Framework Design

Question 1

3 imp areas for framework design of a single crown MCC:

Answer 1

Margin, contact point, occlusal/lingual

Question 2

3 designs for margin of a metal ceramic crown:

Answer 2

metal collar, knife edge (ceramic-metal / metal disappearing), ceramic

Question 3

Ceramic margin:

Answer 3

usually labial area in esthetic zone, smooth, 1.2mm wide finish line, slightly sub-gingival (equigingival), technique sensitive

Question 4

Metal-ceramic margin:

Answer 4

mid-sulcus prep, acceptable result, simplifies crown fabrication (?)

Question 5

Problems w metal-ceramic margin:

Answer 5

gingival over-countour, porcelain surface is rough, non-esthetic after recession, not recommended

Question 6

Is the gingival overcountou what leads to recession?

Answer 6

ask?

Question 7

Metal collar:

Answer 7

easier procelain application, compromised appearrance, useful for non-esthetic area

Question 8

3 reasons metal collar leads to compromised appearance:

Answer 8

shallow sulcus, thin gingival tissue, recession

Question 9

2 options for occlusal/lingual design of metal-ceramic crown:

Answer 9

metal or ceramic on metal framework coverage

Question 10

Metal-Lingual occlusal:

Answer 10

covers facial, proximal, incisal, less tooth reduction req, max intercuspation contacts in metal

Question 11

Ceramic-lingual/occlusal:

Answer 11

covers facial, incisal, lingual, more tooth red req, macx intercusppation contats on ceramic

Question 12

ceramic is aka:

Answer 12

porcelain

Question 13

The ceramic contacts of any metal ceramic restoration should be located:

Answer 13

all in one material, 1-1.5mm away from occlusal/incisal contacts

Question 14

Lingual reduction of ant tooth when metal or metal-ceramic framework is designed on the lingual of the resto:

Answer 14

metal: 1mm, metal-ceramic: 1.5mm

Question 15

Occlusal red of pos tooth when metal-ceramic framework is designed on the occlusal of the resto,

Answer 15

functional cups: 2mm, non-f cusp: 1.5mm, lingual axial wall follow buccal

Question 16

Occlusal red of pos tooth when metal-only occlusal framework is designed on the occlusal of the resto:

Answer 16

same as CCC: functional cusp: 1.5mm, non-f: 1mm, margin: 0.5mm

Question 17

Why are contacts more frequently placed all in ceramic?

Answer 17

easily cleaned, good esthetics

Question 18

Benefit of metal contact points:

Answer 18

more conservative prep, but not esthetic

Question 19

Proximal contacts should be how from from metal-ceramic junction?

Answer 19

1.5mm

Question 20

Advantage of ceramic design in the proximal contacts:

Answer 20

if the contact is shy, you can add ceramic (by sending back to lab or in clinic?)

Question 21

Guidelines to metal ceramic resto framework design:

Answer 21

no unsupported porcelain, proper metal contour (?), incisal ceramic thickness must not exceed 2.0mm

Question 22

Benefit of metal-ceramic resto for pt:

Answer 22

acceptable esthtics, high durability