Dental Materials

Question 1

The chemical attraction between like molecules?

Answer 1

Cohesion

Question 2

An index which indicates how one material reacts to temperature extremes in relation to another is called?

Answer 2

Coefficient of thermal expansion

Question 3

The force at which a material breaks under pressure is called?

Answer 3

Compressive strength

Question 4

Slow dimensional change caused by compression is called?

Answer 4

Creep

Question 5

The ability to undergo change of form without breaking is called?

Answer 5

Ductility

Question 6

A materials ability to recover its initial shape after undergoing a force is called?

Answer 6

Elasticity

Question 7

An electrical current generated by dissimilar metals in an acidic environment is called?

Answer 7

Galvanism

Question 8

The process of gelling (solidification by cold) is called?

Answer 8

Gelatin

Question 9

Absorption of a solvent by a gel is called?

Answer 9

Imbibition

Question 10

A materials capacity to be shaped by force or pressure is called?

Answer 10

Malleability

Question 11

The passage of oral fluids/bacteria into and out of tooth structure due to a marginal gap or failure of the marginal seal is called?

Answer 11

Micro leakage (percolation)

Question 12

The linking, branching, or cross linking of smaller molecules to generate a larger molecule is called?

Answer 12

Polymerization

Question 13

The force at which a material cannot return to its original shape is called?

Answer 13

Proportional limit

Question 14

Contraction of a gel due to the loss of a solvent is called?

Answer 14

Syneresis

Question 15

The force needed to stretch a material to the point of fracture is called?

Answer 15

Tensile strength

Question 16

Resistance to flow?

Answer 16

Viscosity

Question 17

An alloy of mercury with silver, copper, tin and zinc is called?

Answer 17

Amalgam

Question 18

Is silver susceptible to corrosion?

Answer 18

Yes

Question 19

Why is copper added to amalgam?

Answer 19

To minimize corrosion (gamma II phase eliminated)

Question 20

What bonding agent establishes micromechanical retention with enamel and dentin by adapting to relief areas created by conditioning with phosphoric acid?

Answer 20

Dental resins (BIS-GMA or urethane dimethacrylate)

Question 21

Name the barrier used to protect the occlusal surfaces of teeth from bacterial assault by sealing anatomically unprotected tooth structure with resin?

Answer 21

Pit and fissure sealants

Question 22

Name the 3 most common filler particles for composites:

Answer 22

1. Silicates
2. Quartz
3. Glass

Question 23

What 2 ingredients are usually added to composites for radiopacity?

Answer 23

1. Barium

2. Strontium

Question 24

What are generally used to seal Dentin or medicate the dental pulp (seal/medicate)?

Answer 24

Liners

Question 25

What liner stimulates reparative dentin formation/pulp exposure?

Answer 25

Calcium hydroxide

Question 26

Which liner soothes the pulp, is oily, and is contraindicated with composites?

Answer 26

Zinc-oxide/eugenol

Question 27

Which liner seals tubules and releases fluoride?

Answer 27

Resin-modified glass ionomer

Question 28

What are generally used to provide thermal insulation or mechanical protection for the dental pulp (insulate/protect)?

Answer 28

Bases

Question 29

Name the cement that has an exothermic reaction on mixing (use a cool glass slab) and creates a mechanical interlock between tooth and casting

Answer 29

Zinc phosphate

Question 30

Which cement has a high chemical affinity for enamel and its powder is mixed with polyacrylic acid?

Answer 30

Polycarboxylate cement

Question 31

Which cement is : Resin-modified glass ionomer Seals dentin effectively to minimize sensitivity Releases fluoride

Answer 31

Hybrid cements

Question 32

Which cement is commonly used for temporary cementation?

Answer 32

Zinc-oxide/eugenol cement

Question 33

Name a reversible hydrocolloid that undergoes a physical reaction only

Answer 33

Agar

Question 34

Name a irreversible hydrocolloid that undergoes a chemical reaction

Answer 34

Alginate

Question 35

Which elastomeric material is messy, smelly and must be poured the same day?

Answer 35

Polysulfide rubber

Question 36

Which elastomeric material is relatively rigid, has good tissue detail, and is unstable in presence of moisture( will distort if left wet)?

Answer 36

Polyether rubber

Question 37

Which elastomeric material is putty-like and rarely used?

Answer 37

Silicone rubber

Question 38

Beta-calcium sulfate hemihydrate is which gypsum product?

Answer 38

Plaster

Question 39

Alpha-calcium sulfate hemi-hydrate is which gypsum product?

Answer 39

Stone

Question 40

Inorder to modify your working time with gypsum products you: Add ___________ to accelerate set Mix with _________water to accelerate set Add __________ to slow set

Answer 40

Add potassium sulfate to accelerate Mix with warm water to accelerate Add borax to slow set

Question 41

Which type of wax is used for cast restorative patterns?

Answer 41

Inlay and casting wax

Question 42

Which type of wax is useful in removable prosthetic procedures?

Answer 42

Baseplate wax

Question 43

Which type of wax is useful to obtain occlusal records?

Answer 43

Bite registration wax

Question 44

Which type of wax is used in pouring models (vertical wall around impression)?

Answer 44

Boxing wax

Question 45

Which type of wax becomes sticky when heated, used to attach models?

Answer 45

Sticky wax

Question 46

Which type of wax is used to modify the shape of impression trays and cushion braces?

Answer 46

Utility wax

Question 47

List 3 noble metals used in dentistry

Answer 47

1. Gold 2. Platinum 3. Palladium

Question 48

List 5 base metals used in dentistry:

Answer 48

1. Silver 2. copper 3. Zinc 4. Tin 5. Nickel

Question 49

What is the leading cause of failure for implants?

Answer 49

Mobility

Question 50

The chemical attraction between unlike molecules?

Answer 50

Adhesion