Chapter 14: Vocabulary

Question 1

positive replicas of the teeth produced from impressions that create a negative representation of the teeth; commonly called study models and used for diagnostic purposes and numerous chairside and laboratory procedures

Answer 1

Diagnostic Casts

Question 2

an impression of the occlusal relationship of opposing teeth in centric occlusion (patient’s normal bite)

Answer 2

Bite Registration

Question 3

glue-like material composed of two or more substances in which one substance does not go into solution but is suspended within another substance; it has at least two phases, a liquid phase called a sol and a semisolid phase called a gel

Answer 3

Colloid

Question 4

a water-based colloid used as an elastic impression material

Answer 4

Hydrocolloid

Question 5

an agar impression material that can be heated to change a gel into a fluid sol state that can flow around the teeth, then cooled to gel again to make an impression of the shapes of the oral structures

Answer 5

Reversible Hydrocolloid

Question 6

an alginate impression material that is mixed to a sol state and as it sets converts to a gel by a chemical reaction that irreversibly changes its nature

Answer 6

Irreversible Hydrocolloid

Question 7

a powder derived from seaweed that is a major component of reversible hydrocollide

Answer 7

Agar

Question 8

liquid state in which colloidal particles are suspended; by cooling or chemical reaction, it can change into a gel

Answer 8

Sol

Question 9

a semisolid state in which colloidal particles form a framework that traps liquid (e.g., Jell-O)

Answer 9

Gel

Question 10

the property of a material to have two different temperatures for melting and solidifying, unlike water, which has one temperature for both

Answer 10

Hysteresis

Question 11

a characteristic of gels to contract and squeeze out some liquid that then accumulates on the surface

Answer 11

Syneresis

Question 12

a versatile irreversible hydrocolloid that is the most-used impression material in the dental office; it lacks the accuracy and fine surface detail needed for impressions for crown and bridge procedures

Answer 12

Alginate

Question 13

highly accurate elastic impression materials that have qualities similar to rubber; they are used extensively in indirect restorative techniques, such as crown and bridge procedures

Answer 13

Elastomers

Question 14

the act of absorbing moisture

Answer 14

imbibition

Question 15

a chemical that lowers the surface tension of a substance so that it is more readily wet; for example, oil beads on the surface of water, but soap acts as a surfactant to allow the oil to spread over the surface

Answer 15

Surfactant

Question 16

an elastic impression material that has sulfer-containing (mercaptan) functional groups; it has also been referred to as rubber base impression material

Answer 16

Polysulfide

Question 17

a silicone rubber impression material that sets by linking molecules in long chains but produces a liquid by-product by condensation

Answer 17

Condensation Silicone

Question 18

a silicone rubber impression that also sets by linking molecules in long chains but produces no by-product; the most commonly used addition silicones are the polyvinyl siloxanes

Answer 18

Addition Silicone

Question 19

very accurate addition silicone elastomer impression material; it is used extensively for crown and bridge procedures because of its accuracy, dimensional stability, and ease of use

Answer 19

Polyvinyl Siloxane (PVS)

Question 20

a rubber impression material with ether functional groups; it has high accuracy and is popular for crown and bridge procedures

Answer 20

Polyether

Question 21

a compression material composed of resin and wax with fillers added to make it stronger and more stable than wax

Answer 21

Impression Compound

Question 22

an impression material composed of a gypsum product similar to plaster of Paris

Answer 22

Impression Plaster

Question 23

a hard and brittle impression material used in complete dental procedures

Answer 23

Zinc Oxide Eugenol (ZOE)