Endodontics · single question
What is the PURPOSE of a dental post (dowel)?
Show answer and explanation
Correct answer: A. Core retention — retaining the core buildup
Core retention (A). The purpose of a post is SOLELY to retain the core buildup material in a tooth with insufficient coronal structure. Posts do NOT strengthen the root — in fact, post placement requires removal of healthy dentin and can WEAKEN the root.
• A post is indicated when: insufficient coronal tooth structure remains to retain a core buildup on its own (typically <50% crown structure remaining after RCT).
• A post is NOT indicated when: sufficient coronal structure is present to retain the core without a post.
• Post complications: root perforation, root fracture, loss of apical seal, PDL damage.
• Fiber posts (composite resin) have modulus of elasticity similar to dentin — preferred over metal posts which are stiffer and can cause root fracture.
• A post is indicated when: insufficient coronal tooth structure remains to retain a core buildup on its own (typically <50% crown structure remaining after RCT).
• A post is NOT indicated when: sufficient coronal structure is present to retain the core without a post.
• Post complications: root perforation, root fracture, loss of apical seal, PDL damage.
• Fiber posts (composite resin) have modulus of elasticity similar to dentin — preferred over metal posts which are stiffer and can cause root fracture.