fp Flashcards
Q: What are the consequences of pulp removal on dentin?
Dehydration and increases brittleness, making the tooth more prone to fracture under occlusal forces.
Which materials are suitable for a crown on tooth #46?
A: Zirconia (strength), Lithium Disilicate (esthetics), PFM (traditional option), Gold Crown: Best longevity, biocompatible, high strength, resistant to corrosion but lacks esthetics.
What esthetic materials are ideal for anterior metal-free single crowns?
High-glass ceramics like lithium disilicate (EMAX), feldspathic porcelain, and leucite-reinforced glass ceramics.
Which material is best for posterior single crowns requiring high strength?
Monolithic zirconia or densely sintered alumina (e.g., Procera AllCeram).
Why is opacity important in material selection for crowns?
To mask discolored teeth.
e.g., using zirconia layered with porcelain.
What is the minimum tooth reduction required for lithium disilicate crowns?
1.0–1.5 mm for strength and esthetics.
What is the minimal reduction for zirconia crowns?
0.3 mm (anterior) to 0.5 mm (posterior) for 3Y zirconia due to high strength; lowest translucency.
0.8mm (anterior) to 0.8-1.0mm(posterior) for 4Y[balanced translucency and strength] and 5Y[esthetic but lower strength]
Why is wear resistance important in material selection?
To avoid excessive wear on opposing natural teeth.
What prep design principles improve restoration success?
Avoid undercuts, maintain emergence profile, allow 0.5 mm subgingival margins, and ensure self-cleansing embrasures.
What happens if the crown contour is overbuilt at the gingival third?
Plaque retention and gingival inflammation.
How does lithium disilicate compare in axial thickness needed for veneers?
Allows conservative veneer prep: 0.3–0.7 mm thickness.
Which material offers both esthetics and moderate strength for anterior crowns?
Lithium disilicate.
Which material is most wear-resistant but may affect opposing teeth?
Zirconia.
What is the preferred cementation protocol for feldspathic and lithium disilicate crowns?
Adhesive resin bonding.
What is the cementation protocol for zirconia crowns?
Conventional cementation with RMGI or GIC.
What factors impact the longevity of metal-free crowns?
Material properties, prep design, occlusal forces, and bonding protocol.
What occlusal factors affect crown material choice?
Occlusal scheme stability, space, and presence of parafunctional habits.
Which material is better suited for patients with bruxism?
Monolithic zirconia due to high strength and wear resistance.
Why is biocompatibility important in ceramic crown selection?
To prevent allergic or adverse soft tissue reactions.
What materials are best for anterior FDPs requiring esthetics?
Layered zirconia or lithium disilicate (if connectors allow).
Which material is preferred for posterior FDPs requiring strength?
Monolithic zirconia.
What span length considerations affect FDP material choice?
Longer spans increase deflection, needing high-strength materials like zirconia.
What minimum flexural strength is ideal for FDP materials?
700–1000 MPa.
How does abutment health affect FDP material choice?
Compromised abutments may need stronger materials like zirconia.
