1. Provisionals

Question 1

Indications for provisional fabrication

Answer 1

1. Pulpal protection
2. Positional stability
3. Maintain occlusal function and comfort
4. Esthetics
5. “Test drive” intended occlusal scheme
6. Optimize supporting tissue
7. Custom incisal guide table

Question 2

What materials are preformed provisionals made from (4)?

Answer 2

1. Polycarbonate plastic
2. Tin-silver metal
3. Custom-made acrylic resin shell
4. Cellulose acetate

Question 3

What are the most commonly used provisional materials (4)?

Answer 3

1. Methyl methacrylate (jet, alike)
2. Bis-acryl (integrity)
3. Poly-R’ methacrylates
4. Urethane dimethacrylate (Triad)

Question 4

What are advantages of methyl methacrylate (6)?

Answer 4

1. Marginal adaptation
2. Color stability
3. Good polishability
4. Good strength
5. Esthetics, durability
6. Easy to reline

Question 5

What are disadvantages of methyl methacrylate (4)?

Answer 5

1. Highly exothermic reaction (up to 7 degree pulp temp increase)
2. 6% shrinkage
3. Free monomer toxic to tissue
4. Strong odor

Question 6

Bis-acryl - Advantages? (8)

Answer 6

1. Good marginal fit
2. Low exothermic reaction
3. Good abrasion resistance
4. Good transverse strength
5. Low polymerization shrinkage
6. Easy to mix/dispense
7. Repairable
8. Acceptable color

Question 7

Bis-acryl - Disadvantages (7)?

Answer 7

1. Lower surface hardness
2. Limited shade selection
3. May not be strong enough for FPD’s
4. Brittle
5. Limited polishability
6. Challenging to reline
7. Expensive