05 Principles of FPD Design

Question 1

Framework Primary Functions

Answer 1

1. Casting provides fit of restoration to prepared tooth
2. Metal forms oxides that bond chemical to dental porcelain
3. Coping serves as a rigid foundation to which brittle porcelain can be attached for increased strength and support
4. Substructure restores proper emergence profile

Question 2

Most significant theory of porcelain metal attachment

Answer 2

Chemical bonding - Between metal oxide in porcelain and oxide layer in metal

Question 3

Better for thermal expansion of porcelain or metal to be higher?

Answer 3

Better for metal expansion - that porcelain is placed under a state of compression and not tension or shear

Question 4

Opaque porcelain

Answer 4

Masks metal and responsible for metal-ceramic

Question 5

Body porcelain

Answer 5

Gives color in dentin (pigmented metal oxides)

Question 6

Enamel (incised) porcelain

Answer 6

Provides translucency. Fired with body

Question 7

What are the advantages to a two piece casting technique?

Answer 7

1. Less porosity
2. Less oxidation
3. Safer

Question 8

What are the disadvantages to a two piece casting technique?

Answer 8

Costly - Laser units 15-31k and phaser 12k

Question 9

Is presider or postsolder stronger?

Answer 9

Post-ceramic solder for strength

Question 10

What are some pontic designs in FPD’s?

Answer 10

1. Modified ridge lap
2. Conical
3. Ovate
4. Sanitary (no contact)

Question 11

What are pre-existing healed ridge considerations for an FPD ovate pontic site?

Answer 11

1. Requires 2 mm gingival tissue over ridge
2. Plasty tissue 0.5 to 1 mm
3. Provide direct contact with provisional
4. Healing time min 2 weeks