post Flashcards
What is the main indication for using a prefabricated post and core?
When there is sufficient remaining coronal tooth structure and a relatively regular, straight root canal.
What ferrule dimension is recommended before placing a prefabricated post?
At least 1 mm thickness 360° and 1.5–2 mm height of sound dentin but with <4 intact walls.
What is the ideal post length for prefabricated posts?
Two-thirds the root length, while preserving apical seal and avoiding perforation.
Why are fiber posts often preferred in anterior teeth?
They are esthetic and have an elastic modulus similar to dentin, reducing root fracture risk.
What post design improves retention for prefabricated posts?
Parallel-sided are better than tapered or and serrated designs > smooth posts.
What are limitations of prefabricated posts in flared or irregular canals?
Poor adaptation, lower retention, and increased risk of failure.
What are advantages of prefabricated posts?
Cost-effective, Quick placement, minimal chair time, and retrievable if endo retreatment is needed.
What cement is used for fiber posts and composite core build-ups?
Adhesive resin cements for strong bonding and sealing.
What is a key disadvantage of prefabricated posts in high-load cases?
Lower resistance to rotational and occlusal forces; prone to debonding.
When must anti-rotation features(slots/pins) be added for prefabricated posts?
When minimal coronal tooth structure remains.
When is a cast post and core indicated over a prefabricated one?
When there is extensive coronal structure loss or a flared/irregular canal.
Why is cast post ideal for small teeth with minimal remaining structure? What other cases needs cast post?
It provides custom adaptation and high retention even in minimal or angled cores.
What makes cast posts suitable for posterior load-bearing teeth?
They are strong, wear-resistant, and distribute occlusal forces better.
What is the ferrule requirement for cast post and core?
1.5–2 mm height and at least 1 mm thickness of sound dentin around the post ideally.
What is a disadvantage of cast post placement?
Requires more dentin removal and is less conservative than prefabricated posts.
What materials are used for cast post and core?
Gold alloy (strong, biocompatible), base metal alloy (cost-effective, but risk of corrosion).
What cement is typically used for cast post and core?
Zinc phosphate or RMGIC for strong mechanical retention.
What esthetic disadvantage does cast post have in anterior teeth?
Metal color may show through translucent ceramic crowns.
What procedural disadvantage is associated with cast post and core? What property that may causes harm to root?
Requires at least two appointments (prep+imp, 2placement) and lab work; risk of contamination RCT between visits; stiff(risk of root fractures.
