EFDA Impression Materials and Techniques 5

Question 1

A heavy-body PVS material placed in the impression tray is also called:

Accepted Answer

Putty or tray material

Answer

Heavy-body or putty PVS fills the tray and provides bulk support while light-body (wash) material captures fine detail.

Question 2

Which factor most significantly shortens the working time of alginate?

Accepted Answer

Using warm water during mixing

Answer

Warm water accelerates the chemical setting reaction of alginate, reducing working time; cold water retards it.

Question 3

What is the purpose of the 'two-step putty-wash' PVS technique?

Accepted Answer

To allow putty to set first, creating a rigid tray, then a thin wash captures fine detail

Answer

The set putty acts as a rigid custom tray, and the subsequent thin wash flows to capture precise marginal detail without distortion from tray flex.

Question 4

Which impression material contains eugenol and is contraindicated in patients with eugenol sensitivity?

Accepted Answer

Zinc oxide eugenol (ZOE) paste

Answer

ZOE impression paste contains eugenol (oil of cloves) and can cause allergic reactions or tissue irritation in sensitive patients.

Question 5

An impression that records only the occlusal surfaces and interproximal contacts without capturing soft tissue is called a:

Accepted Answer

Bite registration

Answer

A bite registration records the spatial relationship of opposing teeth in occlusion and is not intended to capture tissue or tooth detail for a restoration.

(EFDA) Expanded Function Dental Auxiliary Practice Test

(EFDA) Expanded Function Dental Auxiliary Practice Test

EFDA Impression Materials and Techniques 5