9/18: All Ceramic and Metal-Ceramic Crown Preps

Question 1

1. A metal-ceramic crown is also known as

Answer 1

PFM

Question 2

2. This type of crown takes the strength of metal and combines it with the tooth matching esthetic ability of porcelain

Answer 2

PFM

Question 3

3. What are the indications for PFM?

Answer 3

a. Opposing teeth are porcelain/ceramic
b. High level of aesthetics is needed
c. Preparation are unusual
d. Bridges and other long span fixed restorations

Question 4

4. Are PFM or all-ceramic crowns more resistant to fractures?

Answer 4

PFM

Question 5

5. Can PFM be used for any tooth?

Answer 5

Yes

Question 6

6. What are the PFM components, specifically the porcelain?

Answer 6

a. Opaque porcelain
b. Body porcelain
c. Incisal porcelain
d. Shoulder porcelain

Question 7

7. What is the minimal thickness of metal in PFM?

Answer 7

a. 0.3-0.5mm

Question 8

8. How much metal coping do you need in PFM?

Answer 8

a. Veneered = 0.3-0.5mm
b. Unveneered area = 0.8-1.00mm

Question 9

9. How much opaque porcelain is needed in PFM?

Answer 9

a. 0.1-0.2mm

Question 10

10. How much shoulder porcelain is needed in PFM?

Answer 10

0.8mm

Question 11

11. How much gingival, body, and incisal porcelain is needed in PFM?

Answer 11

a. 0.8-2mm

Question 12

12. In a PFM, how much metal and porcelain occlusion do you need?

Answer 12

a. 0.5 metal
b. 1.5 porcelain

Question 13

13. What is the importance of 2 plane reduction?

Answer 13

a. Even thickness of material

Question 14

14. You want porcelain esthetics to be carried into what regions?

Answer 14

a. Contact regions so it is not seen from the facial

Question 15

15. Without two planes, what can we endanger?

Answer 15

Pulp

Question 16

16. Why is a modified shoulder preferred on PFMs?

Answer 16

a. Less stress on the tooth
b. Harder to mill to 90 degrees

Question 17

17. What are the types of PFM margin designs?

Answer 17

a. Metal collar → subgingival, 1.2mm
b. Disappearing metal → used when the margin is not deep enough to allow the ceramic and metal to meet, 1.2mm
c. Porcelain →1.2mm, pure esthetics

Question 18

18. Ideally, you want PFMs to be placed how in relation to the gingiva?

Answer 18

a. 0.5mm below

Question 19

19. If the crown margin violates the biological width, what happens?

Answer 19

a. Gingival inflammation and resorption of bone

Question 20

20. This is the crown and tooth contour which preserves the gingiva health

Answer 20

a. Emergence profile

Question 21

21. Porcelain has to be how thick?

Answer 21

a. Less than 3mm

Question 22

22. Is porcelain abrasive to natural dentition?

Answer 22

Yes

Question 23

23. This is the most realistic restoration for esthetics

Answer 23

a. Ceramic

Question 24

24. What is the chemical name of ceramic?

Answer 24

a. Lithium disilicate
b. Lithium silicate

Question 25

25. What are the indications for ceramic?

Answer 25

a. Esthetics
b. Light occlusal load

Question 26

26. What are contraindications for ceramic?

Answer 26

a. Heavy occlusal loads
b. Short prep with ceramic thickness greater than 3mm

Question 27

27. What are the reductions for ceramic?

Answer 27

a. Incisal: 2-2.5
b. Facial: 1.2-1.7
c. Lingual: 1-1.2
d. Margin: 1-1.2

Question 28

28. On what teeth will you do ceramics?

Answer 28

a. Anterior
b. Posterior will not work, not enough room

Question 29

29. What is required 90% of the time with ceramics?

Answer 29

a. Resin cement

Question 30

30. Do ceramics or PFM use e.max?

Answer 30

Ceramics

Question 31

31. E.max is a

Answer 31

a. Glass ceramic

Question 32

32. Is there enough room for a Ceramic on the mandibular 2nd molar?

Answer 32

a. No, you will break

Question 33

33. What increases the strength of a ceramic crown?

Answer 33

a. Resin composite

Question 34

34. More than ____mm porcelain left incisally will result in risk of fracture

Answer 34

3mm

Question 35

35. What is an alternative to ceramics that is becoming increasingly more popular?

Answer 35

PFZ