layered zirconia PFZ and lithium disilicate prep criteria

ideal

supragingival margin is —mm

0.65mm

outline

ideal

proper gingival separation from adjacent teeth >= —mm

0.5mm

outline

ideal

occlusal/incisal reduction

2mm

internal

ideal

mid-axial reduction

1.3mm

internal

ideal

lingual clearance (anterior)

1 mm

Internal

ideal

properly tapered walls are — to — degrees

6-10

retention

ideal

proper wall height is — to — mm

3-4mm

retention

Ideal

shoulder with rounded internal at — degree to the external tooth structure

90

retention

Good

supragingival margins deviate within range — to — mm (preclinical)

0.1 - 1mm

outline

good

occlusal reduction deviates slightly within range — to — mm

1.5 to 2.5

internal

good

gingival axial reduction deviates within the range buccal— to —, lingual — to —-

0.8-1.3

0.8-1.1

good

mid-axial reduction deviates slightly within range — to — mm

1-1.5mm

internal

good lingual clerance anterior deviates within range

0.8-1.1

internal

ideal good acceptalbe unacceptable

small local undercut

good

internal

good

taper slight deviation within range — to —- degrees

4 to 15

retention

good

wall heigh slight deviation within range — to —-mm

2.5-3mm

retention

ideal good acceptable unacceptable

local small blockable undercut

good

retention

good

slight deviation of shoulder anuglation within range — to — degrees

75-105

marginal finish

unacceptable

subgingival margin >= —mm

gingival separation <= -mm

1.3mm

.25mm

both outline

unacceptable

occlusal reduction >=

gingival axiial reduction buccal >=——- lingual >=——-

ideal 2, unacceptable >=3mm

idea b.l: 1-1.3, 1-1.1 unacceptable is >=1.5 buccal , >=1.3 lingual

internal

unacceptable

lingual clerance (anterior) >=——mm

lingual clerance ideal is 1mm., unacceptable is >=1.3

internal

unacceptable

overtapered walls >= —- degrees

wall height <= ——mm

ideal is 6-10 degrees, 20 degree unacceptable

2mm

shoulder angulation severely deviates < — to —-

unacceptable

75 105

ideal is 90

good is slight deviation within range

this is under marginal finsih