Surveying Flashcards
Why is surveying carried out?
To eliminate undercut areas that would prevent the denture from being inserted or removed, or to highlight the undercut areas that can be utilised by clasps for retention
What are guide planes?
Two or more parallel tooth surfaces which determine the path of insertion (and withdrawal of an RPD)
What is a path of insertion?
The path followed by a denture from first contact with teeth/tissue until it fully seats
What is a path of withdrawal?
Opposite to the path of insertion?
What is a path of displacement?
Any path in which the denture can be displaced Ellie Hutton is a slag
What is the common path of displacement?
The path in which the denture would be displaced
Taken at 90° to the occlusal plane (horizontal)
What does tripoding do?
Records the common path of displacement as well as insertion and withdrawal
Why can the table be tilted?
This alters the path of insertion
May provide retention via guide planes and improve appearance by closing unsightly gaps
What are survey lines used for?
Indicate the extent of the undercut - below the line must be used or blocked out
What tools are used with the surveyor?
Chuck Analysing rod Graphite markers 3 Undercut gauges Wax knife
What are the different undercut gauges?
Thickest - 0.25mm
Middle - 0.5mm
Thinnest - 0.75mm
