EFDA Bases, Liners, and Matrices 3

Question 1

The Automatrix system differs from the Tofflemire system primarily in that it:

Accepted Answer

Is a self-tightening matrix that needs no external retainer

Answer

The Automatrix system is a retainerless matrix that is self-contained and tightened by its own internal mechanism.

Question 2

What thickness of remaining dentin requires placement of a protective base before an amalgam or composite restoration?

Accepted Answer

Less than 0.5 mm

Answer

When remaining dentin thickness is less than 0.5 mm, a protective base is required to shield the pulp from thermal and chemical insults.

Question 3

Which type of matrix system is most appropriate for Class III and Class IV composite restorations?

Accepted Answer

Celluloid strip matrix

Answer

Celluloid (Mylar) strip matrices are transparent and used for anterior composite restorations to allow light curing through the band.

Question 4

Zinc phosphate base is indicated primarily in situations requiring:

Accepted Answer

Thermal insulation under metallic restorations

Answer

Zinc phosphate provides excellent thermal insulation and compressive strength, making it ideal as a base under metallic restorations.

Question 5

When removing the Tofflemire matrix after condensing amalgam, what is the correct sequence?

Accepted Answer

Loosen retainer first, then remove wedge, then remove band facially

Answer

The retainer is loosened first to free the band, the wedge is removed, and then the band is carefully pulled facially to avoid fracturing the marginal ridge.

(EFDA) Expanded Function Dental Auxiliary Practice Test

(EFDA) Expanded Function Dental Auxiliary Practice Test

EFDA Bases, Liners, and Matrices 3