EFDA Provisional Crown Fabrication 5

Question 1

A patient returns with a loose provisional crown 3 days after placement. After recementing, which factor should be evaluated FIRST?

Accepted Answer

Occlusal contacts and parafunction habits

Answer

Repeated loosening of a provisional is most often caused by occlusal forces or parafunctional habits such as bruxism that exceed the retention of temporary cement.

Question 2

During the 'remove and reline' phase of direct provisional fabrication, when should the initial shell be removed from the mouth?

Accepted Answer

During the rubbery or doughy stage, before final set

Answer

Removing the shell during the rubbery stage prevents locking into undercuts while preserving the shape needed for the final reline.

Question 3

Which statement about PMMA shrinkage during polymerization is CORRECT?

Accepted Answer

PMMA shrinks volumetrically by 6–7% during polymerization

Answer

PMMA undergoes approximately 6–7% volumetric shrinkage during polymerization, which can affect marginal fit of the provisional.

Question 4

A provisional crown placed on a tooth with a recent pulp cap should ideally be cemented with:

Accepted Answer

Zinc oxide eugenol (ZOE) temporary cement

Answer

ZOE has mild sedative and obtundent effects on the pulp, making it suitable when a recent pulp cap requires pulpal soothing during the provisional phase.

Question 5

The term 'open margin' on a provisional crown refers to:

Accepted Answer

A gap between the provisional crown edge and the tooth preparation

Answer

An open margin is a gap where the crown edge does not contact the tooth, allowing microleakage, sensitivity, and bacterial ingress.

(EFDA) Expanded Function Dental Auxiliary Practice Test

(EFDA) Expanded Function Dental Auxiliary Practice Test

EFDA Provisional Crown Fabrication 5