Chapter 06: Composites, Glass Ionomers, and Compomers

Chapter 06: Composites, Glass Ionomers, and Compomers

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

MULTIPLE CHOICE

1. Which of the following is a direct-placement esthetic material?

ANS:  A

Composite resin is a direct-placement esthetic material. Direct-placement esthetic materials are those that can be placed directly into the cavity preparation or onto the tooth surface by the clinician without first being constructed outside of the mouth. Esthetic materials are those that are tooth colored.

REF:   p. 66               TOP:   Direct-Placement Esthetic Restorative Materials

2. Composite resins are composed mainly of an organic resin matrix and inorganic silica filler particles joined together by a _____ coupling agent.

ANS:  A

Composite resins are composed mainly of an organic resin matrix and inorganic silica filler particles joined together by a silane coupling agent. The silane coupling agent sticks (adheres) the particles to the matrix. Also added are initiators and accelerators that cause the material to set and pigments that give color to the material and match tooth colors.

REF:   p. 66               TOP:   Composite Resin

3. The fillers used in composite resins are:

ANS:  B

The fillers used in composite resins are inorganic silica particles. Silica may be in crystalline form such as quartz or in noncrystalline form such as glass. The addition of filler particles makes the organic resin stronger and more wear resistant. Fillers also are added to control the handling characteristics of the composite resin and to reduce the shrinkage that occurs when the resin matrix polymerizes, or sets.

REF:   p. 66               TOP:   Composite Resin (Components)

4. In the polymerization process for composite resins, an activator causes an initiator molecule to form a _____ that breaks one of the carbon-to-carbon double bonds to form a single bond and another free radical.

ANS:  D

In the polymerization process for composite resins, an activator causes an initiator molecule to form a free radical that breaks one of the carbon-to-carbon double bonds to form a single bond and another free radical. That free radical can cause the same reaction with another monomer to add to the polymer chain.

REF:   p. 67               TOP:   Composite Resin (Polymerization)

5. The catalyst paste of a chemically cured composite resin contains _____ as an activator.

ANS:  B

The catalyst paste of a chemically cured composite resin contains composite and a tertiary amine as an activator. The other paste, called a base, contains composite and benzoyl peroxide as an initiator. Equal parts of these two pastes are mixed together, and the polymerization reaction begins.

REF:   p. 67               TOP:   Composite Resin (Modes of Cure)