Midterm

Question 1

The part of an FPD that is not directly on any tooth structure is called the ______.

Answer 1

Pontic

Question 2

The __________ tooth is the one which is prepped to support the FPD.

Answer 2

Abutment

Question 3

A __________ is any type of device used for the stabilization or retention of a prosthesis.

Answer 3

Retainer

Question 4

T/F: It is important that the patient can clean and pass floss under the pontic.

Answer 4

True

Question 5

If the decay is at the JE, what must be done before the preparation in order to not violate the biological width?

Answer 5

Crown lengthening

Question 6

What are the primary factors for retention?

Answer 6

1. Proper taper
2. Proper length
3. Proper width/surface area

Question 7

What margin design is indicated for a metal-ceramic crown with a disappearing metal collar?

Answer 7

Sloped shoulder

Question 8

What are some disadvantages of the disappearing collar and sloped shoulder?

Answer 8

1. Difficult prep
2. Greater creep
3. Rough margin area
4. Potential gray line
5. Can be overcontoured

Question 9

Which type of margin gives optimum esthetics?

Answer 9

Butt

Question 10

What are some absolute indications for a butt margin?

Answer 10

1. Minimal sulcus depth of less than 1 mm
2. Thin labial tissue
3. High smile line

Question 11

What is Ante’s law?

Answer 11

Determines what types of FDPs will be successful based on the root surface area of the abutments

Question 12

Which teeth have the highest root surface area?

Answer 12

Canines and molars

Question 13

Which types of ceramics are used for denture teeth and porcelain jacket crowns?

Answer 13

High-fusion and medium-fusion

Question 14

Which types of ceramics are used for metal-ceramic crowns?

Answer 14

Low-fusion and ultra low-fusion

Question 15

Feldspar is a naturally occuring glass that contains what three compounds?

Answer 15

Silica
Fluxes
Alumina

Question 16

Feldspar, quartz, and other oxides are heated and rapidly cooled which causes the glassy matrix to fracture into many small fragments causing a ______.

Answer 16

Frit

Question 17

Zinc oxide is contained in _______-fusing porcelain.

Answer 17

Medium

Question 18

_______-fusing porcelain has the highest percentage of silicon oxide.

Answer 18

High

Question 19

________-fusing porcelain has the highest percentage of aluminum-oxide.

Answer 19

Medium

Question 20

What are the steps for preparing the metal surface for porcelain application?

Answer 20

1. Clean with cleaning solution in ultrasonic cleaning unit (5 min)
2. Clean with distilled water in ultrasonic cleaning solution (5 min)
3. Do not touch after cleaning
4. Oxidation

Question 21

Which enamel for MCC is most translucent?

Answer 21

Incisal/Enamel porcelain

Question 22

During oxidation of the metal, should it be done under a vacuum?

Answer 22

NO

Question 23

In an MCC, in what order is the porcelain applied to the metal?

Answer 23

Opaque -> body -> enamel/incisal

Question 24

T/F: Adjustments to the porcelain should be made with the low-speed hand piece after the first bake.

Answer 24

True

Question 25

What must be done before the seconds bake?

Answer 25

1. Clean crown in distilled water in ultrasonic unit for 10 min 2. Add porcelain to deficient areas

Question 26

What are the advantages to a porcelain margin?

Answer 26

1. Improved esthetics | 2. Less plaque retention

Question 27

What are the disadvantages to a porcelain labial margin?

Answer 27

1. Generally inferior marginal adaptation 2. Decreased strength 3. More time consuming 4. Slightly more expensive than MCC

Question 28

What is the direct lift technique?

Answer 28

A quick way to add porcelain to the margin of the prep

Question 29

What is the number one cause of failed FPDs?

Answer 29

Caries

Question 30

What are four key points to creating optimum occlusion with FPDs?

Answer 30

1. Minimize sliding contacts 2. Establish anterior guidance 3. Opposing contacts in same material 4. Control parafunction

Question 31

T/F: The occlusal contact should be at least 1.5mm from the metal-porcelain junction.

Answer 31

True

Question 32

What is required for porcelain to bond to metal?

Answer 32

A thin layer of oxide

Question 33

Why would an adhesive failure between metal and porcelain occur?

Answer 33

No oxide layer

Question 34

T/F: Cohesive failure in metal is common.

Answer 34

FALSE

Question 35

What causes cohesive failure in metal oxide?

Answer 35

Excessive oxidation

Question 36

What are the five keys to framework design?

Answer 36

1. Even porcelain thickness 2. Rounded internal angles 3. 90 degree metal/porcelain junction 4. Porcelain wrap-around 5. Metal thickness of .3 mm