EFDA Bases, Liners, and Sealants 3

Question 1

Before placing a resin-based pit and fissure sealant, the tooth surface is conditioned with:

Accepted Answer

Phosphoric acid etchant

Answer

Phosphoric acid (usually 35–37%) etches enamel to create microporosities for micro-mechanical retention of the sealant.

Question 2

A glass ionomer base is described as being 'biocompatible' primarily because:

Accepted Answer

Its final pH is close to neutral and it chemically bonds to tooth structure

Answer

Glass ionomer's final pH approaches neutral and its chemical adhesion to hydroxyapatite makes it well-tolerated by pulpal tissue.

Question 3

Which sealant type does NOT require a separate curing light and polymerizes through a chemical reaction when two components are mixed?

Accepted Answer

Autopolymerizing (self-cured) sealant

Answer

Autopolymerizing sealants undergo chemical polymerization when base and catalyst are mixed, without requiring a curing light.

Question 4

When evaluating a placed sealant, an EFDA uses an explorer to check for:

Accepted Answer

Tactile retention and absence of voids or lifted margins

Answer

An explorer is used to confirm that the sealant is firmly retained and that there are no voids, bubbles, or lifted edges that could allow leakage.

Question 5

In a very deep preparation approaching the pulp, the FIRST material placed is typically:

Accepted Answer

A layer of calcium hydroxide over the deepest point

Answer

Calcium hydroxide is placed first over the deepest area closest to the pulp to stimulate secondary dentin and protect pulpal tissue.

(EFDA) Expanded Function Dental Auxiliary Practice Test