Bases, Liners, and Matrices Flashcards

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

Answer: Calcium hydroxide

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

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

Answer: Buccal

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

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

Answer: To replace the missing tooth wall during condensation

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

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

Answer: Resin-modified glass ionomer

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

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

Answer: To slow the exothermic reaction and extend working time

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

Which wedge placement is correct when using a Tofflemire matrix system for a Class II restoration?

Answer: Gingival embrasure, buccal to lingual

The wedge is inserted from the buccal into the gingival embrasure to seal the gingival margin and prevent flash.

Which base material is contraindicated under composite resin due to its eugenol content interfering with polymerization?

Answer: Zinc oxide eugenol (ZOE)

Eugenol in ZOE inhibits the polymerization of composite resin, preventing adequate setting of the restoration.