Preparation for investing, sprue placement

Question 1

What is a sprue?

Answer 1

• Channel for metal
• Wax, plastic or metal
• 2.5 mm diameter for molars and 2mm for others
• At 45 degrees
• 6mm length
• Attached to crucible former

Question 2

Investment material types

Answer 2

High noble alloys
Noble metal alloys
Base metal alloys

Question 3

What is burnout?

Answer 3

• Removal of wax pattern by melting

- Mould into which metal is placed is created

Question 4

What is casting?

Answer 4

Introduction of molten alloy into previously prepared mould