.max): ~350-400 MPa; Zirconia (Y-TZP): ~900-1200 MPa. Zirconia has BY FAR the highest flexural strength of any dental ceramic material, making it ideal for high-stress areas like posterior bridges and implant frameworks.
- A. Incorrect. Feldspathic porcelain has the LOWEST flexural strength (~60-70 MPa) of the ceramics listed — it is very esthetic but brittle.
- B. Incorrect. Leucite-reinforced ceramics (IPS Empress) have ~120-160 MPa — significantly stronger than feldspathic but far weaker than zirconia.
- C. Incorrect. Lithium disilicate (e.max) has ~350-400 MPa — strong and esthetic, but still ~3x weaker than zirconia.
- D. CORRECT. Zirconia (Y-TZP) has the highest flexural strength (~900-1200 MPa) of any dental ceramic — it is used for posterior bridges, implant abutments, and full-contour crowns.
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