Fixed Partial Dentures

Question 1

What is the optimum crown-root ratio for a tooth to be utilized as a FPD abudment? What is the minimum ratio?

Answer 1

2:3

Minimum 1:1

Question 2

What is Ante’s law?

Answer 2

• The root surface area of the abutment teeth had to be equal or surpass that of the teeth being replaced with pontics

Question 3

What’s a rigid connector?

Answer 3

• A single unit bridge connector that provides strength and stability to the prosthesis while minimizing stresses associated with the restoration

Question 4

What is the preferred way of fabricating most FPDs?

Answer 4

Rigid Connectors

Question 5

What are non-rigid connectors used for?

Answer 5

• To relieve stress or to accommodate mal-aligned FPD abutments

Question 6

What are the common non-rigid connectors?

Answer 6

• Dovetails (Key-keyways)
• Split pontics (connector inside pontic)
• Tapered pins

Question 7

During opening and closing the mandible flexes which way? What type of connectors will inhibit mandibular flexure?

Answer 7

1. Mediolaterally
2. Rigid connectors - to accomodate for the flexure, non-rigid connectors can be used

Question 8

What term describes the gold content of the alloy boeing soldered?

Answer 8

Carrot - gold per 24

Question 9

What term describes the gold content of the solder?

Answer 9

Fine - gold per 1000

Question 10

What’s the difference between pre- and post-solder?

Answer 10

• Pre - join units before application of porcelain
• Post - join units after application of porcelain

Question 11

What must pontic design incorporate?

Answer 11

1. Biologic
2. Mechanical
3. Esthetic

Question 12

List what type of pontics are mucosal contacting and which ones are not.

Answer 12

• Mucosal contact
  
  • Ridge lap
  • Modified ridge lap
  • Ovate
  • Conical
• No mucosal contact
  
  • Sanitary (Hygienic)
  • Modified sanitary (Hygienic)

Question 14

What pontic design is used on the posteriod mandible that is least tooth like?

Answer 14

Sanitary Pontic

*Modified sanitary allows for increased connector size

Question 15

What pontic design can be described as “saddle,” and concave - fitting to both sides of the residual ridge?

Answer 15

Ridge lap

Question 16

Which pontic design combines the best of hygienic and saddle pontic designs, that resembles a “T”, with vertical arms end at crest of ridge?

Answer 16

Modified ridge lap

Question 17

Which pontic design is bullet-shaped and convex?

Answer 17

Conical pontic

Question 18

Which pontic design is most esthetically appealing, becaue it sits in a tissue depression, and is the strongest due to broad convex geometry?

Answer 18

Ovate pontic

Question 19

What is the term to describe a FPD in which only one side of the pontic is attached to a retainer?

Answer 19

Cantilever - long term prognosis = poor

Question 20

What is used to determine path of withdraw?

Answer 20

• Direct vision
• Large mouth mirror
• Dental surveyor on snap stone model