PRS03 - Lecture 4 - Secondary Impressions

Question 1

What is the aim for secondary impressions? (2)

Answer 1

To enable you to pour a very accurate secondary “working” cast

In which the partial denture will be made

Question 2

What must be done prior to recording secondary impressions? (6)

Answer 2

Tooth preparations - explain to patient + ask for consent

Occlusal rest seats (round bur)

Cingulum rest seats (cylindrical bur)

Approach facets

Guide planes

Dimples - when there is no or little usable undercut (low survey line)

Question 3

Why is it important to get an anccurate secondary impression of the lingual sulcus when making a lower partial denture?

Answer 3

Just incase a lingual bar or plate is going to be used as a major connector

Question 4

Does the technique for secondary impressions differ from primary?

Answer 4

No - just need to do tooth preparations and get an accurate impression of lingual sulcus.

Question 5

How would the prescription differ after secondary impressions for acrylic and cobalt-chrome denture? (2)

Answer 5

Cobalt-chrome - please construct a cobalt-chromium framework to design drawn

Acrylic - please construct a wax base and occlusal rims to deisgn drawn