EFDA Amalgam and Composite Restorations 2

Question 1

Which type of cavity preparation design is MOST commonly used for amalgam restorations?

Accepted Answer

Black's preparation with 90-degree cavosurface margins

Answer

Amalgam requires a 90-degree cavosurface margin (butt joint) to prevent fracture at the margin, as developed by G.V. Black.

Question 2

When placing a matrix band for an amalgam Class II restoration, the band should be contoured to create:

Accepted Answer

A convex proximal contour with a tight contact

Answer

The matrix band must be burnished to create a convex proximal surface and a proper tight contact to prevent food impaction.

Question 3

The trituration time for amalgam capsules is controlled to ensure:

Accepted Answer

Optimal consistency with proper plasticity for condensation

Answer

Proper trituration time creates the ideal mix consistency — not too dry or too wet — for adequate condensation and adaptation.

Question 4

Which bonding step in composite placement helps prevent post-operative sensitivity?

Accepted Answer

Application of a dentinal bonding agent

Answer

A dentinal bonding agent seals dentinal tubules and bonds the composite to dentin, significantly reducing post-operative sensitivity.

Question 5

The incremental placement technique for composite restorations is used primarily to:

Accepted Answer

Reduce polymerization shrinkage stress

Answer

Placing composite in small increments (≤2mm) reduces the overall polymerization shrinkage stress placed on the bond to tooth structure.

(EFDA) Expanded Function Dental Auxiliary Practice Test