EFDA Bases, Liners, and Matrices 2

Question 1

Which material is most commonly used as a cavity liner under composite resin restorations to promote pulpal healing?

Accepted Answer

Calcium hydroxide

Answer

Calcium hydroxide is the preferred liner under composites because it stimulates secondary dentin formation and has excellent biocompatibility.

Question 2

A Tofflemire retainer and matrix band are assembled with the retainer positioned on which surface of the tooth?

Accepted Answer

Buccal

Answer

The Tofflemire retainer is typically placed on the buccal surface so the knob-tightening mechanism is accessible.

Question 3

What is the primary purpose of using a matrix band when restoring a proximal surface?

Accepted Answer

To replace the missing tooth wall during condensation

Answer

A matrix band temporarily replaces the missing proximal wall to contain the restorative material and help create proper contour.

Question 4

Which liner has the advantage of releasing fluoride while also bonding chemically to dentin?

Accepted Answer

Resin-modified glass ionomer

Answer

Resin-modified glass ionomer liners release fluoride and bond chemically to dentin, making them ideal for caries-prone patients.

Question 5

When placing zinc phosphate cement as a base, why must mixing be done on a cool glass slab?

Accepted Answer

To slow the exothermic reaction and extend working time

Answer

A cool slab dissipates the heat generated during mixing, slowing the exothermic reaction and extending working time.

(EFDA) Expanded Function Dental Auxiliary Practice Test